Traction & Stock

摘要

The 15 Class 68 locos delivered so far to DRS are performing better than expected, particularly in respect of fuel economy, according to the company's project manager Tony Bush. The positive news come despite some expected problems surfacing during the locos' introduction into service. Mr Bush said fuel economy was a 12% improvement over a Class 66, helped by the Class 68 stop/start engine technology. Last year, the locos suffered from a spate of false track circuit and TPWS problems, resulting in overspeed or SPAD alerts. This restricted the movement of the fleet, because the error conditions were occurring on some lines, but not all. DRS worked with manufacturer Vossloh and also Unipart, which supplied the TPWS4 system fitted to the locos. Initially it was thought to be related to the TPWS aerial being mounted behind the leading axle rather than in front, but deeper investigations revealed it was related to a TI21 track circuit issue. As the track circuits got weaker, the voltage was increased, but that introduced 'noise; and it was this that was triggering the alerts. In the end, the problem was engineered out electronically.