Stagecoach Metrolink Fit Trams With New Speed Probes

A successful trial of speed probes from rail systems specialist Rowe Hankins on two Stagecoach Metrolink Limited (SML) 17 year old tram vehicles has concluded. After 50,000 Km operation and a zero failure rate, SML is now to adopt the new system on its fleet of 26 original T68 trams.

Bury, UK (PRWeb UK) May 30, 2009 -- A successful trial of speed probes from rail systems specialist Rowe Hankins on two Stagecoach Metrolink Limited (SML) 17 year old tram vehicles has concluded. After 50,000 Km operation and a zero failure rate, SML is now to adopt the new system on its fleet of 26 original T68 trams.

SML operate a high frequency tram service on the routes from Bury to Altrincham through Manchester centre, with a spur running from the city to Salford Quays. High and rising passenger numbers mean that the fleet is intensively used and unscheduled downtime can disrupt services severely.

Against this background SML were experiencing problems with the original speed sensing equipment. This manifested itself as an irregular speed signal and loss of slide protection on the affected axle. This was tolerable with a single sensor failure, but if two or more sensors failed then the trams had to be taken out of service. This was required 13 times in the twelve months ending in March 2008.

Rowe Hankins were approached in July 2008 to provide better speed sensing equipment. By December 2008 the company had concluded their engineering study and the first tram-set with the new speed probes went into service on Christmas Eve 2008. A second unit was fitted with the new speed probes early in 2009. Both trams were then subject to intensive usage to prove the system.

The original equipment installed on the Metrolink used variable reluctance passive probes with magnetic coils providing a voltage directly proportional to speed. This provided the analogue signal output for the driver speedometer. The Rowe Hankins speed probes replacing these are active Hall-effect sensors providing a speed-proportional digital signal. To interface with the driver's instruments, the original signal processors have been retained but modified and upgraded to accept the new speed signal input.

Previously, two types of sensors were in use. Rowe Hankins replaced these with a standardised sensor, customising the housing to fit the different installation requirements. For future maintenance purposes SML will now only need to hold the one model of sensor in stock.

To avoid unnecessary fleet disruption, fitting of the new probes was scheduled to coincide with planned outages for routine servicing. Rowe Hankins engineers worked closely with SML depot staff to coordinate the production and fitting of the new parts.

Since the fitting of the new speed sensors, tram drivers have reported positively on vehicle performance. Speedometer readings are now smooth and progressive and drivers even report that vehicles seem more responsive to the controls. Clive Pennington, head of engineering at Stagecoach Metrolink commented, "Rowe Hankins were very positive and proactive in working with SML to produce a cost effective answer to the problem. The Rowe Hankins speed probes are more reliable, give a better quality output and are easier and quicker to install than the original equipment."

More Information

Tim Allard, Tel. +44 (0)161 765 3000 Fax. +44 (0)161 763 1421

E-mail: sales@rowehankins.com Web: www.rowehankins.com

Rowe Hankins Ltd, Power House, Parker Street, Bury, Lancashire, BL9 0RJ, UK

High/low resolution images are on the web at www.ainsmag.co.uk/rh109/4668rh1a_speed_probes.htm

###