Proficiency of early steam engines?

[Snoop]

I have a textbook that says the best at least are around 88% proficient, but it only mentions modern steam engines. What I'm wondering though is the proficiency of the early steam engines of the late 1700s/early 1800s, like those used for the first trains.

[The original Peter G]

Steam turbine systems used in modern power generation can indeed reach high efficiencies, I doubt 88% though. The early railroad engines had very low efficiencies, probably around 5% of the energy in the fuel got transferred to the track, mainly because all the energy used to heat the water to boiling point and turn it to steam was sent up the smokestack as steam, only the pressure energy being used in the pistons. That's one of the reasons diesel and electric took over, another reason being the convenience of switch on and go.