A gantry crane shown in figure above acts an auxiliary to bridge cranes. It is provided with wheels and can be moved from open place to another as per requirements.
These devices are used for transporting the materials in horizontal direction these are:
Industrial Railways: Industrial railways are nor row gauge rail road's in general little use is made of such equipment because it requires a heavy investment in the road bed and tracks. It possesses little flexibility and is difficult to change after some period If required. Industrial railways were used in the days before the development of rubber tyre equipment. They are still found in metal working industries ( blast furnaces copper refineries and steel rolling operation) and in mining activities where it is cheaper or more desirable to lay tracks than to pave the entire area.