Increasing train loads at the beginning of the 20th century necessitated more powerful units even in Bavaria. In the early part of 1907, Maffei was therefore given the contract to build a Pacific compound locomotive for the Bavarian State Railroad. The first unit left the builder as early as in July of 1908. Another six locomotives followed it in the same year (road numbers 3601-3607). By 1911, Maffei delivered another 16 mostly identical units in three builder series (a to c) (road numbers 3608-3623). Departing from these first 23 locomotives, the next 18 units (Series d and e, Maffei 1912/1913, road numbers 3624-3641) were equipped with driving wheels with 2,000 mm / 78-3/4" diameter instead of 1,870 mm / 73-5/8". This also caused the boiler to sit higher on these units and they were quickly known as the "High Steppers". The locomotives were initially based in Munich at the main station and they ran from there mainly in express trains in all directions, such as the line Munich – Ulm – Stuttgart.

Prototype: Train set consisting of a class S 3/6 express steam locomotive, the "High Stepper", three type CCü express train passenger cars, 3rd class, one type ABBü express train passenger car, 1st/2nd class, and one type PPü express train baggage. Train route Stuttgart - Ulm - Augsburg - Munich. Royal Bavarian State Railroad (K.Bay.Sts.B.). Locomotive road number 3629. The locomotive looks as it did around 1912. Passenger cars in a fictitious paint scheme of bottle green / ivory.