This really nice and unusual 3-rail AC HO gauge railcar by Marklin is 3121 a Micheline Type 11 railcar in green livery. 

A Michelin is a light railcar , whose wheels are equipped with special tires , developed by the Michelin company in the 1930s .By extension, other railcars were then colloquially referred to — wrongly — by the word “Micheline”.

In the 1930s , André Michelin aimed to improve the comfort of passenger trains. To do this he developed a special hollow tire, capable of rolling on the reduced rolling surface offered by the head of a rail, of crossing points and also capable of withstanding the load of railway vehicles.

With the pneurail, the tire provides traction and braking functions and a metal flange attached to the rim allows the wheel to be guided on the rail. Compared to steel- tyred wheels , the pneurail offered increased grip and comfort but at the cost of limited axle load. To overcome this restriction, it was necessary to increase the number of wheels and build lighter vehicles , using techniques from aviation such as the use of riveted duralium for their bodies.

In 1932 , the “24-seater Michelin” was put into service, called the type 11, eleven examples were manufactured. Very similar to a road vehicle, it was composed of a three-axle tractor (central drive axle) and a semi-trailer equipped with a two-axle bogie at the rear. The trailer body was aluminum framed , covered in plywood . As they only had a driving position at the front, it was necessary to turn them round at the end of the journey. The first were put into service by the Eastern Railway Company on March 21, 1932 on the Charleville – Givet line . These railcars were withdrawn from circulation in 1939 .

The railcar is in good condition as you can see in the pictures, We are unable to test it as we do not have a three rail AC test rig or track, so we have not tested it but can see no reason why it would not run. It is sold in untested condition, this means that it may not run, and as such it is not being sold in running condition. However a complete external visual inspection has shown no reason why this loco would not run and the overall condition is very good. The box is in good if slightly shelf worn condition. 

Overall this is a really nice scale railcar and would look fantastic on a layout.

Do please have a look at my other listings, I typically have various HO and OO locos on offer as well as an extensive range of imported N gauge locos and other items. 

Note: I do recommend all locos are cleaned & serviced, as they have some age to them even if the quality looks at the highest level (fairly standard advice for all locos!).