Pullman-built troop kitchen car	Troop sleeper layout

During World War II, most troops were moved around the country by train. Standard passenger service and passenger cars allowed troops to be moved from base to base and assignment to assignment. However, there were not enough standard passenger cars to go around, so the government requested a fleet of quickly-manufactured cars. These became known as troop sleepers, which also included troop kitchen cars. The vast majority of these were built by the Pullman company.

Pullman advertisements showing troops riding on regular passenger cars:

1942 ad showing troops boarding a standard Pullman heavyweight passenger car. Notice the porter; even though these cars carried troops, a porter was still assigned to them.
1943 ad showing a soldier waiting for a train. He is leaving from a civilian train station, purportedly on leave.
1945 ad showing a soldier riding in Pullman comfort.

The troop sleepers were built essentially like standard-model A.A.R. 50 foot box cars, but with flat ends and end doors like regular passenger cars and windows cut in the sides. The door was centered. The troops squeezed in three tiers of berths for sardine-like comfort in the sleepers. The cars also rode hard, as they were built using freight trucks, were dark, and stuffy. There was little to do aboard except play cards, sleep, or talk. The cars were only 9 feet high inside, at a time when standard box car height was moving from 10 feet to 10-1/2 feet high.

Jim Eager, in Model Railroader, March 13, 1997 metions  that the cars were not delivered until late 1943 or early 1944, so they didn't see all that much service. Eager cites a Dick Kindig photo, taken in March, 1946, on the Rio Grande at Tennessee Pass, coming down empty to load at Camp Hale at Pando. The consist was pulled by a 2-8-2, and it was:

t, H, t, k, H, t, t, t, t, t, t, H, k, H, H, H, t, t, k, H
(H = heavyweight, t = troop sleeper, k = troop kitchen).

Eager pointed out that Pullman built 1,200 of the troop sleepers, while ACF built 440 kitchen cars. ACF built 200 hospital cars and Pullman built 10.