It's also the city's job to inspect the cranes, but we saw how well that worked out in 2008 with falsified inspection reports from NYC DOB inspectors. You guess a lot in your comments. You assume everyone is doing their job.
It might be the oilers responsibility to *do* the maintenance. But that doesn't mean that the operator is off the hook (ethically) for not *verifying* the work was done. E.g. legally the driver of a truck is responsible for the load being secure regardless of who loaded and secured it. Another one; the caption of a ship is on the hook for everything that happens on the ship, even when people disobey orders. Even if someone isn't allowed to do the work, they still should verify for themselves that it was done correctly.
I can't imagine looking at a disaster of this scale and being like, "eh, things happen." Like, that's absolutely not an acceptable excuse?!? Things happen, and we examine them to see what caused those things, so that things don't happen again.
Many years ago I was told that a series of crain colapses in Perth Western Australia were put down to operator error and then someone looked for commonalities and found that all the operators involved were trained at the same company and the same instructor.He got sacked and all his students were retrained and the problem went away.
The crane collapses that I knew about(1 in the Army, and 3 civilian) all involved overloading. In the Army, it was a Major ordered the the Spec5 to exceed to safe reach and the barge flipped and dumped the crane. The civil ones were all cases of the customer lying about the weight to get a cheaper crane. Most catastrophes have a bunch of errors that lead up to it. When I was called up for Desert Storm, I served with a Major from the Hawaiian National Guard. He told me that they were being flooded with chinesium and they were having a lot of failures. He warned me to watch out for it. Another good video. Good Luck, Rick
@@V100-e5q Yes they do tip over, even when there's protection. I've seen it with my own eyes at a company I worked for a couple of decades ago. A similar crane like the last one shown (but a Demag instead) had all the protections it needed and all where in working order. That crane in particular came in for maintenance and since the maintenance took a while the crane had to be re-inspected (here in Belgium it's mandatory every 3 months + a bigger one each year). The inspector had just checked the crane, did severe testing to it and gave it the all clear. When he just walked into our office to issue the paperwork the crane came crashing down (tipped over like the last one). Since it was the end of the day the operator was in a hurry to get out of there and instead of taking it slowly he rushed to get the mainboom and the jib down, unfortunately the safety system was a bit slow in shutting the controls down and preventing certain operations, in the second or so it took for the system to shut down the crane started to tip, the operator felt it fortunately and he jumped out of the cab before the counterweight came crashing into it. The crane was perfectly fine, it was just inspected and yet it failed. It was only after that incident that we found out that the safety system didn't react quick enough. No injuries occured but the car of the inspector was totalled in the process, the hook came crashing right on top of his car, merely a meter of our office. Parts of the boom crashed about a meter deep into heavily reinforced concrete. Obviously the crane's certificate was revoked by the inspector since he was quite pissed at that moment 🤣 But our maintenance department repaired the crane, even some boomparts were recovered and repaired but the crane received a full upgrade of security systems. And the same inspector cleared the crane -again- months later (with his new car parked far far away) 😂
So sad when accidents like this happen. My uncle was a tower crane repair man, in California. He was one of the ones that worked on the crane in place, not in a shop, or on the ground. He made a butt tonne of $$$$$, because of the danger, and liability involved. He gave me two pieces of advice, when it came to cranes. 1.) "If you're not making a living, being near the crane, stay the hell away from them and every place around them. That goes double for one of them." (pointing to a tower crane) 2.) "IF you fail at your job, one of the other guys could get hurt, or god forbid a regular person get's hurt. The second your hand hits that first rung, you inspect as you go. All the way from the bottom up. If you see ANYTHING, you note it and go back down immediately, and report it. And your @$$ better not even THINK of going back up until the problem is fixed properly AND... to your satisfaction." . R.I.P. Uncle Johnny, and save some Scotch for the rest of us.
As someone who has worked with construction equipment and farm equipment sometimes a hydraulic hose can burst unexpectedly with no warning, especially if moving a heavy load and applying high forces to the hydraulics.
Am I wrong to expect some redundancy for something that swings and lifts loads 100 stories?? Horizontal directional drills are the same way,,when a line bursts your done,but again it's not responsible for overhead lifrting.
No excuse there - if you are relying upon a hydraulic hose to keep a load in the air, you are doing it wrong. There are load-holding valves used in the aerial work platform industry that are built into the base of each hydraulic cylinder such that if a hose breaks, nothing moves.
My friend you know about as much about cranes as i rickety submarines my only question is why does it not have q built in fire suppression system in the engine compartment for fires since there so high up in case of a fire pull a lever
45 degrees give you the longest trajectory with 0 air resistance, the ideal angle with a water hose would be a lot less where wind is also a factor as well. It's not exactly difficult maths to factor in air resistance either, I did it in high school.
The best angle is less than 45° for water moving through air. But the calculation is probably a lot more difficult than what would be done in high school. At least what we did was add in the coefficient of friction between the projectile and the air. But with water this is constantly changing. At first the water comes out as a solid stream with only the outside of the steam interacting with the air. Then it breaks into small drops with each drop interacting with air. These drops are so light that they also change direction. Then even if you get the maximum distance, the steam may be so dispersed that the amount of water actually hitting the target may be very small. The best thing to do is understand these variables and try different angles until you find the one that puts the most water on the fire. Shooting straight at it may fall short giving 0%. Shooting at 45% may reach it but only 25% coverage. Something in between may be the best. It’s like if my shooting target is 10 feet in front of me. There are two angles that will hit it. I can shoot almost straight, or I can shoot up at about 80°. Both will hit the mark, but if the projectile (or water spray) is going to break apart before it hits the target, then one is definitely better then the other. The fire hose in the video may have been at a low angle, but it may have been delivering more water than a shower would if they had aimed it at 45°
@@bobh6728 Yeah, for sure. The stuff I did in school was just different shapes and air resistance, which is enough to know that 45 degrees isn't the universal best angle. A stream of water would be extremely difficult to calculate, but logically the angle that delivers the most water to the target is going to be as flat and direct as possible.
@bobh6728 AIR resistance can be simplified by treating as a constant force pushing against the water stream. 44 to 45 degrees still gives the best angle for maximum distance .
@@electrictroy2010 If it stayed a solid stream then it would be close. But looking at the video, the distance and effect of wind made it more of a misting than a stream. Since we didn’t see the whole time they were spraying water, we don’t know if they tried other angles and decided which one was the best.
Just mentioned this in another comment, but a good real-world rule of thumb is that the optimum range will be achieved when the object being fired is **coming down** on the target at 45 degrees. .....no maths required. Just adjust your angle until the thing being fired is arriving at 45 degrees as that's the max range you're going to get. This is what the firefighters were doing in the video (at least with the larger stream which had a chance of getting close).
I worked on building steel towers. On one job it was convenient to use a crane to hoist completed 20' sections onto an existing tower. I was on the tower top putting in the bolts into each new section as it came up. One section started swinging a bit wild due to 0:06 sudden wind gusts that were getting nasty. As I wrangled the first bolt in place the ground workers let me know about lightning. I heard the boom and saw a flash, and I started climbing down like a scared squirell. We left to get under cover during a horrendous storm. When we next looked out the tower section and crane were at seemingly impossible angles, and the rigging had fouled everything. The crane was up to its axles in mud and tilted a bit. The operator had set 3 wheels in 2 different swales, and the downpour buried the crane in mud. 0:06
There’s corruption everywhere, don’t kid yourselves. People should also be worrying about smaller towns that lack oversight, nor have independent resources to investigate, audit records, or keep the “good ole boys” clubs in check.
_"What Caused 2023 New York Crane Collapse?"_ He was old and tired. Regardless of how many times he was rubbed down and repainted _(Though he liked the rubbing down bit!),_ there comes a time when a crane stops and thinks, _"Can I really go on with this for another year? Build myself up. Lift this here. Place this there. Lift that there. Put it there. All day long and for weeks on end. Then it's dismantle myself and back into some storage for god knows how long. And then there's the wind when I can't do anything. And then there are the holiday's for my keepers. They go and leave me here. especially at winter. Covered in ice and snow while they're having parties in warm houses."_ So this old fella... This old crane we've seen... He just got tired of life. He thought he'd have to stop. *_But he just wanted to go out in a spectacular way. Which he did._* And try hot to hurt anyone in doing so. Which he didn't quite manage to do. _But then... After all... He was just an old crane._
Great video. You're on point with just about everything you spoke about. I work in construction in NYC. We work with and erect and assemble and disassemble lots of these cranes, from the smallest cherry-picker to the tallest tower cranes. We are still yet to determine what started the fire, it could be anything, of course, but you are right. The damage done to the main cable on the boom was the problem. Right after this latest collapse (thank God, no one was killed) I got on a social media chat with some of my union brothers that have a lot more experience than I do in the tower crane department...and one of the first things that came up was the fact that Lomma cranes was involved, yet again. The corruption levels of this company are well-known in the industry...and we always talk in hushed tones about the corruptibility of DOB inspectors as well. Even the fact that Lomma got off in the criminal case has been alleged to have been corruption. I wouldn't doubt it. Regarding the crane that collapsed in that bonus footage, everything you said was exactly how it happened. The crane operator started lowering the jib too fast and with the wrong angle on the boom. The only other thing I might add is that the one victim that died, word on the street is that he was told not to walk into a restricted area, and he (allegedly) flipped the bird to the flaggers on duty and did so anyway. Allegedly. Condolences to his family all the same, and may he R.I.P.
Thanks Jeff, always good to see and hear you give your thoughts and reviews on our every day comings and goings. No smoke and mirrors here, very informative as always. Please keep the great content coming.
Please continue this video including the Seattle crane collapse in April 27 2019. I was told by a construction worker that the giant bolts that hold it in place at the base, were taken up too early while dismantling it. Also the wind was a factor. Would love to hear your explanation.
Taking the bolts out early killed the crane in Seattle and was done by a subcontractor to a subcontractor of another subcontractor for the contractor , Totally a leadership /safty issue , Letting the Schedule drive the work instead of letting the work dictate the the schedule.
as a crane operator i can tell you that your more likely to get hit by lightening than hit by a falling crane. also its very common for cranes to be operating right on the edge of stability limits, and to a degree but less common, structual limits. every day someone will ask you to do something thats beyond your reach or capacity. without doubt. sometimes you do it when experience tells you you can get away with it, and some times you have to put your foot down and say no. and almost everytime its the foreman or someone in an office telling you to do it. crane load charts are very conservative. lifting %110 of your capacity is usually fine, but its the extra factors that make it dangerous and why the load charts exist. wind on the boom de-rates everything. this is one of many unseen factors that can compound the error and give you the accidents you see.
Two points: Point 1: Cranes are one of the simplest machines found on a construction site. Even so, I've been amazed over the years at how often they are involved in accidents. There is no end to people's ability to screw up a lift. This includes the ever-present mobile crane and bridge cranes. Point 2: A hose stream does not act like a projectile in flight. Even a well-formed hose stream will begin to splinter as it gets further and further from the nozzle. To get optimum reach a suitable nozzle with the water being supplied to the nozzle at optimum pressure is needed. If, for example, the pressure is less than optimum the stream will begin to splinter much sooner and will have less reach. Once splintering starts to occur, range will quickly be reduced.
I think the only supression system that would work on that sorta fire is the co2 foam which would proabably get pumped into the cab killing the operator. Hence why its probably left to burn since water would just make it worse and you would need a lot of sand
As far as the 45° angle you mentioned that's all we'll and good until you figure in the Wind up there and it was blowing pretty good that day ! So the Line has to constantly be moved to counter the extreme winds at that hight !
In California, I have seen them put the booms down just at the end of the work day since you never know when there's going to be an earthquake around here. Don't know what the procedure is if they're working when one happens. I'd hate to be the person in cab in that case, especially if the earthquake is a big one.
I had to come back here because I just looked it up and apparently they design earthquake-resistant cranes. They design them so that they won't collapse or drop their load during severe shaking, which is the ultimate requirement for them, and that, in the case of just moderate shaking, they are designed to continue to be fully operational. I have noticed that I've never seen a crane around here that looked anything like the ones in these collapse videos. I didn't go as far as to look into the exact specs but, from the pictures, I would guess that part of what makes them resistant to shaking is that they use a huge counterbalancing weight instead of just some hydraulics. I would imagine that this means less load is imparted to the supporting structure when things start shaking. I can see why they don't do this all the time, though, because it takes up a lot more space. I don't know how they'd do something like that in New York City at all due to the already limited space but they should come up with something as there are actually faults capable of producing a pretty significant earthquake running right through New York City.
I don't think 45 degrees gives you more distance with a stream of water. The further you push a stream of water through the air the more the air resistance breaks it up until its too small to maintain any momentum and becomes subject strictly to gravity and wind currents. It's not like a cannonball that maintains its mass throughout the arc. A higher arc just means it has travel further and overcome more air resistance to try and reach the same distance. Of course, having no arc at all is going to give you less distance than having some, but I think they weren't trying to reach the fire with the flat trajectory hose. Likely they were trying to hose down everything below the fire in case anything burning fell off.
Physics tells you that 45° is the angle you can throw anything to get the widest reach. Other factors might get into that. But not holding the hose up to 45° will never result in max reach. And those factors are equally at play if you aim lower.
I developed an allergy to truck cranes early on Jeff. Just a preference for old school crawlers that were typically stretched way beyond modern chart limits. -Bob... PS: Time to require an adequate plus Fire Suppression System onboard. May not save a header, but helps prever a total combine loss.
Okay, not sure where they left off in physics class but unless they're launching cannonballs, the ballistic trajectory doesnt hold true with a water stream that breaks up over distance. The ballistic, no air resistance, academic idea goes out the window as the water and air interact and the stream turns into droplets without the mass to force thru the air. A certain amount of lob may help at short distances or when at or below the level of the fire. When the fire is lower then the platform its entirely possible that a horizontal or even downturned stream is on target and offers the most effective applicaton of wet stuff on red stuff.
I'm no expert, but a couple of thoughts. On the angle of the firehoses: distance is not the only factor. It is also essential that the water stream hold together. A higher angle would have put the water stream into the unobstructed wind flow above the highest buildings in the area. It might not have worked. I wonder if they tried it earlier, before the video clip that focused on the drone, not the start of the hoses. From a safety prevention perspective. Cargo aircraft are required now to have fire suppression systems in each cargo compartment. This was implemented when we realized just how dangerous fires can be when they are in high altitude locations that cannot be reached in time. It seems to me that regulations requiring fire suppression systems on elevated crane platforms would be worth investigating.
Many years ago in Minneapolis I witnessed from my car on a side street, a scaffolding being blown to the ground by strong winds around 7pm. I heard the next day that they unhooked it as it would be taken down as they were finished with it. Who decided this stuff?
I'm surprised he didn't mention the crane holding up the roof components of a stadium ( sorry can't remember where) and that crane collapse also caused fatalities. Of course when it comes to engineering 'oversights) no one can forget the condos in Florida. Geesh makes one afraid to go anywhere.
I've had to work around cranes. I've learned to stay clear of the operating zone unless I'm actively directing or controlling the load. As far as the collapse due to fire it could be operator error on the operator's routine safety inspection, insufficient/improper maintenence, something missed on the owner's equipment inspections, or just an unpredictable failure. I suspect that noone was keeping the engine clean so the oil on the engine was hiding the existence of a small fuel leak.
Couple of points, First off the angle of the water, you can see the water is dispersing from a jet right near the crane, if they angled it any more the jet would have dispersed further away from the crane, so it didnt have the range to hit with it at 45 degrees. you can also tell the aditional hose has less pressure than the first as it disperses alot futher away from the crane. Second point is while indeed it could be a lack of inspection, its also possible inspections were carried out and everything was in ordered, minor hydraulic leaks on construction equipment can start at any second in time as nothing externaly visual will be present at the time of inspection on the hoses or connections, assuming the initial report of an oil leak starting the fire.
I was witness to "professional" firefighters trying to put out a fire at the top of a dead tree and they had no idea how to angle the hose/water to reach it! It was so frustrating to watch! They eventually just gave up and left the fire to burn out (which was on our property!), so we climbed up there and stuck our hose directly into the hole at the top of the tree and directly onto the fire, which was promptly distinguished by our "amateur" attempts!
I can tell you from reading hundreds of incident reports and being on at least that many related phone calls, hydraulic hoses and seals often burst with little to no warning. When this happens on the ground, it is bad enough. If it was a bad hose or seal, my guess is that one of two things is true. (1) The company failed to do preventative maintenance, or (2) thye got a bad part. Statistically, #1 is far more likely, but #2 does happen.
I was in the fire department when I was younger and they didn't teach us anything about the angle of the water coming out of the hose. However, I also worked for a department that didn't have any really tall buildings or many instances where just the pressure available to us wouldn't be enough to easily reach the fire. Also, literally all the fires I fought were wild land fires and we did medical calls around town other than that. The other thought I had is that perhaps that lower line was trying tower down the building onto which that crane was anchored so that the fire wouldn't spread to the building. In fact, I'm almost certain that they would be putting water on the building because that's something we do if we can to keep fire from spreading from one house to another and also on brush to slow the fire down and help us contain it when it's a wild fire. This still doesn't explain the other hose other than perhaps there being a lack of communication between the drone operators and the firefighters on the roof aiming the hose line since it may have appeared to all of them that they were hitting it. They would have been aiming at the base of the fire since you have to do that to put it out. If you just aim at the flames above the thing that is on fire, all you'll do is make a bunch of steam. I wouldn't be surprised if the firefighters aiming the hose thought they were hitting the base of the fire from their angle. Hopefully, word got through from the drone pilot that they needed to aim higher.
So here's something even more ridiculous about the fire fight. If that was fuel or oil burning, they should have been fighting it with foam, not water, as oil and fuel will simply float on top of the water and continue to burn, spreading the fire instead of putting it out. Maybe the hoses were actually being aimed in an attempt both to cool the surrounding structure and to prevent the building from catching fire while they waiting for an engine with the proper firefighting foam, probably an ARFF unit from the airport.
If you look at 3:41, you will be able to see they do in fact arc the stream upwards. If Jeff is using the video he shows us as the reference point, then I'm not sure he's accounted for the fact that they may have been holding that hose for hours upwards and it's not exactly light. It looks like there simply isn't enough water/mass to take it the distance and more pressure is needed.
@@whoever6458 You may right about just keeping the crane cool enough to avoid further collapse and not spreading an oil fire. I wonder how the fire was eventually put out. Foam is a good idea but how do you deliver it to the fire? Would it travel that far from the other building when water wouldn’t go that far? Shooting from the ground would take tremendous pressure. An airdrop from a helicopter might work. I don’t know what they finally used to get it out, maybe just let it burn itself out.
"How do you miss a worn hose or loose fitting"... Spoken like a true engineer. Would be just as reasonable to ask the engineer to design an entire system that never succumbs to vibration.
Right. I'm a quality inspector and even we're expected to mis up to 30% of problems. Humans are just gonna miss stuff no matter how hard we try not to, and especially during routine checks. This is usually why checks in my area of work are done by more than one person, are done multiple times, and/or are done more than necessary (something that might only need checking once a week may be done daily just to ensure if something is missed once, its hopefully picked up the next check).
I always send a quick prayer towards those high-loft crane operators. You could NOT pay me enough to operate one of those things. Be safe out there, fellas.
On our drill rigs we did daily inspections, kept everything clean and painted white, and we’d still have sudden blow outs. We had Pirtek on speed dial.
Forgot to add that after one bad voluminous blow out (no fire but smokey) we added protective sleeves and hose whip restraints to everything had thick spill kit diapers under the rigs as a precaution. We also installed these grapefruit sized balls of highly compressed dry-chem extinguisher that explode when fire touches them and shower the compartment. Doesn’t stop the occasional blow out, but reduces the danger. But still, who knows if any or all of these could have prevented that crane fire. Seems the only thing that would is installing one of those aircraft engine extinguisher sysyems or having a small diameter stand pipe up to the crane.
Stumbled across your channel. Full disclosure i am not an engineer, however i am a retired Firefighter/Paramedic Instructor and Field Training Officer. The only thing i feel experienced enough to talk about are your comments on the water streams. One hose stream reached the fire and the other was basically useless which i totally agree with, it's the reason why I'd like to share insight on. When you look at the close ups you have at the hose/nozzles. particularly the 2:15 and 3:35 mark, especially the 3:35 mark, the useless stream with nozzle closest to the camera has a different type of nozzle and it APPEARS to have a smaller hose diameter hooked to it. So to start there is not as much water pressure and flow, the useless nozzle and hose is being held by one firefighter with no assistance. That hose diameter is either a 2-1/2 or 3" diameter. They USUALLY flow at 75-80 PSI and about 180GPM. If you look at the hose farthest from the camera it is a different type nozzle that is called a smooth bore nozzle so there is no flow restriction. If you look on the ledge you will see a black anchor extended across the ledge with hooks to secure it to the end of the ledge. That is assisting the firefighter in holding the hose in place. Since they were obviously not hooked dirrectly to the firetruck there is no way for us to determine psi, velocity or gpm. However, considering the firefighter with the useless hose stream was able to hold it by himself and not have it tied down, that hose did not have the psi or flow rate to reach like the other hose did. Since I was not there I could only speculate that possibly his stream was trying to be directed to the rooftop itself to put out any drop fires that were started by burning material/embers falling and possibly landing onto the roof of the building. So while I agree with you wholeheartedly that the second stream was useless as far as the main fire, i do not think it was tasked with that to begin with. Otherwise I do appreciate your engineering insight into everything else that occurred. Thank you for the time you spend making these videos. Eric
Thank you. Very informative. It was worth the wait. So it was indeed a diesel engine and hydraulic system up there. I believe, direct electric drive would be a safer option in a city where plenty of electricity is readily available. At one of the video fragments, it was clearly visible when the end of the broken cable whipped out of the pulley that held the jib up. The shock created a plume of dust and debris, clearly visible against the blue sky.
45 degrees is only the best for a solid projectile with no drag, no wind and where you don't care about the direction it arrives in. A water stream has high drag and the drops disperse rapidly. That drag might actually give better reach to lower angles under some conditions. If a lower angel works at all, it will also likely get more water on target.
It is amazing how one small detail can mess up the structure of any machine, a possibly leaky hose of oil, a broken strap, a faulty baring, etc. Normally the videos you show of disastrous results of a structure of some sort collapsing or imploding has some big key lessons, but really the hindsight of this case is to inspect probably at least twice a day or maybe twice every time someone uses it. It’ll be interesting to know if there was a missing responsible party and it could lead to more updated regulations, or at least what comes out of the report. While the fall of a crane can be fatale, it tends to be a rare exception given that if it happens, it happens in a small amount in just over a 15 year span. If certain details does add up and it leads to being an updated process of inspections, will it help prevent this scenario to happen 0 times in the next 15 years will be interesting. We’re probably going to have to remember this case by the time 15 years has gone by to know whether it has worked or not.
ChatGPT gave this response to the optimal angle of a fire hose: The optimal angle for a fire hose to reach the farthest horizontal distance is typically around 30 degrees, not 45 degrees. When a fire hose is aimed at a 30-degree angle above the horizontal, it strikes a balance between maximizing the horizontal range and minimizing the effects of air resistance and gravity. This angle allows the water to travel the greatest distance before it begins to fall back down to the ground. The 30-degree angle is often considered the optimum angle of projection for achieving the maximum horizontal distance with a fire hose. However, practical considerations such as water pressure, nozzle design, wind conditions, and other factors can influence the actual angle that firefighters use in real-world situations to effectively combat fires.
The physics answer for a projectile ignoring air resistance is 45 degrees taking into account only gravity. However, because of air resistance, one needs more horizontal force for a water stream. If you have a fire hose in hand, the real life solution with would be to vary the elevation till you achieved maximum distance hopefully reaching the intended object fire. In the video, neither hose stream appeared to reach the fire adequately even though it looks like they were higher than the fire.
I’m a sculptor. I was installing a 6.6 ton, 35 foot by 17 foot by 12 foot sculptural shade structure of my design that required a 155 foot reach from a crane parked on a street with a 20 degree slope. The crane had been propped up at one end on shoring with its outriggers fully out. It took nearly 3 hours just to load all the counterweights to balance the reach of that load. They lifted the sculpture up and over the brand new building, and as they were lowering it I stood next to the guy with the walkie talkie who was directing the crane operator. With the sculpture still about 30 feet in the air we hear the operator say, “ you got about 30 seconds to get this off the hook cause the street’s starting to give way under the outrigger.” I stopped breathing, but the guy directing just kept giving instructions to line it up with the columns and lower away. 23 seconds later the cable went slack and I felt relieved. The guy then explained to me that if it had fallen it would not have been the crane company’s fault, as they had done the calcs and the load on the foot pad should not have been enough to cave in the street. He said the county would have been in trouble for making a road that did not meet minimum load bearing capacities. The foot pad was a good 36 inches wide. After the crane packed up and left, I went and looked and sure enough, for the next ten years there was a circular depression in the road right where that footpad had been. They just recently repaved that road and its finally gone.
With how many of these cranes are in use (and how often, too) in cities like NYC, I'm not too surprised that it happens this often. It's something that most likely will happen at some point. All you can do is update inspection guidelines after the incident, and try to minimize injuries during. If it comes to who is to blame, it's everyone who works on and in the crane. Regardless of if you are freelance or an employee, you should always check the equipment you are using and report any issues you come across. Then it passes the blame to the person who gives the go-ahead to continue the crane's operation. Unless it's obvious it's going to lead to a disaster, you will never be to blame if something does go wrong.
Thanks Jeff, the engineering is fascinating., The practical, "Stay away" is very helpful. I stay back from cars or trucks towing things. We all know what can happen, and i know it happens often. or a big rig that is swerving. I almost lost my life to that last year. He was swerving and had an over hanging load. He almost hit some barriers and signs, i was well back. I'll be more mindful of cranes.
Isn't the remaining portion of the crane now in danger of collapse? The boom and the counterweights offset each other to keep it in balance. With the boom now gone, all of the weight is now biased towards the counterweight end. This is putting an extreme amount of strain unevenly on that turntable part. I think they may have to set up a second crane to dismantle this one before it falls and kills someone.
I think it's kind of nuts that we can even build all this stuff without constant disasters and failures happening. We just take it for granted that these things are possible, and should always be successful. If the climate gets much crazier, we'll be seeing really high winds going after these super-tall buildings.
Just had a couple crane incidents occur in Bangkok. In May a crane collapsed and in June a crane malfunction caused an overpass under construction to collapse.
At 5-mins, the power pack is shown and the device on top is not the fuel tank, but is actually the muffler and you can just see it's flapper rain cap on top.
A 45° angle will only give the greatest range when you take momentum and gravity into account. Meanwhile, air resistance, wind, altitude difference, water jet dissipation and others play a role.
Two streams may have been the issue. And yes 45° may have helped, maybe not due to the loss of laminer stream due to wind/air pressure. Water flow is much different than a solid shell flying through the air. Air/ wind is different with water ... As a retired firefighter 45° is not always the answer. I am sure they adjusted the angle for maximum actual distance. It looks like the FD was using a smooth bore nozzle which will send water the most distance. I wonder if the second nozzle took too much pressure away. Maybe, maybe not. If they were at maximum pressure no issues of the second hose line.
Great Videos Jeff, love the analytics on the engineering side of tragedies so that mistakes are not repeated! Everything has limits: reminds me of my part time job loading 48 foot “ Pup trailers “ for a trucking company. These are hooked up double-tandem and deliver freight to our main Hubs & distribution centers. In the first 4 feet of the nose you CANNOT EXCEED 3,000 lbs. OR, the combined weight of your forklift and freight in nose of the trailer will FLIP the trailer forwards with YOU in it!
I thoroughly enjoy watching each of your episodes and the detail you provide us, your voice and the way you explain things is very enjoyable. Thank you for your hard work providing us accurate and easy to understand information!
Not sure if this was already said in the comments, but I couldn't help but think if we had the drone technology we have today back when 9/11 happened, images and video would have been crazy.
I watched the new 35W bridge as it was built from pre-cast pre-stressed concrete segments of 200-240 tons each. I was on the 10th Street Bridge adjacent as the first segment was hoisted and secured to the stub on shore. I watched several more segments put into place over the next two weeks or so, and was lucky enough to watch, virtually alone on a cold day, as the final segment was slowly lowered into place. A crew of workers in each end of that hollow concrete structure then connected the interior chord arrangement for post-tensioning. Another day at the office for them, I’m sure. Pretty cool process to watch from my vantage point, but with sad cognizance that the previous steel bridge was poorly constructed (thin gussets), and improperly loaded during surface replacement…falling without warning, killing several and injuring many more….. For the hoisting of the concrete segments a massive old Manitowoc (model number escapes me now), it’s red paint job mostly faded to a pinkish hue, was situated atop two barges which were welded side by side. The crane bore the name “Big Ben,” which the operator explained in a Minneapolis newspaper article was in honor of his grandson Ben. (The casting yard city blocks away utilized a gantry crane to load the concrete segments onto truck beds for a truly short haul to Bohemia Flats. Once there another land based crane (the make escapes my recollection, but it was all blue) picked the segments from the trailers and arranged them by designation on the site. That crane soon bore the moniker “Bohemian Blue,” and subsequently loaded the concrete segments from the queue onto a barge tended by small tugboats to the appropriate site for Big Ben to perform its pick. One very interesting part of the process, amongst so many others, was that once the two-masted Manitowoc had raised a concrete segment to the proper height, the operator let out the mast winch line and “coasted” the boom forward/down and directionally proximate to attachment point of prior segment string and new piece. There was a definite run-out sound as if hand pulling fishing line from a reel! Due to how many “parts” of line were run on the mast assembly of 650 ton capacity Big Ben, the concrete segment slowly, assuredly, accurately “floated” into place as the boom was lowered! It truly was impressive, and when within reach of “home,” the brake would be heard slowing the boom descent under full control. Remarkable operation each time; like a slowly moving game of darts! I remember the scale of the white-painted traveling block on Big Ben, and the even larger alternative block resting, lashed to the barge, also white, as workers labored at the pylon corners of the barge! Massive!! Although I grip my steering wheel tightly when driving over the “new” 35W bridge, I think about having watched these very segments put precisely in place and strung together by workers standing upright in the hollow belly of the bridge! The newest, the third in my lifetime, Minnesota Vikings stadium, not but perhaps two miles from the 35W bridge, required a HUGE yellow and blue Sarens crane to be assembled inside the footprint of the building, on the field of eventual play. I had noted a very(!) oversized load on a flatbed trailer crawl ahead of me at a stop sign, it’s cargo but a single yellow boom section! It was the tallest, widest and longest bit of crane I had ever seen only yards away in traffic. As the crane was erected over the course of weeks, and as it could be seen as both taller and “thicker” than any crane I’d ever seen from miles away on the city skyline, I knew that this was, as Charlotte might say, “Some Crane!!” That Sarens, at 1,130(?) ton capacity, billed in the newspaper as “the second or third largest crawler crane in North America,” absolutely dwarfed the 500 ton Manitowoc, itself truly gigantic, set up outside the stadium footprint! The crawler tracks were about eight feet high. It had two masts of course, plus outrigger counterweight straps just in case it had to lift anything actually heavy…which it did not hear. Absolutely everything was massive!! I arrived once to watch the action through the fence, in good company as we all expressed our awe, only to find the workers laying about after their lunch. I recall one guy getting up, as others were stretching back to life, and nonchalantly strolling past the big Sarens. I thought to myself that if I were on such a worksite I’d take every spare minute to marvel at the yellow and blue steel lattice beast in my neighborhood! And then, back that man returned, climbed a ladder onto the eight foot tall track, and stepped into the operator compartment… He wasn’t in awe of the crane as I was; he was the primary operator. A subsequent newspaper article stated that he and a backup operator travel with that crane! Most recently they had been at a nuclear power plant build, if I recall correctly. Each evening, come the close of the work day, the giant Sarens, with a jib as long and thick as the boom of most run of the mill cranes(!), would be “jack knifed” onto a set of off-white polyethylene wheels at its apex. So I know what you mean Jeff about that safe-resting procedure. The parts, all the parts, of that crane were beyond my prior reconning!! (I realize that there were and are far bigger cranes even within North America; but not in my “near neighborhood!”) One night I heard a hum and saw some faint lights coming from the bowl of the stadium build. Having nothing else to do on a night off from work, I walked over to the fence. An operator and one other worker were slowly moving the Sarens through maneuvers which varied but slightly one from the other. It occurred to me that they may have been planning out angles and placement priorities for a big lift the next day, though that is only my speculation… The Sarens was not needed for its gross maximum lifting capacity, but for its security at jib height with bulky, awkward and expansive steel structural loads. If I had to guess, nothing I saw the Sarens lift weighed over 300 tons. Everything was on the end of the jib; the boom line never came into play once! Taking down, packing up, and hauling off the Sarens took another week or so. I’m glad that I took photos, for I may never again see another crane with eight foot crawlers!! (Though perhaps if the Vikings decide that they require a fourth iteration of a stadium to make up for the fact that we STILL haven’t won the Super Bowl . . . )
A 45 degree angle giving the largest distance is only valid when neglecting friction. For a canonball, that is a somewhat appropriate approximation, but for a water stream it is certainly not. The stream quickly breaks apart into tiny droplets that feel a large amount of air resistance.
If what you are saying is true, why doesn't rain dissipate before it hits the ground, falling from thousands of feet? Yes, you would have some separation of the spray, but for sure at that distance may be 50 feet above the Crane, the water would be landing on it for sure, maybe not all of it, but at least some of it period at least what they have right now. Without horizontal spray, none of it is even reaching anywhere near the Crane.
I believe the reason they had the hoses angled the way they did was because they had to find a way of getting the stream there by the shortest route possible in order to maximize the streams effectiveness. You will notice as the stream gets farther away, the stream begins breaking up and separating, making it less effective. If they angle up, that increases the distance, but it also means the stream will break up more. Obviously, there are a lot of factors that have to be considered. The diameter of hose they're using. The type of nozzle. Wind speeds. And what PSI they are using at the pump. Now the 45 degree angle might very well have been the most effective. But you just can't use that as if it is always the best one to use. I used to be a firefighter, however its been many years since I last worked as one. And I'm trying to recall what I learned and its definitely a little hazy. So I know there is probably a better way to explain what I'm talking about. And for that, I apologize.
You would think living in NYC and paying high tax rates means you don't have to worry about a crane falling on you. You'd be wrong. Accidents are the result of either negligence, corruption, or ineptness. Cutting corners, not educating employees, poor maintenance, these are all a disaster waiting to happen. Be outraged this company was allowed to operate at all after 2 previous accidents. Be outraged that you have to constantly be on guard around cranes, buildings, pretty much everything. Jeff, I love your videos man. You are the educator we need when things like this appear to be "just an accident". You zoom in on the pixelated footage or dig a little deeper so we don't have to. Most of us wouldn't know where to start so, Thanks man.
I guess the problem with the water stream from the hose is that the best possible angle is not 45 degrees because the stream will separate into mist before the water travels the whole arch. If they were shooting metal balls from the hose without air friction, then 45 degrees would be optimal. Other than that, great video. And I think it would be better to underline which parts are speculation and which are actual data in future.
Note to self - if I was stuck in one of those top floors, I would not wait around for someone to help me. The officers just keep telling people where they can walk. Did they even check to see if they could help anyone within an hour or 2?
Each nozzle has progressive larger diameters the closer you get to the base. You unscrew a 2” section to get a larger diameter stream but you loose distance.
2 things here... 1 the nozzle laying on the ledge at a horizontal angle is a 2.5 line that flows water through a 2 inch opening to the nozzle and the one arched at an angle is a blitzfire/ ground monitor on a 3 inch line forced through a 2.5 inch opening to the tip... the 2.5 line isn't going to the ability to reach that far even at a 45° angle and the ground monitor on a 3 inch line was barely getting it with droplets from the end of the stream as it was breaking up and maxed out in distance and that didn't even end up putting the fire out.. they got a hoseline up through the building that the crane was building to finally extinguish the fire... and water doesn't work like everything else you learned in engineering class.. it is affected by many things. Friction loss being the biggest especially when going up an elevation. Wind is going to push the stream left right and even back at you. No matter what angle the 2 hoselines were put at it wasn't going to make a difference in its ability to extinguish the fire
45 degrees is only maximal in theory, it does not allow for aero drag slowing the projectile down. And I am guessing that for a stream of water, all 45 degrees does is add so much distance that the stream turns into a cloud and does not reach as far horizontally.
If you went to engineering school, you would know 45 degrees is not actually ever the optimal angle. You need to account for all of the factors that effect the stream. Zero degrees can be best sometimes. Also when fighting a fire, you want the stream to hit the fire, not the mist.
Another good engineering analysis. I have a different question concerning the Maui fire: In videos showing the total devastation caused by the fire, it was pointed out that the only surviving items were those BLUE items (blue cars, blue garden umbrellas, blue sponges and flower pots). Everything around these items were totally incinerated, including cars parked next to the blue ones. Any ideas on this "blue fireproofing"?
I've been watching people do really strange things while lifting things for decades. Be it a crane, or a fork lift, they just have to try it their way. There's a video out there of a forklift hoisting up a forklift with a load on it. Ladders on a pallet on a forklift. My first real job was in the airline cargo business. We used to get 5 or 6 Ferrari cars in on our 707 freighter. The company {Yonge-Steeles Motors) would send out drivers with gas and drive them to their ship. Because we were a small operation, we didn't have the pallet moving equipment or ramps or anything. We picked up the cars with a forklift using extensions and blocks of wood. One afternoon, I was with a coworker, he was operating the forklift. The car came up off the pallet nice as could be, but he backed into a small pot hole on the ramp. The jolt caused the car to start bouncing on the forks and before he could drop it, it came off abut 3 feet up, landed on it's side and rolled over. The guy walked into the office. Half an hour later the lead cargo hand came out and freaked. Apparently the guy just picked up his gear and left, never to be seen again. Working as a millwright later on, I saw some of the strangest lifts. Like I said, people do weird stuff with lifts.
It's the oiler's responsibility to maintain the crane on site. Local 15. You guess a lot in your videos. Things happen.
It's also the city's job to inspect the cranes, but we saw how well that worked out in 2008 with falsified inspection reports from NYC DOB inspectors. You guess a lot in your comments. You assume everyone is doing their job.
Not any “oiler’s” job to maintain a crane that is built with substandard metal
It might be the oilers responsibility to *do* the maintenance. But that doesn't mean that the operator is off the hook (ethically) for not *verifying* the work was done. E.g. legally the driver of a truck is responsible for the load being secure regardless of who loaded and secured it. Another one; the caption of a ship is on the hook for everything that happens on the ship, even when people disobey orders. Even if someone isn't allowed to do the work, they still should verify for themselves that it was done correctly.
No not the oiler. That's false
I can't imagine looking at a disaster of this scale and being like, "eh, things happen." Like, that's absolutely not an acceptable excuse?!? Things happen, and we examine them to see what caused those things, so that things don't happen again.
Many years ago I was told that a series of crain colapses in Perth Western Australia were put down to operator error and then someone looked for commonalities and found that all the operators involved were trained at the same company and the same instructor.He got sacked and all his students were retrained and the problem went away.
The crane collapses that I knew about(1 in the Army, and 3 civilian) all involved overloading. In the Army, it was a Major ordered the the Spec5 to exceed to safe reach and the barge flipped and dumped the crane. The civil ones were all cases of the customer lying about the weight to get a cheaper crane. Most catastrophes have a bunch of errors that lead up to it. When I was called up for Desert Storm, I served with a Major from the Hawaiian National Guard. He told me that they were being flooded with chinesium and they were having a lot of failures. He warned me to watch out for it. Another good video. Good Luck, Rick
Stockton Crane Company
Every crane should be fitted with an overload protection system. These construction cranes simply do not react if the load is too heavy.
@@V100-e5q Yes they do tip over, even when there's protection. I've seen it with my own eyes at a company I worked for a couple of decades ago. A similar crane like the last one shown (but a Demag instead) had all the protections it needed and all where in working order. That crane in particular came in for maintenance and since the maintenance took a while the crane had to be re-inspected (here in Belgium it's mandatory every 3 months + a bigger one each year). The inspector had just checked the crane, did severe testing to it and gave it the all clear. When he just walked into our office to issue the paperwork the crane came crashing down (tipped over like the last one). Since it was the end of the day the operator was in a hurry to get out of there and instead of taking it slowly he rushed to get the mainboom and the jib down, unfortunately the safety system was a bit slow in shutting the controls down and preventing certain operations, in the second or so it took for the system to shut down the crane started to tip, the operator felt it fortunately and he jumped out of the cab before the counterweight came crashing into it. The crane was perfectly fine, it was just inspected and yet it failed. It was only after that incident that we found out that the safety system didn't react quick enough. No injuries occured but the car of the inspector was totalled in the process, the hook came crashing right on top of his car, merely a meter of our office. Parts of the boom crashed about a meter deep into heavily reinforced concrete. Obviously the crane's certificate was revoked by the inspector since he was quite pissed at that moment 🤣 But our maintenance department repaired the crane, even some boomparts were recovered and repaired but the crane received a full upgrade of security systems. And the same inspector cleared the crane -again- months later (with his new car parked far far away) 😂
@@jeffostroff Savagery spotted 😂
Thank you for your service Rick!
So sad when accidents like this happen.
My uncle was a tower crane repair man, in California. He was one of the ones that worked on the crane in place, not in a shop, or on the ground. He made a butt tonne of $$$$$, because of the danger, and liability involved.
He gave me two pieces of advice, when it came to cranes.
1.) "If you're not making a living, being near the crane, stay the hell away from them and every place around them. That goes double for one of them." (pointing to a tower crane)
2.) "IF you fail at your job, one of the other guys could get hurt, or god forbid a regular person get's hurt. The second your hand hits that first rung, you inspect as you go. All the way from the bottom up. If you see ANYTHING, you note it and go back down immediately, and report it. And your @$$ better not even THINK of going back up until the problem is fixed properly AND... to your satisfaction."
.
R.I.P. Uncle Johnny, and save some Scotch for the rest of us.
I work with cranes almost everyday. Seeing those cranes collapsing is frightening to say the least.
it goes to show if you see something wrong with your crane get it fixed do not ignore it cause as you can see the warning signs kill if ignored
No doubt. I only receive materials from the crane on the roof. The hook would be the closest I get to the actual crane.
As someone who has worked with construction equipment and farm equipment sometimes a hydraulic hose can burst unexpectedly with no warning, especially if moving a heavy load and applying high forces to the hydraulics.
Am I wrong to expect some redundancy for something that swings and lifts loads 100 stories?? Horizontal directional drills are the same way,,when a line bursts your done,but again it's not responsible for overhead lifrting.
No excuse there - if you are relying upon a hydraulic hose to keep a load in the air, you are doing it wrong. There are load-holding valves used in the aerial work platform industry that are built into the base of each hydraulic cylinder such that if a hose breaks, nothing moves.
My friend you know about as much about cranes as i rickety submarines my only question is why does it not have q built in fire suppression system in the engine compartment for fires since there so high up in case of a fire pull a lever
45 degrees give you the longest trajectory with 0 air resistance, the ideal angle with a water hose would be a lot less where wind is also a factor as well.
It's not exactly difficult maths to factor in air resistance either, I did it in high school.
The best angle is less than 45° for water moving through air. But the calculation is probably a lot more difficult than what would be done in high school. At least what we did was add in the coefficient of friction between the projectile and the air. But with water this is constantly changing. At first the water comes out as a solid stream with only the outside of the steam interacting with the air. Then it breaks into small drops with each drop interacting with air. These drops are so light that they also change direction.
Then even if you get the maximum distance, the steam may be so dispersed that the amount of water actually hitting the target may be very small.
The best thing to do is understand these variables and try different angles until you find the one that puts the most water on the fire. Shooting straight at it may fall short giving 0%. Shooting at 45% may reach it but only 25% coverage. Something in between may be the best.
It’s like if my shooting target is 10 feet in front of me. There are two angles that will hit it. I can shoot almost straight, or I can shoot up at about 80°. Both will hit the mark, but if the projectile (or water spray) is going to break apart before it hits the target, then one is definitely better then the other.
The fire hose in the video may have been at a low angle, but it may have been delivering more water than a shower would if they had aimed it at 45°
@@bobh6728 Yeah, for sure. The stuff I did in school was just different shapes and air resistance, which is enough to know that 45 degrees isn't the universal best angle.
A stream of water would be extremely difficult to calculate, but logically the angle that delivers the most water to the target is going to be as flat and direct as possible.
@bobh6728 AIR resistance can be simplified by treating as a constant force pushing against the water stream. 44 to 45 degrees still gives the best angle for maximum distance
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@@electrictroy2010 If it stayed a solid stream then it would be close. But looking at the video, the distance and effect of wind made it more of a misting than a stream. Since we didn’t see the whole time they were spraying water, we don’t know if they tried other angles and decided which one was the best.
Just mentioned this in another comment, but a good real-world rule of thumb is that the optimum range will be achieved when the object being fired is **coming down** on the target at 45 degrees.
.....no maths required. Just adjust your angle until the thing being fired is arriving at 45 degrees as that's the max range you're going to get. This is what the firefighters were doing in the video (at least with the larger stream which had a chance of getting close).
I worked on building steel towers. On one job it was convenient to use a crane to hoist completed 20' sections onto an existing tower. I was on the tower top putting in the bolts into each new section as it came up.
One section started swinging a bit wild due to 0:06 sudden wind gusts that were getting nasty. As I wrangled the first bolt in place the ground workers let me know about lightning. I heard the boom and saw a flash, and I started climbing down like a scared squirell.
We left to get under cover during a horrendous storm. When we next looked out the tower section and crane were at seemingly impossible angles, and the rigging had fouled everything.
The crane was up to its axles in mud and tilted a bit. The operator had set 3 wheels in 2 different swales, and the downpour buried the crane in mud. 0:06
Nooooo! Not corruption??? In NYC? How COULD it be??
Isn't that what NYC stands for? "New York Corruption," right? 😂
There’s corruption everywhere, don’t kid yourselves. People should also be worrying about smaller towns that lack oversight, nor have independent resources to investigate, audit records, or keep the “good ole boys” clubs in check.
Amusement Park rides are a problem this summer, too.
_"What Caused 2023 New York Crane Collapse?"_
He was old and tired. Regardless of how many times he was rubbed down and repainted _(Though he liked the rubbing down bit!),_ there comes a time when a crane stops and thinks,
_"Can I really go on with this for another year? Build myself up. Lift this here. Place this there. Lift that there. Put it there. All day long and for weeks on end. Then it's dismantle myself and back into some storage for god knows how long. And then there's the wind when I can't do anything. And then there are the holiday's for my keepers. They go and leave me here. especially at winter. Covered in ice and snow while they're having parties in warm houses."_
So this old fella... This old crane we've seen... He just got tired of life. He thought he'd have to stop.
*_But he just wanted to go out in a spectacular way. Which he did._*
And try hot to hurt anyone in doing so. Which he didn't quite manage to do. _But then... After all... He was just an old crane._
Love this!
@@jeffostroff Thank you 8-))...
I thought your video's on that Titanic submersible were very good. Full of really good and well diagnosed information.
Great video. You're on point with just about everything you spoke about. I work in construction in NYC. We work with and erect and assemble and disassemble lots of these cranes, from the smallest cherry-picker to the tallest tower cranes. We are still yet to determine what started the fire, it could be anything, of course, but you are right. The damage done to the main cable on the boom was the problem. Right after this latest collapse (thank God, no one was killed) I got on a social media chat with some of my union brothers that have a lot more experience than I do in the tower crane department...and one of the first things that came up was the fact that Lomma cranes was involved, yet again. The corruption levels of this company are well-known in the industry...and we always talk in hushed tones about the corruptibility of DOB inspectors as well. Even the fact that Lomma got off in the criminal case has been alleged to have been corruption. I wouldn't doubt it.
Regarding the crane that collapsed in that bonus footage, everything you said was exactly how it happened. The crane operator started lowering the jib too fast and with the wrong angle on the boom. The only other thing I might add is that the one victim that died, word on the street is that he was told not to walk into a restricted area, and he (allegedly) flipped the bird to the flaggers on duty and did so anyway. Allegedly. Condolences to his family all the same, and may he R.I.P.
I love these analysis videos that you do. You are so smart Jeff!! Thanks, Melaney from SoCal
Thanks Jeff, always good to see and hear you give your thoughts and reviews on our every day comings and goings. No smoke and mirrors here, very informative as always. Please keep the great content coming.
Please continue this video including the Seattle crane collapse in April 27 2019. I was told by a construction worker that the giant bolts that hold it in place at the base, were taken up too early while dismantling it. Also the wind was a factor. Would love to hear your explanation.
I think he already covered that one.
Taking the bolts out early killed the crane in Seattle and was done by a subcontractor to a subcontractor of another subcontractor for the contractor , Totally a leadership /safty issue , Letting the Schedule drive the work instead of letting the work dictate the the schedule.
as a crane operator i can tell you that your more likely to get hit by lightening than hit by a falling crane.
also its very common for cranes to be operating right on the edge of stability limits, and to a degree but less common, structual limits.
every day someone will ask you to do something thats beyond your reach or capacity. without doubt. sometimes you do it when experience tells you you can get away with it, and some times you have to put your foot down and say no. and almost everytime its the foreman or someone in an office telling you to do it.
crane load charts are very conservative. lifting %110 of your capacity is usually fine, but its the extra factors that make it dangerous and why the load charts exist.
wind on the boom de-rates everything. this is one of many unseen factors that can compound the error and give you the accidents you see.
Thanks Jeff, always interesting to see the nuts and bolts behind these mechanical failures.
Thanks, I'm glad you liked it!
Two points:
Point 1: Cranes are one of the simplest machines found on a construction site. Even so, I've been amazed over the years at how often they are involved in accidents. There is no end to people's ability to screw up a lift. This includes the ever-present mobile crane and bridge cranes.
Point 2: A hose stream does not act like a projectile in flight. Even a well-formed hose stream will begin to splinter as it gets further and further from the nozzle. To get optimum reach a suitable nozzle with the water being supplied to the nozzle at optimum pressure is needed. If, for example, the pressure is less than optimum the stream will begin to splinter much sooner and will have less reach. Once splintering starts to occur, range will quickly be reduced.
It seems crazy that there isn’t some sort of mandatory fire suppression system near the fuel and engine compartments 😮
I've never heard of this happening before. Maybe they will consider in future.
@@geniferteal4178 most cranes in europe use a ground generator and have power cables going up to the motors exactly for this reason
I think the only supression system that would work on that sorta fire is the co2 foam which would proabably get pumped into the cab killing the operator. Hence why its probably left to burn since water would just make it worse and you would need a lot of sand
@@harrythompson6977 interesting. Make you wonder how they refuel this type.
@@geniferteal4178 they use the same crane to hoist a fuel tank.
As far as the 45° angle you mentioned that's all we'll and good until you figure in the Wind up there and it was blowing pretty good that day ! So the Line has to constantly be moved to counter the extreme winds at that hight !
A lot of the engineers I’ve dealt with lack real world experience. This is a perfect example.
In California, I have seen them put the booms down just at the end of the work day since you never know when there's going to be an earthquake around here. Don't know what the procedure is if they're working when one happens. I'd hate to be the person in cab in that case, especially if the earthquake is a big one.
I had to come back here because I just looked it up and apparently they design earthquake-resistant cranes. They design them so that they won't collapse or drop their load during severe shaking, which is the ultimate requirement for them, and that, in the case of just moderate shaking, they are designed to continue to be fully operational. I have noticed that I've never seen a crane around here that looked anything like the ones in these collapse videos. I didn't go as far as to look into the exact specs but, from the pictures, I would guess that part of what makes them resistant to shaking is that they use a huge counterbalancing weight instead of just some hydraulics. I would imagine that this means less load is imparted to the supporting structure when things start shaking. I can see why they don't do this all the time, though, because it takes up a lot more space. I don't know how they'd do something like that in New York City at all due to the already limited space but they should come up with something as there are actually faults capable of producing a pretty significant earthquake running right through New York City.
I don't think 45 degrees gives you more distance with a stream of water. The further you push a stream of water through the air the more the air resistance breaks it up until its too small to maintain any momentum and becomes subject strictly to gravity and wind currents. It's not like a cannonball that maintains its mass throughout the arc. A higher arc just means it has travel further and overcome more air resistance to try and reach the same distance. Of course, having no arc at all is going to give you less distance than having some, but I think they weren't trying to reach the fire with the flat trajectory hose. Likely they were trying to hose down everything below the fire in case anything burning fell off.
Physics tells you that 45° is the angle you can throw anything to get the widest reach. Other factors might get into that. But not holding the hose up to 45° will never result in max reach. And those factors are equally at play if you aim lower.
@@V100-e5q These people are into "alternative" physics , hehe
Blah blah blah you said nothing of value
Different pumps, different size hoses, different size nozzles, all have an effect on how far water shoots.
@@OttoByOgraffey But the basic calculation is about angle. And that applies to all other factors in the same way.
Thanks so much for your hard work in these videos. Keep on keeping us informed.
I developed an allergy to truck cranes early on Jeff. Just a preference for old school crawlers that were typically stretched way beyond modern chart limits. -Bob... PS: Time to require an adequate plus Fire Suppression System onboard. May not save a header, but helps prever a total combine loss.
Ooh, good idea.
I am binge watching your videos! Excellent work!
Glad you like them!
Okay, not sure where they left off in physics class but unless they're launching cannonballs, the ballistic trajectory doesnt hold true with a water stream that breaks up over distance. The ballistic, no air resistance, academic idea goes out the window as the water and air interact and the stream turns into droplets without the mass to force thru the air. A certain amount of lob may help at short distances or when at or below the level of the fire. When the fire is lower then the platform its entirely possible that a horizontal or even downturned stream is on target and offers the most effective applicaton of wet stuff on red stuff.
I'm no expert, but a couple of thoughts. On the angle of the firehoses: distance is not the only factor. It is also essential that the water stream hold together. A higher angle would have put the water stream into the unobstructed wind flow above the highest buildings in the area. It might not have worked. I wonder if they tried it earlier, before the video clip that focused on the drone, not the start of the hoses.
From a safety prevention perspective. Cargo aircraft are required now to have fire suppression systems in each cargo compartment. This was implemented when we realized just how dangerous fires can be when they are in high altitude locations that cannot be reached in time. It seems to me that regulations requiring fire suppression systems on elevated crane platforms would be worth investigating.
Many years ago in Minneapolis I witnessed from my car on a side street, a scaffolding being blown to the ground by strong winds around 7pm. I heard the next day that they unhooked it as it would be taken down as they were finished with it. Who decided this stuff?
Great, informative video! What you described from each crane incident basically boils down to; corruption, greed and laziness. Scary and infuriating!
Enough with the conspiracies. Operator error and mechanical failure are the root cause of most construction accidents.
Jeff, thanks for providing this information-and this service of reporting public safety issues!
I'm surprised he didn't mention the crane holding up the roof components of a stadium ( sorry can't remember where) and that crane collapse also caused fatalities. Of course when it comes to engineering 'oversights) no one can forget the condos in Florida. Geesh makes one afraid to go anywhere.
Love your vids Jeff. I will always look out for cranes and mark them with my finger, walking around them. Life saved.
I've had to work around cranes. I've learned to stay clear of the operating zone unless I'm actively directing or controlling the load. As far as the collapse due to fire it could be operator error on the operator's routine safety inspection, insufficient/improper maintenence, something missed on the owner's equipment inspections, or just an unpredictable failure. I suspect that noone was keeping the engine clean so the oil on the engine was hiding the existence of a small fuel leak.
Couple of points, First off the angle of the water, you can see the water is dispersing from a jet right near the crane, if they angled it any more the jet would have dispersed further away from the crane, so it didnt have the range to hit with it at 45 degrees. you can also tell the aditional hose has less pressure than the first as it disperses alot futher away from the crane. Second point is while indeed it could be a lack of inspection, its also possible inspections were carried out and everything was in ordered, minor hydraulic leaks on construction equipment can start at any second in time as nothing externaly visual will be present at the time of inspection on the hoses or connections, assuming the initial report of an oil leak starting the fire.
0:12 Incredible to see that the road below remained open with traffic flowing. What were they thinking?
I was witness to "professional" firefighters trying to put out a fire at the top of a dead tree and they had no idea how to angle the hose/water to reach it! It was so frustrating to watch! They eventually just gave up and left the fire to burn out (which was on our property!), so we climbed up there and stuck our hose directly into the hole at the top of the tree and directly onto the fire, which was promptly distinguished by our "amateur" attempts!
I can tell you from reading hundreds of incident reports and being on at least that many related phone calls, hydraulic hoses and seals often burst with little to no warning. When this happens on the ground, it is bad enough.
If it was a bad hose or seal, my guess is that one of two things is true. (1) The company failed to do preventative maintenance, or (2) thye got a bad part. Statistically, #1 is far more likely, but #2 does happen.
I agree with scenario number one
That one on westlake? Scary stuff.
I was in the fire department when I was younger and they didn't teach us anything about the angle of the water coming out of the hose. However, I also worked for a department that didn't have any really tall buildings or many instances where just the pressure available to us wouldn't be enough to easily reach the fire. Also, literally all the fires I fought were wild land fires and we did medical calls around town other than that.
The other thought I had is that perhaps that lower line was trying tower down the building onto which that crane was anchored so that the fire wouldn't spread to the building. In fact, I'm almost certain that they would be putting water on the building because that's something we do if we can to keep fire from spreading from one house to another and also on brush to slow the fire down and help us contain it when it's a wild fire. This still doesn't explain the other hose other than perhaps there being a lack of communication between the drone operators and the firefighters on the roof aiming the hose line since it may have appeared to all of them that they were hitting it. They would have been aiming at the base of the fire since you have to do that to put it out. If you just aim at the flames above the thing that is on fire, all you'll do is make a bunch of steam. I wouldn't be surprised if the firefighters aiming the hose thought they were hitting the base of the fire from their angle. Hopefully, word got through from the drone pilot that they needed to aim higher.
So here's something even more ridiculous about the fire fight. If that was fuel or oil burning, they should have been fighting it with foam, not water, as oil and fuel will simply float on top of the water and continue to burn, spreading the fire instead of putting it out. Maybe the hoses were actually being aimed in an attempt both to cool the surrounding structure and to prevent the building from catching fire while they waiting for an engine with the proper firefighting foam, probably an ARFF unit from the airport.
If you look at 3:41, you will be able to see they do in fact arc the stream upwards. If Jeff is using the video he shows us as the reference point, then I'm not sure he's accounted for the fact that they may have been holding that hose for hours upwards and it's not exactly light. It looks like there simply isn't enough water/mass to take it the distance and more pressure is needed.
shouldnt build anything that you cant rescue from. Sensible
@@whoever6458 You may right about just keeping the crane cool enough to avoid further collapse and not spreading an oil fire.
I wonder how the fire was eventually put out.
Foam is a good idea but how do you deliver it to the fire? Would it travel that far from the other building when water wouldn’t go that far? Shooting from the ground would take tremendous pressure. An airdrop from a helicopter might work.
I don’t know what they finally used to get it out, maybe just let it burn itself out.
Right, it’s pretty hard to see exactly what is happening /over there/ through the spray.
great video Jeff, thanks for covering this.
"How do you miss a worn hose or loose fitting"... Spoken like a true engineer.
Would be just as reasonable to ask the engineer to design an entire system that never succumbs to vibration.
Right. I'm a quality inspector and even we're expected to mis up to 30% of problems. Humans are just gonna miss stuff no matter how hard we try not to, and especially during routine checks. This is usually why checks in my area of work are done by more than one person, are done multiple times, and/or are done more than necessary (something that might only need checking once a week may be done daily just to ensure if something is missed once, its hopefully picked up the next check).
You would think this equipment would be inspected and serviced like transport aircraft.
I always send a quick prayer towards those high-loft crane operators. You could NOT pay me enough to operate one of those things. Be safe out there, fellas.
On our drill rigs we did daily inspections, kept everything clean and painted white, and we’d still have sudden blow outs. We had Pirtek on speed dial.
Forgot to add that after one bad voluminous blow out (no fire but smokey) we added protective sleeves and hose whip restraints to everything had thick spill kit diapers under the rigs as a precaution.
We also installed these grapefruit sized balls of highly compressed dry-chem extinguisher that explode when fire touches them and shower the compartment.
Doesn’t stop the occasional blow out, but reduces the danger. But still, who knows if any or all of these could have prevented that crane fire.
Seems the only thing that would is installing one of those aircraft engine extinguisher sysyems or having a small diameter stand pipe up to the crane.
Always good to hear from you Bro. Madd Love. Peace.
Thanks, I'm glad you liked it!
Stumbled across your channel. Full disclosure i am not an engineer, however i am a retired Firefighter/Paramedic Instructor and Field Training Officer. The only thing i feel experienced enough to talk about are your comments on the water streams. One hose stream reached the fire and the other was basically useless which i totally agree with, it's the reason why I'd like to share insight on. When you look at the close ups you have at the hose/nozzles. particularly the 2:15 and 3:35 mark, especially the 3:35 mark, the useless stream with nozzle closest to the camera has a different type of nozzle and it APPEARS to have a smaller hose diameter hooked to it. So to start there is not as much water pressure and flow, the useless nozzle and hose is being held by one firefighter with no assistance. That hose diameter is either a 2-1/2 or 3" diameter. They USUALLY flow at 75-80 PSI and about 180GPM. If you look at the hose farthest from the camera it is a different type nozzle that is called a smooth bore nozzle so there is no flow restriction. If you look on the ledge you will see a black anchor extended across the ledge with hooks to secure it to the end of the ledge. That is assisting the firefighter in holding the hose in place. Since they were obviously not hooked dirrectly to the firetruck there is no way for us to determine psi, velocity or gpm. However, considering the firefighter with the useless hose stream was able to hold it by himself and not have it tied down, that hose did not have the psi or flow rate to reach like the other hose did. Since I was not there I could only speculate that possibly his stream was trying to be directed to the rooftop itself to put out any drop fires that were started by burning material/embers falling and possibly landing onto the roof of the building. So while I agree with you wholeheartedly that the second stream was useless as far as the main fire, i do not think it was tasked with that to begin with. Otherwise I do appreciate your engineering insight into everything else that occurred. Thank you for the time you spend making these videos. Eric
Hi Jeff I really enjoy your insight into all these topics. Is there any update on the Champlain Towers Report? Keep up the good work.
I have one in the works for next week
Looks like the 2nd stream had less pressure. Not so much the angle… but what do I know lol
Thank you. Very informative. It was worth the wait.
So it was indeed a diesel engine and hydraulic system up there. I believe, direct electric drive would be a safer option in a city where plenty of electricity is readily available.
At one of the video fragments, it was clearly visible when the end of the broken cable whipped out of the pulley that held the jib up. The shock created a plume of dust and debris, clearly visible against the blue sky.
Or just a separate generator wherever tf, but not hundreds of feet up in the air.
45 degrees is only the best for a solid projectile with no drag, no wind and where you don't care about the direction it arrives in. A water stream has high drag and the drops disperse rapidly. That drag might actually give better reach to lower angles under some conditions. If a lower angel works at all, it will also likely get more water on target.
Lucky nobody was killed 😲
It is amazing how one small detail can mess up the structure of any machine, a possibly leaky hose of oil, a broken strap, a faulty baring, etc. Normally the videos you show of disastrous results of a structure of some sort collapsing or imploding has some big key lessons, but really the hindsight of this case is to inspect probably at least twice a day or maybe twice every time someone uses it. It’ll be interesting to know if there was a missing responsible party and it could lead to more updated regulations, or at least what comes out of the report. While the fall of a crane can be fatale, it tends to be a rare exception given that if it happens, it happens in a small amount in just over a 15 year span. If certain details does add up and it leads to being an updated process of inspections, will it help prevent this scenario to happen 0 times in the next 15 years will be interesting. We’re probably going to have to remember this case by the time 15 years has gone by to know whether it has worked or not.
ChatGPT gave this response to the optimal angle of a fire hose:
The optimal angle for a fire hose to reach the farthest horizontal distance is typically around 30 degrees, not 45 degrees.
When a fire hose is aimed at a 30-degree angle above the horizontal, it strikes a balance between maximizing the horizontal range and minimizing the effects of air resistance and gravity. This angle allows the water to travel the greatest distance before it begins to fall back down to the ground.
The 30-degree angle is often considered the optimum angle of projection for achieving the maximum horizontal distance with a fire hose. However, practical considerations such as water pressure, nozzle design, wind conditions, and other factors can influence the actual angle that firefighters use in real-world situations to effectively combat fires.
The physics answer for a projectile ignoring air resistance is 45 degrees taking into account only gravity. However, because of air resistance, one needs more horizontal force for a water stream. If you have a fire hose in hand, the real life solution with would be to vary the elevation till you achieved maximum distance hopefully reaching the intended object fire. In the video, neither hose stream appeared to reach the fire adequately even though it looks like they were higher than the fire.
I’m a sculptor. I was installing a 6.6 ton, 35 foot by 17 foot by 12 foot sculptural shade structure of my design that required a 155 foot reach from a crane parked on a street with a 20 degree slope. The crane had been propped up at one end on shoring with its outriggers fully out. It took nearly 3 hours just to load all the counterweights to balance the reach of that load. They lifted the sculpture up and over the brand new building, and as they were lowering it I stood next to the guy with the walkie talkie who was directing the crane operator. With the sculpture still about 30 feet in the air we hear the operator say, “ you got about 30 seconds to get this off the hook cause the street’s starting to give way under the outrigger.” I stopped breathing, but the guy directing just kept giving instructions to line it up with the columns and lower away. 23 seconds later the cable went slack and I felt relieved. The guy then explained to me that if it had fallen it would not have been the crane company’s fault, as they had done the calcs and the load on the foot pad should not have been enough to cave in the street. He said the county would have been in trouble for making a road that did not meet minimum load bearing capacities. The foot pad was a good 36 inches wide. After the crane packed up and left, I went and looked and sure enough, for the next ten years there was a circular depression in the road right where that footpad had been. They just recently repaved that road and its finally gone.
I really enjoy your videos. I always learn so much.
With how many of these cranes are in use (and how often, too) in cities like NYC, I'm not too surprised that it happens this often. It's something that most likely will happen at some point. All you can do is update inspection guidelines after the incident, and try to minimize injuries during.
If it comes to who is to blame, it's everyone who works on and in the crane.
Regardless of if you are freelance or an employee, you should always check the equipment you are using and report any issues you come across. Then it passes the blame to the person who gives the go-ahead to continue the crane's operation. Unless it's obvious it's going to lead to a disaster, you will never be to blame if something does go wrong.
Thanks Jeff, the engineering is fascinating., The practical, "Stay away" is very helpful. I stay back from cars or trucks towing things. We all know what can happen, and i know it happens often.
or a big rig that is swerving. I almost lost my life to that last year. He was swerving and had an over hanging load. He almost hit some barriers and signs, i was well back.
I'll be more mindful of cranes.
Isn't the remaining portion of the crane now in danger of collapse? The boom and the counterweights offset each other to keep it in balance. With the boom now gone, all of the weight is now biased towards the counterweight end. This is putting an extreme amount of strain unevenly on that turntable part.
I think they may have to set up a second crane to dismantle this one before it falls and kills someone.
I think it's kind of nuts that we can even build all this stuff without constant disasters and failures happening. We just take it for granted that these things are possible, and should always be successful. If the climate gets much crazier, we'll be seeing really high winds going after these super-tall buildings.
man I like so much your engineering analysis about different daily subject, keep shouting us good content !
Just had a couple crane incidents occur in Bangkok. In May a crane collapsed and in June a crane malfunction caused an overpass under construction to collapse.
Fire Marshall Bill caught me off guard, I remember watching In Living Color when it came out late 80's I think. Good video. 👍🏻🇺🇲
He's been using Fire Marshall Bill a lot lately.
@@mommachupacabra I just found the channel lol. Fire Marshall Bill was the best character. Jim Carrey on In Living Color still is funny today.
14:52 I agree; your videos on Stockton Rush are among the best on TH-cam.
At 5-mins, the power pack is shown and the device on top is not the fuel tank, but is actually the muffler and you can just see it's flapper rain cap on top.
I was off the grid this weekend so I'm just seeing this now. Damn!!!
How do cranes not have electric nominally closed breaks at the top of the rig if power is gone it locks the wire in place
A 45° angle will only give the greatest range when you take momentum and gravity into account. Meanwhile, air resistance, wind, altitude difference, water jet dissipation and others play a role.
But but but the melting point of steel…😂
Facts lol
Two streams may have been the issue. And yes 45° may have helped, maybe not due to the loss of laminer stream due to wind/air pressure. Water flow is much different than a solid shell flying through the air. Air/ wind is different with water ... As a retired firefighter 45° is not always the answer. I am sure they adjusted the angle for maximum actual distance. It looks like the FD was using a smooth bore nozzle which will send water the most distance. I wonder if the second nozzle took too much pressure away. Maybe, maybe not. If they were at maximum pressure no issues of the second hose line.
Great Videos Jeff, love the analytics on the engineering side of tragedies so that mistakes are not repeated! Everything has limits: reminds me of my part time job loading 48 foot “ Pup trailers “ for a trucking company. These are hooked up double-tandem and deliver freight to our main Hubs & distribution centers. In the first 4 feet of the nose you CANNOT EXCEED 3,000 lbs. OR, the combined weight of your forklift and freight in nose of the trailer will FLIP the trailer forwards with YOU in it!
I thoroughly enjoy watching each of your episodes and the detail you provide us, your voice and the way you explain things is very enjoyable. Thank you for your hard work providing us accurate and easy to understand information!
Jeff, did you ever research the stage rigging collapse at Toronto that killed the drum tech for Radiohead?
I would love an analysis of that. I'm just getting into tech theater and know nothing about engineering. Every tiny thing helps!
Hi Jeff thanks for this great video! I am new to your channel and have been bin watching the Champlain Towers videos, very insightful. 😊
nice video as always! there's just something funny to me about saying, "i've got a BONUS crane collapse for you" lol
Love these videos!!!
Glad you like them!
Not sure if this was already said in the comments, but I couldn't help but think if we had the drone technology we have today back when 9/11 happened, images and video would have been crazy.
I enjoyed this so darn much. I actually used my brain to fully get this.
Awesome glad you liked it
@@jeffostroff I subscribed. I could understand the forces involved. It was incredibly well explained by yourself. Greetings from freezing South Africa
I watched the new 35W bridge as it was built from pre-cast pre-stressed concrete segments of 200-240 tons each. I was on the 10th Street Bridge adjacent as the first segment was hoisted and secured to the stub on shore. I watched several more segments put into place over the next two weeks or so, and was lucky enough to watch, virtually alone on a cold day, as the final segment was slowly lowered into place. A crew of workers in each end of that hollow concrete structure then connected the interior chord arrangement for post-tensioning. Another day at the office for them, I’m sure. Pretty cool process to watch from my vantage point, but with sad cognizance that the previous steel bridge was poorly constructed (thin gussets), and improperly loaded during surface replacement…falling without warning, killing several and injuring many more…..
For the hoisting of the concrete segments a massive old Manitowoc (model number escapes me now), it’s red paint job mostly faded to a pinkish hue, was situated atop two barges which were welded side by side. The crane bore the name “Big Ben,” which the operator explained in a Minneapolis newspaper article was in honor of his grandson Ben. (The casting yard city blocks away utilized a gantry crane to load the concrete segments onto truck beds for a truly short haul to Bohemia Flats. Once there another land based crane (the make escapes my recollection, but it was all blue) picked the segments from the trailers and arranged them by designation on the site. That crane soon bore the moniker “Bohemian Blue,” and subsequently loaded the concrete segments from the queue onto a barge tended by small tugboats to the appropriate site for Big Ben to perform its pick. One very interesting part of the process, amongst so many others, was that once the two-masted Manitowoc had raised a concrete segment to the proper height, the operator let out the mast winch line and “coasted” the boom forward/down and directionally proximate to attachment point of prior segment string and new piece. There was a definite run-out sound as if hand pulling fishing line from a reel! Due to how many “parts” of line were run on the mast assembly of 650 ton capacity Big Ben, the concrete segment slowly, assuredly, accurately “floated” into place as the boom was lowered! It truly was impressive, and when within reach of “home,” the brake would be heard slowing the boom descent under full control. Remarkable operation each time; like a slowly moving game of darts!
I remember the scale of the white-painted traveling block on Big Ben, and the even larger alternative block resting, lashed to the barge, also white, as workers labored at the pylon corners of the barge! Massive!!
Although I grip my steering wheel tightly when driving over the “new” 35W bridge, I think about having watched these very segments put precisely in place and strung together by workers standing upright in the hollow belly of the bridge!
The newest, the third in my lifetime, Minnesota Vikings stadium, not but perhaps two miles from the 35W bridge, required a HUGE yellow and blue Sarens crane to be assembled inside the footprint of the building, on the field of eventual play. I had noted a very(!) oversized load on a flatbed trailer crawl ahead of me at a stop sign, it’s cargo but a single yellow boom section! It was the tallest, widest and longest bit of crane I had ever seen only yards away in traffic. As the crane was erected over the course of weeks, and as it could be seen as both taller and “thicker” than any crane I’d ever seen from miles away on the city skyline, I knew that this was, as Charlotte might say, “Some Crane!!”
That Sarens, at 1,130(?) ton capacity, billed in the newspaper as “the second or third largest crawler crane in North America,” absolutely dwarfed the 500 ton Manitowoc, itself truly gigantic, set up outside the stadium footprint! The crawler tracks were about eight feet high. It had two masts of course, plus outrigger counterweight straps just in case it had to lift anything actually heavy…which it did not hear. Absolutely everything was massive!! I arrived once to watch the action through the fence, in good company as we all expressed our awe, only to find the workers laying about after their lunch. I recall one guy getting up, as others were stretching back to life, and nonchalantly strolling past the big Sarens. I thought to myself that if I were on such a worksite I’d take every spare minute to marvel at the yellow and blue steel lattice beast in my neighborhood! And then, back that man returned, climbed a ladder onto the eight foot tall track, and stepped into the operator compartment… He wasn’t in awe of the crane as I was; he was the primary operator. A subsequent newspaper article stated that he and a backup operator travel with that crane! Most recently they had been at a nuclear power plant build, if I recall correctly.
Each evening, come the close of the work day, the giant Sarens, with a jib as long and thick as the boom of most run of the mill cranes(!), would be “jack knifed” onto a set of off-white polyethylene wheels at its apex. So I know what you mean Jeff about that safe-resting procedure. The parts, all the parts, of that crane were beyond my prior reconning!!
(I realize that there were and are far bigger cranes even within North America; but not in my “near neighborhood!”)
One night I heard a hum and saw some faint lights coming from the bowl of the stadium build. Having nothing else to do on a night off from work, I walked over to the fence. An operator and one other worker were slowly moving the Sarens through maneuvers which varied but slightly one from the other. It occurred to me that they may have been planning out angles and placement priorities for a big lift the next day, though that is only my speculation…
The Sarens was not needed for its gross maximum lifting capacity, but for its security at jib height with bulky, awkward and expansive steel structural loads. If I had to guess, nothing I saw the Sarens lift weighed over 300 tons. Everything was on the end of the jib; the boom line never came into play once!
Taking down, packing up, and hauling off the Sarens took another week or so. I’m glad that I took photos, for I may never again see another crane with eight foot crawlers!! (Though perhaps if the Vikings decide that they require a fourth iteration of a stadium to make up for the fact that we STILL haven’t won the Super Bowl . . . )
A 45 degree angle giving the largest distance is only valid when neglecting friction. For a canonball, that is a somewhat appropriate approximation, but for a water stream it is certainly not. The stream quickly breaks apart into tiny droplets that feel a large amount of air resistance.
If what you are saying is true, why doesn't rain dissipate before it hits the ground, falling from thousands of feet? Yes, you would have some separation of the spray, but for sure at that distance may be 50 feet above the Crane, the water would be landing on it for sure, maybe not all of it, but at least some of it period at least what they have right now. Without horizontal spray, none of it is even reaching anywhere near the Crane.
I believe the reason they had the hoses angled the way they did was because they had to find a way of getting the stream there by the shortest route possible in order to maximize the streams effectiveness. You will notice as the stream gets farther away, the stream begins breaking up and separating, making it less effective. If they angle up, that increases the distance, but it also means the stream will break up more. Obviously, there are a lot of factors that have to be considered. The diameter of hose they're using. The type of nozzle. Wind speeds. And what PSI they are using at the pump. Now the 45 degree angle might very well have been the most effective. But you just can't use that as if it is always the best one to use. I used to be a firefighter, however its been many years since I last worked as one. And I'm trying to recall what I learned and its definitely a little hazy. So I know there is probably a better way to explain what I'm talking about. And for that, I apologize.
You would think living in NYC and paying high tax rates means you don't have to worry about a crane falling on you. You'd be wrong. Accidents are the result of either negligence, corruption, or ineptness. Cutting corners, not educating employees, poor maintenance, these are all a disaster waiting to happen. Be outraged this company was allowed to operate at all after 2 previous accidents. Be outraged that you have to constantly be on guard around cranes, buildings, pretty much everything.
Jeff, I love your videos man. You are the educator we need when things like this appear to be "just an accident". You zoom in on the pixelated footage or dig a little deeper so we don't have to. Most of us wouldn't know where to start so, Thanks man.
how many ton does that crane lift?
it looks like pretty big.....
Great job as usual jeff!! Thank you!!!!👍🏼👍🏼👍🏼👍🏼👍🏼
Jeff, this was marvelous, cheers from Orlando, FL....Paul
I'm amazed that they can get that kind of water pressure that high up in the building!
thank you Tony Dong
Great video ❤
Great video on these unnecessary failures.
I guess the problem with the water stream from the hose is that the best possible angle is not 45 degrees because the stream will separate into mist before the water travels the whole arch. If they were shooting metal balls from the hose without air friction, then 45 degrees would be optimal.
Other than that, great video. And I think it would be better to underline which parts are speculation and which are actual data in future.
The boom hoist cable to the equalizer melted/failed which connects the boom pennant lines to the boom point.
Open to more videos on thos incident. Grewt work, again!
Hey Jeff - Have you ever done a video on the Miller Park crane collapse in Milwaukee, Wisconsin in 1999?
Note to self - if I was stuck in one of those top floors, I would not wait around for someone to help me. The officers just keep telling people where they can walk. Did they even check to see if they could help anyone within an hour or 2?
Each nozzle has progressive larger diameters the closer you get to the base. You unscrew a 2” section to get a larger diameter stream but you loose distance.
2 things here... 1 the nozzle laying on the ledge at a horizontal angle is a 2.5 line that flows water through a 2 inch opening to the nozzle and the one arched at an angle is a blitzfire/ ground monitor on a 3 inch line forced through a 2.5 inch opening to the tip... the 2.5 line isn't going to the ability to reach that far even at a 45° angle and the ground monitor on a 3 inch line was barely getting it with droplets from the end of the stream as it was breaking up and maxed out in distance and that didn't even end up putting the fire out.. they got a hoseline up through the building that the crane was building to finally extinguish the fire... and water doesn't work like everything else you learned in engineering class.. it is affected by many things. Friction loss being the biggest especially when going up an elevation. Wind is going to push the stream left right and even back at you. No matter what angle the 2 hoselines were put at it wasn't going to make a difference in its ability to extinguish the fire
Guess you didn't figure out firing high at 45 degrees has the water coming down dispersed and blown by the wind making less water reaching the area.
45 degrees is only maximal in theory, it does not allow for aero drag slowing the projectile down. And I am guessing that for a stream of water, all 45 degrees does is add so much distance that the stream turns into a cloud and does not reach as far horizontally.
Jeff you should make a breakdown on the railroad collapse in Mexico City.
If you went to engineering school, you would know 45 degrees is not actually ever the optimal angle. You need to account for all of the factors that effect the stream. Zero degrees can be best sometimes. Also when fighting a fire, you want the stream to hit the fire, not the mist.
Another good engineering analysis. I have a different question concerning the Maui fire: In videos showing the total devastation caused by the fire, it was pointed out that the only surviving items were those BLUE items (blue cars, blue garden umbrellas, blue sponges and flower pots). Everything around these items were totally incinerated, including cars parked next to the blue ones. Any ideas on this "blue fireproofing"?
I've been watching people do really strange things while lifting things for decades. Be it a crane, or a fork lift, they just have to try it their way. There's a video out there of a forklift hoisting up a forklift with a load on it. Ladders on a pallet on a forklift. My first real job was in the airline cargo business. We used to get 5 or 6 Ferrari cars in on our 707 freighter. The company {Yonge-Steeles Motors) would send out drivers with gas and drive them to their ship. Because we were a small operation, we didn't have the pallet moving equipment or ramps or anything. We picked up the cars with a forklift using extensions and blocks of wood. One afternoon, I was with a coworker, he was operating the forklift. The car came up off the pallet nice as could be, but he backed into a small pot hole on the ramp. The jolt caused the car to start bouncing on the forks and before he could drop it, it came off abut 3 feet up, landed on it's side and rolled over. The guy walked into the office. Half an hour later the lead cargo hand came out and freaked. Apparently the guy just picked up his gear and left, never to be seen again. Working as a millwright later on, I saw some of the strangest lifts. Like I said, people do weird stuff with lifts.
Correction-The crane is a Favelle M440. Also,
It has been 6 weeks since the fire and the crane has not been removed.