view of a self-propelled concrete pump with a five-arm jointed mast in a collapsed state; FIGS. 2a and b are a side view and a top view of a self-propelled concrete pump with an extended jointed mast; FIG. 3 shows a section of the jointed mast according to FIG. 2a with a mechanically operated remote-control device arranged at the top of the mast; FIG. 4 shows a section corresponding to FIG. 3 with