Crossectional drawing of an automotive component used in heavy goods vehicles to operate the parking brake which finds an alternative railway use as a driver's brake valve.

Crossection of a drivers brake valve

Brake System Safety Assessment

The Leighton Buzzard Narrow Gauge Railway were converting their single line 'Westinghouse' air brake system to a twin pipe system using automotive components. Although the proposed arrangement copied existing systems at a technical schematic level it used equipment not necessarily proven for this application. Additionally, as the local operational requirements differed slightly from other railways it was unwise to assume that all the relevant safety issues had been covered. With safety critical systems it is necessary to undertake a rigorous and well documented review of the system and operational issues to ensure all of the potential failure modes have been identified and take appropriate measures to correct matters where necessary. We ran a FMEA (Failure Mode Effect Analysis) Workshop for the railway and identified one technical change for the emergency braking system which was implemented and a number of operating procedural changes which were required. This approach not only ensured that the railway was duly diligent but provided the necessary documentary evidence for HMRI.