M105 1 1/2 Ton Trailer with 600 Gal Fuel Pod

[thathaway3]

I’m continuing to build models representing the equipment from my first unit, 1st Bn. 2nd FA in Germany in the early 70’s. I’m considering adding a 5 Ton truck with the Fuel Pod dispensing unit from PSM. The TO&E from that period (along with my memory from closing in on 50 years!) shows that the prime mover also towed an M105 1/1/2 ton trailer with an additional 600 gal Fuel Pod, which PSM also makes.

I recall that when we refueled in the field, the two tanks on the prime mover contained diesel, and the pod mounted on the trailer (or at least ONE of the trailers, as the Battalion had two truck trailer combos on the TO&E) contained MOGAS. Given that we had 33 Mogas burning 1/4 tons plus the odd assortment of generators, compared to 101 diesel burning vehicles that seems to be about right.

Now with a 400 lb tank filled with 600 gal of gasoline at 6.3 lb per gallon, the payload comes out to almost 4200 lb which is of course greater than the 1 1/2 rating of the trailer.

I have seen various discussions indicating that the 3000 lb limit was for “off road” operation only and that the trailer could actually handle the 4200 easily on the highway. And I’ve also seen discussions that since we always had to be able to go off road, that to stay under the 3000 lb limit that the fuel pods were not filled to capacity.

Reading through the specs of the trailer, it appears that neither the axle, the wheels nor the tires would limit the Gross Axle Weight Rating to 3000 lb, so perhaps the 3000 lb was a conservative value due to the more harsh conditions of operating off road.

And of COURSE none of this matters when building a scale model.

EXCEPT the PSM M105 trailer model with fuel pod is equipped with Dual Wheels.

I have been unable to find any references that indicate that the M105 was ever fielded with Dual Wheels.

So the question to the forum is can anybody verify that the version PSM has with Dual wheels is correct?

I will certainly not rely on my memory to say I don’t recall seeing the trailers with the wheels outside the width of the trailer body, but it doesn’t seem to be correct.

Given that tires are almost ALWAYS the limiting factor in determining the GAWR of a vehicle, Dual wheels would certainly eliminate any concerns with overloading the trailer. The latest TM for the Pod which is from the 90’s shows mounting on a 5 Ton M1061 trailer which has Tandem wheels, effectively solving the problem in a different way.

SO is the PSM Dual Wheel version correct? And if so, is it perhaps a version which was introduced AFTER the period of the mid-70’s for the very purpose of making the fuel pod on the trailer less of an “problem”?

[Denimo]

Im also considering the psm tank unit for an ODS-era 5 ton. I guess given your period of interest yours will be an AFV M54?

[thathaway3]

Correct. I’ve never built the AFV M-54, but I have built two of their M35s and have another one on order. I’ve also built the Real Model or I should say I did the conversion to build an M54 using the cab and kit bashing the Italeri M-923 and M-925, prior to the AFV kit coming out, so I’m looking forward to the AFV kit.

The two tank pumper unit looks great, and the trailer with the single pod also looks very good. I’m just skeptical about building it with Dual Wheels, as I can’t find anything that shows the M105 that way.

I did find a picture showing the trailer with the wheels mounted outside the normal track and thus the wheels were outboard of the cargo bed in the same location as they would be if you mounted Dual wheels. However there is no indication that there is or was an inner wheel, so it’s a bit curious.

[Denimo]

Those M35’s are great kits. Ive built the GS and have the shop truck and fueler in my stash.

That two-tank unit’s going on either an Italeri M923 Bigfoot or a kitbashed Hillbilly guntruck. The new one from Merit’s on order and that could be the donor for my HF wrecker.

This site, like our hobby - is just so damned interesting!

[thathaway3]

The two M-35s that I built represent the Battery Supply truck, which was built as a straight cargo version, and that is pulling a scratch built M-149 Water Trailer. The second one that I built, I scratch built a large walk in shelter and fitted it out as the Mess Truck. That had a side panel that opened up and out (think a standard street food “roach coach”) as well as a PSP platform that folded down which was accessed by stairs on either end. The mess section had three field stoves mounted inside the shelter, and cooked the meals in there and then the mess line was fed off the side of the truck. That vehicle tows a standard cargo M-105 where additional items such as the immersion heaters were stowed.

I realized after I completed the Supply Truck that building it with the winch on the front was incorrect, as only one of the M-35s in the Battery had one and THAT was mounted on the Maintenance Truck.

So I’ve decided that I’ll take the new M-35 that’s coming and build a shelter on the back of it similar to the mess truck, except without the serving line on the side. It will be set up as a shop inside instead.

I’ll cut the bumper with the winch off of the Supply truck and put it on the Maint truck instead, and put the regular bumper on the Supply Truck. And the M105 trailer I’ve ordered from PSM will go with the Maint Truck.

For the Fuel Truck, that will be the AFV 5-Ton with the twin pod towing the PSM M-105 trailer with the single fuel pod. And unless someone can convince me otherwise, I will build that with Single rather than Dual wheels which is how PSM offers it.

[MKP]

"SO is the PSM Dual Wheel version correct? "
Hello, in the Tankograd book 3024 “Constant Enforcer 1979” are some pictures of a M813 towing the M105 fueler with dual wheel.

[thathaway3]

Interesting, I’ll have to check that out. I have the Tankograd 3007 which covers the REFORGERs from 1979-1985, but it doesn’t cover the Constant Enforcer Exercise as that was not part of the REFORGER exercises.

Oddly enough the photos from the 1979 Reforger “Certain Shield” contain one of an M813 with fuel pods towing an M105 also with a fuel pod. This is the one which shows a Single Wheel installation, but the wheel is offset out from the hub and sits outside of the edge of the trailer. It’s in the exact position that an outer wheel in a Dual wheel configuration would be, but there is no inner wheel.

I wonder if there was some sort of modifications made in this time period, after I was there in which dual wheels were mounted.

But as I said, there is absolutely no mention of dual wheels in the TM for the M105. I wonder where there may have been a unique model specifically WITH Dual wheels which was NOT designated as the M105 at all?

Thanks for the information!

[Frenchy]

This one was for sale on the Government Liquidation website …back in 2008 !

H.P.

[thathaway3]

And once again you come through with photos! I don’t know how you do it!!

I’ve just created an account on the steelsoldiers website where these were evidently posted. Given all the expertise over there, I’m going to ask if anyone can shed light on perhaps when this dual wheel version may have been introduced and if in fact it may have a different designation.

Clearly somebody had them, and my only remaining question is whether they were around as early as th 1972-1975 period.

Thanks again!!

[Frenchy]

You’re welcome. According to some related threads on Steelsoldiers forum, it was rather an unofficial field mod used on sandy ground…

H.P.

[MKP]

Now I saw in the same TANKOGRAD book (Constant Enforcer 1979) an additional photo of a M577A1 (11th ACR) towing a M105 with “hard top” and also double wheels. In the text the writer metioned that the double wheel should be an experiance from Vietnam to prevent the trailer from flip over.

[thathaway3]

Certainly a possibility. Troops were constantly making field modifications to equipment. There’s no question that replacing a Single wheel with a Dual not only increases the load capacity of the trailer, but widening the track also helps with lateral stability somewhat.

[Uncle-Heavy]

Google found this when I asked:
"Guess it’s time to introduce myself, I’m a retired Motor Sgt (78-02) I spent most of my career in SP Artillery units. I’ve been lurking here about a year or so.

To answer the question about dual wheels on M105’s its way to easy to do all you need is the inner and outer lug nuts from the duals on a duce and of course the tires and wheels. Many of the Maintenance Sections would do it to gain some stability due to the amount of weight we would carry in our trailers, that often had 6-7 foot boxes built in them making them pretty top heavy. The S4 would do the same on the M105’s that carried the 600 gal fuel pod. In one unit in Germany we also used modified fenders off of a water buffalo to cover our dual not a perfect fit but it worked.

Somewhere in the mid to late 80’s the Army said we had to take them off due to excessive wear and tear on the wheel bearings and axels, we never saw it at the user level and kept putting it off until the issue was forced. So its kind of funny to hear it’s happening again.

Bret"

dual wheeled M105 on GL ........

[thathaway3]

Thanks, Robin! I just recently joined the Steel Soldiers Forum and have found similar answers.

Based on what I’ve found it seems like the idea to add Dual Wheels to the M105 in situations where either increased payload or additional stability was desired certainly occurred to quite a few people. Maintenance guys usually know a lot about vehicles and as described and from my own experience as a truck suspension design engineer it’s a reasonably easy modification to make. Design engineers tend to design in a fair amount of excess load capacity when designing components not only for a fudge factor, but because they realize that end users do NOT always go by the rules. As Bret stated in his comments routinely running those trailers over the “rated” capacity, by adding a second set of wheels and tires has consequences. The wider track does put increased loads on the wheel bearings of the axle. And the braking system also gets a lot more loading which causes it to wear out faster.

So to the question of whether or not there WERE dual wheel M105 trailers, the answer is clearly yes. As to whether they were a PRODUCTION model, the answer appears to be a no. As to the question of WHEN they started showing up, that’s a huge unknown, but it appears that it may have been later than the period I’m planning on building, which is the early 1970’s.

So I while I haven’t decided which way I’ll go (I haven’t even ordered the kits since there’s another project in front of this one!), at the moment I’m leaning towards a Single Wheel version, since that appears to be the more common one, particularly in the earlier years.

[namengr]

In the Vietnam Order of Battle book there is a picture of an M577 pulling a trailer with the wheels turned out. I had read somewhere else that this was done to make the trailer run in the same track as the towing vehicle to lessen the risk from mines. Not sure if true, but it makes sense. Wayne

[Frenchy]

Another example :

Duals :

H.P.