Working as a ship fitter at BIW, brand new destroyers have this issue. Years ago this was fixed by straightening all bulkheads by using a fine spray of water and a heat from a torch. This would straighten the ripples in the bulkheads. This is still done, but only on badly warped or rippled bulkheads.
Yep, I worked Dept. O9 at the yard in the mid 2000s and I only ever saw the weather deck plating being straightened. I assume because indentations would make a puddle and/or a tripping hazard. A bunch of the old timers I talked to said that the Arleigh Burke DDG-51 was beautifully smooth. Apparently, they flame straightened everything for the first run of ships. I'm sure it got cut for cost. Keep up the good work, brotha'. Bath Built Is Best Built! 🇺🇸
Thanks for what you guys did at Bath Iron Works. I was a sailor for a couple years on U.S.S. Preble DDG-46, and I’m sure you didn’t work on that particular ship, but Preble was built at BIW way back when. The tin can fleet owes a hearty salute to all the shipyard workers and engineers who turn out great ships. 🫡 🇺🇸 ⚓️
Until they invent a metal that can stretch and regain its shape, this isn't so much an issue as it is a design choice. You could most definetly make a rigid enough ship to not have oil canning, but do you want to? - is the question. The more they travel, the more stretch they get, until the "belly" between frames reaches its max potential and it just exists there. Oil canning are ... essentially tiger stripes on boats - for the same reason we have them as well. Moving about, the skin stretches between rigid portions.
I worked @ BIW in the early '80s in production planning department - some of the "oil canning" is caused by welding heat shrinkage (the heat makes the metal shrink and pucker). I worked with the IHI (Japanese) consultants on flame straightening / bending techniques. We watched them lay out and form a piece of shell plating with nothing more than a torch, a water hose, and some wedges/sledgehammer in less time than the yard guys could do it with the 3-roller bending press. Took incredible skill and lots of experience to do that.
I was stationed at Barksdale AFB from 2002-2005. They said it was designed this way, as flying high up in altitude, the pressurized cockpit will even those wrinkles out.
Mesh doors have it too. Same reason. Rigid framing for a thin skin + movement = stretch and deformation in the skin. It's actually part of the design in most applications of this methodology. I might have it wrong, because this is just based on what i've visually seen, but i think in some parts of airframes, they specifically reinforce (extra fabric - fiberglass or carbon or whatever they may use) the edges leaving an oval shape of lesser material towards the center of the "segment" to allow it to buckle and move rather than be rigid and crack. It's also the reason why long, lloooooooong boats, when you look down the centerline in rough seas look like a 3D variant of the empty metro, bending and twisting ... but not breaking apart (like they used to, for example, on the great lakes, where many a boat was lost because they were too rigid).
USS Peleliu LHA 5 came into LBNSY for some finishing work shortly after being constructed. When work was completed she was homeported at Long Beach Naval Station. She went on a cruise into Alaskan waters and encountered 50 foot waves (or higher), some crashing into her superstructure. When she came back she had those marks all over her superstructure.
I've watched brand spanking new ships go to sea for sea trials, all sleek and smooth. They all come back from 3 days of sea trials, all oil canned! It just everything 'settling' in to place.😊
Was just thinking about this…. Imagine ships with ice breaker hulls…. The hull shrinks in the cold, and steel under tension is strong, but deep sub zero steel is brittle. I wonder how they prevent ships that serve in heat and ice from having major hull issues.
@@rizash A better grade in steel alloy and/or heat treatment meant for those temperature ranges. Thicker than average plating. Extra structural members behind the ice breaking side.
@@rizash The steel that is used for building ship hulls varies tremendously, according to intended use. I've never worked on an ice breaker, but I would guess that the bow and along the waterline would be similar to armor plating. Most ice breakers work by riding up on the ice and use the weight and inertia of the ship to break the ice from the top, vs cutting through it. I can't confirm, but it seems as though I read an article about a breaker that had a large weight they rode up on the ice with it placed aft, to raise the bow, then once atop the ice, it was brought forward to help break through with it's weight added to the bow. Kinda like the Dahli in Baltimore with an Interstate Highway on it.
It's not just settling, it's also flexing. I've been on both short and long boats and while you don't "see" it on short boats, they flex as well. On long boats... oh boy, ever been in an empty metro? :)) When that happens, the resistance the boat has against it is in part because of the skin acting like "lattice" between frames and horizontal segments (name escapes me atm). So it "crumples" and deforms as a result, because it stretches diagonally and makes a "belly" as a result. One place one can see this all the time, old bug doors or frames. The older it gets, the more "belly" it has, it's also why old doors that aren't fit anymore crack their windows.
My father had one of those oil cans is the garage when I was a kid. It would make a "dunk ah dunk ah" sound when you used it. I haven't thought about that can until just now, watching this video.
Not the oil cans I used. They were a half sphere with a flat bottom with a spout in the center. You depress the flat part with your thumb and out comes the oil.
I've seen "oil canning" on bulkheads on the cargo holds and engine rooms. I've worked 3 decade in shipbuilding and I have questions about his explanation. Also I've never heard of any ship with 48 inch frame spacing. I guess it might happen however I've only seen ships with 36 inch frame spacing. Even the metric blueprints I expected 1 metre space however the print where 9144 mm 🙄
@@davea4245 i dont buy his theory either. most people just dont think how much ships flex, because on most of them you cant see it happening. my first ship in the navy, i caught it in the PI, we pulled out on the edge of a typhoon, so it was a bit sporty out, not to mention it was a flat bottom lst, but on this lst you can look from the stern to the bow, right through the superstructure. first morning out my lpo says come here, look at the jack staff. mind you we were almost at the fantail at muster, and i looked through the superstructure to the bow, and holy heck the danged ship was bending 4-5 foot while riding through the waves. imo, the twisting, bending, and flexing is what causes the skin of the ship to stretch, causing the "oil can" affect.
@@leftyo9589if it’s waves that make oil canning, why does it ripple on the ends of the ship instead of the middle where most of the distortion takes place? It happens where the ship is the most curvaceous. Any welder will tell you that during the welding process, the weld metal and the adjacent base metal will expand and contract throughout the heating and cooling cycle. During these cycles, it's inevitable that some distortion will occur due to the movement of the metal. If all of this isn’t true then I have one very simple question for you. Why do we not see oil canning on ships that are riveted together?
@@leftyo9589 I live on a narrowboat, on the canal network in the UK. There are no waves or rough weather but oil canning happening partly during construction, due to the heat of welding, but also in the sunlight. The expansion is so great that it creates gaps in the internal wooden bulkheads as well as cracking sounds from the expansion and also contraction when the sun goes down.
@@danieljones7843 Weld causes metal to shrink more than it expands ,in more depth molten metal cannot expand to its desired size since surrounding area is cooler and stronger than molten area ,molten area would grow in all directions it can plasticly never going back to its original shape ,while cooling metal will regain its strengths pulling and bending straight areas to new oil canned shapes ,To minimize this all welded area is preheated to high temps of plasticity welded and cooled down evenly .
Heat expansion is true. I used to be a welder at Newport News shipbuilding, and carriers are built in sections in various places throughout the yard. These sections come to the dry dock already canned. This is from the skin being welded to the frame. A tremendous amount of heat is introduced from welding in that square pattern, so to speak, causing that effect.
I served on a Charles F. Adams-class guided missile destroyer and on a Knox-class frigate, and the oil-canning was immediately apparent all the way down the hull, especially right at or above the waterline. I had (apparently incorrectly) believed that this was from water repeatedly striking the steel over the years that caused it over time. Yet again, I learn something new thanks to this excellent channel.
As a non nautical person I had always assumed this was from heavy waves battering the sides of ships over the years and pushing the metal in between the supporting ribs. I’m glad to finally know what the real cause of it is.
You are actually also correct. Not heard it called 'Oil canning' before, maybe its an Americanism? We UK seafarers call this 'panting' and it refers to the flexing in and out like an oil can when a ship is making way in large seas. If you Google Panting in ships, it will describe exactly this
I was just there on Saturday, and while you can explain the bilge keel dings, the bow ones were not explained. At least tracked to known incident. The hull pitting (all dead rust) was quite surprising. I assume most of that came from being in storage. I had very strong urge to start welding the pits back up and grinding them smooth. I wonder how that effects hydrodynamics. It was a great experience, and I was able to see a Tico and CV67.
Usually caused by the welding, it can be rectified by applying heat on the opposite side , but there is a knack to this , and it will burn off the paint inside and out, as well as take a lot of time.
It's very common on the Great Lakes freighters. There's youtube channels that show these ships going in/out of Duluth and other harbors, and the Soo Locks. You can see the oilcanning on them in the videos.
I've noticed this so many times that I realised that it probably wasn't grounds for concern, but then I assumed it was the result of heavy weather... Thanks from the UK for straightening that one out!
I've always considered the term "oil canning" to be related to the old metal and paper cylindrical oil cans used before the switch to plastic packaging. You'd stab an oil spout through the top of the can and when emptying it the bottom would pop in and out as air replaced the oil as it drained from the can.
Fun fact, you can actually still buy oil in cans like that, BUT only if your daily driver has a turbine engine. For whatever reason, jet/gas turbine oil still comes in cans, so if you daily an M1 Abrams or a Cirrus VisionJet you still gotta have the funky little spout.
The oil cans he is talking about are quite old. Using them made a cool "poink" noise as you oiled, clicking your thumb in and out on the thin metal bottom. My grandfather had one back in the 70's and we would play with it as kids.
I still have my old oil spout I used years ago. It got put in the tool box thinking someday the plastic containers wouldn’t be used any more and the cans would be back. I looked at it a couple years ago thinking I should just throw it away but I wiped it off and put it back.
I was in Bristol, UK, in 1988 at a military show day. The Royal Navy were there with the Sea Cadets in a smallish craft. About the size of a Coastguard Cutter. Whilst trying to navigate the lock system, they made a massive cock up, and backed it hard into the concrete dockside, which put a rather spectacular dent in the transom on one corner. The kind of dent which doesn't buff out. Oops. They didn't stick around for everyone to see. Someone got a major bollocking after that little bump.
There's a saying in the USN. If your ship runs a ground, so does your career. Same with running into a dock and causing damage. Funny thing. We were at lunch and I asked if one of the Nuclear Carriers ran a ground. I forget which one. It turned out that carrier had run a ground in California. It caused a lot of damage. He went on to tell me what happened to that guy.
My dad was on the New Jersey when it was stationed in Long Beach. CW03 Rivera. He was down below in the boiler room. I will never forget being onboard that ship.
Ryan, I think a lot of us would be interested in how you became the Curator of the New Jersey. What kind of career path did you take? How were you educated in relation to the ship? What was your journey to the BB New jersey?
It is something I often wondered about . It's almost universal on modern ships and I assumed nothing anyone worried about . Thanks to Ryan I've found out . Certainly on the older ships that were riveted and much more heavily built I never noticed much .
I got to see USS Little Rock last Friday. It was my first time ever seeing a large warship up close and photos or videos do not do justice for these behemoths, they have to be seen in person to truly marvel in their glory. Leaves you breathless. I hope one day to see an Iowa class.
Thanks as always! As other people have said, I have wondered this for years! For me at least, in my opinion, it makes the battleship (and other ships) look cool.
As someone else pointed out, these deformations are commonly called "hungry horse". While heating from sunlight may be an issue, these distortions look like plate yielding due to wave slam loading - huge dynamic seawater pressures from wave impacts in high seas exacerbated on flared bows where the plating deforms, plastically, to a more stable and resistant bent or curved shape. It's not usually considered "damage" unless it significantly decreases performance or results in bent framing or stiffeners. Navy ship bows (aircraft carriers, in particular, which can be severely flared) have been destroyed by wave slam in severe storms. Similar, but less severe, distortions also reflect weld-bead shrinkage during hull construction on the internal side of thin plating, which unavoidably pulls the plate to the inside ... they are pretty much always seen on thinner plating.
@@geronimo5537 I'm sure that this *can* cause it to some degree or deepen existing oil canning by stretching out the metal. That being said, you can find pictures of oil canning on ships that are still under construction and haven't even touched a wave yet. For instance, search up 'DDG 123 under construction Ingalls Shipbuilding'. You can find a picture of her port bow before she was launched and you'll see some pretty pronounced oil canning going on. There are ways to eliminate oil canning. Both to minimize its formation during welding and to correct it after the fact. That being said, I don't think anyone considers it to be a priority on warships. No one goes to go to the work and expense to do anything about it. If you want to know more about those sorts of techniques, you can find accessible versions looking into videos by guys that do sheet metal work on custom cars. Same principles, just at a smaller scale.
I'd never thought of this issue before watching this video, and I would have thought it was water pressure until you explained this blindly obvious cause. Nice and simple. Good vid. 👍🏼
Did you say "...if you visit my old Torsk down in Baltimore"? Almost my home town. (Baltimore County resident 56 years.) This was a cool trivia video. I've wondered about 'oil canning' for many years, but it was on YT that I finally learned the answer! I don't think I would have guessed it was expansion from repeated exposure to sunlight/darkness, but it sure as hell explains it simply enough!
Hi Ryan, I’ve been following & watching your videos on the dry docking of battleship New Jersey. Thank you for all of the videos and the hard work that you put into them. It is appreciated. In 1969. I was in first grade. Our elementary school took a field trip to Seattle. We went to various sites and saw different things. And then we went to the Bremerton shipyard and we took a tour on the decks of battleship Missouri . As the first grader, I was quite impressed. With your videos about battleship, New Jersey and Iowa class battleships, it puts everything into perspective and I understand the ship even more. Once again, thank you for all of your hard work!
I'm 45 Years old and almost this long interested in ships, maritime warfare and so on. But I did learn today what oil canning ist! Great video, thank you, enjoyed it very much. All the best from germanry.
There seem to be several ways this can happen, but as a non practicing naval architect and occasional welder what I was taught and have seen is that welding all around the inside perimeter of a shell section (between longitudinal and transverse frames) causes the steel to expand a bit and as it cools it tends to set with slight warpage. Intermittent welding can avoid it by either not welding as much all over or if you complete with a second pass closing the gaps, the heat input hasn’t got such strong peaks so less bending each pass. But that multiplies the time and cost compared to welding a whole seam at once. I have seen it happen in my own welds sometimes that never saw daylight during assembly. They’re not professional grade welds by any means but pros at shops have seen the same. And shipyards with inside under cover steel fabrication, sometimes you see the effects anyways. It’s truly just cosmetic, won’t affect tertiary or secondary or primary bending strength of the hull noticeably.
This oil canning can be seen on the B-1B Lancer and the B-52 as well, and for the same reasons. Heat causes the aluminum to expand and contract and the skin pops in and out.
Thank you for answering a years-long question I had about these distortions. My best guess up until now was from the years of hammer-chipping to remove the old paint.
Rose bud torch the seams and spray with water..draws the steel tight..we used it on oil drilling rig construction in Vicksburg, MS back in the day...heat will move anything, even pipe
I love learning about this stuff, im a contemporary diesel mechanic, i work on locomotives mostly, but i love seeing the engineering that goes into these incredible machines, if a battleship were deployed today, i'd be one of the first to signup as crew
Oil canning is common on aircraft as well and generally not a grounding discrepancy, unless it’s popping rivets between the skin and supporting structure.
You know, I knew all this stuff before I clicked on the video. I think I had pieced it together from different bits of trivia over the years, but I've never heard anyone put it together in a clear simple explanation before. Well done.
Ryan. I went aboard NJ when she came to Brisbane Oz. What an impressive ship. I've always wondered about the parts of the hull resting on wooden blocks. How do these bits get cleaned and repainted?
i use to build navy ships after welding it pulls the steel in we use to put plates across the frames heat the short welds let it cool remove the plates and its becomes flat again not really needed on warships but some navy's like things looking nice , during war time ships were built fast no time to fix minor problem's like this .oil canning is caused by shrinkage in the heat affected zone of the welding process, after the stress has been removed .
Thanks. I've been told that when they attached the last connection of the two halves of the St. Louis Arch, they did it on a worm sunny day so the steel would be hot, then they used fire trucks with water cannons to cool the exact spots needed in order to align the bolt holes at the top.
I always heard of it as "waffling" and it is something that is rarely seen on pre-1920s vessels because they rarely employed as thin a steel shell over frames spaced as wide. It is much more common on welded construction as opposed to riveted. Take a look at the USS Olympia for example, you really need to look hard to find any distortions.
Thanks for answering a question that I always wondered about but didn't ask anyone. I guess straightening out a plate isn't as important unless it increases radar cross section if you don't or something consequential like that.
Hi Ryan. Sorry to disagree with you but "oil canning" is NOT caused by the heat of the sun. It is more properly called, in structures circles that is, diagonal semi-tension buckling or simply shear buckling and is common in thin (relative to the length and width dimensions) skin structures where the shear stress exceeds the critical shear stress for buckling (most practical shell structures) and the shear load is the caried by a diagonal tension field similar to the way a girder truss works. It is very common in aircraft (even at night or in the hangar).
it can be caused by the sun. have you ever been inside of or near a metal object all day long? many of them will oil can under the sun, announcing themselves *PING* when they have oilcanned.
Thanks for the explanation, Ryan! It makes sense. Temperature differentials, different materials, different densities, the effects of sun on different paint schemes/colors. Science actually can explain many things!
OK. Small correction. In the video you said that the lighter colors absorb the rays of the sun and prevent heating. The way i was taught in high school, in theater programs, and independent research into the statement. Dark colors absorb the the rays of the sun which intensifies heating. Light colors reflect the rays of the sun which minimizes heating. It's a smallish nit to pick, but when I had to worry about picking up black painted objects from the stage that had been lit up for 2 hours being too hot to handle vs objects painted pink or white, it gets you a bit.
Did my apprenticeship in the early 80s RNZ there were two Leander class there at the time one was built during piece work and was badly effected due to the extra high amps used to achieve faster completion. I am a Bioler maker welder and this made sense to me.
when a ship is dry docked does it need any sort of interior structural support to keep it from flexing apart due to lack of exterior water pressure trying to crumple it up? ...like chains from port to starboard ribs or tethering braces or straps, so it doesn't bow flex outward from lack of spring tension pressure the water provides. i had a great uncle in the navy, but i had never seen this process done for large ships just a destroyer he once commanded on, so this question never occurred to me when he was still alive. 2:00 the word he is looking for is conical, as in cone shaped. the plating is expansion and contraction from many factors: heat is one, water pressure stress when in motion, blast pressure shockwaves from larger caliber weapons for thicker armor plating, also flex stress when a ship goes into a turn you can watch one side oil can, and the other side go taunt.
I don’t know if you were asked this, What is the font name of the 62 number on the bow, is that font used on all US Navy ships and do the numbers ever change?
Hi Ryan I've been following this channel for some time now. Loving seeing this ship in dry dock and your videos on various subjects. Some time before dry docking you said one of the things you wanted to check were the glands in the stern tubes. Has this been done. What was the condition of them. Cheers from New Zealand
I think that another component of oilcanning is the impact of waves on certain areas of the hull - as you say, nothing to be concerned about, but one often sees it in those areas where seas impact.
Oil canning is also common on aluminum skinned aircraft. If you ever saw a 747 on jacks and not on its landing gear in a maintenance hanger the entire aft section of the aircraft under the vertical stabilizer is puckered in or out depending where the supporting frames under the skin of the plane are at It is just another example of oil canning and it does not hurt or even damage the aircraft. Once the 747 is in the air the oll canning will go away as the aircraft is pressurized.
In my last career after the military I was a welder/fabricator (not on ships), and we always had to watch for oil-canning when welding sheet metal (>1/4") to any heavy ribs or supports as this happens frequently if you don't watch your heat.
Thanks for that. I was in the Royal Canadian Naval Reserve during the late sixties early seventies, and always wondered why the hulls of our DDE and DDH destroyers looked like that.
I had always thought it was a result of repeated stresses of water hitting those places as she ship goes through waves over many years. It's nice to know the actual reason for sure now! I've seen a lot of DDGs and CGs with oil canning on Naval Base San Diego. I haven't really seen it on the Independence class LCSs (the aluminum ones) but maybe the material or their relative newness has spared them from them.
So why does the oil canning only cause the plating to buckle inwards? Oil canning below the waterline only buckling inwards I can understand, water pressure would easily cause that but why would oil canning above the waterline also only buckle inwards? What's to stop the plating from buckling outwards?
Thank you very much for the video. I've always wondered where the dents come from. To be honest, I was expecting something with waves, as they usually occur at the bow, where the sheet metal is particularly thin.
" Old style oil cans", now I feel old as I still have and use them. From the small ones to the bigger pump style with the triggers. LOL If it ain't broke, don't fix it. Love the info.
I never knew there was an official term for this type thing. Beautiful explanation to those who do not understand this. Also, you slightly misstated something: White and light colors *reflect* more UV light and heat. You accidentally said it absorbs it. Dark colors absorb it.
This does not as likely to appear on riveted ships since there is not a heat affected zone like the double fillet welds at the frames and bulkheads. Yes flat areas are most susceptible while curved plates being more ridged will offer greater resistance to this. This is also called "Hungry Horse". Two British destroyers a new welded one, and the other an older riveted. The skipper on the riveted ship sent a message saying that the other skipper needed to feed his horse since she was showing her ribs.
I "woke up" to oil canning when my supplemental heating coils kicked in on my heating system. It was like a really loud firecracker went off under the floor. The ducts will distort when the temperature changes rapidly and that sometimes makes large areas suddenly snap in or out.
Hi Ryan, you remarked in this video that some of the weakest armor on the ship is at the bow. That got me thinking. Are the Iowas especially susceptible to a torpedo bow shot then? If so, is there any critical functions, ammunition, etc. located in the forecastle that would exacerbate a bow hit?
Oil canning or Panting is an in-and-out movement of the shell plating resulting from the variations of water pressure waves passing along the hull and when the vessel pitches. The location of the most significant stresses is at the bow when making headway. These are greatest in fine bowed vessels. So, it is more than a temperature issue; but can be a combination of issues.
In regards to the 16" guns, were the Iowas able to fire on the move, or did they have to be stationary so to say to fire? Would they be able to integrate if they had to be reactivated the technology the Abrams battle tanks use to train the gun while on the move?
I would like to know how much paint is applied during this drydocking. Do the different coatings have different viscosities; how much under layer/primer vs final coat. And, this may be a guess for you, total volume of paint to recoat the entire ship... like maybe the 1st time right out of the dock.
Is the thin armor near the bow so armor piercing shells won't detonate? ... they would just pass through and explode beyond the ship? ... we do that with house boats, thick armor around the water heater and furnace, but super thin around bedrooms and living room ...
Would love to see an update/info about what the museum is doing at the dock back in Camden, and any of the other things the Home Port Alliance has to take care of while the ship isn't there. Like is there any dredging or facilities changes? Can i still visit the pierside gift shop? Great video as always
When I was in the navy I served on a destroyer that was 30 years old. Sometimes when we were in port and the rising or setting sun hit the ship properly you could clearly see all the frames and longitudinals along the hull.
I'll be there on May 19th for the drydock tour. I am curious as to why only the waterline and below is being done and the entire hull is not getting painted while she is in drydock. Certainly, a great opportunity to get the hull completely refurbished while she is high and dry.
The above water part can be painted back home while the museum is open and earning revenue, no reason to spend the money to do it in the yard. We do it every few years.
Thank you for converting 7/16" to milimeters for us Central Europeans. (while I can do halves and quarter inches from top of my head easily back and forth, this definately helped) Very informational as always! +][+
“Oil canning” is caused by welding distortion - in particular as the welds cool from high temperature (melting point) they contract and pull the plate towards the weld. Shipbuilding 101.
YOU ARE DOING A 4.0 OUTSTANDING JOB OF ANSWERING MANY THINGS AND GIVING THIS SHIP THE HONOR AND THE RIGHTFUL ATTENTION IT DESERVES. SHE IS A BEAUTIFUL LADY AND YOU ARE PRESERVING SO MUCH MORE THAN HER EXISTENCE. I can’t help but think that her crews living and dead consider you and your shipmates guardian angels at a time this country hungers for something of its former honor and glory. FAIR WINDS AND FOLLOWING SEAS TO ALL OF YOU WHO SERVE HER NOW. 🇺🇸
One also sees this in travel trailers that are either metal monocoque or metal cladding over wood construction -- no way to avoid the skin heating up and undergoing thermal expansion and contraction more than the underlying structure. As someone who has homebuilt such machines, I knew exactly what you were describing.
When the steel gets hot from the sun beating down on it that flex has to happen. It can't flex where it's attached to the frame so it has to stretch wherevit can.
Working as a ship fitter at BIW, brand new destroyers have this issue. Years ago this was fixed by straightening all bulkheads by using a fine spray of water and a heat from a torch. This would straighten the ripples in the bulkheads. This is still done, but only on badly warped or rippled bulkheads.
Yep, I worked Dept. O9 at the yard in the mid 2000s and I only ever saw the weather deck plating being straightened. I assume because indentations would make a puddle and/or a tripping hazard.
A bunch of the old timers I talked to said that the Arleigh Burke DDG-51 was beautifully smooth. Apparently, they flame straightened everything for the first run of ships. I'm sure it got cut for cost.
Keep up the good work, brotha'.
Bath Built Is Best Built! 🇺🇸
Bath Iron Works?
Thanks for what you guys did at Bath Iron Works. I was a sailor for a couple years on U.S.S. Preble DDG-46, and I’m sure you didn’t work on that particular ship, but Preble was built at BIW way back when. The tin can fleet owes a hearty salute to all the shipyard workers and engineers who turn out great ships. 🫡 🇺🇸 ⚓️
Until they invent a metal that can stretch and regain its shape, this isn't so much an issue as it is a design choice. You could most definetly make a rigid enough ship to not have oil canning, but do you want to? - is the question.
The more they travel, the more stretch they get, until the "belly" between frames reaches its max potential and it just exists there. Oil canning are ... essentially tiger stripes on boats - for the same reason we have them as well. Moving about, the skin stretches between rigid portions.
I worked @ BIW in the early '80s in production planning department - some of the "oil canning" is caused by welding heat shrinkage (the heat makes the metal shrink and pucker). I worked with the IHI (Japanese) consultants on flame straightening / bending techniques. We watched them lay out and form a piece of shell plating with nothing more than a torch, a water hose, and some wedges/sledgehammer in less time than the yard guys could do it with the 3-roller bending press. Took incredible skill and lots of experience to do that.
Ryan loves the abrupt "end of video" joke and I'm always here for it
@@AlexanderBrown77wat
Every time!
I caught the the pause after the "thin skin" comment at the beginning.
It is funny when he does it. Some of the questions deserve a short ... Sometimes just a yes or no answer.
You can see similar oilcanning on the fuselage of the B-52s still in service.
I was stationed at Barksdale AFB from 2002-2005. They said it was designed this way, as flying high up in altitude, the pressurized cockpit will even those wrinkles out.
A lot of aircraft get it.
The wings on a B-52 "flap" in flight. The wing tips move up and down.
If they didn't flap, turbulence would cause them to break off. 🤠
@jamesburns2232 pretty sure that's most aircraft. Wing has to be strong but flexible.
Especially at the tip when there's no winglet or fence.
Mesh doors have it too. Same reason. Rigid framing for a thin skin + movement = stretch and deformation in the skin. It's actually part of the design in most applications of this methodology. I might have it wrong, because this is just based on what i've visually seen, but i think in some parts of airframes, they specifically reinforce (extra fabric - fiberglass or carbon or whatever they may use) the edges leaving an oval shape of lesser material towards the center of the "segment" to allow it to buckle and move rather than be rigid and crack.
It's also the reason why long, lloooooooong boats, when you look down the centerline in rough seas look like a 3D variant of the empty metro, bending and twisting ... but not breaking apart (like they used to, for example, on the great lakes, where many a boat was lost because they were too rigid).
USS Peleliu LHA 5 came into LBNSY for some finishing work shortly after being constructed. When work was completed she was homeported at Long Beach Naval Station. She went on a cruise into Alaskan waters and encountered 50 foot waves (or higher), some crashing into her superstructure. When she came back she had those marks all over her superstructure.
yeah I always thought it was caused by waves hitting the ship over time
Exactly - water hammer
I was on the FFG 37 in the Gulf of Alaska during a September storm. A roller coaster was a tame ride after that.
I've watched brand spanking new ships go to sea for sea trials, all sleek and smooth. They all come back from 3 days of sea trials, all oil canned!
It just everything 'settling' in to place.😊
Was just thinking about this…. Imagine ships with ice breaker hulls…. The hull shrinks in the cold, and steel under tension is strong, but deep sub zero steel is brittle. I wonder how they prevent ships that serve in heat and ice from having major hull issues.
@@rizash A better grade in steel alloy and/or heat treatment meant for those temperature ranges. Thicker than average plating. Extra structural members behind the ice breaking side.
@@rizash The steel that is used for building ship hulls varies tremendously, according to intended use.
I've never worked on an ice breaker, but I would guess that the bow and along the waterline would be similar to armor plating. Most ice breakers work by riding up on the ice and use the weight and inertia of the ship to break the ice from the top, vs cutting through it. I can't confirm, but it seems as though I read an article about a breaker that had a large weight they rode up on the ice with it placed aft, to raise the bow, then once atop the ice, it was brought forward to help break through with it's weight added to the bow. Kinda like the Dahli in Baltimore with an Interstate Highway on it.
It's not just settling, it's also flexing. I've been on both short and long boats and while you don't "see" it on short boats, they flex as well. On long boats... oh boy, ever been in an empty metro? :))
When that happens, the resistance the boat has against it is in part because of the skin acting like "lattice" between frames and horizontal segments (name escapes me atm). So it "crumples" and deforms as a result, because it stretches diagonally and makes a "belly" as a result.
One place one can see this all the time, old bug doors or frames. The older it gets, the more "belly" it has, it's also why old doors that aren't fit anymore crack their windows.
Now we solved that issue why do we call it spanking new
My father had one of those oil cans is the garage when I was a kid. It would make a "dunk ah dunk ah" sound when you used it. I haven't thought about that can until just now, watching this video.
I used those oil cans when I was a kid. They were round. I don’t know what Ryan is talking about with the triangle shape.
@@bebo4807 They were funnel shaped, I guess that's what he meant to say. 🤔
Not the oil cans I used. They were a half sphere with a flat bottom with a spout in the center. You depress the flat part with your thumb and out comes the oil.
I've inherited two of those. Now we have cans that dispense oil for 3 times the cost.
If you've ever seen the Wizard of Oz, the oil can that Dorothy uses to un-freeze the Tin Man is the oil can in question.
Jersey is a welded ship. Welding causes heat distortion, so some of this could date all the way back to construction.
I've seen "oil canning" on bulkheads on the cargo holds and engine rooms. I've worked 3 decade in shipbuilding and I have questions about his explanation.
Also I've never heard of any ship with 48 inch frame spacing. I guess it might happen however I've only seen ships with 36 inch frame spacing. Even the metric blueprints I expected 1 metre space however the print where 9144 mm 🙄
@@davea4245 i dont buy his theory either. most people just dont think how much ships flex, because on most of them you cant see it happening. my first ship in the navy, i caught it in the PI, we pulled out on the edge of a typhoon, so it was a bit sporty out, not to mention it was a flat bottom lst, but on this lst you can look from the stern to the bow, right through the superstructure. first morning out my lpo says come here, look at the jack staff. mind you we were almost at the fantail at muster, and i looked through the superstructure to the bow, and holy heck the danged ship was bending 4-5 foot while riding through the waves. imo, the twisting, bending, and flexing is what causes the skin of the ship to stretch, causing the "oil can" affect.
@@leftyo9589if it’s waves that make oil canning, why does it ripple on the ends of the ship instead of the middle where most of the distortion takes place? It happens where the ship is the most curvaceous. Any welder will tell you that during the welding process, the weld metal and the adjacent base metal will expand and contract throughout the heating and cooling cycle. During these cycles, it's inevitable that some distortion will occur due to the movement of the metal.
If all of this isn’t true then I have one very simple question for you. Why do we not see oil canning on ships that are riveted together?
@@leftyo9589 I live on a narrowboat, on the canal network in the UK. There are no waves or rough weather but oil canning happening partly during construction, due to the heat of welding, but also in the sunlight. The expansion is so great that it creates gaps in the internal wooden bulkheads as well as cracking sounds from the expansion and also contraction when the sun goes down.
@@danieljones7843 Weld causes metal to shrink more than it expands ,in more depth molten metal cannot expand to its desired size since surrounding area is cooler and stronger than molten area ,molten area would grow in all directions it can plasticly never going back to its original shape ,while cooling metal will regain its strengths pulling and bending straight areas to new oil canned shapes ,To minimize this all welded area is preheated to high temps of plasticity welded and cooled down evenly .
Heat expansion is true. I used to be a welder at Newport News shipbuilding, and carriers are built in sections in various places throughout the yard. These sections come to the dry dock already canned. This is from the skin being welded to the frame. A tremendous amount of heat is introduced from welding in that square pattern, so to speak, causing that effect.
I served on a Charles F. Adams-class guided missile destroyer and on a Knox-class frigate, and the oil-canning was immediately apparent all the way down the hull, especially right at or above the waterline.
I had (apparently incorrectly) believed that this was from water repeatedly striking the steel over the years that caused it over time.
Yet again, I learn something new thanks to this excellent channel.
As a non nautical person I had always assumed this was from heavy waves battering the sides of ships over the years and pushing the metal in between the supporting ribs. I’m glad to finally know what the real cause of it is.
As a person who uses TH-cam often, I also guessed that would be the case.
I’m still going with the atmospheric and physical pressure changes over the giant invisible thumb chasing ships… 😂
Yep I thought the same.
You are actually also correct. Not heard it called 'Oil canning' before, maybe its an Americanism? We UK seafarers call this 'panting' and it refers to the flexing in and out like an oil can when a ship is making way in large seas. If you Google Panting in ships, it will describe exactly this
@@GlenMartinyeah but you guys speak english and not mickey mouse
I was just there on Saturday, and while you can explain the bilge keel dings, the bow ones were not explained. At least tracked to known incident.
The hull pitting (all dead rust) was quite surprising. I assume most of that came from being in storage. I had very strong urge to start welding the pits back up and grinding them smooth. I wonder how that effects hydrodynamics.
It was a great experience, and I was able to see a Tico and CV67.
It actually makes the ship go faster!
@@tedmoss Is that like the dimples on a golf ball? 😃
Usually caused by the welding, it can be rectified by applying heat on the opposite side , but there is a knack to this , and it will burn off the paint inside and out, as well as take a lot of time.
I have noticed for many years and have always wondered what the real explanation was. Thank you Ryan for what you are doing to educate all of us.
When you said 4ft of the spacing it really help but the size of the ship into perspective.
It's very common on the Great Lakes freighters. There's youtube channels that show these ships going in/out of Duluth and other harbors, and the Soo Locks. You can see the oilcanning on them in the videos.
I've noticed this so many times that I realised that it probably wasn't grounds for concern, but then I assumed it was the result of heavy weather...
Thanks from the UK for straightening that one out!
I've always considered the term "oil canning" to be related to the old metal and paper cylindrical oil cans used before the switch to plastic packaging. You'd stab an oil spout through the top of the can and when emptying it the bottom would pop in and out as air replaced the oil as it drained from the can.
Fun fact, you can actually still buy oil in cans like that, BUT only if your daily driver has a turbine engine. For whatever reason, jet/gas turbine oil still comes in cans, so if you daily an M1 Abrams or a Cirrus VisionJet you still gotta have the funky little spout.
Me too
The oil cans he is talking about are quite old. Using them made a cool "poink" noise as you oiled, clicking your thumb in and out on the thin metal bottom. My grandfather had one back in the 70's and we would play with it as kids.
@@Xanman64-p6q Ever time I hear about those oil cans I think of the Tin Man in the Wizard of Oz.
I still have my old oil spout I used years ago. It got put in the tool box thinking someday the plastic containers wouldn’t be used any more and the cans would be back. I looked at it a couple years ago thinking I should just throw it away but I wiped it off and put it back.
I was in Bristol, UK, in 1988 at a military show day.
The Royal Navy were there with the Sea Cadets in a smallish craft. About the size of a Coastguard Cutter. Whilst trying to navigate the lock system, they made a massive cock up, and backed it hard into the concrete dockside, which put a rather spectacular dent in the transom on one corner. The kind of dent which doesn't buff out.
Oops.
They didn't stick around for everyone to see.
Someone got a major bollocking after that little bump.
put a big suction cup onit and it may pop out..
Haha wow, sounds like you saw Troutbridge come in to dock!
I saw cops smash one of their twin merc 250 outboards by backing in to a piling. My laughter resulted in a rather hostile safety inspection.
@@davidncw4613 Were they state cops? They 're the most fragile egotistical tyrants.
There's a saying in the USN. If your ship runs a ground, so does your career. Same with running into a dock and causing damage.
Funny thing. We were at lunch and I asked if one of the Nuclear Carriers ran a ground. I forget which one. It turned out that carrier had run a ground in California. It caused a lot of damage. He went on to tell me what happened to that guy.
My dad was on the New Jersey when it was stationed in Long Beach. CW03 Rivera. He was down below in the boiler room. I will never forget being onboard that ship.
I've wondered this forever. Sorry for being one of the 1,000 people asking about it! LOL.
If people didn't ask questions Ryan's job would be much harder. Finding topics for one video per day is not an easy feat.
Did you really laugh out loud? I doubt it.
A sailor got angry, and went psycho with a power hammer. Simples i dont think.
But funny image to me!
@@Michael_Brock Yep, Popeye after downing too much spinach! 😃
@@ronsamborski6230 Popeye eating some rotten spinach and having a bit of a backwards burp. :))
Ryan, I think a lot of us would be interested in how you became the Curator of the New Jersey. What kind of career path did you take? How were you educated in relation to the ship? What was your journey to the BB New jersey?
The video was 3 yrs ago-
How to become a ship museum curator.
It is something I often wondered about . It's almost universal on modern ships and I assumed nothing anyone worried about . Thanks to Ryan I've found out . Certainly on the older ships that were riveted and much more heavily built I never noticed much .
I got to see USS Little Rock last Friday. It was my first time ever seeing a large warship up close and photos or videos do not do justice for these behemoths, they have to be seen in person to truly marvel in their glory. Leaves you breathless. I hope one day to see an Iowa class.
B-52 56-0687 located at MCO (Orlando Airport FL) has the same skin wrinkles although it is a Vietnam era Strategic Bomber.
Every B-52 I have seen pictured has those. I wonder if there is a different cause on aircraft?
that's exactly what I was thinking on b52s after I heard his explanation
Almost every aircraft has them, it's normal for aluminum.
It's the air pushing against the fuselages. With water it's hydraulic action.
I would have figured on aircraft it's from the the airframe flexing. Ryan stated in the video it's due to heat on the ships hull, is that not correct?
Thanks as always! As other people have said, I have wondered this for years! For me at least, in my opinion, it makes the battleship (and other ships) look cool.
As someone else pointed out, these deformations are commonly called "hungry horse". While heating from sunlight may be an issue, these distortions look like plate yielding due to wave slam loading - huge dynamic seawater pressures from wave impacts in high seas exacerbated on flared bows where the plating deforms, plastically, to a more stable and resistant bent or curved shape. It's not usually considered "damage" unless it significantly decreases performance or results in bent framing or stiffeners. Navy ship bows (aircraft carriers, in particular, which can be severely flared) have been destroyed by wave slam in severe storms. Similar, but less severe, distortions also reflect weld-bead shrinkage during hull construction on the internal side of thin plating, which unavoidably pulls the plate to the inside ... they are pretty much always seen on thinner plating.
yeah I always thought it was caused by waves hitting the ship over time
@@geronimo5537 I'm sure that this *can* cause it to some degree or deepen existing oil canning by stretching out the metal. That being said, you can find pictures of oil canning on ships that are still under construction and haven't even touched a wave yet.
For instance, search up 'DDG 123 under construction Ingalls Shipbuilding'. You can find a picture of her port bow before she was launched and you'll see some pretty pronounced oil canning going on.
There are ways to eliminate oil canning. Both to minimize its formation during welding and to correct it after the fact. That being said, I don't think anyone considers it to be a priority on warships. No one goes to go to the work and expense to do anything about it.
If you want to know more about those sorts of techniques, you can find accessible versions looking into videos by guys that do sheet metal work on custom cars. Same principles, just at a smaller scale.
I'd never thought of this issue before watching this video, and I would have thought it was water pressure until you explained this blindly obvious cause. Nice and simple. Good vid. 👍🏼
Did you say "...if you visit my old Torsk down in Baltimore"? Almost my home town. (Baltimore County resident 56 years.) This was a cool trivia video. I've wondered about 'oil canning' for many years, but it was on YT that I finally learned the answer! I don't think I would have guessed it was expansion from repeated exposure to sunlight/darkness, but it sure as hell explains it simply enough!
I see it on Great Lakes freighters all the time. Many of those vessels are straight sided and between 700 to 1000 feet long.
Interesting. I wouldn't have thought those vertical lines were 4' apart. As always, thanks for sharing.
Also referred to as "hungry horse" because it looks like you can see the ribs...
Ah, thanks for posting. That's what I was told it was called years ago. Thanks for confirming my memory!
Hi Ryan,
I’ve been following & watching your videos on the dry docking of battleship New Jersey.
Thank you for all of the videos and the hard work that you put into them. It is appreciated.
In 1969. I was in first grade. Our elementary school took a field trip to Seattle. We went to various sites and saw different things.
And then we went to the Bremerton shipyard and we took a tour on the decks of battleship Missouri . As the first grader, I was quite impressed.
With your videos about battleship, New Jersey and Iowa class battleships, it puts everything into perspective and I understand the ship even more.
Once again, thank you for all of your hard work!
I'm 45 Years old and almost this long interested in ships, maritime warfare and so on. But I did learn today what oil canning ist! Great video, thank you, enjoyed it very much. All the best from germanry.
There seem to be several ways this can happen, but as a non practicing naval architect and occasional welder what I was taught and have seen is that welding all around the inside perimeter of a shell section (between longitudinal and transverse frames) causes the steel to expand a bit and as it cools it tends to set with slight warpage. Intermittent welding can avoid it by either not welding as much all over or if you complete with a second pass closing the gaps, the heat input hasn’t got such strong peaks so less bending each pass. But that multiplies the time and cost compared to welding a whole seam at once.
I have seen it happen in my own welds sometimes that never saw daylight during assembly. They’re not professional grade welds by any means but pros at shops have seen the same. And shipyards with inside under cover steel fabrication, sometimes you see the effects anyways.
It’s truly just cosmetic, won’t affect tertiary or secondary or primary bending strength of the hull noticeably.
This oil canning can be seen on the B-1B Lancer and the B-52 as well, and for the same reasons. Heat causes the aluminum to expand and contract and the skin pops in and out.
NOPE read up on the aircraft. NOT oil canning!
Thank you for answering a years-long question I had about these distortions. My best guess up until now was from the years of hammer-chipping to remove the old paint.
Rose bud torch the seams and spray with water..draws the steel tight..we used it on oil drilling rig construction in Vicksburg, MS back in the day...heat will move anything, even pipe
glad to see yall still around!
I love learning about this stuff, im a contemporary diesel mechanic, i work on locomotives mostly, but i love seeing the engineering that goes into these incredible machines, if a battleship were deployed today, i'd be one of the first to signup as crew
Oil canning is common on aircraft as well and generally not a grounding discrepancy, unless it’s popping rivets between the skin and supporting structure.
You know, I knew all this stuff before I clicked on the video. I think I had pieced it together from different bits of trivia over the years, but I've never heard anyone put it together in a clear simple explanation before. Well done.
Ryan. I went aboard NJ when she came to Brisbane Oz. What an impressive ship. I've always wondered about the parts of the hull resting on wooden blocks. How do these bits get cleaned and repainted?
i use to build navy ships after welding it pulls the steel in we use to put plates across the frames heat the short welds let it cool remove the plates and its becomes flat again not really needed on warships but some navy's like things looking nice , during war time ships were built fast no time to fix minor problem's like this .oil canning is caused by shrinkage in the heat affected zone of the welding process, after the stress has been removed .
Thanks.
I've been told that when they attached the last connection of the two halves of the St. Louis Arch, they did it on a worm sunny day so the steel would be hot, then they used fire trucks with water cannons to cool the exact spots needed in order to align the bolt holes at the top.
I always heard of it as "waffling" and it is something that is rarely seen on pre-1920s vessels because they rarely employed as thin a steel shell over frames spaced as wide. It is much more common on welded construction as opposed to riveted. Take a look at the USS Olympia for example, you really need to look hard to find any distortions.
Thanks for answering a question that I always wondered about but didn't ask anyone. I guess straightening out a plate isn't as important unless it increases radar cross section if you don't or something consequential like that.
Hi Ryan. Sorry to disagree with you but "oil canning" is NOT caused by the heat of the sun. It is more properly called, in structures circles that is, diagonal semi-tension buckling or simply shear buckling and is common in thin (relative to the length and width dimensions) skin structures where the shear stress exceeds the critical shear stress for buckling (most practical shell structures) and the shear load is the caried by a diagonal tension field similar to the way a girder truss works. It is very common in aircraft (even at night or in the hangar).
it can be caused by the sun. have you ever been inside of or near a metal object all day long? many of them will oil can under the sun, announcing themselves *PING* when they have oilcanned.
Yep.
It will also be there permanently if some of the members (spars, ribs, frames, stringers, etc) have gone beyond their yield strength.
More like "hungry horse" thermal expansion and rarefaction
Mhhm. Yes. Indubutably. I totally understand.
Sorry to disagree with you but look the location where it is happening that blows your argument out of the water.
Awesome discussion of the What, How and Why. I learned a lot. Thanks.
Keep up the good work Ryan. I always learn lots from your videos
Enjoying the journey of New Jersey into drydock after having visited her a number of years ago.
Was wondering that too. Thought it was where tugs would push against to maneuver the ship to/from the dock. Thanks!
Saw this on USS Hornet recently and was curious why it exists. Thanks for the info!
but wrong this is not due to the sun its the welding process, extream differences in heat, sun has not enough power
@@hmcredfed1836 I'm sure it's a combination of both, bud. Sun is pretty powerful
Thanks for the explanation, Ryan! It makes sense. Temperature differentials, different materials, different densities, the effects of sun on different paint schemes/colors. Science actually can explain many things!
but wrong this is not due to the sun its the welding process, extream differences in heat, sun has not enough power
OK. Small correction.
In the video you said that the lighter colors absorb the rays of the sun and prevent heating.
The way i was taught in high school, in theater programs, and independent research into the statement.
Dark colors absorb the the rays of the sun which intensifies heating. Light colors reflect the rays of the sun which minimizes heating.
It's a smallish nit to pick, but when I had to worry about picking up black painted objects from the stage that had been lit up for 2 hours being too hot to handle vs objects painted pink or white, it gets you a bit.
Good question Charles
Did my apprenticeship in the early 80s RNZ there were two Leander class there at the time one was built during piece work and was badly effected due to the extra high amps used to achieve faster completion. I am a Bioler maker welder and this made sense to me.
when a ship is dry docked does it need any sort of interior structural support to keep it from flexing apart due to lack of exterior water pressure trying to crumple it up? ...like chains from port to starboard ribs or tethering braces or straps, so it doesn't bow flex outward from lack of spring tension pressure the water provides.
i had a great uncle in the navy, but i had never seen this process done for large ships just a destroyer he once commanded on, so this question never occurred to me when he was still alive.
2:00 the word he is looking for is conical, as in cone shaped. the plating is expansion and contraction from many factors: heat is one, water pressure stress when in motion, blast pressure shockwaves from larger caliber weapons for thicker armor plating, also flex stress when a ship goes into a turn you can watch one side oil can, and the other side go taunt.
Nope
I don’t know if you were asked this, What is the font name of the 62 number on the bow, is that font used on all US Navy ships and do the numbers ever change?
When do you re-float the ship to paint under the blocks?
Another commenter asked a similar question and now I’m curious about it too. 👍🏼
Hi Ryan
I've been following this channel for some time now. Loving seeing this ship in dry dock and your videos on various subjects.
Some time before dry docking you said one of the things you wanted to check were the glands in the stern tubes. Has this been done. What was the condition of them. Cheers from New Zealand
My dad's ships had this and I always wondered what was going. Thanks for this video!
I think that another component of oilcanning is the impact of waves on certain areas of the hull - as you say, nothing to be concerned about, but one often sees it in those areas where seas impact.
Oil canning is also common on aluminum skinned aircraft. If you ever saw a 747 on jacks and not on its landing gear in a maintenance hanger the entire aft section of the aircraft under the vertical stabilizer is puckered in or out depending where the supporting frames under the skin of the plane are at It is just another example of oil canning and it does not hurt or even damage the aircraft. Once the 747 is in the air the oll canning will go away as the aircraft is pressurized.
In my last career after the military I was a welder/fabricator (not on ships), and we always had to watch for oil-canning when welding sheet metal (>1/4") to any heavy ribs or supports as this happens frequently if you don't watch your heat.
Thanks for that. I was in the Royal Canadian Naval Reserve during the late sixties early seventies, and always wondered why the hulls of our DDE and DDH destroyers looked like that.
I had always thought it was a result of repeated stresses of water hitting those places as she ship goes through waves over many years. It's nice to know the actual reason for sure now! I've seen a lot of DDGs and CGs with oil canning on Naval Base San Diego. I haven't really seen it on the Independence class LCSs (the aluminum ones) but maybe the material or their relative newness has spared them from them.
So why does the oil canning only cause the plating to buckle inwards? Oil canning below the waterline only buckling inwards I can understand, water pressure would easily cause that but why would oil canning above the waterline also only buckle inwards? What's to stop the plating from buckling outwards?
Thank you very much for the video. I've always wondered where the dents come from. To be honest, I was expecting something with waves, as they usually occur at the bow, where the sheet metal is particularly thin.
" Old style oil cans", now I feel old as I still have and use them. From the small ones to the bigger pump style with the triggers. LOL If it ain't broke, don't fix it. Love the info.
Interesting as per always Ryan. Thank you.
but wrong this is not due to the sun its the welding process, extream differences in heat, sun has not enough power
I never knew there was an official term for this type thing. Beautiful explanation to those who do not understand this. Also, you slightly misstated something: White and light colors *reflect* more UV light and heat. You accidentally said it absorbs it. Dark colors absorb it.
Also, in days of very old, oil, particularly vegetable oils were sold in rectilinear cans that would dent in the centers, particularly from handling.
How is the energy of the recoil of the main guns absorbed dissipated etc
Ryan, you are getting ridiculously funny these days. Love it brother
Do both metals contract and does the oilcanning reverse itself in very cold weather?
OK, I get the expansion bit when it warms up due to CTE but what about the contraction again when it cools down or operates in cold climates?
You learn something new every day ,now I know ,thank you 🎉
This does not as likely to appear on riveted ships since there is not a heat affected zone like the double fillet welds at the frames and bulkheads. Yes flat areas are most susceptible while curved plates being more ridged will offer greater resistance to this. This is also called "Hungry Horse". Two British destroyers a new welded one, and the other an older riveted. The skipper on the riveted ship sent a message saying that the other skipper needed to feed his horse since she was showing her ribs.
I "woke up" to oil canning when my supplemental heating coils kicked in on my heating system.
It was like a really loud firecracker went off under the floor.
The ducts will distort when the temperature changes rapidly and that sometimes makes large areas suddenly snap in or out.
Hi Ryan, you remarked in this video that some of the weakest armor on the ship is at the bow. That got me thinking. Are the Iowas especially susceptible to a torpedo bow shot then? If so, is there any critical functions, ammunition, etc. located in the forecastle that would exacerbate a bow hit?
BB62, Watched her come into Long Beach for refitting. Took the tour, many years later. Amazing.
Oil canning or Panting is an in-and-out movement of the shell plating resulting from the variations of water pressure waves passing along the hull and when the vessel pitches. The location of the most significant stresses is at the bow when making headway. These are greatest in fine bowed vessels. So, it is more than a temperature issue; but can be a combination of issues.
In regards to the 16" guns, were the Iowas able to fire on the move, or did they have to be stationary so to say to fire? Would they be able to integrate if they had to be reactivated the technology the Abrams battle tanks use to train the gun while on the move?
I would like to know how much paint is applied during this drydocking. Do the different coatings have different viscosities; how much under layer/primer vs final coat. And, this may be a guess for you, total volume of paint to recoat the entire ship... like maybe the 1st time right out of the dock.
this honeslty answered a question i've been wondering for years. thanks
Is the thin armor near the bow so armor piercing shells won't detonate? ... they would just pass through and explode beyond the ship? ... we do that with house boats, thick armor around the water heater and furnace, but super thin around bedrooms and living room ...
one mistake i noticed, mentioned lighter colours absorb light, but it reflects more, other than that, another awesome video and explainer thank you!
Would love to see an update/info about what the museum is doing at the dock back in Camden, and any of the other things the Home Port Alliance has to take care of while the ship isn't there. Like is there any dredging or facilities changes? Can i still visit the pierside gift shop?
Great video as always
When I was in the navy I served on a destroyer that was 30 years old. Sometimes when we were in port and the rising or setting sun hit the ship properly you could clearly see all the frames and longitudinals along the hull.
This was a total "huh, I never thought that was it" moment. Love it.
Thanks, those marks have always puzzled me. However, they don't appear on older riveted hulls?
Thanks, I thought it was caused by waves. How is a ship blocked up perfectly so stress is distributed correctly in dry dock?
I'll be there on May 19th for the drydock tour. I am curious as to why only the waterline and below is being done and the entire hull is not getting painted while she is in drydock. Certainly, a great opportunity to get the hull completely refurbished while she is high and dry.
The above water part can be painted back home while the museum is open and earning revenue, no reason to spend the money to do it in the yard. We do it every few years.
Thank you for converting 7/16" to milimeters for us Central Europeans.
(while I can do halves and quarter inches from top of my head easily back and forth, this definately helped)
Very informational as always!
+][+
“Oil canning” is caused by welding distortion - in particular as the welds cool from high temperature (melting point) they contract and pull the plate towards the weld. Shipbuilding 101.
I've always wondered about those ripples on the ship. Now. I know thanks Ryan.
YOU ARE DOING A 4.0 OUTSTANDING JOB OF ANSWERING MANY THINGS AND GIVING THIS SHIP THE HONOR AND THE RIGHTFUL ATTENTION IT DESERVES. SHE IS A BEAUTIFUL LADY AND YOU ARE PRESERVING SO MUCH MORE THAN HER EXISTENCE. I can’t help but think that her crews living and dead consider you and your shipmates guardian angels at a time this country hungers for something of its former honor and glory. FAIR WINDS AND FOLLOWING SEAS TO ALL OF YOU WHO SERVE HER NOW. 🇺🇸
WHAT????
So glad to see the Jersey up on blocks receiving some needed TLC.
One also sees this in travel trailers that are either metal monocoque or metal cladding over wood construction -- no way to avoid the skin heating up and undergoing thermal expansion and contraction more than the underlying structure. As someone who has homebuilt such machines, I knew exactly what you were describing.
When the steel gets hot from the sun beating down on it that flex has to happen. It can't flex where it's attached to the frame so it has to stretch wherevit can.