for example: erection, technical data...
Well now Slartybardfast may be tried lol but he is correct give him the points lol.
A bridge crane is one that looks like a bridge (sorry I am tired). It sits on two railway tracks. One at either side of say a building. The tracks are at a fair height. The crane bridge spans between the tracks. Long travel is when the crane moves along the tracks. Cross travel is when the 'crab' moves sideways along the bridge. The crab has the hoist on it with a drum and cable type arrangenment. The lifting gear or hook is attached to the cable. They are very useful in factories for transporting large parts from one process to another. They transport pretty well anywhere in a well designed building in that Long Travel can be X cross travel can be Y and hoist up and down can be Z.
