Cranes with operating pressure of water are usually fixed, the driving movement plays when it is provided, only a subordinate role (port cranes) and will not be made ​​hydraulically. Accordingly, eligible for pressurized water operation
only be considered: raising and lowering, swiveling, and change the radius. for
all three movements is the way of the water the same: by
special control devices regulated acts: it is on single-or double-acting piston, whose motion is utilized directly or indirectly through the intermediary of rope or chain hoists for the intended movement of the load: for Panning and cross travel are very often provided no pressure cylinder, the movement of the load by pulling on the hook in the desired Direction. For loading and unloading purposes (port cranes), the projection is almost always immutable (see illustration).