The aim of the “trolling valve” (Masson-Marine term “DML”) is to let the clutch slip in a controlled fashion to reduce the rotational speed of the propeller.
To satisfy this requirement, the solution consists in letting the main engine (the prime energy source) run as closely as possible to its nominal speed, and to reduce the speed of the output shaft.
To do so, Masson-Marine transmissions can be fitted with a “trolling valve”, which is in fact a device to make the clutch slip.
In order to define the operating range of the “trolling valve”, while ensuring that the client will not “burn” his propulsion clutch, Masson-Marine compute every case individually.
The calculation is made from the following data:
Based on these different parameters, Masson-Marine determine the operating range of the “trolling valve”.