Because their speeds are too high for the propeller, all other types of machinery require a reduction gear, which however is an advantage since it permits several engines to be geared to a single propeller thereby enabling the propulsion power to be considerably increased.
Ngenxa yokuba izantya zazo zingaphezulu kakhulu kumqhubi, zonke ezinye iintlobo ntlobo zeematshini zifuna igiyeri yokunciphisa, ethi ibe luncedo ngenxa yokuba ivumela ii-injini ezininzi ukuba zilungelelaniswe nomqhubi omnye njengokuba inceda amandla okuqbubela phambili ukuba inyuswe.