Until we are waiting for Epic to let us play with all our content, I am practicing with some steam stuff. Well, unbraked loaded coal wagons uphill are slow. Very slow. I wonder if this is normal I should I do something differently? I have a print screen picture where you can see actually all my settings.
You need to reduce the cut-off to about 25% to keep pressure high and therefore give more power though don't expect too much more speed on a 1:100 ( I think that's what 1% converts to) climb. If you are unsure how to do anything go and do the steam driving tutorial as it is surprisingly useful.
Also make sure you have enough momentum to make it up the hill. With heavy freight trains I find I never needed to go more than 40% cutoff in TSW2, maybe that is the same in TSW3. Granted I haven't played SoS in a while - should really get back into it!