2011 – March – Clendon and Skilton – Axle Counters – The New Zealand Experience

James Clendon BE Hons. (Electrical and Electronic) CPEng, MIPENZ KiwiRail John Skilton BE Hons. (Electrical and Electronic) CPEng, MIPENZ, MIRSE KiwiRail In New Zealand axle counters are now the preferred method of train detection on electrified lines. This paper examines the historical use of axle counters on the New Zealand railway network and looks at some of the reasons why this decision has been made. Axle counters offer a number of advantages over track circuits including the ability to operate over large distances and under environmental conditions that are not suitable for track circuits. This paper also looks at some of the disadvantages of track circuits and the operational and technical mitigations that overcome these disadvantages. Additionally this paper investigates some of the interfaces required to ensure that axle counters are able to provide an operationally robust method of train detection. These interfaces include those with vehicles operating on the railway and those with interlocking equipment and control systems.