not just track tensioning... the axles must also be evenly positioned, so you may have to have one less tensioned than the other three. THERE ARE FOUR CHAINS!
The advantage of air vs hydraulic (as I was told by my CDL instructor) is two fold: air doesn't boil when brakes get hot and it makes connecting to a trailer much easier than a messy leaky hydraulic connection that is also a source of contamination for the brake fluid. It also handles minor leaks much easier since it has an unlimited resupply of "fluid"
This was a great "inside the hatch" video- I know we all like seeing tanks and APCs and other armored vehicles; but seeing a WWII recovery vehicle was very awesome and informative. Please keep sending the chieftain out to various vintage military equipment, even if what is covered isn't quite game material lol. It is all so very good to see and learn about
As a former Canadian Forces Lineman (1980s) - whose truck was more than occasionally found where wheeled vehicles should never have dared to go - I greatly appreciate these unsung heroes: recovery vehicles and their inventive crews. I am impressed by this truck - a lovely example of the marriage of brute force and some very clever engineering. Thanks to you and Mr Levy both.
Thanks for covering this vehicle Chieftain and thanks to the owner for showing us around his giant Tonka Truck. I have occasionally seen the Dragon Wagon in videos but have previously had little knowledge about the unit. Mark from Melbourne Australia
I never knew this vehicle existed, but this has to be one of my favorite Chieftan's Hatch videos for sure! It's pretty amazing just how well this vehicle was designed and equipped, especially for it's time period! I guess tanks were still adapting on limited experience and possible future concepts, while a strong foundation for heavy trucks/tractors and trailers already had a proven solid foundation in the USA... Although the multiple functionalities/tool and equipment stowage/redundancy/capabilities of this beast is very impressive! (I'm just gonna pretend those chain driven rear axles probably weren't a nightmare off-road 🤫) Thanks David for walking The Chieftain (and us) through this incredible machine in your collection! 👍With all the on-board tools, vice, stowed crane, winches, oxy-acetylene, on board air power, and storage, I wonder if these were often used as semi-mobile field workshops and custom modification centers for working on/modifying all sorts of vehicles, equipment, and other random projects? 🤔 I know dedicated engineering vehicles exist, but I'm sure the non-recovery capabilities of this vehicle likely didn't go to waste! 👍
Nice to see a very knowledgable owner who is a great foil for the Chieftain. More of David Levy please! Great to see some of the logistics behind the tanks.
When I first came to the US in '76, I saw a couple of these behemoths at a salvage yard in Seattle: the biggest truck I had ever seen, and I fell in love with them immediately! I don't remember what they wanted for one, but to this foolish young man, it was just doable . . . however, the cost and logistics of getting it to Alaska, where I was headed, was on the far side of impossible, so the dream died. I've always had a thing for massive old trucks: Check out the WW II SCAMMEL EXPLORER 6 x 6 tank retriever, with the wildest articulating front and rear axles.
Two just sold at a salvage yard auction in Western Nebraska a couple of months ago. Mind you they were not running, but were still excellent candidates for restoration.
There is another one on these in running condition at the ww2 American experience in Gettysburg PA. They are a relatively new museum but they feature a conglomerate of privates collections now on display. Nearly everything runs. I highly recommend that the chieftain check the place out.
Overloon in the Netherlands has a great collection. They also have the armoured version of this. Interesting to know these and the Diamond T where used by heavey haulage special transport companies all over Europe after the war for several decades.
Many years ago, my parent's next door neighbor talked about serving on one of these during World War II. The comment that has stuck was that it "would go anywhere except across wet grass". Many years later, while TDY at Fort Hood, I saw one of the soft skin tractors about 100 meters beyond a fence. It did not look like it was is very good condition; but at that distance that was really only an impression.
In the 1980's the military had trailers with different size kingpins on trailers. My unit had the M920 tractors but had to use a dolly to tow certain trailers like part vans that were temporarily assigned to the unit. Having had some bad experiences with changing flat on large vehicles on soft ground a major problem wound be having something to spread the load while jacking this thing up to keep the jack from sinking into the ground.
A standard 4x4 item is a 12" to 18" square piece of plywood to put under your hi-lift jack. I suspect you'd want a metal plate to put under the jack for a heavy military vehicle.
As to the tire valves. Large air chucks, like for semi's, have a double headed value to either push or to pull onto the valve. And, so I'm informed, the valves pointing to the inside of the rim protects the valve from damage from debris, in addition to being able to access the valve for filling whither on the inside or outside of the duals. Great video
That is 100% correct. On some sizes and wheels, the valve stems are rotated to different or opposite position, to better facilitate access with a air chuck, and to prevent one hazard from damaging both stems. - - But both valve stems should face each other.
@@cavscout6b I can confirm this as the M923 I drove had the dual direction air chuck and I put the tire valve stems not directly facing each other when having to deal with the wheels when throwing on the spare.
To answer Chieftain's question about why no hydraulic brakes, there are many reasons but they all boil down to air brakes are simpler and safer on big vehicles because you never have to worry about losing your hydraulic fluid. Air is ambient and hydraulic fluid is not so anything less than a major leak is a minor issue as long as your air pump has the capacity to keep up and any air leak big enough to cause problems will call attention to itself. To heck with radios the Brits were constantly amazed that every American vehicle came with a set of tools and/or critical spares. The Armored Carriers channel has an interview with a former Royal Navy mechanic who, ordered to toss unused spare Pratt & Whitney R2800 engines overboard at the end of the war, mourned the loss of the tool set that came packed with each crated engine. This practice goes all the way back to World War One. I don't think it was extravagance so much as insurance against a "for a want of a nail" situation.
I came here to mention the same thing about air brakes. That's alot of fluid to chance leaking out on such a long truck. Especially on modern civilian trucks, that can get to 60 to 70ft long with trailer. Also, air is better with trailers because there is no mess when hooking up. (63s turned 88m turned CDL-A) 🇺🇸🫡
Air brakes are not as susceptible to contamination when disconnecting and reconnecting on a regular basis and there's no concern about getting air bubbles in the brake system during the process. The glad hands can be easily cleaned out by cracking the isolation valves, as well. For connecting and disconnecting semi-trailers, the air connection is more effective. This is one of the reasons the air-over-hydraulic systems exist, as well. Hydraulic systems don't have brake lag, but you can make connections between vehicles on the air side of the system. The older 2.5 ton and 5 ton trucks use air-over-hydraulic brakes.
Even in the 2nd Gulf War we were dealing with differences between Military Kingpin and Commercial Kingpin. Unit I was with had tractors that could do both, so for deployment we ordered 2 trailers for 20' cargo containers (since the unit packed its own extra gear in 8 of those containers) and the unit could retrieve its own stuff without waiting for commercial trucks to be available.
What he was saying about the spring brakes coming on it there was no air pressure in the system, this is how train brakes work. If there is no air in the system train brakes come on (the Emergency Stop in older trains just opens a valve). Another similarity to trains is a rescue engine for a train books up to the broken train's air system, same as this touch does.
Some added information for anyone who is interested. I’m not sure when they stopped putting left hand thread on driver side I know it was done at least until 66 I have an old Air Force truck with left hand thread. No front brakes is not surprising. In America most road going tractors didn’t have front brakes until the 70’s. And. The 5th wheel plate. On a road tractor they. Don’t tilt side to side only front and back. Also much much lower to the ground. Awesome video. thanks for doing the dragon wagon !
As a mechanic that works on Semis and trailers and is a massive history nerd. I got way to excited about this video series. Are they looking for mechanics haha
Really loved the in-depth look at all the random inner workings. Factinating stuff compared to modern day equipment. Another of many advantages of air brakes is that they won't boil over like hydraulic brakes. If your hudraulic fluid boils over, you lose brakes. Air doesn't have that problem. Air brakes do however take slightly longer to apply and release.
Incredible restoration of a very important vehicle. Its complexity and the engineering required really makes you appreciate the industrial capabilities of the US during the war.
I was a VII Corps Maintenance Platoon leader with three M-88A1 recovery vehicles (M-60 tank hull and engine). Love seeing this unsung hero. Harley-Davidson still (2023) uses chain drive from engine to drive sprocket of the transmission. There was much controversy when Harley-Davidson stopped using a Timken bearing in their Twin Cam engines in the early 2000's.
TORQUE. Hall-Scott engines were monsters. Magnificent creations-overhead camshafts, hemispherical combustion chambers-even had a PCV system so as to extend the service life of the engine oil. Many fire departments on the West Coast used Hall Scott power for their utmost reliability well into the 1970's until diesel power took over.
There your chain transmission that was not mentioned on part no.1. I was a bit surprised that it was was tensioned by moving the rear axle but apparently it worked! Nevertheless it was quite complicated to operate and mantain. One thing is for sure: it was heavy on consumption like most of the AFV of 2nd WW using gasoline! Really a good job again 👏 👌 👍👍
Standard 3.5" fifth wheel used right up todate for tank transporters. 2" fifth wheel is standard civi and military upto and including LET and line haul tractors/trailers.
Essentially this truck and the armoured version were just War Emergency vehicles to recover tanks and other vehicles during the war and then let the Army sort out a better vehicle after the war when fewer would be required. Remember also that the size of tanks were growing rapidly in the early war years, so this vehicle could have become out dated due to size and weight restrictions. Just look at how big some of the tanks got to in the late 50s and early 60s.
The engine that the Dragon Wagon used was quickly made obsolete by improved diesel engines... [ Diesel engines can scale to enormous sizes, while the larger cylinder gasoline engines have issues such as failing to burn all the fuel air mixture, detonation, etc. This is why the big block V-8 gasoline engines were replaced by V-10s...] Imagine the logistics of feeding gasoline powered tanks and tank recovery vehicles...
Great modification to the brake system. In the National Guard a few trucks have started rolling when the driver turned off the parking break before there was enough air pressure
Lovely Chain-Drive. Much like the Diamond-T my Great-great uncle drove. (the man was great) tension, tension, tension. just so much tension. Chieftain is happy, as am I. ^~^
Perhaps a follow-up episode describing the destination to which the Draggin Wagon would haul the disabled tank? An exploration of the specialists and their equipment at the maintenance point that would change out transmissions, engines, repair battle damage, and such.
The red driving light is because it doesn't bleach your retina as badly as white would for a given intensity, so you preserve more night vision, and can thus see more outside of the headlight, or straight after turning it off. The disadvantages are firstly that red stands out even more than white does, making your position extremely obvious, and secondly that it confuses other road users, who expect white forwards and red aft. It was also common on interior lights for a while, but fell out of favor because it makes colored maps near impossible to read.
This was the most interesting series I've yet seen on this channel. As a former truck driver, I am amazed at how many modern features are on this vehicle that I did not know existed on tractors that far back. I wonder if this vehicle influenced rigs designed post WW2? I'm not sure of the reason they went with chain drive unless it was some type of mechanical advantage over the gear ratios that would be possible within a standard axle. Although without the differential bulge in the center of the axles I suppose it would give you a bit more ground clearance. Reminds a bit of a truck (can't remember who built it or what it was called) that my great-grandfather drove in WW1 that was used to deliver supplies directly up to the front lines where no or only very bad roads existed. The axles were bolted straight to the frame and the wheels were on spindles that raised the vehicle way off the ground and driven by chains. There were no axles to get dragged through mud and ground clearance was basically up to the bottom of the frame and must have been close to 3' of clearance. The design of this vehicle is obviously not that extreme, but it still gives probably a 4-6" clearance improvement in the center axle area. Anyway, great video!
Apparently back then they were simply unable to build a conventional system which was considered reliable enough to take the strain of hauling 60-ton tanks around.
Your grandfather probably drove a Mack truck. My grandfather bought a couple war surplus Macks in 1920 after our city made the horse & mule stables move further away from the growing residential areas. Mack used chain drives into the 1940's.
@@TheChieftainsHatchChain drives are superior to gear drives for power transmission by delivering more power (96 to 99% efficiency due to power loss caused by friction), can deliver much higher torques for long periods of time, will hold up in extreme environments and are easy to repair or replace. Chain drives were used in Mack heavy trucks thru the 1930's and into the 1940's.
I drove a army 6x6 cargo transport truck for parks&rec. a 1000 gal water tank was mounted in the cargo bed to water all the plants in planters in down town Little Rock, Ark. - it was slow and dangerous to drive on city streets because it was to wide - 8.5 ft wide - and hard to steer - manual steering - but it was fun non the less lol coming up behind cars and all they could see was the front bumper and huge tires lol
Just for interest, my 1952 cj-3B Willys Jeep with PTO also had left hand thread wheel nuts on the left-hand side and right hand thread wheel nuts on the right-hand side.
Two distributers makes perfect sense. All aircraft with piston engines have two distributers for better efficiency and safety. Since this is a recovery vehicle and its job may be close to the fighting having two distributers makes perfect sense. If one distributers gives out the vehicle can still move. Would have loved to have seen it in action more.
THAT was cool! A lot of thought went into the engineering of this vehicle. Loved the details on the engine! Gonna look up Hall-Scott right now! Very impressive!
The gladhands behind the front bumper, are there so if another recovery vehicle tows it, they can hook their air bakes hoses up and both will have brakes, controlled by the tow vehicle.
Bearings tend to be in standard sizes. I don't work with that size but OTR trucks and busses might as well as industrial equipment. I'm sure a Terex has big bearings.
The fifth wheel looks like the Heavy Haulage 3" king pin with an off road pivoting bed. Normal trucks and 5th wheel campers run a 2" king pin. A heavy haulage truck might be able to tow that trailer if they ever get in a bind and need it moving in the future.
Wow. I'm familiar with the M88 and M88A1, now we've seen the M51, the M25, and it would be great if you could do a video on the pre-war tank recover/transporter vehicles as well.
Nasa ended up with a few of these (M26A1) tractors to tow the dolly that carried the Saturn V first stage. The last one I personally saw was at the John C. Stennis facility in the mid 1990's. No Idea of what happened to it. I would assume that the Michoud Assembly facility probably had one or two and there was probably at least one at Kennedy Space center to get the first stages off of the barges that transported them.
In the early 90s someone in Sedro-Woolley Washington an armored Dragon Wagon parked by the road for sale. From what was on the back of the tractor it was used to haul logs and a lot of them!
12:45 For those rare and hard-to-find parts that simply don't exist anymore, I would seriously look into and consider places that perform metallic additive-manufacturing or custom part prototyping. Expensive perhaps, but if it's a choice between expensive custom part and your vehicle not running...
Dual chamber air brakes were put on comercial trucks in the 1970s. Before that, no air no brakes. The glad hands (air line connectors) at the front were also for if you are towing the truck it will have brakes too. The "band" brakes wear quickly so they need to be adjusted often. If you park it's best to chock the wheels. Otherwise the truck might not be where you left it when you come back. Chain final drives were standard for highway trucks in the 1930's. The tire valve stem can face in or out. Truck air chucks have two outlets, one straight and another at an angle facing back you you can air up either tire no matter which the stems are facing. Modern trucks are still that way. But it is easier if the tire valve stem is point towards the inside (towards where the bolts hold the wheel on.)
I saw this truck in the mid 90s when it first came back to the States. A collector (who made his fortune as a cranberry farmer) just go it while I was looking at CCKW parts to buy. This this is massive and I told him I wanted one.
Great video!! I've seen several of these M25's on the west coast. My friend has one with a M26A1 tractor and spare cab near Sacramento and I've seen another two complete M25's, one with a M26 tractor and the other with a M26A1 tractor. Awesome vehicles.
You can see the anchor winch on the front there under the front centre of the cab! You see them anchor around trees and one I seen round a boulder! They used this to anchor the vehicle like was mentioned how it didn't have an anchor blade
Great video. Thanks. FYI there is an axle tag number. Bring info to FleetPride for bearing replacement. Should not need replacement of bearing, just seal
Just so everyone knows, chain drive was almost universal for trucks though the mid 20s, and common until the mid 30s, DUI this wasnt really anything outlandish in the 1940s, a mild throwback, but they all would have seen chain drive trucks at work at some point. Nothing wrong with chain drive, it's just loud, and needs lubricant and maintenance a bit more.
In the seventies I drove a couple of tow trucks that had winch set ups like the two on the back of this. The industry had long since moved on to hydraulics but they were fun to run. Except that there was only one clutch the other levers were duplicated for each winch. One would engage the shared power axle, so either or both would wind the cable in. One would engage the ratchet to keep the cable from winding out. Not sure what that third one is, maybe a reverse shifter, the trucks I drove did not have power out. You can see the short free wheel lever on the side of the winch to make it easier to pull out a bunch of cable with less friction. The ratchet was a little tricky, even after throwing the control the cable had to be pulled in a bit so the gear teeth would kick it out. If this does have a reverse it is simpler that what I used, with a car or truck hanging from the boom controlling the speed was done by feathering the clutch, the same way you could hold a car going up hill in one place without the brake by letting the clutch slip in first gear just enough that you would not roll backwards or power forward. The winch axle is connected through the clutch to the engine`s power take off axle, with the clutch fully engaged the winch will keep pulling until the engine died, unlike hydraulic winches that are designed to stall before reaching the cable breaking point. Generally when the nose of your truck starts getting pulled up in the air it is time to rethink your methodology.
Chain drives were pretty common in the first half of the 20th century for trucks, like the Mack Sterling. It was the easiest way to get the gear reduction you needed and the torsion for towing or carrying heavy things, and because nobody needed trucks to go fast..... highways hadn't been invented yet.
The term is a force multiplier. If you have enough Dragon Wagons tanks that break down are quickly towed to well-equipped repair shops fixed up with adequate supplies of spare parts and shipped back into action. It was even possible to receive upgrades at that point. The crew gets back on the tank and 1 more unit is added to the division. In most armies when your tank broke down you were turned into the infantry. That truck and its related machinery and trained personnel were putting tanks and other vehicles back in service. How many Shermans did that thing take back to the shop to be repaired and returned to service?
One "gotcha" with a park brake on the drive shaft is that on slippery surfaces on a slope, with the drive shaft locked by the brake, you can get the situation where one wheel will start to slip and rotate backwards and the other side will rotate forwards and off your vehicle goes down the hill. I have actually had that happen to me with a 5 tonne Isuzu 4wd truck on a Lord of the Rings movie set on Mount Sunday (Golden Hall set).
The reason for air brakes is because of the trailer. Hydraulic brakes would need to be bled every time the trailer was reconnected. With glade hands connectors and air there is no bleeding, just build pressure, like millions of semi trucks (18-wheelers) on the road today. and for many decades, simple, fast and safe.
The final-drive chains and the axle bearing shown, appear to be industrial standard components. You could order them from Grainger, or McMaster-Carr (or other industrial supply houses) and have them overnighted if you needed them that badly. I'm a little surprised that the Chief doesn't seem to be aware of this.
Went to the war and peace show at beltring in Kent many years ago with my dad and 3 dragon wagons snuck in without us noticing! So watch em they’re sneaky
Also, a whiffletree is a standard part on wagons and carriages, anything that is drawn by a team, that's where that tern derives from. Apparently it's the part where the tongue connects to the body. I had thought it was something else, but okay.
What a vehicle definitely my favourite of ww2 I can't stop building model's of them! I eventually got my hands on the m26A1 non armour cab model kit that's next so really nice to see this up close
See, all the detail about the winch, that's where it would be really great to be able to see the chaun drive and the PTO, not just hear you talking about it. If the PTO takes off the output shaft of the transmission, they must have another way to disengage the drive train so it stays in place, i presume a neutral position on the transfer case. And they must have a good parking brake to hold it in place with the engine running when winching, although i bet big blocks of wood under the wheels was standard procedure as well. Especially since he specifically says the parking brake won't hold it...yet the tractor is designed to winch 30 ton deadweighs up inclines. I guess wheel chocks it is. Interesting that he says the brake is "in the power shaft". Cleary that can't be the transmission output shaft, since that needs to be running to operate the winch, still im not sure what he refers to.
Only Chieftain can find a wheeled vehicle that would require track tensioning. This is officially beyond Meme territory....
not just track tensioning... the axles must also be evenly positioned, so you may have to have one less tensioned than the other three. THERE ARE FOUR CHAINS!
I came here and was not disappointed.
11:25 the joy in the Chieftans voice when he finds a wheeled vehicle that needs tensioning.
The advantage of air vs hydraulic (as I was told by my CDL instructor) is two fold: air doesn't boil when brakes get hot and it makes connecting to a trailer much easier than a messy leaky hydraulic connection that is also a source of contamination for the brake fluid. It also handles minor leaks much easier since it has an unlimited resupply of "fluid"
Also air systems tend to lock the brakes.Rather then Loose all pressure.
@@Modernnannenginemarineengine well that's just the way it's designed. You could build a hydraulic system that works the same.
This was a great "inside the hatch" video-
I know we all like seeing tanks and APCs and other armored vehicles; but seeing a WWII recovery vehicle was very awesome and informative.
Please keep sending the chieftain out to various vintage military equipment, even if what is covered isn't quite game material lol. It is all so very good to see and learn about
They could add this to the game, imagine at the end of a match, a fleet of these go out and pick up the hulks
As a former Canadian Forces Lineman (1980s) - whose truck was more than occasionally found where wheeled vehicles should never have dared to go - I greatly appreciate these unsung heroes: recovery vehicles and their inventive crews. I am impressed by this truck - a lovely example of the marriage of brute force and some very clever engineering. Thanks to you and Mr Levy both.
Thanks for covering this vehicle Chieftain and thanks to the owner for showing us around his giant Tonka Truck. I have occasionally seen the Dragon Wagon in videos but have previously had little knowledge about the unit.
Mark from Melbourne Australia
I never knew this vehicle existed, but this has to be one of my favorite Chieftan's Hatch videos for sure! It's pretty amazing just how well this vehicle was designed and equipped, especially for it's time period! I guess tanks were still adapting on limited experience and possible future concepts, while a strong foundation for heavy trucks/tractors and trailers already had a proven solid foundation in the USA... Although the multiple functionalities/tool and equipment stowage/redundancy/capabilities of this beast is very impressive! (I'm just gonna pretend those chain driven rear axles probably weren't a nightmare off-road 🤫) Thanks David for walking The Chieftain (and us) through this incredible machine in your collection! 👍With all the on-board tools, vice, stowed crane, winches, oxy-acetylene, on board air power, and storage, I wonder if these were often used as semi-mobile field workshops and custom modification centers for working on/modifying all sorts of vehicles, equipment, and other random projects? 🤔 I know dedicated engineering vehicles exist, but I'm sure the non-recovery capabilities of this vehicle likely didn't go to waste! 👍
Nice to see a very knowledgable owner who is a great foil for the Chieftain. More of David Levy please! Great to see some of the logistics behind the tanks.
Amateurs speak of tactics. Professionals speak of logistics
Their company motto: "Theres nothing like Nooky". And this baby is the best nooky you'll ever have. The generals were impressed.
When I first came to the US in '76, I saw a couple of these behemoths at a salvage yard in Seattle: the biggest truck I had ever seen, and I fell in love with them immediately! I don't remember what they wanted for one, but to this foolish young man, it was just doable . . . however, the cost and logistics of getting it to Alaska, where I was headed, was on the far side of impossible, so the dream died. I've always had a thing for massive old trucks: Check out the WW II SCAMMEL EXPLORER 6 x 6 tank retriever, with the wildest articulating front and rear axles.
Two just sold at a salvage yard auction in Western Nebraska a couple of months ago. Mind you they were not running, but were still excellent candidates for restoration.
There is another one on these in running condition at the ww2 American experience in Gettysburg PA. They are a relatively new museum but they feature a conglomerate of privates collections now on display. Nearly everything runs. I highly recommend that the chieftain check the place out.
Do they have the armored one or another unarmored like this one?
Oil drip systems are still used to oil motorcycle chains, fitted after market they increase the life of a chain tremendously.
Overloon in the Netherlands has a great collection. They also have the armoured version of this. Interesting to know these and the Diamond T where used by heavey haulage special transport companies all over Europe after the war for several decades.
I wasn't aware that the Army used an unarmored version so was thinking this was a post-war version used to haul tanks at the training bases.
As a person that spent 3 years driving an M983 HEMTT it was cool to see an OG big military truck.
Many years ago, my parent's next door neighbor talked about serving on one of these during World War II. The comment that has stuck was that it "would go anywhere except across wet grass". Many years later, while TDY at Fort Hood, I saw one of the soft skin tractors about 100 meters beyond a fence. It did not look like it was is very good condition; but at that distance that was really only an impression.
In the 1980's the military had trailers with different size kingpins on trailers. My unit had the M920 tractors but had to use a dolly to tow certain trailers like part vans that were temporarily assigned to the unit.
Having had some bad experiences with changing flat on large vehicles on soft ground a major problem wound be having something to spread the load while jacking this thing up to keep the jack from sinking into the ground.
A standard 4x4 item is a 12" to 18" square piece of plywood to put under your hi-lift jack.
I suspect you'd want a metal plate to put under the jack for a heavy military vehicle.
As to the tire valves.
Large air chucks, like for semi's, have a double headed value to either push or to pull onto the valve. And, so I'm informed, the valves pointing to the inside of the rim protects the valve from damage from debris, in addition to being able to access the valve for filling whither on the inside or outside of the duals.
Great video
That is 100% correct.
On some sizes and wheels, the valve stems are rotated to different or opposite position, to better facilitate access with a air chuck, and to prevent one hazard from damaging both stems.
- - But both valve stems should face each other.
@@cavscout6b I can confirm this as the M923 I drove had the dual direction air chuck and I put the tire valve stems not directly facing each other when having to deal with the wheels when throwing on the spare.
To answer Chieftain's question about why no hydraulic brakes, there are many reasons but they all boil down to air brakes are simpler and safer on big vehicles because you never have to worry about losing your hydraulic fluid. Air is ambient and hydraulic fluid is not so anything less than a major leak is a minor issue as long as your air pump has the capacity to keep up and any air leak big enough to cause problems will call attention to itself.
To heck with radios the Brits were constantly amazed that every American vehicle came with a set of tools and/or critical spares. The Armored Carriers channel has an interview with a former Royal Navy mechanic who, ordered to toss unused spare Pratt & Whitney R2800 engines overboard at the end of the war, mourned the loss of the tool set that came packed with each crated engine. This practice goes all the way back to World War One. I don't think it was extravagance so much as insurance against a "for a want of a nail" situation.
I came here to mention the same thing about air brakes. That's alot of fluid to chance leaking out on such a long truck. Especially on modern civilian trucks, that can get to 60 to 70ft long with trailer.
Also, air is better with trailers because there is no mess when hooking up.
(63s turned 88m turned CDL-A) 🇺🇸🫡
the tools thing is a good point
Air brakes are not as susceptible to contamination when disconnecting and reconnecting on a regular basis and there's no concern about getting air bubbles in the brake system during the process. The glad hands can be easily cleaned out by cracking the isolation valves, as well. For connecting and disconnecting semi-trailers, the air connection is more effective.
This is one of the reasons the air-over-hydraulic systems exist, as well. Hydraulic systems don't have brake lag, but you can make connections between vehicles on the air side of the system. The older 2.5 ton and 5 ton trucks use air-over-hydraulic brakes.
Even in the 2nd Gulf War we were dealing with differences between Military Kingpin and Commercial Kingpin. Unit I was with had tractors that could do both, so for deployment we ordered 2 trailers for 20' cargo containers (since the unit packed its own extra gear in 8 of those containers) and the unit could retrieve its own stuff without waiting for commercial trucks to be available.
What he was saying about the spring brakes coming on it there was no air pressure in the system, this is how train brakes work. If there is no air in the system train brakes come on (the Emergency Stop in older trains just opens a valve). Another similarity to trains is a rescue engine for a train books up to the broken train's air system, same as this touch does.
Some added information for anyone who is interested. I’m not sure when they stopped putting left hand thread on driver side I know it was done at least until 66 I have an old Air Force truck with left hand thread. No front brakes is not surprising. In America most road going tractors didn’t have front brakes until the 70’s. And. The 5th wheel plate. On a road tractor they. Don’t tilt side to side only front and back. Also much much lower to the ground. Awesome video. thanks for doing the dragon wagon !
As a mechanic that works on Semis and trailers and is a massive history nerd. I got way to excited about this video series. Are they looking for mechanics haha
The owner sure knows his stuff.
Well he has to! Can't just take this unit to the local truck service centre, they wouldn't know where to start repairs from.
Really loved the in-depth look at all the random inner workings. Factinating stuff compared to modern day equipment.
Another of many advantages of air brakes is that they won't boil over like hydraulic brakes. If your hudraulic fluid boils over, you lose brakes. Air doesn't have that problem. Air brakes do however take slightly longer to apply and release.
Yes. I have been there and done that, using a guard rail to stop on the continental divide...
Incredible restoration of a very important vehicle. Its complexity and the engineering required really makes you appreciate the industrial capabilities of the US during the war.
Anytime I think something like Warhammer is going over the top, I reflect on the sheer, everything, the US mounted 50 cals on
The M2HB and the Vickers HMG are the OG dakka😆
The could have placed dozens of 50cals and some armor on the trailer. What a waste of space ! 🤣
I was a cook in the 82 had a 50 on our 2&1/2 use call us big guns good times
More dakka
Even more extravagant is a Thomson on a tow truck!
I was a VII Corps Maintenance Platoon leader with three M-88A1 recovery vehicles (M-60 tank hull and engine). Love seeing this unsung hero.
Harley-Davidson still (2023) uses chain drive from engine to drive sprocket of the transmission. There was much controversy when Harley-Davidson stopped using a Timken bearing in their Twin Cam engines in the early 2000's.
Finally a vehicle that makes even the Chieftain look small😁
Well, there's always the Maus...
Always amazed by the fact you can tow massive weight with a lowly 240hp!
Torque and gear reduction. You can move mountains with low horepower engines, if you have the traction.
A 25hp steam tractor can usually embarrass any 5 engine tractor pull monster.
Ludicrous torque and traction.
TORQUE. Hall-Scott engines were monsters. Magnificent creations-overhead camshafts, hemispherical combustion chambers-even had a PCV system so as to extend the service life of the engine oil. Many fire departments on the West Coast used Hall Scott power for their utmost reliability well into the 1970's until diesel power took over.
It makes like 800 ft-lbs of torque though and I’m sure the peak torque is around 1000 rpm and remains flat
There your chain transmission that was not mentioned on part no.1. I was a bit surprised that it was was tensioned by moving the rear axle but apparently it worked! Nevertheless it was quite complicated to operate and mantain. One thing is for sure: it was heavy on consumption like most of the AFV of 2nd WW using gasoline! Really a good job again 👏 👌 👍👍
Standard 3.5" fifth wheel used right up todate for tank transporters. 2" fifth wheel is standard civi and military upto and including LET and line haul tractors/trailers.
Essentially this truck and the armoured version were just War Emergency vehicles to recover tanks and other vehicles during the war and then let the Army sort out a better vehicle after the war when fewer would be required. Remember also that the size of tanks were growing rapidly in the early war years, so this vehicle could have become out dated due to size and weight restrictions. Just look at how big some of the tanks got to in the late 50s and early 60s.
The engine that the Dragon Wagon used was quickly made obsolete by improved diesel engines...
[ Diesel engines can scale to enormous sizes, while the larger cylinder gasoline engines have issues such as failing to burn all the fuel air mixture, detonation, etc. This is why the big block V-8 gasoline engines were replaced by V-10s...]
Imagine the logistics of feeding gasoline powered tanks and tank recovery vehicles...
Great modification to the brake system. In the National Guard a few trucks have started rolling when the driver turned off the parking break before there was enough air pressure
Civilian standard air brakes: no air, no move.
Awesome Machine, our guys must have loved it. Imagine the stories.
It nice to see someone really knows his tank recovery truck.
Lovely Chain-Drive. Much like the Diamond-T my Great-great uncle drove. (the man was great) tension, tension, tension. just so much tension. Chieftain is happy, as am I. ^~^
The whiffletree is common on horse drawn wagons
Perhaps a follow-up episode describing the destination to which the Draggin Wagon would haul the disabled tank? An exploration of the specialists and their equipment at the maintenance point that would change out transmissions, engines, repair battle damage, and such.
The red driving light is because it doesn't bleach your retina as badly as white would for a given intensity, so you preserve more night vision, and can thus see more outside of the headlight, or straight after turning it off. The disadvantages are firstly that red stands out even more than white does, making your position extremely obvious, and secondly that it confuses other road users, who expect white forwards and red aft. It was also common on interior lights for a while, but fell out of favor because it makes colored maps near impossible to read.
This was the most interesting series I've yet seen on this channel. As a former truck driver, I am amazed at how many modern features are on this vehicle that I did not know existed on tractors that far back. I wonder if this vehicle influenced rigs designed post WW2?
I'm not sure of the reason they went with chain drive unless it was some type of mechanical advantage over the gear ratios that would be possible within a standard axle. Although without the differential bulge in the center of the axles I suppose it would give you a bit more ground clearance. Reminds a bit of a truck (can't remember who built it or what it was called) that my great-grandfather drove in WW1 that was used to deliver supplies directly up to the front lines where no or only very bad roads existed. The axles were bolted straight to the frame and the wheels were on spindles that raised the vehicle way off the ground and driven by chains. There were no axles to get dragged through mud and ground clearance was basically up to the bottom of the frame and must have been close to 3' of clearance. The design of this vehicle is obviously not that extreme, but it still gives probably a 4-6" clearance improvement in the center axle area.
Anyway, great video!
Apparently back then they were simply unable to build a conventional system which was considered reliable enough to take the strain of hauling 60-ton tanks around.
@@TheChieftainsHatch Appreciate the response!
Your grandfather probably drove a Mack truck. My grandfather bought a couple war surplus Macks in 1920 after our city made the horse & mule stables move further away from the growing residential areas. Mack used chain drives into the 1940's.
@@TheChieftainsHatchChain drives are superior to gear drives for power transmission by delivering more power (96 to 99% efficiency due to power loss caused by friction), can deliver much higher torques for long periods of time, will hold up in extreme environments and are easy to repair or replace. Chain drives were used in Mack heavy trucks thru the 1930's and into the 1940's.
I drove a army 6x6 cargo transport truck for parks&rec. a 1000 gal water tank was mounted in the cargo bed to water all the plants in planters in down town Little Rock, Ark. - it was slow and dangerous to drive on city streets because it was to wide - 8.5 ft wide - and hard to steer - manual steering - but it was fun non the less lol coming up behind cars and all they could see was the front bumper and huge tires lol
A few years ago, I had a HEMTT truck pull up behind my Subaru. All I could see was the differential pumpkin!
Just for interest, my 1952 cj-3B Willys Jeep with PTO also had left hand thread wheel nuts on the left-hand side and right hand thread wheel nuts on the right-hand side.
Great explainer and great access to everything you wanted to show. Thank you, Nick.
Two distributers makes perfect sense. All aircraft with piston engines have two distributers for better efficiency and safety. Since this is a recovery vehicle and its job may be close to the fighting having two distributers makes perfect sense. If one distributers gives out the vehicle can still move.
Would have loved to have seen it in action more.
THAT was cool! A lot of thought went into the engineering of this vehicle. Loved the details on the engine! Gonna look up Hall-Scott right now! Very impressive!
The gladhands behind the front bumper, are there so if another recovery vehicle tows it, they can hook their air bakes hoses up and both will have brakes, controlled by the tow vehicle.
It's also there to push/pull from the front, or power air tools.
@@cavscout6b All US Army tactical vehicles with airbrakes have them. Using a tow bar is a lot safer if both vehicles have brakes working.
Tracktension heaven!😘
Bearings tend to be in standard sizes. I don't work with that size but OTR trucks and busses might as well as industrial equipment. I'm sure a Terex has big bearings.
Maybe.
The question is metric or imperial sizes.
The fifth wheel looks like the Heavy Haulage 3" king pin with an off road pivoting bed. Normal trucks and 5th wheel campers run a 2" king pin.
A heavy haulage truck might be able to tow that trailer if they ever get in a bind and need it moving in the future.
Very detailed, very good episode of "Inside the Chieftan's Hatch".⭐⭐⭐⭐⭐
"Musiem of American Armor", and "David Levy" were very informative.👍
Wow. I'm familiar with the M88 and M88A1, now we've seen the M51, the M25, and it would be great if you could do a video on the pre-war tank recover/transporter vehicles as well.
there was an armoured one running at a vintage armour rally last year in northern england
Nasa ended up with a few of these (M26A1) tractors to tow the dolly that carried the Saturn V first stage. The last one I personally saw was at the John C. Stennis facility in the mid 1990's. No Idea of what happened to it. I would assume that the Michoud Assembly facility probably had one or two and there was probably at least one at Kennedy Space center to get the first stages off of the barges that transported them.
In the early 90s someone in Sedro-Woolley Washington an armored Dragon Wagon parked by the road for sale. From what was on the back of the tractor it was used to haul logs and a lot of them!
Outstanding videos on the Dragon Wagon- always interesting to see how much thought was put into even a relatively low production vehicle.
That was a really fascinating vehicle. I actually love New York City but I like military vehicles as well.
This thing is impressive as hell.
12:45 For those rare and hard-to-find parts that simply don't exist anymore, I would seriously look into and consider places that perform metallic additive-manufacturing or custom part prototyping. Expensive perhaps, but if it's a choice between expensive custom part and your vehicle not running...
I cannot believe I did not notice before now that this series' acronym is "ITCH"
Dual chamber air brakes were put on comercial trucks in the 1970s. Before that, no air no brakes. The glad hands (air line connectors) at the front were also for if you are towing the truck it will have brakes too. The "band" brakes wear quickly so they need to be adjusted often. If you park it's best to chock the wheels. Otherwise the truck might not be where you left it when you come back. Chain final drives were standard for highway trucks in the 1930's.
The tire valve stem can face in or out. Truck air chucks have two outlets, one straight and another at an angle facing back you you can air up either tire no matter which the stems are facing. Modern trucks are still that way. But it is easier if the tire valve stem is point towards the inside (towards where the bolts hold the wheel on.)
I was entranced by what I perceived to be a very boring subject thank you Chieftain and David Levy. Great video!
There is something "sexy" about tractors and trucks from this time period, no matter which country you look.
Engineering magnificence back in the day and highly inspiring today
I saw this truck in the mid 90s when it first came back to the States. A collector (who made his fortune as a cranberry farmer) just go it while I was looking at CCKW parts to buy. This this is massive and I told him I wanted one.
A very comprehensive recovery operator training session. Thanks 👍🙃🙃
Very interesting video. I would love to videos on the High Speed Artillery Tractors as well. Thanks Chieftain!
It seems they may have used classic wheel chocks? Crew jump out and place chocks in case the brakes fail?
Great video!! I've seen several of these M25's on the west coast. My friend has one with a M26A1 tractor and spare cab near Sacramento and I've seen another two complete M25's, one with a M26 tractor and the other with a M26A1 tractor. Awesome vehicles.
Not a Chieftain video without the "Oh bugger! The (x) is on fire!"
What a monster. It's a mobile shop as well as a recovery vehicle. Thanks for this great walk through!
I want to take a nap now but I'm hanging on for the "Oh bugger my Nooky is on fire". segment.
You can see the anchor winch on the front there under the front centre of the cab! You see them anchor around trees and one I seen round a boulder! They used this to anchor the vehicle like was mentioned how it didn't have an anchor blade
Great video. Thanks. FYI there is an axle tag number. Bring info to FleetPride for bearing replacement. Should not need replacement of bearing, just seal
10 tons of armor on a truck is rather impressive.
Fascinating. Obviously, someone has read the whole manual.
Just so everyone knows, chain drive was almost universal for trucks though the mid 20s, and common until the mid 30s, DUI this wasnt really anything outlandish in the 1940s, a mild throwback, but they all would have seen chain drive trucks at work at some point. Nothing wrong with chain drive, it's just loud, and needs lubricant and maintenance a bit more.
In the seventies I drove a couple of tow trucks that had winch set ups like the two on the back of this. The industry had long since moved on to hydraulics but they were fun to run.
Except that there was only one clutch the other levers were duplicated for each winch. One would engage the shared power axle, so either or both would wind the cable in. One would engage the ratchet to keep the cable from winding out. Not sure what that third one is, maybe a reverse shifter, the trucks I drove did not have power out. You can see the short free wheel lever on the side of the winch to make it easier to pull out a bunch of cable with less friction.
The ratchet was a little tricky, even after throwing the control the cable had to be pulled in a bit so the gear teeth would kick it out. If this does have a reverse it is simpler that what I used, with a car or truck hanging from the boom controlling the speed was done by feathering the clutch, the same way you could hold a car going up hill in one place without the brake by letting the clutch slip in first gear just enough that you would not roll backwards or power forward.
The winch axle is connected through the clutch to the engine`s power take off axle, with the clutch fully engaged the winch will keep pulling until the engine died, unlike hydraulic winches that are designed to stall before reaching the cable breaking point. Generally when the nose of your truck starts getting pulled up in the air it is time to rethink your methodology.
Chain drives were pretty common in the first half of the 20th century for trucks, like the Mack Sterling. It was the easiest way to get the gear reduction you needed and the torsion for towing or carrying heavy things, and because nobody needed trucks to go fast..... highways hadn't been invented yet.
The term is a force multiplier. If you have enough Dragon Wagons tanks that break down are quickly towed to well-equipped repair shops fixed up with adequate supplies of spare parts and shipped back into action. It was even possible to receive upgrades at that point. The crew gets back on the tank and 1 more unit is added to the division. In most armies when your tank broke down you were turned into the infantry. That truck and its related machinery and trained personnel were putting tanks and other vehicles back in service. How many Shermans did that thing take back to the shop to be repaired and returned to service?
All the Shermans.
One "gotcha" with a park brake on the drive shaft is that on slippery surfaces on a slope, with the drive shaft locked by the brake, you can get the situation where one wheel will start to slip and rotate backwards and the other side will rotate forwards and off your vehicle goes down the hill. I have actually had that happen to me with a 5 tonne Isuzu 4wd truck on a Lord of the Rings movie set on Mount Sunday (Golden Hall set).
The reason for air brakes is because of the trailer. Hydraulic brakes would need to be bled every time the trailer was reconnected. With glade hands connectors and air there is no bleeding, just build pressure, like millions of semi trucks (18-wheelers) on the road today. and for many decades, simple, fast and safe.
Very interesting, thank you for your time! I enjoyed it.🤗
The final-drive chains and the axle bearing shown, appear to be industrial standard components.
You could order them from Grainger, or McMaster-Carr (or other industrial supply houses) and have them overnighted if you needed them that badly.
I'm a little surprised that the Chief doesn't seem to be aware of this.
Hasn't really come up before. I don't normally look to buy spare parts for WW2 vehicles...
Went to the war and peace show at beltring in Kent many years ago with my dad and 3 dragon wagons snuck in without us noticing!
So watch em they’re sneaky
I don't know about now but there used to be several of the armored version at Fort Hood
There is a Dragon Wagon at the WWII American experience museum in Gettysburg PA
They have three of them. Each is a different version. Armored, unarmored and one with a .50 gun mount.
Of course it still runs, its a Nooky. Best Nooky on the road!
Awesome vehicle thanks for the video. That device on the front is a whippletree not a wiffletree.
Another Excellent video.
You can brake one side. I like that, I used to have that feature on my landrover and it was ace :D
Also, a whiffletree is a standard part on wagons and carriages, anything that is drawn by a team, that's where that tern derives from. Apparently it's the part where the tongue connects to the body. I had thought it was something else, but okay.
Fantastic video - never seen one of these before! Pardon my ignorace, but what's a whiffle tree's purpose?
Heh, the engine swpa procedure. "Step one: remove vehicle from engine." There were some early '00s Ford pickups like that.
this must have been fun to drive around europe in back in the day. its practically an RV
"two sledge hammers"
"wow! that's so cool! your division lets you have TWO sledge hammers!"
if you know the meme you know the meme.
What a vehicle definitely my favourite of ww2 I can't stop building model's of them! I eventually got my hands on the m26A1 non armour cab model kit that's next so really nice to see this up close
What are tracks if not really, really beefy chains?
See, all the detail about the winch, that's where it would be really great to be able to see the chaun drive and the PTO, not just hear you talking about it. If the PTO takes off the output shaft of the transmission, they must have another way to disengage the drive train so it stays in place, i presume a neutral position on the transfer case. And they must have a good parking brake to hold it in place with the engine running when winching, although i bet big blocks of wood under the wheels was standard procedure as well. Especially since he specifically says the parking brake won't hold it...yet the tractor is designed to winch 30 ton deadweighs up inclines. I guess wheel chocks it is.
Interesting that he says the brake is "in the power shaft". Cleary that can't be the transmission output shaft, since that needs to be running to operate the winch, still im not sure what he refers to.
I'm guessing it's a 6-volt electrical system due to generator opposed to an alternator but if I'm wrong is it 9 or 12-volt?