During the past fifty years, the broad trend in all transfer equipment has been to change from steel wheels running on steel rails or on metalled roadways to rubber tyred wheels running on roadways of almost any kind. For example, earth-moving and quarrying equipment of all types is now in the main rubber shod whilst in factory equipment such as fork lift trucks and straddle cars etc., rubber tyres have virtually ousted steel wheeled bogies. Indeed, heavy rubber tyred transfer cars for liquid metal are mooted for steelworks. The main reasons for this change-over are increased speed and manoeuvrability in operation and overall economy.
E.M. Lewis