Here’s a bus that caught my eye when doing a little research on the Mercedes O321H – this is a 1954 Krauss-Maffei KML (Krauss-Maffei Lightweight) 110 coach, and as you can see, it’s quite the looker…
Krauss-Maffei was a company formed in Munich in 1931 that manufactured both trucks and locomotives. During the war, they produced a variety of armored vehicles, the most famous being the Sd. Kfz. 7 half track prime mover – an eight ton bruiser that could carry 12 troops and pull a 88mm flak gun.
Early post-war Krauss-Maffei Coach
After the war, the Allied Occupation realized buses were a key element in re-establishing public transportation networks and commissioned Krauss-Maffei to produce both urban transit and intercity coaches. These coaches were pre-war designs that featured a separate body and frame.
In the early 1950’s, several manufacturers were exploring semi-monocoque, stressed-skin models which were much lighter and cheaper to operate than those with a heavier body-on-frame. Krauss-Maffei’s entry was the KML 110 – and in addition to its stressed skin body, it was unique in several other aspects…
Screen capture from the Elvis Presley movie “GI Blues”
The body was shaped with aerodynamics in mind and given rigorous wind tunnel testing. The resulting wind-cheating, enclosed body brings to mind a similar era Hudson or Nash.
The engine was also unique – a rear mounted 8.0 litre Deutz air cooled diesel V6, putting out 125 hp
The wind cheating avant-garde body may have been a little too much too soon, as the 110 was fairly quickly superseded by the KM 125, with more traditional bodywork, here in transit form.
Krauss-Maffei is still in business today, though no longer producing buses. The main company now manufactures injection molding machines, but an off-shoot, Krauss-Maffei Wegmann, produces locomotives and defense equipment to include tanks and self-propelled artillery.
The KM 125 looks a lot like a gigantic Microbus–or should it be called a “Macro”bus? But no doubt there is a resemblance in the front end to that of the bi-color VW vans (1962 model shown). It even has split front windows as well as Samba-like roof windows too! Other similarities are being rear-engined & built in Germany.
This was a look that the VW largely pioneered in 1949 and became widespread in Germany. The Krauss-Maffei V200 diesel locomotive looks like a really big VW bus, eh?
Wunderbar! I have memories of seeing so many colorful German tourist buses lined up in front of the Hofburg (palace) in Innsbruck, where they discharged their passengers to tour the Altstadt. I want to say I remember these specifically, but I might be stretching it. I loved the German expression of aerodynamics in the early 50s; they were still really caught up in it.
Krauss-Maffai also built the V200 diesel locomotive, which has similar styling and is the icon of a diesel locomotive for Germans, like an EMD E or F series would be for Americans.
In the mid 60’s two US railroads bought into Krauss-Maffei diesel-hydraulic locomotives. The Southern Pacific purchased a total of 18 units, and the Denver and Rio Grande Western purchased 3. The units were not up to the tasks required by the western railroads, and only after a couple years, all but one were scrapped.
Here’s an SP unit with original nose. Photos taken from the web.
Here’s D&RGW unit with original nose and headlight arrangement.
The Krauss-Maffei ML-4000 locomotive was tried out by Southern Pacific and Denver and Rio Grande Western, which hoped they would overcome the limitations of electric drive in the diesel-electric locomotives of the late 1950s/early 1960s. They used Voith hydraulic transmissions (think “torque converter” as an approximation) linked to Maybach diesel engines.
Due to poor engine cooling in its many tunnels, including the Moffat Tunnel (6.2 miles at 9200 feet altitude), the DRGW gave up on its “Krauts” early on, selling them to SP, which stuck with them longer and ordered more of them with a roadswitcher body having a narrow enclosure for the mechanicals and walkways on the sides, resulting in better air flow to its radiators. Ultimately even SP found them unsuitable for use in the mountains and relegated them to its flat routes in California’s Central Valley between Roseville/Sacramento and Bakersfield. When time for heavy overhaul came, SP had enough and they were retired due to excessively high costs for routine diesel engine maintenance, which may have been acceptable on Government-owned and subsidized railroads but not on privately owned ones. Electric drive had also advanced substantially by then.
One of the second-order Krauss-Maffeis was saved and used as a nonpowered camera car, with appurtanences built onto its nose to house cameras for providing moving pictures and later, video for SP’s locomotive simulator for training locomotive engineers. It was rendered surplus by modern video synthesis technology and donated to a museum in the San Francisco Bay Area. After many years of parts-scrounging, it has been restored to operation on one of its two Maybach diesel engine-Voith hydraulic transmission sets. It ran under its own power in February 2017, for the first time since it was sidelined by fatal damage to its other Maybach diesel engine in 1968.
An aside: SP and for that matter, DRGW found the Voith hydraulic transmission to perform well. It was the Maybach diesels that were troublesome and expensive to keep up. SP tried out the Voith transmission, suitably modified for large-displacement, lower-rpm diesels, in a small order of diesel-hydraulic locomotives from the American Locomotive Company. With low diesel maintenance costs, the ALCo units survived in service years longer than the Krauss-Maffeis but they were also surpassed, as electric locomotive drive advanced from direct current generation to alternator-rectifier systems…much as happened in automotive battery charging systems, in Chrysler cars in the early 1960s.
Trivia: ALCo, after exiting the locomotive business, became a subsidiary of Studebaker-Worthington for a time.
SP units after modifications to nose.
Could do with less underbite up front, but I’m still filing the whole thing under “Why can’t we have things that look like this?”.
The Maybach engine used in the KM locomotives and the V200 was a high performance unit (it had twin overhead cams, 6 valves per head, 4 oil pumps and many aluminium castings) which originally was designed to be used in torpedo boats or similar, where maintenance schedules were strictly adhered to. We had them in the Israeli missile strike crafts and generally reliability was not an issue, and I believe the same applied to the V200s – but then those were maintained by DB personnel in the country of origin who were familiar with the design. They would not thrive on neglect like EMDs and Alcos could do, and when in Israel we got Esslingen railcars (see below pic by Hanan Sadé) with that type engine and transmission they did not last long and ended – engines and transmissions having been removed – being pulled by G12 EMDs. But back then Israeli Railways was in the process of converting from steam to diesel and not really having the facilities for maintaining such complex German engineering. It is no coincidence why IR is, to this day, an EMD reserve.
As for the transmission I’ve heard it from more than one source they were not up to use in mountainous conditions given the constant slip of the torque converter which meant very high oil temperatures. I have a feeling DB only used the V200s on relatively flat routes because of that.
The Krauss-Maffei name did ring a bell, but I’d never connected them to buses and coaches. Another great Jim Brophy lesson.
Yes, another fine lesson from Mr. Brophy! I knew about the locomotive side (had a model of an SP one) but never knew about buses.