Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

@Stoker @Nick
I believe that we nailed it, and Nick confirmed by mentioning that the early case had a much lower hp is due to the boiler pressure limitations in the early days compared to the 100s of psi steam pressure when boilers manufacturing improved.
Ps. Break Horse Power Bhp is the same as hp. A 1 hp is 0.76 kW compared to electric motor.