Abstract: A rope pulling machine is convertible into a walking machine, and has a machine frame composed of a pulling station movable back and forth and a gripping station connected to the pulling station via a main cylinder/piston arrangement, the pulling and gripping stations each having an auxiliary cylinder/piston arrangement for a gripper, and the two grippers are linked via bearing shafts to the auxiliary cylinder/piston arrangement. The grippers have clamping jaws aligned in a rope direction and linked via bearing shafts to the pulling and gripping stations, respectively. The bearing shafts are designed as detachable shafts, making the grippers exchangeable with walkers having the same bearing points and bearing shafts and which form a walk station and a slave station. The walkers have pawls engaging a rack alternately, and running gears guided on the rack.

Abstract: A suspension bridge has a pair of horizontally spaced towers between which is spanned a main catenary cable. A flexible spacer element, normally a cable, extends along the main cable between the towers and is provided with generally equispaced spacers. Respective hanger assemblies are fixed at the spacers and can slide on the main cable between the towers. Respective upright hangers defining a vertical plane with the main cable have upper ends connected to the hanger assemblies and lower ends and are provided with adjusters between these ends for shortening and lengthening the distance therebetween. Respective girders are secured to the lower ends and extend generally perpendicular to the plane and respective path sections extend generally horizontally and each have one end hooked over a respective one of the girders and another end hooked over an adjacent girder.

Abstract: An apparatus for hauling in and letting out a flexible element such as a cable comprises a generally stationary housing defining a cable path and having a predetermined number N equal to at least three of grippers spaced in a row and shiftable along the path. These grippers can be clamped on the element in the path by respective actuators which can displace the grippers parallel to the path in a pulling direction and in an opposite letting-out direction. A controller responsive to gripper position and connected to the actuators operates them sequentially. Thus all but one of the grippers is first clamped on the element and the one gripper is unclamped from the element. Then the clamping grippers are displaced by the respective actuators with the element in one direction at a rate V.sub.w through a distance S/(N-1) while simultaneously the nonclamping gripper is displaced oppositely through a distance S along the element at a rate V.sub.r equal substantially to 2.multidot.V.sub.