Don fuelconserving.
You are entering into a very complex area in the operation of the submarine diesels, introducing many unknown elements as the submarines variation in water resistance related to the speed, propeller efficency in relation to revs., dieselengine variation of specific fuelconsumption related to the bmep ( brake mean effective pressures) etc. We did not have access to all these figures so we did not have any instructions as to the variation in the operation modes.
The specific fuelconsumption is usually measured at the testbed using a waterbrake, following the theoretical propellerlaw, the result is not always matching the real thing onboard, certainly not on a submarine having so many variables. In your proposal you introduce a load which increases the BMEP outside the propellerlaw graph (waterbrake). I have no figures, but should imagine your theoretical suggestion could be viable, but you have to watch your engine (exhaust temperatures) carefully not to overload the engine (excessive BMEP). I don`t think you should include this topics in the Skizzenbuch, its a topic for the real theoretical experts.
Tore