This Giant Mercedes-Benz Bus Was Much More Than A People-Carrier

Jun. 04, 2023 8:15 AM ET by Karl Furlong Classic Cars / 2 Comments

Maneuvering it must've been a nightmare, so it took on jobs that didn't require as much driving.

If you think the three-row Mercedes-Benz GLS-Class has a large footprint, the historic O 10000 bus that is a highlight of the Mercedes-Benz Museum is a truly gargantuan blast from the past that the German marque is now fondly looking back on. With three axles, an 11.2-liter six-cylinder diesel engine, and a length of over 45 feet, this long-distance bus was built in 1938 and served duty as both a long-distance bus and a mobile post office over a period of four decades. Its curb weight was over 37,000 pounds, roughly equivalent to four Hummer EVs.

This was the largest bus from Mercedes in the 1930s, with the chassis presented at the International Automobile and Motorcycle Exhibition in Berlin in 1936. Little did Mercedes know just how versatile the big-bodied O 10000 would prove to be in the decades to follow.

In operation in Germany and Austria, the buses could reach a top speed of about 40 mph and could accommodate up to 60 passengers. A double-decker version was also used at some stage and could transport 80 people. Its 150-horsepower diesel engine was situated under the long hood, complete with a grille that looks to be about the size of Alaska.

Two guide rods with rounded rearview mirrors are situated on the front bumpers, and these were necessary to give the driver a chance to maneuver the massive bus safely. Besides transporting passengers, the O 10000 was used for scheduled long-distance deliveries for postal services, known then as "powered post." It was after the Second World War that the Austrian Post elected to convert the bus for the first time for operation as a parcel carrier between Vienna and Salzburg.

We did a little digging and found that the O 10000 had a turning radius of around 78 feet, which must've been a nightmare in any remotely congested space. It's little wonder, then, that other uses for the bus that did not require as much driving came to light. Its conversion into a mobile post office, likely in the 1960s, added many more years to the O 10000's life.

As a mobile post office, the bus had three telephone booths, each with a rotary-dial telephone on a tiny table that had been screwed to the wall. The third booth allowed visitors to make international long-distance calls; that was quite something in an era where one couldn't dream of conducting virtual meetings using in-car cameras no matter where you were in the world.

Meanwhile, counter clerks were seated on sliding seats attached to the interior floor, from where they could accept letters, telegrams, and parcels. Customers even had access to a writing facility.

Staff working in the bus also had access to a refrigerator and hand basin, but air conditioning was a step too far, and fresh air came from a screen door at the rear. Above all, the bus was able to offer these services in multiple locations as needed, and this versatility meant that it remained in service until the 1970s with the Austrian Post.

Besides its post office duties, the bus made appearances at various cultural events such as the Salzburg Festival. Its yellow and black livery is a visual link to European post history as these are Imperial colors, not that you'd miss this beast even if it were finished in a nondescript grey or black.

We wonder how many behemoths of the modern age will still find use three decades after they were built. Probably not many.