In the process of resistance furnace heat transfer, the effect is often not ideal, so how to improve the heat transfer effect is a problem to be discussed.

The mechanical part includes locomotor pole plate set, static pole plate set, the lifting set, which changes the water resistance and transfer locomotive's electric current.

Wound-rotor induction motors that adjust speed by connecting resistors in series to rotor circuit have been easily found in the electrically controlled systems of shaft hoist.