Abstract: A structural support that can be used as a truss girder bridge crane, or the like. The support includes one or more rows 13 of segments 15, that are arranged in side by side relation along the length of the support. Each row 13 has extending there through at least one tensioning element 14 which is anchored at opposite ends of the row and is pretensioned with respect to the row in order to hold the segments of the row together. A support preferably includes one row 13 of segments 15 in a lower chord 11 of the support and another row 13 of segments in an upper chord of the support. Vertical framework is mounted between the chords with ends secured adjacent the segments 15 by the tensioning element. The individual segments and the tensioning elements may be directed to a construction site at the location of use and assembled into rows and the appropriate structural construction.

Abstract: A hoisting device or crane can be operated with at least two different maximum loads. The maximum load that can be hoisted in each case is correlated with the hoisting speed in order to prevent the dynamically developed peak load from exceeding the predetermined allowed load limiting values of the components of the crane or the hoisting device.

Abstract: A joint connector for the lower flanges of adjoining running rails is assembled from two abutment pieces that each is seated in a lower flange of a respective rail that forms the joint. By use of centering devices, the correctly aligned positioning of the two abutment pieces is assured, wherein the abutment pieces transfer their aligned positioning to the lower flanges that meet each other without offset at the joint and the positioning cannot be negatively affected by transverse forces. The connection also provides a positive-fit in a transverse direction of the rails. Another joint connector arrangement connects the two running rails in the region of the top side. Abutment pieces in this case are seated as riders on a support rib and are connected to each other by tension rods.

Abstract: A guide-roller arrangement for gantry cranes(1) has two rotatably mounted axial carriers (21) on which the guide rollers are seated. The guide rollers (11, 12) are mounted on journals which are arranged in the carrier plate (15) in a manner eccentric to the axis of rotation (41) of the axial carrier (21). The selected eccentric position of the journal can be fixed in a formfitting manner with the aid of toothing formations (29, 36) on the axial carrier and on the carrier plate.