Why Gun Tractor Shape

[David Herbert]

At the start of WW2 they had only just moved on from pulling guns with horses. The limber was there to carry the tools and ammo. The tractor was just to pull it and carry the crew and their kit. It needed to be manoeverable so was as short as possible and easy to hide when the gun was in action. As the war went on the thinking changed and tractor and limber morphed into a full sized truck.

David

[Mike Cecil]

Interesting, Lang. Always good to have first-hand observation.

The Studebaker was the front-line, overseas deployable truck for the regular army from the late 50s (when they were pulled out of storage) until progressively replaced by the No.1 Mk.3 Inter 2.5 ton trucks from the early 1960s.

By 1964, sufficient Studebakers had been replaced in reg units by No.1 Mk3 Inters to see them with CMF units, as you observed. In Victoria, 2 Fd Regt remained with CCKW353 and Tractors No.8 & 9 until the early to mid-60s. Don't remember ever seeing Studebakers with 2 Fd Regt, and as a young lad, I was a frequent visitor (father was BSM, Q Bty) but I may be wrong - it was a long time ago. Studebakers were retained until sold off in the early 1970s. I wrote an article on their Aust use a long time ago, for Army Motors. I think there were about 1,300 in total in Aust service.

Still, that is getting us away from your original question: why the odd shape of the British FAT? (Morris, CMP, Guy, etc)

Mike

[Dan Martel]

Originally Posted by David Herbert

At the start of WW2 they had only just moved on from pulling guns with horses. The limber was there to carry the tools and ammo. The tractor was just to pull it and carry the crew and their kit. It needed to be manoeverable so was as short as possible and easy to hide when the gun was in action. As the war went on the thinking changed and tractor and limber morphed into a full sized truck.

I think Dave has hit the nail on the head. The first tractor-limber-gun set was made to replace the horse-drawn set, and the horse-drawn set didn't carry anything but two members of the gun crew. A tractor could carry the entire crew. A real step forward for the Artillery. Large trucks capable of carrying men, equipment and ammunition were in short supply in the late 30's, and not as capable as they would become later in the war.

The C8 tractor was designed to replace six horses and three riders, and tow the limber and gun, nothing more. The Artillery wasn't looking to make radical leaps in technology at that time, but in a couple years they would be leading the Army in change. and had the trucks to prove it.

Just my 2 pfennings.

Cheers,
Dan.

[Lang]

Apart from the 18 pounder ring theory (later replaced by a spare tyre carrier)
why did they continue to have the strange shape cutting their potential load and usefulness by 50%.

The same number of people were in the crew regardless of horses or trucks. The riders were all gun crew members just like later gun-truck drivers are also just a member of the crew.

The short wheelbase theory does not explain the sloping back as a square box would hold so much more on the same wheelbase.

I am currently of the opinion it is one of those mindless "we have always done it that way" decisions to continue to produce that shape after the traverse ring storage problem had long passed.

Lang

[rob love]

I think Bruce had it right. The early trucks had run flat tires so no need for a spare. The ring for the 25 pounder was not kept on the gun for any long distance...it was stowed on that slanted back. After Burma fell, and rubber became scarce, the vehicles were built without runflats, so needed a spare. At that time the stowage location for the firing platform went onto the top of the limber, and the spare tire location was the slanted backside of the truck.

The move to mechanization was the death of the limber. As mentioned, the limber removed the weight of the gun trail from the backs of the horses. But with mechanization, the towed loads actually need the weight on the hitch for stability. And why not just build a bigger truck so you can carry all the ammunition, tooling, and the gunners kit as well as the gunner? The limber also would have made it a real bitch to back up more than a couple feet.

The Canadians actually built artillery tractors in the early 30s out of locally sourced Leyland trucks. The purpose built DND designed bodies had a large stowage capacity, but the setup still retained the 18 pdr limber. I suspect that when we started building trucks for the British, we ended up following their basic design of the artillery tractor.

[Lang]

Why didn't somebody say "Give us a proper truck so our regiment workshop guys don't need to build racks on the sloping back to carry all the required gear".

[rob love]

They did. From the AEDB Design Records:

"Reports from the field, however, indicated that the 7b2 -FAT did not full-fill all the requirements that had been anticipated, in that the payload was restricted, due to the design of the body. It was decided, therefore, to pilot a new FAT using the same chassis as heretofore, but considerably modifying the body. The sloping after deck was eliminated, and an all steel, open roof body, with superstructure and tarpaulin, was pilotted, the spare tire being housed in a compartment at the rear of the body. Considerably more stowage space was provided, particularly for ammunition which was for either the 17pdr or 25 pdr, role, and more room was available inside the body for the personal and their kits. This was the 7b3 body, and proved to be quite satisfactory."

[Lang]

Well done Rob!

Answers the question.

Lang

[David Herbert]

And of course Morris did the same changes eventually in the UK.

David

[m606paz]

Originally Posted by rob love

They did. From the AEDB Design Records:"Reports from the field, however, indicated that the 7b2 -FAT did not full-fill all the requirements that had been anticipated, in that the payload was restricted, due to the design of the body. It was decided, therefore, to pilot a new FAT using the same chassis as heretofore, but considerably modifying the body. The sloping after deck was eliminated, and an all steel, open roof body, with superstructure and tarpaulin, was pilotted, the spare tire being housed in a compartment at the rear of the body. Considerably more stowage space was provided, particularly for ammunition which was for either the 17pdr or 25 pdr, role, and more room was available inside the body for the personal and their kits. This was the 7b3 body, and proved to be quite satisfactory."

A pity that the 7B3 body was never used during the war.

[rob love]

Originally Posted by m606paz

A pity that the 7B3 body was never used during the war.

The real pity is that they all seem to have been exported and few to none remain in Canada.

Also odd that being this late in the war, they used POW cans in the racks instead of the 5 gallon jerry-can.

[Richard Scott]

Originally Posted by rob love

I think Bruce had it right. The early trucks had run flat tires so no need for a spare. The ring for the 25 pounder was not kept on the gun for any long distance...it was stowed on that slanted back. After Burma fell, and rubber became scarce, the vehicles were built without runflats, so needed a spare. At that time the stowage location for the firing platform went onto the top of the limber, and the spare tire location was the slanted backside of the truck.

The move to mechanization was the death of the limber. As mentioned, the limber removed the weight of the gun trail from the backs of the horses. But with mechanization, the towed loads actually need the weight on the hitch for stability. And why not just build a bigger truck so you can carry all the ammunition, tooling, and the gunners kit as well as the gunner? The limber also would have made it a real bitch to back up more than a couple feet.

The Canadians actually built artillery tractors in the early 30s out of locally sourced Leyland trucks. The purpose built DND designed bodies had a large stowage capacity, but the setup still retained the 18 pdr limber. I suspect that when we started building trucks for the British, we ended up following their basic design of the artillery tractor.

I have some memory that the odd Shape was for the ease of chemical decontamination?