Autocar U8144T (1941)
USA COE tractor (1941-45; 2,711 built)
The Autocar Model U8144T was called officially "5- to 6-Ton, 4×4, Ponton Tractor Truck". Its supply catalog was number G511. Behind these tedious numbers, this was by far largest, and most heavy-duty four-wheel drive truck tractor (hence the "T") developed and deployed for United States Army in World War II. This was a new type of vehicle called at that time "cab over engine" or COE design. It was produced by the Autocar Company, from 1941 to 1945. In all, 2,711 of these were manufactured. But this was less than previous types; notably the very close U7144T. Indeed the Truck, 4- to 5-ton, 4×4, COE tractor, Autocar U7144T G-511 was so close as to be difficult to recoignise. The U8144 shared its chassis mated with the van body by York Hoover 607 giving the SCR-270 mobile early warning radar system used from 1944 by the U.S. Signal Corps.
Back to the U7144T, over 11,000 were made, plus 2,750 virtually identical White 444T used as rear area tractor trucks to haul semi-trailers. All three indeed towed trailers ranging from simple flatbed to communications vans (details below). The trailers were intercangeable beteen models by the way. In all, this made of 16,461 COE truck tractors. They were used for the bulk in Western Europe, attached to the fampus Red Ball Express. Aside the "Jimmy" they became their most recoignisable item. Aside their capacity was twice the payload of the latter, they also gave their driver an unpredecented view forward. Albeit they were rarely engaged, running far fron the frontline, from ports to rear lines depots, but some had a ring mout for the always dependable cal.50 as self defence (plus the crew's M1 carbines).
Development
In the 1938 as war seemed close, the Autocar Company, a truck specialist notably providing the U.S. Army since 1909, started to market their their commercial cab over engine (C.O.E.) truck t the Army as well. In 1939 Autocar developed a new two-wheel drive, 5-ton (4,536 kg based on road cargo rating) Model U70 truck. It was converted as a four wheel drive range vehicle:
-2+1⁄2 ton (2,268 kg, off-road load rating) U2044, U4044 and U4144 trucks and U4044-T and U4144-T tractors
-5 ton (4,536 kg) model U5044-T
-4-5 ton, model U7144-T, 4×4, tractor truck
-4-5 ton, model U8144 (trucks) and U8144-T (tractors).
In the nomenclature for U0000, "U" was for the COE as "(engine) Under (the seats)". The first two numbers were the core model number, the next two indicated wheels and drive (so 44 for a 4×4) while added option "T" indicated "tractor." By default these were trucks. The difference was that the latter had a longer chassis supporting a flatbed or utility cabin, whereas the tractors had a shorter wheelbase and attachment nob for the trailer.
Autocar 4044-T/4144-T 2½-ton tractor truck (1940/1941)
The 2.5-ton model U2044 truck had a 320 cu in (5.2 L) Hercules JXD engine rated for 84HP. It was later provided by Autocar's 377 cu in (6.2 L) a 6-cyl. gasoline rated for 100HP evolving to the U4000 range. Autocar built 233 U2044 and U4044 as well as 548 model U4044-T tractors in 1940–1941, then 138 model U4144 trucks and 274 model U4144-T tractors in 1941.
The model U2044, U4044 and U4144 trucks from Autocar shared the same cab and chassis but had third-party bodies, such as:
-2+1⁄2-ton, L-1, 660 gallons Oil Servicing tanker (371 made)
-Same in towing tractors (822 made)
-U4044-T and 274 models U4144-T: 548 made
All above constituted a total of 1,193 units, mechanically almost identical so they rwere collectively under the SNL G-626.
The U5044-T was given the number G-635. It was powered by the same 1941 Autocar's 6.2 L 100HP engine, but twice the load rating. 97 made in 1940-1941 mostly as line haul tractor for fuel tank trailers. In 1941, the U8144T became the go-to pontoon tractor, whic flatbed trailer accomodated piled up bridge sections. Production unknown.
The U7144 (G-510) was a shorter version of the U8144-T but using the same driveline on a shorter wheelbase, without the behind cab toolbox and lacking the U8144’s oversize tires. They used the 9.00x20s instead, payload rating was 4-tons off road. These were made by Autocar and after 1953 by the White Motor Company and after bought Autocar in 1953. The truck was then renamed Model 444T.
Design of the U8144
Engine and driveline
The U8144 model was powered by an Hercules RXC engine which developed 529 cu in (8.7 L) for a L-head inline 6 cylinder gasoline engine. It was rated for 131 hp (98 kW) at 2300 rpm (almost twice as much as for the U-2044). Thus power unit provided a generous 368 lbf/ft (499 N/m) of torque; at 900 rpm. This power unit was coupled with a 5-speed manual transmission, in direct drive on 4th gear and overdrive gear for 5 total. This tranmission was coupled with the A 2-speed transfer case, also engaging or disengaging the front axle. It had a ladder frame, for a 21 feet 11 inches (6.68 m) wheelbase (longest of all types), fitted with two banjo style live beam axles resting on thick leaf springs as suspensions. Brakes used compressed air. There were connecting lines at the rear to plug-in the trailer's own braking system and activate the tail lights. The tires were a gargantuan 12.00x20 size. As payload, the model T was designed for towing semi-trailers with 10-ton or 25-ton ponton bridging equipment.
Bodies
U8144T2, mid-war production version with canvas roof.
The U8144T tractor shared about the same cab as previous models, a reworked bonnet, muguard arches only over the forward wheels, and semi-arches over the rear axle, buty not on all models. The main fuel tank was located on the left side, and the toolbox, oil tank and utility generator for compressed air, on the right under the chassis, right behind the cab. The cabin was accessed through a square door, quite tall, thus a large step was cutout behind the front arches. There was a handlebar close to the door to open it. The bonnet had two air louvres intakes on both sides. Two foldable rear mirrors were installed close to the side doors to be accesses. There were two blackout lights installed on either side of the bonnet, behind and above the main light.
The windshield, in the close cab version was fixed and composed of two windows and a wiper above each. The Autocar grille was quite tall and large, with a simple vertical grille motive. The two lights were protected by robust military brush guards in front. They were connected to a bar above the main bumper. The latter protected inside a self-unditching winch connected to the transmission. The hook end was generally attached to one of the two bumper hooks. Behind the cab was a large toolbox. In other versions, there is instead a spare wheel. The later production was simplified: The metal roof was replaced by a simple canvas roof, anchored on a rear folding frame, and to the front windshield, all flat and folding forward. Due to its bulkn, the cabin could house three: The driver on the seat in front of the steering wheel, and two extra personel seated on a larger bunk seat on the right.
Trailer variants
2/10 tons pontoon trailer carrier
Simple ftabed trailer with trestled load
10 tons pontoon bridge trailer
Large pontoon trailer
K-31 5-6 tons 4x4 van of the signal corps, note the longer wheelbase. Associated to the K32.
Autocar U7144-T tractor truck/White 444T
U7144 open cab Body
The U7144-T Tractor, 4- to 5-ton, 4×4/White 444T: Albeit it will be seen in a standalone post, this more common tractor codenamed G-510 was shorter but shared the same driveline, but with a shorter wheelbase, without the toolbox behind cab and with smaller tires, plus rated at 4-tons off-road. It towed various trailers, as the 25-foot and 40-foot, 12+1⁄2-ton type C-2 flatbeds as well as the AAF type F-2 and F-2A fuel tankers. There was also an optional trailer with SCR-270 antenna support components. This and the White 444T had a max towed cap at 30,000 lbs base don their Hercules RXC 529 cu.in. 112HP. The White 444T was a perfect copy and no technical manual was published for it as the U7144-T one was used. It had however the SNL G-691 supply parts catalog associated.
Federal 94×43 Tractor, 4/5-ton, 4×4 (G-513)
The Federal 94×43 Tractor, 4/5-ton, 4×4 (G-513) was another copy, but with a different cab, yet sharing the same Hercules engine, same chassis components as the ones above. Some 8,119 manufactured for a grand total of similar tractors at 21,974 units.
Official OAI documentation
⚙ specifications |
| Weight (Ibs) | 15,660 net, Gross 27,120 |
| Payload (Ibs) | 10,450 |
| Dimensions | 246-1/2 x 93 inches |
| Propulsion | Hercules RXC 4 cyl. Lh 6 cyl. petrol 130 hp |
| Speed | 45 mph governed |
| Range | 270 miles |
| Armament | Optional pintle-ring mount cal.50 M2, personal weapons. |
| Protection | None |
| Crew | 1-3 |