Answer by Mark for Were there engineers in airship nacelles, and why were they there?

The engine mechanics were there for two reasons:

1. The engines needed to run continuously for 120+ hours during a typical Frankfurt-to-Rio de Janero flight. For diesels of the era, this means frequent minor maintenance, and occasional major repairs (for example, during the Hindenberg's first return flight from Rio, the #4 engine had a wrist pin failure and was re-built in flight to run with only 15 cylinders).

2. The engines had to be locally controlled. It's roughly 150 meters from the Hindenberg's control car to the aft engine nacelles. Running a mechanical linkage more precise than an engine telegraph over that sort of length is basically impossible, particularly since a zeppelin will flex during the flight. Electrical controls were not an option because running wiring close to the gas cells was too much of a fire risk.