Fasolt

Friction-drive locomotives are extremely rare, probably because having one frictional interface of doubtful dependability, between wheel and rail, is quite enough uncertainty for most people.
It was built in 1876 by Vulcan of Stettin, for the Elsass Lothringen railway, which was in Germany at the time. (Elsass and Lothringen are better known these days as Alsace and Lorraine, now that they are back in France)
The aim here was the same as that of geared locomotives- to make a slow locomotive relatively powerful by operating the cylinders at a faster speed (giving more power for the same boiler pressure) than the driving wheels, there being a practical limit to how small the driving wheels could be made.
To this end the cylinders drove three coupled crankshafts placed above the driving wheels; these crankshafts carried small friction rollers that contacted the top of the driving wheel tyres. A system of springs pressed the friction rollers onto the wheels, and were adjustable so the vertical force could actually be greater than the adhesion weight on the track. The friction rollers could be lifted clear of the wheels if it became necessary to tow the locomotive.
The reduction ratio is unknown, but working from the picture above, and estimating the size of the friction rollers, it appears to be about 1:3. The design speed was only 10 km/hr.
Information is scanty but it appears that the friction mechanism gave trouble, though whether by slipping or in some more subtle way is not clear. The locomotive was later rebuilt to a more conventional form by removing all but the central upper crankshaft and coupling it with rods to the wheel beneath. This in turn was coupled to the other wheels by conventional coupling rods. In 1906 the locomotive was still in existence, as No 2044, but after that its fate is unknown.
Category:Friction-Drive Locomotives
Category:Experimental locomotives
Category:Built in 1876
Category:German locomotives
Category:Steam locomotives
Category:Tank locomotives
Category:Germany
Category:Locomotives
Category:0-6-0 locomotives
Category:0-6-0 steam locomotives
Category:0-6-0T steam locomotives
Category:0-6-0T locomotives