In order to reduce wear and tear on the tyres and brake shoes during descents, the engines were fitted with Riggenbach counterpressure brakes.
Albert Riggenbach was a 19th-century meteorologist and co-author of one of the first cloud atlases, the International Cloud Atlas.
Its area of operations was predominantly the routes in Germany's central mountains (Mittelgebirge); as a result the first 10 units were given a Riggenbach counter-pressure brake.
They were employed on the 1-in-10 Honau-Lichtenstein rack railway, 2.2 km long, which employed a Riggenbach-Klose rack system.