Smart Component Technologies: Smart Washer Augmentation

A switch moves trains between tracks; components include switch rails, stretcher bars (SBs)
& a switch motor. SBs keep the rails a set distance apart & ensure both rails move together.
Switch integrity is vital; on the UK’s busiest lines >100 trains will pass over a switch each
day (Ref A). Switch failure is the 3rd biggest cause of UK derailments (Ref B). Missing/faulty
bolts were the cause of both Potters Bar & Grayrigg incidents.
In conjunction with Network Rail, Smart Component Technologies Ltd developed a “Smart
Washer” (SW) to measure the clamp-force of switch fasteners during real-time installation &
routine maintenance. Trials at London Underground confirm the SW’s ability to detect
loose/missing bolts by reporting changes in clamp-force. The SW is also capable of providing
remote periodic data & alerts should the clamp-force deteriorate. It also safeguards against
human error during manual inspection.
During London Underground trials it was requested that capacity to measure the dynamics of
moving components by the SW was added. Thus, SCT propose a £166,054 Proof of Concept
project to evaluate the potential to extend the use of a dynamic SW to address a range of
issues including the remote condition monitoring of the entire switch asset but also track bed
stability including voids & track geometry/inclination. With the upgraded SW (‘SW3’)
attached to switch components, it will sample the dynamic response of the movement of the
switch, in three dimensions, enabling a trace of ‘normal’ switch movement to be gained. Via
the remote condition monitoring & cloud data storage facility, SW3 informs users of the
integrity of the switch. As SW3 permits trend analysis, it improves predictive maintenance
capability & safety of rail networks, leading to cost savings, & meeting Network Rail’s goal
for innovation in cost-effective monitoring.
As a platform technology, SW3 has use in other wider applications such as escalator
maintenance, & on pipework valves.