The many branch lines with few gradients and low passenger numbers in the MÁV network offered themselves early on for the use of railcars. Ganz of Budapest secured the license for the De Dion-Bouton steam railcars and produced 30 or 89 examples for the MÁV, depending on the source. Ten railcars of the types with 35 and 50 hp were found under the generic designations BCMot VIIa to VIId, others were built with 80 hp. 

What was special about the De Dion-Bouton design was the steam engine, which was attached to the axle like a nose-suspended motor and was also sprung. The four cylinders with compound action were arranged horizontally and could run at a high speed of 600 to 800 revolutions per minute thanks to a gearbox. The steam came from a small, vertically arranged water-tube boiler, which operated at a relatively high pressure of 18 bars.

De Dion-Bouton type steam engine

collection György Villányi

In addition to the different power output, the individual variants of type VII were characterized above all by a different layout of the interior. The greatest advantage of the special boilers was that they could be warmed up in an hour and could therefore simply be switched off overnight. It turned out, however, that the railcars had a high consumption and maintenance was relatively expensive. They were all phased out by the start of the First World War and replaced by railcars with combustion engines after the end of the war.

As a development of the railcars of the ABbmot series, Ganz developed the Bbmot. This was also intended for express trains and now only had second class. The basic construction was still the same, based on the Hargita trains. Thus the railcar had a three-axle bogie at one end, the first axle of which was a carrying axle. The engine power had been increased compared to the predecessor from 450 to 500 hp. The vehicles were in use at MÁV until 1988.