Has any one modeled a tire driven loco? These had rubber tires instead of steel wheels.
Look up the history of âMichelinesâ, first in France and then in the United States in the early Thirties. The first application of Budd stainless Shotwelded construction was for the passenger car on the Silver Slipper â covered in Trains Magazine in the same issue that covered the Snuff Dipper and the Yellow Dog Blues.
The underlying patented idea was a bit similar to the principle that let you drive a mid-Seventies Chevy Nova as an impromptu âhi-rail vehicleâ. The vehicle weight would bow the tread concave between the tire sidewalls, giving both centering and self-steering moment. Michelin provided multiple axles in a bogie (up to 5) to provide low individual ground force and redundancy against flats; the tread and shoulders were specially thickened.
The problem in America was one of the things the rubber tires were supposed to mitigate: low rail joints. Not only would the comparatively light cars gallop and twitch, the repeated bangs would cause increased chance of flats⌠which could often not be changed on the road without help. I suspect also that the bouncing and lurching repeatedly brought the âemergencyâ flanges (which projected well beyond the tire shoulder diameter repeatedly and perhaps noisily against the railhead and then rebounding, with harsh lateral jerk that the suspension was probably unable to mitigate.
Self-guiding frogs were a terrible no-no. If there was contamination, moisture, or ice on the rails, the coefficient of braking friction went in the toilet. While the idea survived a while in France, it was not particularly adopted; the system used on the Oaris Metro is completely different in principle and detail design.
I think anybody modeling one of these would just use ordinary metal or plastic wheels with scale âtireâ detail, or perhaps just the dodge of ordinary wheel sets under the skirting. There might be some value for dead rail in having the equivalent of âtraction tiresâ on every wheel, but I donât see particular value in âtrying to build the principle to scaleâ.
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Great photo of the Michelin Rail Bus during a stop in âRubber Cityâ Akron, Ohio. Note the tires are made by Good Year!
The Michelin railcar in Akron, Ohio in 1932 by Historical Railway Images, on Flickr
Also note the wire brushes in an effort to insure signal detection continuity.
Cheers, Ed
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Note also the âemergency flangeâ of greater diameter behind the rubber tire.
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That first was the infamous Silver Slipper â the âpower carâ has conventional steel wheels, with waaaaay too much of the weight on the lead truck; only the trailer passenger car has the âMichelineâ bogies.
Those other two are a couple of the demonstrator cars from the very early Thirties. For some reason I remember Octoraro in connection with that set. They did not keep their rubber tires very long. These cars got leased to the Washington and Old Dominion during WWII (when they had to maintain âessential serviceâ after de-electrifying) but didnât last long in the postwar era.
The first experimental car was (someone check this) an almost comically short Art Decoish thing â might have had only 4 wheels. There is actually film of one of the early running, I think on a Reading branch. This would not be the La Fayette that was sent to France (likely as a demonstrator for the expensive but long-lasting Shotwelded construction) â there is actually a detail photo of that car on Flickr:
Note the American flag and the adorable little air horn. Youâd never guess it was only about 30 feet longâŚ
Clessie Cummins noted in his autobiography that there was a higher-up at PRR who was enthusiastic about the use of internal-combustion power for trains, not only for âeconomicalâ gas cars but for improved service. Cummins said when that official died in 1927, interest in the use of larger power waned abruptly. Again, someone should work through and check the objective PRR history to see who that might have been, and who was involved with the Budd Company in those rubber-tired cars.
It occurs to me that these developments may have had something to do with the evolution of the welded one-piece âBuddâ truck wheels.
Note the early, fairly crude construction, not particularly âstreamlinedâ esthetically. It wouldnât take long for that to be remediedâŚ
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A LMS (British) version:
Note the wheel arrangement: four on the âtractorâ which is towing a trailer with one axle at each end â see the full-width diaphragm?
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For you Faceplanters⌠or for someone who can find the original and post a better link â here is another version of rubber-tired operation over railroads:
Hereâs a story about the Washington-DC-area version:
Note that the Washington and Old Dominion tried four of these in the years before they acquired the PRR ex-Micheline train mentioned in previous posts.
Promotional brochure from the Hagley:
https://digital.hagley.org/islandora/object/islandora%3A2610203/datastream/OBJ/download
Unrecognized by the Wikipedians, Evans somewhat accidentally solved the problem with bouncing derailments: the âhi-railâ wheels were suspended by a long,arched leaf spring with center perch, as on contemporary Fords, and this gave sufficient compliance to hold the flanged wheels on the track even if substantial bounce was communicated through the vehicle tires and suspension to carbody motion.
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