The MB Jeep
Revolutionary concepts and traditional technology gave birth to the first Jeep® .
In reality, the sidecar wasn’t actually completely dismissed by US military technicians – they initially considered it, but later deemed it inadequate for the US Army’s needs for a variety of reasons. One was its poor reliability under extreme use: reports from British intelligence revealed that the sophisticated German sidecar employed in Africa could suffer from any number of faults after the first 450–500 miles (724–805 km).
One of the first Willys MB “slat grille” models during a training exercise on US territory. © FCA © IXO Collections SAS - Tous droits réservés.
Clearly, the unit cost was also a contributory factor, given that the BMW R75 with sidecar produced from February 1941 onward (but which actually didn’t enter service until the following July) cost approximately US$1,052 (2,630 Reichsmarks). In contrast, the MB “slat grille” resulting from the initial contract for 16,000 vehicles – won by Willys in November 1941 – cost just US$748.74 each.
Another factor that was considered important was the average American soldier’s unfamiliarity with the motorcycle. At the beginning of the 1940s, and for the entire duration of the Second World War, the US Army was a people’s army – it was made up of common citizens, not professionals, called up to defend the liberty of the United States and the world. In those days, the car was much more common in America than in Europe or Asia. It meant that the average American citizen-soldier wouldn’t have needed a lengthy training period on a vehicle such as the Willys MB Jeep®.
The specifications required by the US military for the new vehicle called for the same light weight, speed, and versatility offered by the sidecar, together with the capacity to carry a machine gun. All of these features were highlighted by German propaganda, and were held in high regard by military experts at the time as a consequence of the waves of success achieved by the German army during the Blitzkrieg, or “lightning war”.
For this reason it’s worth remembering what the requirements of the German Army’s Supreme Command were for the Wehrmachtsgespann, the above-mentioned BMW R75 and Zündapp KS 750 heavy motorcycles with sidecar. They needed to carry three soldiers or a load of 550 lb (250 kg), a wheelbase of 57 in (144.4 cm), maximum height lower than 39 in (1 m), normal operating speed between 1.8 and 59 mph (3 and 95 km/h), maximum unladen weight of 926 lb (420 kg), gradeability of 40%, and wading depth no lower than 14 in (35 cm).
Keeping these specifications in mind, the initial designs drawn up for the new US military vehicle included dimensions, usage features, and performance characteristics which, in relation to the technologies of that time (July 1940), were particularly exacting. The initial specifications included the ability to carry three soldiers or a load of 600 lb (272 kg), a wheelbase no longer than 75 in (190.5 cm), a maximum height lower than 36 in (91.4 cm), and the ability to run smoothly at both walking speed (minimum 3 mph/5 km/h) and at high speed on roads (maximum speed greater than 55 mph/90 km/h, which had to be continuously maintained). Finally, the maximum unladen weight couldn’t exceed 1,300 lb (590 kg), the fully laden gradeability had to be 60%, and the vehicle had to be able to cross waterways up to 18 in (46 cm) deep without difficulty. Objectively speaking, these specifications wouldn’t be easy to achieve even by today’s technological standards, particularly considering that the US Army needed the new vehicle to cope with the most extreme operational conditions. Drivers of the new vehicle had to achieve military objectives without worrying about the preservation of the vehicle, which was considered just as expendable as an artillery shell or aerial bomb.
In July 1940, the Quartermaster Corps sent a request for proposals to produce the new vehicle to 135 American car producers. Perhaps due to the above-mentioned list of exacting requirements, just three replied: American Bantam, Willys-Overland, and Ford Motor Co.
During the trials, and particularly during the very first test drives undertaken at the Camp Holabird testing ground near Baltimore, Maryland – then the location of the Holabird Quartermaster Depot – the prototypes supplied to the army by the three manufacturers sustained numerous structural breakages and other faults. The military authorities revised the specifications more than once to enable technicians to strengthen the chassis, the suspension, the steering linkages, the bodies, and the mechanical parts, all of which had a knock-on effect in terms of the vehicle’s unladen weight. Just before the responsibility for military vehicles was transferred to the US Ordnance Department, the Quartermaster Corps Motor Transport Service announced the final configuration. For the Willys MB Jeep® slat grille, the “minimum [weight] consistent with service requirements” had increased from 1,300 to 2,450 lb (590 to 1,111 kg) and the total allowable payload had risen from 600 to 800 lb (272 to 363 kg) “for operating personnel (including the driver) and military supplies.” For the engine, the requirement was for “at least four cylinders with a cubic capacity no lower than 130 cu in (2,130 cc),” the wheelbase increased to 80 in (203 cm), the minimum height from the ground was now at least 8 in (20 cm), and the maximum height of the vehicle (with the windshield lowered) was now 52 in (1.32 m). The approach and departure angles were 45° and 35° respectively, while the tires measured 6.00-16/6 ply, and were mounted on combat modular wheel rims with heavy-duty inner tubes.
Considering the period, the dynamic qualities of the Willys MB were remarkable. Enzo Ferrari defined the Jeep® as “the only true American sports car.” © FCA © IXO Collections SAS - Tous droits réservés.
Despite offering performance, versatility, and reliability far superior to that found in similar vehicles used by other contemporary forces at the time, the model was really quite conventional. Its engine incorporated a timing system with side valves, it sat on a classic chassis with longerons and crossbeams with solid double-axle and leaf spring suspension, transmission was a standard three gears (with two-speed reduction), and it sported a simple “torpedo” body. As was usual business practice in the US in those days, the Jeep® had to be covered by a 90-day warranty, no matter what it was to be used for; remarkably, it was also valid if it was assigned to combat units. The warranty was always honored, even when the vehicle broke down in the harshest of conditions. The result was that Jeep® immediately earned admiration and affection from all who used it.
Ernie Pyle was a Pulitzer Prize-winning American journalist who made his name from reporting on GIs during the Second World War. On April 18th, 1945, he was killed in Okinawa by a Japanese machine gun after coming under attack in a Jeep® In his book Here is Your War, written during the North African campaign – which was the first major military operation in the Mediterranean theater to involve US troops – he reported: “The Jeep® – good Lord, I don’t think we could have won the campaign without the Jeep®. It did everything, went anywhere, was as faithful as a dog, as strong as a mule, and as agile as a goat. It consistently carried twice what it was designed for, and still kept going.”
The Jeep® was still only a few years old by the time of Pyle’s death. Yet his glowing tribute highlighted how the US Army’s initiative to develop a versatile new form of battlefield transportation had resulted in a genuinely revolutionary vehicle.
All-wheel-drive and creeper gears enabled the Willys MB Jeep® to tackle every type of terrain. © FCA © IXO Collections SAS - Tous droits réservés.