Ordinarily you would increase cutoff to 45 or 50% and give it the beans with 80% or more regulator. Unfortunately with the current state of steam physics in TSW that is likely to kill your steam pressure in less than a minute. You can try engaging manual firing in options which allows you to open both dampers, but that only buys a little bit extra.
It all depends the the steepness and length of the hill, weight of the train, boiler pressure and steam production. If steam production can not keep up with steam usage and keeping boiler pressure with in acceptable levels, then slowing down will be required and if the engine doesn’t have enough power, then a stall will occur and the crew may have to double or triple the hill.( split the train in half / thirds and take each section to the summit and re assemble.
Trainsimulatordriver has several tutorials for driving steam locomotives. He recently uploaded a driving in adverse weather video
That will work okay for the short trains on WCL but not too well for the longer trains that that engine should be able to pull and is expected to in Spirit of Steam. It’s using all the steam up and it isn’t being replaced effectively.
