Booster Engine - Reasons For Booster Use

Reasons For Booster Use

The booster is intended to address fundamental flaws of the standard steam locomotive. First, most steam locomotives do not provide power to all wheels. The amount of force that can be applied to the rail depends on the weight on driven wheels and the factor of adhesion of the wheels against the track. Unpowered wheels effectively 'waste' weight which could be used for traction. Unpowered wheels are generally needed to provide stability at speed, but at low speed this is not necessary.

Second, the "gearing" of a steam locomotive is constant, since the pistons are linked directly to the wheels via rods and cranks. Since this is fixed, a compromise must be struck between ability to haul at low speed and the ability to run fast without inducing excessive piston speeds (which would cause failure) or the exhaustion of steam. This compromise means that the steam locomotive at low speeds is not able to use all the power the boiler is capable of producing; it simply cannot use steam that quickly, and there is a big gap between the amount of steam the boiler could produce and the amount that can be used. The booster enables that wasted potential to be put to use.