CONDITION MONITORING
Depot-based CM for rail
Using vibration to identify a deterioration in bearing condition can be used as the basis of a
predictive maintenance strategy to improve eet reliability and reduce part repair/overhaul costs
Today’s highly competitive
By S J Lacey, consultant and Richard Poulton, managing director, both of T&RS Engineering
railway industry demands the
need to reduce maintenance
and operational costs
without compromising safety
and regularity standards, while at the same
time meeting commercial objectives, in
particular in-service reliability.
Operational reliability of railway rolling
stock, in particular passenger trains, is key
in maximising availability. That is highly
dependent on the health of the drive
system, which in this context includes
the traction motor, gearbox and axlebox.
Equipment degrades with age and usage.
The commonly-used preventative
maintenance strategy involves equipment
being overhauled on a planned schedule
regardless of the condition of the parts.
This normally involves the scheduling
of trains into a depot where equipment
is inspected, removed and replaced,
irrespective of whether it is needed or
not. This type of approach may cut down
failures before they happen, but it also
leads to increased maintenance costs as
parts are often replaced or overhauled too
frequently. There is also a risk of ‘infant
mortality’ due to human error during
the time the train is taken out of service
for repair, adjustment or installation of
replacement parts. In the rail industry,
preventative maintenance is usually
limited to inspection and lubrication,
which is unlikely to identify a serious
deterioration in equipment condition, for
example deterioration of the bearings.
If key equipment on the train can be
monitored in such a way as to obtain
advance warning of a problem, signi cant
costs savings can be obtained by avoiding
unnecessary repair work/overhaul and
resulting in increased availability of the
number of trains in service. Optimising
railway vehicle maintenance and overhaul
plans to improve availability, reduce
maintenance costs and increase reliability
is becoming increasingly important.
Rail operators are increasingly
adopting remote condition monitoring
to monitor railway assets, including
equipment condition onboard the train
as it operates in service, to predict which
parts are likely to fail and when. In this way,
62 www.operationsengineer.org.uk Winter 2021
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