jeeps After the initial design specification of a maximum weight had been raised to almost double that in production, to achieve the necessary ruggedness on the main ton, the Army still wanted a truly lightweight model for airborne missions and use in the jungles of the Pacific theaters. In 1942 and 1943, at least five companies proposed designs: Crosley, Chevrolet, Ford, Willys, and Kaiser. The Crosley CT-3 "Pup" prototypes were superlight, one- or two-passenger, but still four-wheel-drive buggies, that were transportable and air-droppable from a Douglas C-47 Skytrain. Six of the 2-cylinder, 13 hp, Pups were deployed overseas after undergoing tests at Fort Benning, Georgia, but the project was discontinued due to several weak components. Seven of 36 Pups built are known to Most of the competitors' models were more similar to standard jeeps, just lighter and smaller. Willys managed to reduce the weight on their 'MB-L' (MB Lightweight) to some in 1943; and Army engineers were impressed by the Chevrolet and its advanced features: a single center spar frame, and an integrated gearbox and transfer case. Kaiser created six prototypes with a 42 hp engine but including some unfavorable design trade-offs. Willys eventually produced even more radical designs. The Willys WAC (Willys Air Cooled) had three seats, built around a centrally mounted 24 hp Harley Davidson engine, weighed only , but was noisy and not user-friendly. Still, it showed promise, and was further developed, eventually resulting in the Willys JBC, or 'Jungle Burden Carrier'. By early 1945 this had turned into a mere motorized wheeled load-carrying platform, with a single seat, that preceded the 1950s Willys M274 'Mechanical Mule'. In Britain, Nuffield Mechanizations and Aero cut down a Willys MB in length and width, and stripped it for minimum weight, to serve airborne forces. The Airborne Forces Development Centre in Wiltshire oversaw an entire modification program for jeeps in airborne units, involving many modifications to reduce both weight and or size, including to wedge them into Horsa gliders, for operation Market Garden. Antitank jeeps Besides towing 37mm antitank guns, it was also tested mounted directly on the quartertons. In early 1941, the US Army's Tank Destroyer Command was urgently looking to make their antitank guns more mobile, to better serve their tactical doctrine. One of the first prototypes, the T2 37mm Gun Motor Carriage (GMC), mounted a standard 37mm gun and gun shield on a Bantam BRC-40, aiming forward