Tomorrow's Railway and Climate Change Adaptation Final Report

3.3 Rolling stock
3.3.1 Changes to current practice
In terms of assessing current practice, there may be merit in reviewing the detailed
existing weather sensitivities of different rolling stock types. For example, a past
sensitivity (now remedied) is that of Class 220/221 trains to salt water ingress, as
experienced in 2002 at Dawlish. There may be other rolling stock types that are
particularly sensitive to other weather types (e.g. snow ingress to traction motors).
A further consideration is the choice of ventilation systems for trains (e.g. natural
ventilation by hopper windows versus mechanical or electrical air conditioning). This
may have implications in terms of ensuring passenger comfort during hot conditions.
Overheating of trains can occur on both non-air conditioned trains which do not provide
additional cooling and trains with air conditioning systems which fail during hot
weather.
3.3.2 Review of relevant policies and standards
There may be merit in reviewing the detailed existing weather sensitivities of different
types and ages of rolling stock. This could lead to the improvement of any relevant
policies and standards related to design and operation of existing and new rolling stock.
3.3.3 Further analysis of weather and climate data
An analysis of the likely frequencies of low temperatures in the future was undertaken
in T925 [92, 496], motivated in part by a derailment during winter conditions at
Carrbridge [237]. This could be used to assess the future likelihood of various low
temperature effects on other rolling stock. It could also be coupled with analysis of
snowfall projections using the UKCP09 technical note [480] (subject to caveats within it).
A threshold analysis of how frequently present-day wind speeds pass the speed
thresholds for rolling stock overturning incidents would be useful. However, climate
change projections for wind are relatively less certain than they are for temperature and
precipitation.
3.3.4 Monitoring and measurement of assets
A 2013 ATOC study [545] found that reliability of rolling stock starts to decrease above
25°C. We need to improve understanding of how high temperatures cause reliability
problems for rolling stock and how this can be mitigated. Due to apparent unreliability in
available on-board temperature data, there is also a lack of information about the
impact of high temperature on rolling stock. Better knowledge of this data is needed to
assess the scale of the problem and to determine effective mitigation measures.
15