The designation Gmf 4/4II stands for four multi-purpose diesel locomotives built in 2013 in Germany for the RhB. They are being used as construction trains, snow ploughs, recovery vehicles and as a reserve. To use them on the whole network, they were required to work on lines with curve radii of 45 metres and seven percent inclines and had to have a maximum axle loading of 16 tonnes. To prevent interruptions of other trains, the top speed had to be 100 km/h.
Since the low production quantity dictated the use of standard components, the traction motors were delivered from Siemens and the diesel engine came from MTU. The body of the locomotives was built by FTD Dessau and the final assembly took place at Schalker Eisenhütte with bogies from PROSE of Switzerland. Since the Gmf 4/4II is not intended for use with scheduled trains, it carries a yellow livery.