extending around three of the four sides of each rectangular platform 22a 22b the guarding 26 is open along one edge 23 of each platform for ease of loading of the respective platforms in the embodiment shown the ladder and hoist assemblies are moveable laterally by means of manual propulsion however the lateral motion of the assemblies could be motorised if desired suitable control means such as switch gear and a power supply could be incorporated there may be provided more than the two hoist and ladder assemblies shown in the drawings especially if the framework 11 is constructed having a long length for example many warehouse shelf units are more than 15 meters long it would be impractical in some cases to attempt to provide rapid acces of a hoist and ladder assemblies to all parts of the frontage of such a shelf unit if only two hoist and ladder assemblies are provided in embodiments in which ladders and hoists are laterally moveable independently of one another a disparate number of ladders and hoists may be provided if desired in use of the apparatus an operator would initially position one of the hoist platforms at an appropriate position for loading or unloading by sliding one or other of the ladder and hoist assemblies laterally and actuating the drive means for the hoist in question until the platform is at a desired lateral and vertical position the position of the platform could if necessary be locked by means of an interlock effective on the drive means the operator would then climb the.