quote:The faster the pistons go back and forth the more steam you need and the faster you have to get the steam in and out of the cylinders.
To be a little more clear on this subject, "more steam" is NOT necessarily the answer. Of course "the faster you have to get the steam in and out og the cylinders" is definately the key in maintaining/increasing horsepower for acceleration.
Thus enters the Engineer's PROPER use of the power reverse! At full throttle, the key is to maintain the absolute HIGHEST STEAM TEMPERATURE at the valves, as produced by the superheaters. Shortening the valve cut off, reduces steam flow/volume through the superheaters, so that the steam gains high heat instead of simply "rushing through the superheater units".
The "volume of steam", or "steam pressure" is actually NOT what propels a steam engine. The energy is from the HEAT of the steam, which expands in the cylinders. The higher the boiler pressure, the higher the heat of the steam. When the steam passes through the superheater units, the steam is heated even more, i.e. SUPER HEATED, to temps exceeding 700 degrees F.
If the Engineer does NOT have the valve cutoff set correctly, the steam temp will actually DROP, reducing HP and increase fuel and water consumption.
