- The pony engine heated the diesel to aid in ignition and used a small clutch and transmission to spin up the diesel engine.
- Another version was published under the name " The Pony Engine " in the " Kindergarten Review " in 1910, written by Mary C . Jacobs.
- In todays AC power system, a generator whose steam supply is retired ( like in a closed nuclear plant ) can be run up to synchronous speed with a small pony engine, then paralleled to the AC system bus.
- An AC generator needs some way to get up to near synchronous speed, such as a start winding which is disconected when it is up to speed or the aforementioned pony engine which can be mounted on the generator shaft . If full line voltage AC were connected to a stationary AC generator which was unmodified, it might draw heavy current and present a locked rotor condition and burn out.