🚂 Early Steam Locomotive Boiler: Fire Tubes, Steam Pressure and Tractive Effort (2D cutaway)

Side cutaway of an early steam locomotive boiler. Set the coal burnt, the number and size of the fire tubes, the safety valve, the cylinder size and the cut-off, and watch the water heat up, the pressure rise or fall against the steam the cylinders draw, and the tractive effort that results. The 3D cutaway has gauge pressure, speed and wheel sliders; this page gives them real units, with four in-page numerical checks.