Abstract: A platform type service vehicle or truck having an elevatable platform hydraulically rotatable through 360.degree., self locking as to rotation when not under power, with a single mast of telescoping sections comprising opposing channel-like members linked by crossmembers closely adjacent each end of each section. The sections are nested with a stationary section being outermost of the nest and the most elevatable innermost. The mast is mounted upon the frame members of the chassis of a truck and is tranportable over public highways with the platform in a lowered position to a point of use, whereupon the platform is elevated to a desired height for use.