GB1342840A - Railway headspan erection - Google Patents

Abstract

1342840 Cable erecting PIRELLI GENERAL CABLE WORKS Ltd 24 July 1972 [7 Sept 1971] 41639/71 Heading H2C An apparatus for erecting headspans 12 which carry (overhead) conductors 26 on an electric railway and which are in turn supported by masts 14a and 14b, comprises a wagon 10 with supporting and lifting means 42 carrying a slewable jib 40, which is transported parallel to the tracks, and when wagon 10 is in position, is raised above standard average height and slewed to a transverse position across the tracks, so that the headspan, which is carried prefabricated on the jib may be deployed and attached on to the masts 14a and 14b. The headspan 12 consists of cross-wire 20 supported by masts 14 at its ends and by catenary 18 by means of droppers 22; registration and support equipment comprises further droppers 24 supporting trolley contact wires 26 which are stabilized by lower, cross-wire 28, and insulated by insulators 30, in the rod-type droppers 24, and insulators 32 in cross-wire 28, and tensioning devices 34. The headspan is prefabricated, and packed in a reusable canvas cover secured by, e.g. "Velcro" (Registered Trade Mark), having been neatly bundled such that all the horizontal wires are parallel and the cross-pieces carefully bundled to avoid snagging. Headspan 12 is loaded on to trough 72 of jib 40 while the latter is lowered and in its position parallel to the tracks. Jib 40 is then raised above standard gauge height by lifting means 42, extra support having been imparted to vehicle 10 by lowered hydraulic legs 44a, 44b. Lifting means 42 is hydraulically operated by cylinders 66 which, firstly, raise upper part 56 to its maximum height, jib 40 remaining leveldue to action of follower arms 68, 60 and radius plate 64. The jib 40 may then be slewed across the tracks 16 by the two man crew on the jib by means of slewing apparatus 59. For safety purposes jib 40, which is of box construction and may also comprise a removably mounted extension 40b, is provided with a safety fence 74, consisting of stanchions 78a, 78b, 78c with cable 76a, 76b attached thereto and at the tower end attached to support strut 80 and may have provision for having a waist safety harness attached thereto. The different attachment points at different levels require the jib to be altered in height during assembly of the headspan 12, which results in jib following arc A (Fig. 2). At positions of the arc, e.g. P, where the jib is some distance from the plane of the headspan, platform 82 is mounted on the jib to allow the assembly crew access to the masts. Interlock devices are provided so that the jib may only slew above standard gauge height, and on an hydraulic failure, could not descend below that height.