Abstract: A materials transporting machine, of particular application in mining, has a boom assembly mounted on a vehicle or carriage, which boom assembly includes a telescoping boom which is maneuvering both horizontally and vertically and which can be withdrawn to a stowed position within the vehicle by utilizing pressure fluid operated means which serve for effecting telescoping movement of the boom.

Abstract: A mine roof support of the type having a canopy supported from a base structure by hydraulically extensible legs and a cantilever roof-engaging member pivotally attached to the forward end of the canopy, is provided with a selectively positionable laterally extending cantilever member by means of which the effective roof-engaging surface of the canopy can be extended, the lateral cantilever member being optionally provided with a forwardly projecting cantilever member by means of which the effective width of the roof-engaging member can also be extended.