Tomorrow's Railway and Climate Change Adaptation Final Report

flooding and its relationship with contributing rainfall. This would be useful for several
sub-systems.
Projected changes to wind speed in the UK as a result of climate change are very
uncertain. Because of this, there may be limited value in assessing changes in wind
speed, direction and gustiness for particular asset classes, areas and locations. However,
the planned electrification of certain routes has the potential to increase the proportion
of the network which may be susceptible to risks from high winds. This means that a
study of current vulnerability of OHL assets to wind could be of merit as a baselining
exercise. Modern OLE designs out the vulnerability of the OLE to wind; key issue is the
interaction of the vegetation with OLE.
3.6.4 Monitoring and measurement of assets
Current performance and cost impacts have been identified but no information about
future impacts has been found. However the OHL equipment most susceptible to sag
(Mark 1) is nearing the end of its life and is due to be replaced. Some fixed termination
equipment will remain at terminal stations.
Performance and cost impacts due to snow and ice on third rails can be significant. This
is because most third rail routes are located in London and the southeast of England,
which has a high concentration of commuter routes. Therefore spending large amounts
mitigating the impacts of snow and ice in these areas can be justified. The potential
changes in cold weather in the future may mean that current mitigations need to be
adapted as they may no longer be cost effective. This means it is important to ensure
these impacts are fully understood. It should be noted that RSSB research project T950
(Investigating the economics of the third rail DC system compared to other
electrification systems) [693] proposed the long-term replacement of the third rail
network. Weather resilience was one of several reasons given.
Localised flooding tends to impact many sub-systems and asset classes at once, so
addressing system level gaps will cover traction assets as well. Particular attention
should be paid to flood-related impacts to track in third rail areas as the low elevation of
the assets means they are likely to be at higher risk than OHL.
The impact of high winds on OHL can cause both safety and performance problems, and
these impacts should be assessed further. Post 2006 there has been a programme to
upgrade OHL at vulnerable locations. It is important to ensure that the impact of high
winds on performance following this upgrade is understood and retained in the
‘corporate memory’.
Low temperatures and ice also cause more problems for third rail areas than OHL.
Operational guidance is in place to mitigate the effect of icing on the third rail. A
conductor rail icing forecast is produced, but there are no studies into how often this
happens or how this will change in the future. It is recommended that the industry
captures better incident data relating to performance and cost impacts from delays due
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