This bus caught my eye when doing a little research on European coaches – it has an interesting look, with its low slung stance and central fog light, and as it turns out is a significant model in Mercedes long history of coach-making. It’s a MB model O 6600 H intercity bus.
Why so significant? Mercedes buses prior to the war were all front-engined, conventional designs with a “bonnet” hood – essentially truck-based. The 6600, however, was the company’s first forward-control, rear-engined model. As I’m sure Paul could translate for us, O = Ominibus and H = heck or rear – the 6600 designates its carrying capacity in kilograms.
It appears MB went back and cribbed a little of the styling from its streamliner design study coach of 1935.
Mercedes was driven to produce the 6600 to match Kassborher, which had introduced its revolutionary Setra S8 model that same year. While rear-engined, the Setra also had a stressed-skin, semi-monocoque body which resulted in a much lighter (and fuel efficient) coach.
There was a front-engined conventional O 6600 built concurrently. But the “H” quickly established itself as the more popular model. The rear engine allowing for more seating, a lower coach easing passenger access, and a much quieter interior, as I’m sure those who remember riding in their old front-engined school buses can recall.
The bus was 11 meters long, with 11 seat rows, sitting 43 passengers. Engine was a transversely mounted 8.3 litre six-cylinder MB OM 315 diesel putting out 145 hp – the transmission a ZF six speed manual with an electric gear shift. The power train was mounted in a unique cradle in the rear of the bus.
The 6600 was successful and spawned both a normal diesel-engined urban transit model and a trolley coach. Interesting note – the motors and controllers for the trolley version were provided by Kiepe, which readers may remember is the same company providing motors/controllers for Dayton’s new fleet of trolleys.
Over three-thousand O 6600 H’s were produced during its ten year production run, and it saw use in both Europe and South America.
It was renamed the O 315 H in 1954 when MB went to a 3 digit naming system, though still informally referred to as the 6600.
In 1954 Mercedes introduced the O 321 H, an updated coach with a semi-monocoque body. Built from 1954 to 1970 in Germany, Belgium, Brasil and Argentina, it became Mercedes most successful, best selling bus. We’ll take a look at the 321 in a future post.
Author’s Note – in writing this article I noticed this was my 100th post for CC – I’d like to thank Mr Niedermeyer and all the other editors for allowing me the privilege of contributing to this site. I can’t think of anyplace else that would be so welcoming to a guy that likes to write about buses…