Class 175 Door Control Unit Overhaul

Over recent years the Class 175 rolling stock based at Chester Traincare depot had been experiencing an increase in failures of the Door Control Units (DCU’s).

On behalf of its customer TP Matrix performed a detailed Condition Assessment on a small batch of DCU’s to determine those components deemed to be at risk of failure or past their operational life expectancy.

The objective of the project was to significantly improve the fleet Reliability, reduce Repair Lead Times and reduce Operational Costs.

With limited technical information available, TP Matrix engineers used Reverse Engineering techniques to produce a detailed Technical Specification to fully understand the functionality of the product. Following this process, software was written to enable full testing of the DCUs on Automatic Test Equipment (ATE).

In total, 135 like for like (or better) components were replaced on each DCU at a rate of 4 units per week.
All work was carried out to IPC7711 & IPC610 standards.

Rail Project - Virgin Trains

212 DCU’s have been overhauled resulting in a 90% reduction in failures compared to figures prior to the overhaul.

Rail Project - Virgin Trains
Rail Project - Virgin Trains
Internal images of a DCU – all components were assessed for condition, signs of ageing and end of operational life expectancy.