From 1915 onwards, Maffei started manufacturing G 4/5 H class locomotives. This locomotive was the largest, most powerful and most modern German Locomotive motive with this wheel arrangement. The G 4/5 H corresponded to the Maffei construction principles. It had a slanting four-cylinder engine combined with a filigree underframe. The boiler, which operated on the basis of the relatively new superheated steam process that was developed by Schmitt, was extremely efficient. Thanks to the balanced four- cylinder engine, a maximum speed of 60 km/h could easily be attained despite the compact 1, 270 mm size of the driver wheels. The locomotive had considerable tractive power and was able to pull 1, 000 t on an 11 %o incline at 18 km/h.