Measurement of offset distance of overhead conductor of railway system

摘要

An apparatus for establishing the offset distance of the electrical overhead conductor of a railway system w.r.t. the permanent way employs a calibrated measuring staff (1) which is positioned across the rails (4) located by a fixed stop in contact with the inner surface of one of the rails (4). The staff (1) carries a sliding head (2) from which a laser diode projects a reference beam (22) vertically upwards and when accurately centred on the conductor a reflection is clearly visible to an observer below. At this point the distance (S) between the centreline of the rails (M) and the conductor can be read from the scale on the staff (1).