Production of the Mercedes-Benz O 322 started in 1960
Genuine urban bus with rear-mounted engine and bus stop brake
In-between the Mercedes-Benz O 321 H and the O 302
In the impressive bus development history of Mercedes-Benz, the O 322 is an important link between two outstanding vehicle generations. With a production volume of 959 units between 1960 and 1964, the Mercedes-Benz O 322 itself may not have been a great success, but it stands between the Mercedes-Benz O 321 H and the
O 302 – each boasting five-digit production figures. A third successful bus model – the regular-service O 317 – also played a major role during this period. The O 322 nevertheless ranks high, as the transition from the buses with rounded bodywork contours in the fifties to the modern, generously dimensioned people movers with rear-mounted engines.
Early specialist urban bus
Around 1960, the majority of regular-service urban buses were still variants of the large multi-functional model series, covering everything from regular service bus to touring coach. Examples of this approach are the Mercedes-Benz O 321 H series from 1954 and its successor, the O 302 series from 1965. In-between, however, there were specialists like the O 317 of 1958, a thoroughbred regular-service bus with a horizontally mounted engine between the axles. At the Frankfurt Motor Show in September 1959, Mercedes-Benz presented another urban bus, the O 322, production of which started in August 1960. With a length of just under ten metres and a wheelbase of 5.1 metres, the O 322 was a distinctively compact and easily manoeuvrable bus. A lightweight, vertically arranged six-cylinder in-line engine from the 300 series worked at the back of the bus, generating – initially – 110 hp from just 5.1 litres.
On principle, the exterior appearance of the O 322 resembled that of the O 317. The large, divided windscreen, rounded, small-radius roof edges and doors fitted flush with the outer skin accounted for the bodywork's modern and clean lines. On the other hand, the side windows were clearly larger and therefore more elegant than the O 317's small windows, and the O 322 no longer had bulging wheelarches. The vehicle's distinctive, square face was matched by its rear-end design. Both front-end and rear-end design were adopted for the Mercedes-Benz O 321 H and later on for the O 302. The new regular-service bus offered surprisingly generous space: 32 seats and room for 50 standing passengers. The O 322 was even permitted to carry a total of 100 passengers during the rush hour. Passengers boarded, and alighted from, the bus through a double-wing folding door at the front and a four-wing folding door in front of the rear axle. At the front door, passengers were able to enjoy the convenience of a broad door cutout, made possible by the steeply raked windscreen.
Modern engineering with air suspension and new bus stop brake
There's also a lot to be said about the O 322's engineering. Mercedes-Benz opted for the innovative air suspension all round, without additional leaf springs. This system had been introduced to large-scale bus production two years earlier and first installed in the O 317. The work of the O 322 drivers was for the first time made easier by a small detail feature which can today be found on every urban bus: the bus stop brake operated by means of a small lever in the instrument panel. It conveniently secures the bus during a short stop. Drivers also benefited from the vehicle's ease of manoeuvrability, the excellent all-round view and a turning circle of just 18.4 metres. Among the other new features of the O 322 was a hydrostatic fan drive. The fan did not rotate at all times but was only engaged at coolant temperatures upwards of 84°C.
The Mercedes-Benz O 322 of 1960 was therefore a modern bus, breaking new ground with its detail features. In spite of this, demand was somewhat restrained because this model was an additional regular-service bus variant tugged in between the successful O 321 H and O 317. The O 322's short career ended after only four years. Its successor was an urban bus version of the famous O 302 series which set out on its successful course in 1965. A few years later, in 1969, regular-service bus development started heading in a completely different direction when production of the highly specialised standard O 305 bus began. This model starts a new chapter in bus history, continuing right through to the state-of-the-art Mercedes-Benz Citaro urban bus series of 2000.