Quantifying the Effects of Predicted Changes in Hot and Cold Weather Due to Climate Change on the Railway Network in the UK.

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Quantifying the Effects of Predicted Changes in
Hot and Cold Weather Due to Climate Change on the
Railway Network in the UK.

• Kay Dobney
• Professor Chris Baker
• Dr Andrew Quinn
• Dr Lee Chapman

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Overview the Possible Effects of Climate Change
on the Railway Network
1. Warm, wet winters Wind OH lines, Pans,
trees. Rain bridges, earthworks. Leaves on
line. Less extremely cold days ice and snow on
infrastructure, 2. Hot, dry summers Rail
buckling, Thunder storms (lightening), Thermal
comfort, Equipment overheating, Line side fires,
OH lines stretching, Subsidence. 3. Extreme
events Extreme storms (e.g. 1987, 1991 and
2002), driven rain, winds, storm surge.), Trees
being toppled (combination impact of rain on
earthworks and wind), Sea level rise.
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Methodology Baseline Climate Impacts
Figure 1 map of UK regions

• Regionalise the UK using Network Rail regions
• Assign a regionally representative weather
  station to each region (figure 1)
• Establish trends in the effects hot and cold
  temperatures have on the railway network in the
  UK
• using delay data from Network Rail and real
  recorded weather data from the Met Office

Example of network delays from Network Rail
Date Incident Start location End location Delay minutes
16/06/03 BUCKLED RAIL PL11 STRATFORD 490
16/06/03 SUNNINGDALE RAIL DEFECT ASCOT VIRGINIA WATER 19
17/06/03 Broken fishplate DML C'lands ILFORD GIDEA PARK 8
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Methodology Future Climate Impacts

• Use a weather generator (EARWIG based on UKCIP
  predictions) to establish the effects climate
  change may have on temperature profiles in each
  region
• Apply the future temperature data to the incident
  trends to establish the impact of climate change
  on temperature related delays
• Use the average cost of a delay minute to cost
  the predicted impacts of climate change
• Normalise the cost per region by the area of the
  region and the total length of rail in each region

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Heat Delays Baseline Trends
The effects of baseline climate on the railway in
each of the four regions
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Heat Delays Future Costs
Cost of heat related delays according to future
climate scenarios
Ratio of heat related delay costs to area of
region and length of rail in region
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Cold Delay Trends per Temperature Interval
Minimum Daily Temperature (C)
Minimum Daily Temperature (C)
Minimum Daily Temperature (C)
Minimum Daily Temperature (C)
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Frequency of Cold Delay Events per Temperature
Interval
Minimum Daily Temperature (C)
Minimum Daily Temperature (C)
Minimum Daily Temperature (C)
Minimum Daily Temperature (C)
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Frequency of Delay Events Causing Delay Minutes,
Within Critical Temperature Range
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Future Cold Delay Costs
Cost of cold related delays according to future
climate scenarios
Ratio of cold related delay costs to area of
region and length of rail in region
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Conclusions

• Heat related delays and buckled rails are
  predicted to steadily increase from up to 15m
  to 25m
• Warmer winters are likely to decrease cold
  related delay costs, from up to 550k to 325k
• However, the reduction in ice and snow delays is
  likely to be felt most in the south-east region
  whereas, the midlands and west regions may not
  experience change until the 2050s and the north
  region until the 2080s.
• Cold induced cracked rails (and other cold
  related fatigue) have not been included in this
  study.

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Recommendations

• A new stress free temperature for continuously
  welded rail may be appropriate.
• Continued mitigation against cold related delays
  the critical temperatures causing most ice and
  snow delays is not likely to change for several
  decades.
• Complacency for the potential severity of cold
  snaps should be avoided, as winter 2009
  demonstrated.