Invention and Engineering
A high-pressure steam locomotive is a steam locomotive with a boiler that operates at pressures well above what would be considered normal for other locomotives. Most locomotives operate with a steam pressure of 200 to 300 psi (1.38 to 2.07 MPa). In the later years of steam, boiler pressures were typically 200 to 250 psi (1.38 to 1.72 MPa). High-pressure locomotives can be considered to start at 350 psi (2.41 MPa), when special construction techniques become necessary, but some had boilers that operated at over 1,500 psi (10.34 MPa).
Charles Fenerty.
Canadian National 1551.
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