The design challenge and achievement 's first prototype, shown in front of the
already new for 1940, "light" half-ton, 4×4
Dodge VC-1 Command Car, graphically shows the radically new ton concept. By 1940, U.S. policies had caused a stark disadvantage compared to
Nazi Germany's aim, building a standard fleet of
Wehrmacht (German armed forces) motor vehicles. Since 1933, the German industry could only produce Wehrmacht-approved trucks. The U.S. Quartermaster's only significant success for standardization, through late September 1939 Army Regulations on tactical trucks, was that the War Department limited procurement to just five payload chassis types (categories), from ton to ton—but
only "models produced commercially by two or more competing companies..." The Army was still to use "commercially standard" trucks and parts, with only minor modifications, like brush-guards, tow-hooks, etc. By contrast, Germany had already completed a development program to produce
off-road capable "Standardized Military Vehicles" (the
Einheits-PKW der Wehrmacht), from 1933 to 1938, which had already yielded a fleet of tens of thousands of standardized vehicles for the German Army. In fall 1941, Lt. E.P. Hogan of the
U.S. Army Quartermaster Corps wrote: "Credit for the original design of the Army's truck ton, 4×4, may not be claimed by any single individual or manufacturer. This vehicle is the result of much research and many tests." Hogan credited both military and civilian engineers, especially those working at the
Holabird Quartermaster Depot. Nevertheless, Bantam is credited with inventing the original ton jeep in 1940. However, Willys' advertising and branding during and after the war aimed to make the world recognize Willys as the creator of the jeep. Although first designed and shown on
''Ford's first ton, Willys engineer Delmar G. Roos was the first who submitted and was awarded design patent 136819, assigned to Willys-Overland which describes the characterizing Jeep nose design, having a slightly tapered front clamshell hood, its vertical grille and slats, and integrated headlights into the front fascia, which distinguished it from the original Bantam design. When Willys first applied to trademark the "Jeep" name in February 1943, Bantam, Ford, and other companies objected, because of their contributions to the jeep and the war effort. Although many different companies advertised their patriotic efforts to producing the ton jeeps—including Ford, featuring their own GPW jeeps in their ads—nobody took their claims as far as Willys-Overland, and the U.S.
Federal Trade Commission (FTC) opened a case, charging Willys-Overland with misrepresentation in their advertising and news claims, on 6 May 1943. According to
The New York Times,
the FTC ruled that Willys did not
perform the "spectacular achievement" of creating, designing and perfecting the "jeep" together with U.S. Army Quartermaster officers, but that: "The idea of creating a 'jeep' was said by the FTC ... to have been originated by the American Bantam [Co.] of Butler, PA '[with U.S. Army officers] and to have been [conceived and] developed by that company.''" Willys appealed this ruling, and after a five-year investigation, in 1948 the FTC again ruled that "Willys was unfairly taking credit for the creation and was thus using unfair methods of competition. The FTC ordered Willys to stop claiming they were the sole creator of the Jeep." , here in his jeep in summer 1944, wrote that the jeep was "one of the six most vital" U.S. vehicles to win the war Moreover, in 2015, the
Pennsylvania General Assembly unanimously adopted a non-controversial House Resolution (382): "
...commemorating the 75th anniversary of the Bantam jeep, invented and originally manufactured in Butler, Pennsylvania," therein explicitly resolving that
Bantam of Butler, PA, invented the jeep, calling it "one of the most famous vehicles in the world," were the only party to deliver a working prototype of a light four-wheel drive reconnaissance car within the required seven weeks, which withstood 30 days of Army testing at Camp Holabird, then further developed that car, and manufactured 2,675 jeeps, before losing further production contracts to Willys and Ford Motor Company, for fear that Bantam would not be able to ramp up production to 75 jeeps a day, and after the Army handed Ford and Willys the blueprints of Bantam's detailed technical drawings—though Bantam proved highly capable and productive during the war, entrusted with manufacturing
torpedo-motors and more. However, on 7 April 1942, U.S. patent 2278450 for the WWII jeep, titled "Military vehicle body" had been awarded to
the U.S. Army, which had applied for it, listing Colonel
Byron Q. Jones as the inventor on the patent, though he had performed no work on the design of the vehicle. Filed on 8 October 1941, stating in the application that "The invention described herein, if patented, may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon," the patent relates to a "small car vehicle body having convertible features whereby it is rendered particularly desirable for military purposes" and describes the purpose as being "a convertible small car body so arranged that a single vehicle may be interchangeably used as a cargo truck, personnel carrier, emergency ambulance, field beds, radio car, trench mortar unit, mobile anti-aircraft machine gun unit, or for other purposes." exactly what was wanted for relaying critical orders, getting munitions to machine guns, and scouting miles ahead of advancing units. The quick and nimble motorcycle, "ridden hard through shot and shell to secure victory," has made itself irreplaceable in specific roles on the battlefield to this day. They had poor
off-roading ability and lacked payload capacity. Adding a sidecar provided more stability, but payload and cargo space remained minimal, and having only one powered wheel out of three still meant the combination got stuck a lot.
Royal Page Davidson used patents of Charles Duryea to modify the chassis, with machine guns and armor shield, from 1898. trucks in a mud and ruts road,
1916 Mexican Expedition note FWD logo on grille s truck, 1918 At the same time, the arrival and growing use of automobiles led to various individuals pioneering vehicle trips across the U.S., followed by the first transcontinental trips by
convoys of vehicles. After the U.S. Army purchased its first truck in 1907, of 5-ton payload capacity, in the late summer of 1913, the Army Medical and Quartermaster Corps (QC) took a -ton QC field-truck, on a multi-leg experimental trek through Alaska for the state's Road Commission—both to try the truck's bad-road supply and maintenance abilities as well as test the state of several important overland connections in the rough territory. 1915 followed the first successful
transcontinental motor convoy, traveling the entire
Lincoln Highway, from New York City to the
Panama–Pacific World Exhibition in San Francisco, taking four months—for making a film about it. Starting in 1916, the Quartermaster Corps was servicing over 100 "motor trucks," of as many as 27 "varieties", and in March that year, the U.S. Army decided to form its first two motor companies, to be used immediately in the
Pancho Villa Expedition in Mexico, and British and French forces also wanted them. Ford, an
isolationist, would not sign a contract with an overseas government, but local dealers sold over 50,000 Fords to European forces, who militarized them locally, most famously into ambulances. The United States procured thousands of motor vehicles for its military, including some 12,800 Dodges, plus thousands of four-wheel-drive trucks: 1ton Nash Quads, and 3- and 5-ton FWD trucks. General
John J. Pershing viewed horses and mules as acceptable for the previous three U.S. wars, but in the new century, his cavalry forces had to move quickly, with more range and more personnel. He was the first to deploy motorcycles, in the
Mexican Border War, predominantly a cavalry campaign over vast regions of the Southwest, where
Harley-Davidson motorcycles provided to the Army gave the U.S. the advantage over the horse-mounted Mexicans.
Interbellum tests, and formulating the need for a standardized, 4×4, quarter-ton Immediately after World War I, the further and future use of motor vehicles was considered. In many roles, motorized vehicles had successfully replaced horses and other
draft animals, but several roles remained that required better or more specialized vehicles. In 1919 already, the U.S. Army Quartermaster Corps recommended the acquisition of a new kind of military vehicle, "...of light weight and compact size, with a low silhouette and high ground clearance, and possess the ability to carry weapons and men over all sorts of rough terrain." The U.S. Army started looking for a small vehicle suited for reconnaissance and messaging, while at the same time searching for a light cross-country weapons carrier. However, after World War I, the United States had a big
public debt, and the military had masses of left-over war vehicles, so vehicle budgets were drastically cut. During the first half of the
interwar period, the
Roaring Twenties, despite a booming economy,
United States non-interventionism and
neutrality policies were supported by both elite and popular opinion, to the point of
isolationism, and no real budgets were allocated. Then, the
Wall Street crash of 1929, and the following
Great Depression resulted in economic
austerity policies lasting until the end of the 1930s, thus curtailing any development of new military vehicles, like a light 4WD car. At the same time, there was a drive for standardization. By the end of World War I, U.S. forces overseas had a total of 216 different makes and models of motor vehicles to operate, both foreign and domestic, and no sound supply system to keep them running. Various light motor vehicles were tested—at first motorcycles with and without sidecars, and some modified
Ford Model Ts. But what was needed was a very light, small, battlefield utility vehicle to replace motorcycles (with or without sidecar)—more user-friendly to control, was shown in a 1933 article in
Popular Mechanics magazine. One of the pictures showed that the vehicle was light enough to be man-handled—four soldiers could lift it from the ground entirely. But it was still only rear-wheel drive. After 1935, when the U.S. Congress declared World War I vehicles obsolete, procurement for "remotorization of the Army" gained more traction, The U.S. Army itself had also built an experimental light, low-profile scout and gun mover, the
Howie-Wiley machine gun carrier, ordered by General
Walter Short, then Assistant Commander of the
Army's Infantry School at Fort Benning, Georgia, and built by Captain Robert G. Howie and Master Sergeant Melvin C. Wiley. Completed in April 1937, with a driver and a gunner lying prone, operating a .30 caliber machine gun, the vehicle was nicknamed the "belly flopper." In France, the project has already been developed and put into production since 1937. The
Laffly V15 can be considered the French Jeep. One thousand two hundred of these four-wheeled vehicles were produced before the debacle of 1940. By 1939, the U.S. Army began standardizing its general-purpose truck chassis types by payload rating, initially in five classes from . The Quartermaster Corps saw that the Army needed truck chassis to be standardized in crucial basic functional 'types' (body models), and within "payload capacity" classes. Additionally, some essential features could not be equipped by the QC on commercial trucks after procurement. Cross-country capabilities, like increased ground clearance and multi-axle drive, had to be designed and built into the trucks from the factory. Furthermore, to achieve the needed level of standardization, the Quartermaster General urged trucks should be bought en masse from there on. Acting Chief of Staff,
George C. Marshall, approved the procurement policy in the summer of 1939. The Quartermaster Corps also wanted to require the truck industry to use dimensionally interchangeable components, but further standardization measures were not approved until 1940. the half-ton 4×4 trucks—both from Marmon-Herrington Ford, and the 1940
Dodge VC series—still proved too large and heavy, and insufficiently agile off-road. In 1938, American Bantam again loaned three much-improved cars to the Pennsylvania National Guard for trials during summer maneuvers, which were received as reliable, economical and practical.
during WWII, and for years nicknamed "jeeps" by the soldiers. The Army then ordered the U.S. military's first ever production quantity of
light, ton, 4×4 tactical trucks: going on 5,000
Dodge G-505 VC series, which arrived by the Spring of 1940. Until that point, only a few third party after-market modified four-wheel drive ton trucks, mainly Marmon-Herrington derived Fords, had been bought after 1935, for testing, but the prevailing belief amongst military higher-ups and Congress was, that all the extra four-wheel-drive hardware would make any truck lighter than a ton payload model, so much heavier that the weight-gain would cancel out any benefits gained from adding four-wheel drive. But after the ton 4×4 Dodges arrived, two decisions were made: greatly more of these ton Dodges were ordered (some 80,000 for the 1941 model year revisions), but also, in June 1940, the Army's tactical trucks payload categories were revised. For the first time, the Army introduced a quarter-ton 4×4 truck chassis class, and just above that, the ton chassis were going to be supplanted by a ton class. Bantam officials met with the chiefs of Infantry and Cavalry and suggested a contract to develop military versions of their light car further. But in June 1940—as a collaboration with the Quartermaster Corps (QMC), still responsible for U.S. unarmored tactical military vehicles in 1940—the Ordnance Corps initiated a Technical (sub-)Committee, for the QMC to formulate a comprehensive, exact specification for this new, very lightweight, cross-country tactical vehicle, capable of carrying personnel and equipment across rough terrain. They specified a part-time four-wheel-drive vehicle, with a two-speed transfer case, three bucket seats, a fold-down windshield, and blackout and driving lights, of just , with a payload up to , on a wheelbase no longer than (the wheelbase of American Bantam's pickup truck), a maximum (collapsible) height of (three inches above the Howie-Wiley machine-gun carrier), and an engine and drivetrain, capable of smoothly pulling at speeds ranging from . By now, the war was underway in Europe, so the Army's need was urgent, but also very demanding. No sooner than July 1940, some 135 manufacturers of automotive or similar equipment were approached by a government letter to submit bids, to be received by 22 July, a span of just eleven days. In the first stage, the winning manufacturer(s) were given just
seven weeks (49 days), from the moment of awarding the contract, to submit their first
fully functional prototype and 75 days for completing 70 test vehicles in total. The Army's Ordnance Technical Committee specifications were equally stringent: the vehicle would be
four-wheel drive, have a crew of three, on a wheelbase no longer than , later stretched to , and tracks no wider than . The height with the windshield folded down was also raised, to . The diminutive dimensions were similar in size and weight to American Bantam's compact truck and roadster models. It was now to carry a payload and be powered by an engine capable of of torque. The most daunting demand, however, was an empty weight of no more than . Initially, only American Bantam Car Company and
Willys-Overland entered the competition. And only Bantam provided a proper set of technical drawings.
Ford joined later, after being approached directly. Although Willys was the low bidder, Willys was penalized for needing more days to make a prototype, and the dollars penalty per extra day put Willys' price above Bantam's – earning them the contract, as the only company committing to deliver a pilot model in 49 days and 70 more pre-production units days. museum. was an experienced automobile engineer who had early-on worked on the first
Duesenberg and been an engineer at
Stutz Motor Company of Indianapolis for 18 years, worked a spell for
Marmon, and then for Bantam from 1937 to 1942, Probst laid out full design drawings for the American Bantam prototype, known as the Bantam Reconnaissance Car, or BRC Pilot, in just two days, and worked up a cost estimate the next day. Bantam's bid was submitted, complete with blueprints, on the 22 July deadline. American Bantam had purchased the assets of
American Austin Car Company from the bankruptcy court and had developed its own line of small cars and engine technology, free of licenses from the British
Austin Motor Company. As the only small car manufacturer in the United States at the time, their design concept was initially to leverage their
commercial off-the-shelf components as much as possible. Bantam adapted front sheetmetal body-stampings from its car line: the cowl, dashboard, and curvy front fenders. delivered the last eight 1940 Mk. II prototypes with four-wheel steering. However, once Brown returned to Camp Holabird, Crist reviewed their thinking and realized that the new vehicle would have to be mostly new, rather than simply a modified version of an existing Bantam model. He and others at Bantam immediately set about sourcing the right components: transmission, transfer case, driveshafts, and axles. so a
Continental four-cylinder, making 45
horsepower and of
torque was selected, Using off-the-shelf automotive parts where possible had helped to design the car and draw up its blueprints quickly. By working backwards, Probst and American Bantam's draftsmen converted what Crist and a few other engineers and mechanics had rigged together in the factory back into drawings. and basically untested,
driven by Crist and Probst, to the Army vehicle test center at
Camp Holabird, Maryland. It was delivered at 4.30 pm on 23 September 1940, just half an hour within the deadline. which the soldiers liked very much, in such a lightweight, open-top car. Chief engineer Delmar 'Barney' Roos had been working on Willys' four-cylinder car-engine for years, and with many detail changes had managed to get it to 60 hp from an initial low forties output. The Ford Pygmy, on the other hand, was held back by its tractor engine, Ford's only four-cylinder engine still made in 1940, despite serious efforts to make it stronger. Dale Roeder was Ford's team leader behind the Pygmy, and his team managed to tune the motor from 30bhp to the specified 40bhp by using a different camshaft and a bigger carburettor. that after initially considering 1,500 pre-production units
in total, all three cars were declared 'acceptable', and orders for 1,500 units
per company were given for field testing and export. At this time, it was acknowledged that the original weight limit (which even Bantam's Mk. II could not meet) was unrealistic, and it was raised to . On 22 January 1941, the Quartermaster Corps Technical Committee advised standardization of the jeeps across all manufacturers. For the ensuing pre-production runs, each maker's vehicles received further revisions and new names once more. For 1941, Bantam's got called the Production began on 31 March 1941, with a total of 2,605 built up to 6 December – the number ordered was raised because Britain and the USSR already wanted more of them supplied under
Lend-Lease. {{external media |float=left |width=230px Ford's pre-production jeep was named the "GP", with "G" indicating a "Government" contract, and "P" chosen by Ford to designate a car with a
wheelbase of . The Ford GP was not only the most numerous (at about 4,458) early production jeeps needing to reduce the Quad's weight by . After many painstaking detail changes, Willys renamed their vehicle "MA", for "Military" model "A". Only 1,555 MAs were built, most of which went to the Soviet Union under Lend-Lease. Only 27 units are still known to exist. The jeep, once it entered mass production, introduced several new
automotive technologies. Having
four-wheel drive for the first time introduced the need for a
transfer case, and the use of
constant-velocity joints on the driven front wheels and axle, to a regular production car-sized vehicle. Ford built jeeps with functionally interchangeable parts and components, in part facilitated by using components from common sources: frames from
Midland Steel, wheels from
Kelsey-Hayes, and axles and transfer cases from
Spicer. However, Ford had replaced the welded grate front grille by a single
pressed/stamped sheet steel part, with nine vertical open slots to ventilate the radiator, and circular openings in front of the lights, to simplify production, and save costs. Willys also adopted this in their production of the MB after unit 25,808. Predictably, there were still many minor differences; the Ford chassis had an inverted U-shaped front cross member instead of a tubular bar, and a Ford script letter "F" was stamped onto many small parts. Many body detail differences remained for as long as January 1944, when a composite body, fabricated by
American Central, was finally agreed upon by both Ford and Willys. American Central had been making the jeep's bodies from the first 1500 units order for the Willys MA and had also built Ford's jeep bodies for two years already, but until January 1944, Ford and Willys contracts retained detail differences. However, from then on, features of both designs were integrated. Through the chaotic circumstances of war, sometimes peculiar deviations from regular mass-production came off the assembly line, which are now prized by collectors. For instance, the earliest Ford GPWs had a Willys design frame, and in late 1943, some GPWs came with an unmodified Willys body; while in 1945, Willys produced some MBs with a deep mud exhaust system, vacuum windshield wipers, and a Jeep CJstyle parking brake.
The Ford GPA, the amphibious jeep amphibious jeep Approximately 13,000 additional
amphibious jeeps were built by Ford as the
Ford GPA (nicknamed "Seep" for "Sea Jeep"). Its design was directly inspired by the larger
DUKW, and by the same designer and company, Rod Stephens Jr. of
Sparkman & Stephens yacht designers. The vehicle was produced too quickly, or its operational capability and limitations were misunderstood. Although the GPA came out barely heavier, wider, or taller than standard jeeps, it was
one third longer, and proved unwieldy on land. Adding insult to injury, the Seep would often get stuck in mud or, when wading, where the MB jeeps would not. In water, its disappointing performance was even more problematic, because contrary to the DUKW, it had insufficient
freeboard for
coastal landings from open sea, leading to mixed success and tragic losses in the
allied Sicily landings in July 1943. Many GPAs were passed on under the Lend-Lease program—some 3,500 (more than a quarter of total production) to the USSR alone. Many solutions made the jeep run on rails, popular in the
Pacific theater with U.S., Britain, and
Commonwealth troops, especially in
Burma. A-frames on the front bumper enabled two jeeps to tow heavy trailers (for 2ton trucks) in tandem. For desert cooling,
radiator surge tanks were used in North Africa in 1942. Equally, there were winterization kits, even snowplows, and the jeep's go-anywhere capability was further aided with
deep water fording kits, tire air compressors, and a winch option. For communications, jeeps were modified with rear ditch plows and cable laying reels, such as the RL-31 reel unit.
Off-road enhancements To disembark jeeps in
amphibious landings, in 1943, a deep-water fording kit for the jeep was produced. This enabled jeeps to be driven off
landing craft like the
Landing Craft Mechanized (LCM), wading into relatively deep water, without flooding the engine or short-circuiting the electrical system. After several interim kits were issued, the U.S. Army standardized the universal WV-6 kit (later G9-5700769), which served all WWII ton to 2ton trucks. The kit contained flexible hoses for both the exhaust and the air intake, as well as proper waterproofing equipment.
Westinghouse developed a T1 air compressor, to be used in conjunction with special tires, to deflate the tires off-road, in soft mud or snow, and be able to pressurize them again after. It could be fitted under a maintenance work order from October 1944. There was even a small capstan winch field kit made for the jeep, driven off the motor, for self-extracting, or pulling other jeeps trapped in mud or snow. The winch was very small and made hand-cranking of the jeep impossible. The latter two features remained rare.
Arctic weather measures Willys developed a winterization kit for very cold climates. This included a cold-starting stove, crankcase ventilator, primer, hood insulation blanket, radiator blanket, a body enclosure kit, defroster/de-icer, and snow chains. These kits were, however, frequently unavailable, so units took their own measures in the field, particularly improvising various body enclosures, to protect the crew from extreme weather. In addition, two companies fabricated snowplows for the jeep. Geldhill Road Machinery Company made the 7T1NE plow, an angled single blade, while the JV5.5E was a V-shape design. The
Wausau Iron Works built two similar designs, designated as the J and JB snowplows. Neither of these seems to have been commonly issued in combat. Photos of snowplows in use in the
European theater mostly show improvised plows, likely adaptations of snowplows locally found at hand.
Further development of the jeep Although no other light jeeps were taken into production, it was not for lack of trying. Both key military men, who had been championing the development of military vehicle concepts they had formulated for years—sometimes already since World War I—had led to conclusions about the logic of military mechanization, as well as automakers large and small, who now saw that in wartime, all of a sudden, there were budgets available to work with. Of course, this was primarily true for the firms involved so far. After losing out on mass-production of the four-wheel drive ton, Bantam built the Army one 4×2 quarter-ton chassis in 1942, but to no further consequence. in the
Pacific War. Note that the medical supplies locker is in place of the right front seat. Source: National Archives -modified MB/GPW jeep field-ambulance for U.S.M.C. in the Pacific War, series I. Series II and III were made some 6 inches (15 cm) taller. An exception was an order for a series of some 200 to 500 standardized jeeps to be modified, by
Holden (as General Motors Australia), into field ambulances for the
U.S. Marine Corps in the
Pacific Theater, because they found the standard ton
Dodge WC-54 ambulances too unwieldy, and even their own ton, 4×4
International M-1-4 vehicles both too ponderous
and too scarce. In 1942, Lt. Cmdr. French Moore, MC, a battalion surgeon with the 2nd Marine Division (Camp Elliott, CA), started developing his design for an MB/GPW-based "light field-ambulance." He submitted blueprints and records of performance of his prototype to Marine Corps Commandant Lt. Gen.
Thomas Holcomb. It could carry up to "35 patients 1,000 yards and return, in an hour." Rebuilt to Moore's design, it was approved for fielding in time for the Solomon Island Campaign in 1943. Three series were built in modest numbers but totaling more than the USMC's own ambulance versions of their International M-1-4 and M-2-4s.
Rocket jeeps The jeep, being too light to mount substantial guns, was more suited later in the war as a platform for rocket artillery, which didn't have the enormous recoil of conventional tube
artillery. The
California Institute of Technology developed two different 4.5-inch jeep-based rocket launcher systems for the U.S. Navy. Several other initiatives all used 4.5-inch rockets and tubes. Testing was also done by both the U.S. Army and the Marine Corps, but none of the jeep-mounted rocket launchers were built in any significant number because it was more efficient to use larger trucks that could carry more rockets. The Soviet Red Army deployed twelve units fitted with 12-rail
M-8 82mm rocket launchers in the bed of a jeep, from December 1944 in the
Carpathian Mountains.
Stretched and uprated jeeps The simplest and most frequently used method was the addition of a
rear baggage rack to extend the jeep's luggage space. In exceptional cases, units would actually stretch both body and frame of a jeep to give it more passenger and luggage space, but for this usage, a Dodge WC model was available in many cases. Nevertheless, building stretched, 6×6 jeeps with ton cross-country payload, was explored with much interest. As early as July 1941, after the unsuccessful testing with the T2 and T2E1 37 mm antitank guns mounted on Bantam jeeps, the
U.S. Quartermaster Corps (QMC) thought to lengthen ton jeeps into 6WD for specialized roles, including the 37 mm gun. Willys was contracted that month for both a T13 and a T14 gun motor carriage, based on the Willys MA – one firing forward, and one rearward, like the earlier Bantams. In reality, two models of rearward-firing T14 were built, based on Willys
MBs, one with a slat grille in late 1941, and one or more stamped grilles by January 1942. Moreover, it comprised 65% unaltered standard jeep components, and many of the other parts were also just modified standard jeep parts. By January 1943, the Willys MT-TUG was further evaluated by the Army Transport Command at
Camp Gordon Johnston, FL. It was positively reviewed there for its effortless operation in deep sand. Although the Willys ton's performance was even called 'exemplary' by some. Fifteen 6×6 Willys MT(-Tug)s alone were built as "Truck, ton, 6×6, Tractor", under Ordnance production contract W303ORD4623, production order T6620, and even a maintenance supplement for the "6×6 Willys MBTug" was printed with the 1943 TM101513 technical manual. Including miscellaneous test units, a total of 24 units are believed to have been built, with six known survivors.
Tracked jeeps Several tracked jeep prototypes were built because of such a need in Alaska and Canada. After America entered the war, a Japanese attack on the
Aleutians suddenly made the Alaskan military base a zone of great military importance. The snow-rich circumstances created a need for tracked, jeep-like, all-purpose vehicles, and the Canadian
Bombardier company and Willys created the T29 jeep
half-track out of one of the existing 6×6 Willys MT chassis. The T-29 "Snow Tractor" (Jan 1943) expanded the rear chassis to a total of six wheels: three on each side, with a broad rubber belt serving as a track, running around two Ford Model A wheels, followed by a notably larger wheel at each back corner. Instead of front wheels, the rig got skis, and the front-wheel driveline was omitted to save cost and weight. It was followed up with the T29E1, on which front wheels returned, but mounted on the front skis, and still non-driven, just so that the front could now both glide
and roll. Due to Willys' workload, International Harvester helped assemble a further five T29E1 prototypes. Under the steering front wheels, skis could be mounted or removed. An Aberdeen test report critiqued that the T-29E1 was difficult to steer, as the tracks could not be controlled independently, and that prolonged use caused excessive track component wear. A completely rearranged rear was then proposed, and a T28 litter-carrier was completed for testing by August 1944. Further (fully) tracked "jeeps" were also armored, and developed for, and by Canada (see
armored jeeps).
Armored jeeps Many jeeps received added armor in the field, especially in Europe in 1944–1945. Frequently, a rear slanting armor plate was added in front of the grille, replacing the windshield, as well as the sides, in place of where doors would be. was built on a 6×6 Willys MT "Super-Jeep" chassis. Since reconnaissance was one of the jeep's primary purposes, there was a demand for some armor from the start of production. Starting in April 1942, the second T14 GMC 6×6 Willys MT-Tug chassis was converted to the
T24 Scout Car. Though performing well in trials, the T24 was abandoned in the autumn in favor of the
M8 & M20 Light Armored Car. Concurrently, the Ordnance Corps was pushed to work on a lightly armored reconnaissance design, based on the standard Willys 4×4 jeep. Different armor configurations were tested on the T25 through T25E3 prototypes, respectively. Canada created a light, tracked, armored, and armed vehicle using Jeep automotive components. In late 1942, the
Canadian Department of National Defence (DND)'s Directorate of Vehicles and Artillery (DVA) began work at No.1 Proving Ground in
Ottawa on a small tracked vehicle successively named: 'Bantam Armoured Tracked Vehicle', the 'Light Recce Tank', and finally: the 'Tracked Jeep', TJ. . The vehicle was intended for taking messages over contested ground,
armored reconnaissance, and engaging unarmored enemy troops in airborne and combined operations. Willys and Marmon-Herrington were contracted for five more prototypes, Willys for power train components, and MH for the armored hulls and the Hotchkiss-type running gear. The Tracked Jeep showed excellent cross-country performance, and uphill mobility was better than other light tracked utility vehicles, while its
amphibious capability was adequate, despite its low freeboard. There were, however, serious shortcomings with the running-gear and tracks. Work to fix this delayed testing until late 1944, and British insights demanded such fundamental changes that a Mk . 2 version was developed, of which another six units were fabricated, and not ready until after the war had ended. The problems with tracks and running gear were still not sorted out, and development halted.
Flying jeep The most extreme concept tried was to turn the jeep into a
rotor kite (or gyrokite), similar to an
autogyro—the
Hafner Rotabuggy (officially Malcolm Rotaplane). Designed by
Raoul Hafner in 1942 and sponsored by the
Airborne Forces Experimental Establishment (AFEE), after their
Rotachute enjoyed some success, a passive rotor assembly was added over the jeep cabin, along with a lightweight tail, for stabilization. This jeep could be towed into the air by a transport or bomber tug. The Rotabuggy would then be towed to the drop zone as a rotary-wing glider. It took until autumn 1944 to achieve a decent test flight, and other
military gliders (particularly the
Waco Hadrian and
Airspeed Horsa) made the Rotabuggy superfluous. Incidentally, it was first named the "Blitz Buggy," but that was soon dropped for "Rotabuggy". ==Etymology==