One for all – probably the aptest description of the Mercedes-Benz O 302. Urban regular-service bus, country bus, touring coach – this bus with the three-pointed star was a jack of all trades. And it was the last of its kind before buses became specialized. Launched in May 1965, the O 302 replaced the popular O 321 H, and the step from one to the other could hardly have been greater. The expectations made on the new O 302 were enormous considering that the O 321 H had scored worldwide success with over 20,000 units built in 13 years. However, “there should be no doubt that the O 302 will equally conquer a leading position in international bus manufacture,” the then Daimler-Benz AG wrote to its customers.
Bodywork in the austere Bauhaus style of the sixties
While the predecessor’s rounded contours and small windows identified it as a design from the 1950s, giving the bus a slightly outdated appeal toward the end of its career, the O 302 had been designed in the austere automotive Bauhaus style of the 1960s. The curvatures of roof and back did little to deter from the basic cuboid shape with steeply angled front, generous glazing, slim window pillars, long side windows and large rear screen. Typical luxury features in the 1960s were the chrome surrounds of all windows. The O 302 was a product of the economic miracle period in Germany: people had gained new confidence and wanted to see and be seen. Similar styling features also characterized the passenger cars of the day, for instance the Pagoda, the tailfin sedans and the W 108 and W 109 luxury-class models which were equally launched in 1965.
Only the broad scuff plates and trim strips of the O 302 were still reminiscent of the 1950s. A bare sheet-metal band ran across the front end and connected it with the sidewalls. On many O 302 units, a broad strip or color band extended along the sides, from the front to the rear bumper, giving the bus a well integrated appearance.
Novelty: Panoramic glazing curving into the roof
The O 302 was available with plane side windows or with curved glazing. The latter extended into the roof, thereby converting the bus into a classic panoramic vehicle. On this version, the rear door was adapted to the side contour by means of an additional window at the top. The panoramic glazing had first and foremost been designed for touring coaches but was also optionally available for the regular-service buses with their destination indicators. “The O 302 touring coach is the first from large-scale production to feature curved windows extending into the roof rather than the conventional roof edge glazing,” customers were informed.
The driver’s workplace in the Mercedes-Benz O 302 was visually separated from the passenger compartment in that the lower edges of windshield and front door windows formed a single line that was clearly below the passenger compartment’s cowling. In the versions with high, curved side windows, the roof was slightly raised in the area of the passenger compartment sides. A vertically divided windshield was still state of the art in the mid-sixties, but the partition had been reduced to a narrow strip on the O 302.
Numerous length and equipment versions
Diversity was one of the special hallmarks of the three-meter-high bus with its high floor: it was available with four wheelbase lengths between 9.6 and 11.9 meters (the longest version joined the series in 1967). Equipment and seating versions also varied greatly, ranging from practical urban buses via versatile country buses through to upmarket touring coaches. Hinged doors front and rear were available for the touring coach, hinged or two-part outward-folding doors for the country bus and extra-wide inward-folding doors for the regular-service urban bus – the O 302 left nothing to be desired.
O 302 launched together with direct-injection engine
The O 302 was also the first bus to be fitted with a direct-injection diesel engine in 1965, two years after its introduction in trucks, Until then, Mercedes-Benz had preferred pre-chamber combustion engines which boasted smoother running characteristics but also consumed more fuel. Initially, buyers had to put up with the compact OM 352 six-cylinder in-line unit with a displacement of 5.7 liters and an output of 130 hp as standard-equipment engine in combination with a five-sped gearbox. The large twelve-row bus was powered by the OM 327 with a displacement of eight liters and an output of 150 hp, soon to be boosted to 160 hp. The more powerful engine was optionally available for the smaller O 302 versions. In addition, Daimler-Benz offered the OM 360 with 8.7 liters and 170 hp.
The twelve-meter bus was optionally available with the large 11.6 liter OM 355 with 240 hp – a more than adequate engine output for touring coaches as well. From 1969, the power output of all engines was raised. The output of the standard engine – somewhat meager from today’s perspective – has to be seen in the light of the 1960s. The Mercedes-Benz O 302 weighed in at between 11.6 and 16 tons, and contemporary buses were designed for a top speed of just 90 km/h.
Coil and leaf springs to start with
In the beginning, the suspension of the three compact O 302 versions still included coil springs at the front and trapezoidal leaf springs at the rear as standard equipment. Air suspension all round was standard on the large thirteen-row bus and the urban buses right from the start and was incorporated in the standard equipment of the other O 302 versions from 1971.
The O 302 was the first touring coach from Mercedes-Benz to feature individual nozzle ventilation for every passenger seat. And it was also the first to be optionally available with air conditioning, mounted in a box above the rear end. In coaches without air conditioning, passengers were able to protect themselves against the sun by means of retractable blinds. Overall, the vehicle was advertised with an “extremely meticulously designed ventilation and heating system.”
At his still rather sparsely equipped workplace, the driver had a genuine instrument panel in front of him – a flat panel extending from one side to the other, with only one set of gauges consisting of speedometer, rev counter and instrument cluster being slightly tilted toward the driver. The advantage: “The gauges can be read off at a glance,” as the first brochure for the urban and country bus versions of the O 302 put it.
Wanted: 1974 World Cup bus
The history of the O 302 includes distinctive models. At the time, Daimler-Benz also exported buses to the USA, with the eye-catching stainless-steel paneling that was typical in the States. This paneling was optionally available for European O 302 units. The O 302 experienced a genuine highlight towards the end of its career: All teams competing in the 1974 World Cup in Germany traveled on O 302 coaches painted in their countries’ colors. Today, more than 30 years later, the company is intensively looking for a surviving World Cup bus. Buses of this type are said to be in Afghanistan, the former CIS states and Indonesia – the O 302 was a genuine cosmopolitan and still enjoys great popularity despite its venerable age.
Technical tidbit: The first hybrid bus
The O 302 also had a proper technical tidbit to offer in its day and age: In 1960, the world’s first hybrid bus – an OE 302 – was presented at the Frankfurt International Motor Show. The “E” in the model designation points to the additional electric drive. The direct-current traction motor had a continuous output of 115 kW (156 hp) and a peak output of 150 kW (205 hp) – power in abundance for an urban bus of the day. The electricity for the traction motor was supplied by five battery blocks with 189 cells, a total operating voltage of 380 and a capacity of 91 kWh. A top speed of 70 km/h and a range of some 55 kilometers in regular service outline the limitations of the concept, as does the battery weight of 3.5 tons. For two-shift operation on a long regular-service day, the OE 302 was fitted with a 38 kW (65 hp) diesel engine adopted from the vans. This engine was transversely installed in the rear. It was used to power the bus on the fringes of cities, operating in the optimum range at constant speed.
Successful bus with world-record production volume
The versatile Mercedes-Benz O 302 was highly successful in many ways, also as a chassis. Renowned bodybuilders such as Ernst Auwärter, Drögmöller and Vetter tailored attractive bodies for the O 302 chassis. This had its effect on production figures: In the course of eleven years, Daimler-Benz built over 32,000 units, comprising chassis (a little over 50 percent) and complete vehicles – a world record. The successor, the O 303, reached a production volume that was higher still, but over a longer period. The Mercedes-Benz O 302 – it wasn’t just one for all, it was equally all for one during its successful career.