30.06.15
Heatwave causes rail buckling and points failure fears in Thames Valley
First Great Western (FGW) services in the Thames Valley area will be subject to speed restrictions from midday until 8pm today over fears of rails buckling.
Network Rail has advised that, due to the anticipated exceptionally hot weather in the area, there will be speed restrictions to protect track points. The Met Office has forecast that temperatures are set to hit 30°C in parts of the Thames Valley.
This will mean there will be no fast trains between London Paddington and Bourne End or Henley-on-Thames.
Network Rail said “as rails are made out of steel, they expand as they heat up and are subject to strong compression.
“This expansion has to be managed to reduce the risk of track buckling. If the track does buckle, the line must be closed and the track repaired before services can resume, causing considerable disruption.”
Trains from London Paddington will terminate at Twyford for a connection with a branch line service to Henley-on-Thames.
Passengers travelling to Bourne End from Paddington will see their services terminate at Maidenhead and will also have to complete their journey on a branch line train.
An FGW spokeswoman told RTM that the measures had been put in place as a “proactive” measure to avoid greater disruption, and the points that could potentially be affected by the heat are legacy points.
FGW announced the restrictions will affect the following services:
London Paddington to Henley-on-Thames
Trains from London Paddington will terminate at Twyford for a connection with a branch line train to Henley-on-Thames, which will remain on the branch line.
17:12 London Paddington to Henley-on-Thames, this service will terminate at Twyford.
18:12 London Paddington to Henley-on-Thames, this service will terminate at Twyford.
19:05 London Paddington to Henley-on-Thames, this service will terminate at Twyford.
London Paddington to Bourne End
Trains from London Paddington will terminate at Maidenhead for a connection with a branch line train to Bourne End, which will remain on the branch line.
16:42 London Paddington to Bourne End, this service will terminate at Maidenhead.
17:42 London Paddington to Bourne End, this service will terminate at Maidenhead.
18:42 London Paddington to Bourne End, this service will terminate at Maidenhead.
Update
Network Rail has sent out a briefing note on the issue of ‘Minimising disruption during hot weather’ and what it is doing to prevent track buckling.
Network Rail said efforts include:
- Each part of the network being risk-assessed so that we know at what rail temperature the risks of track buckling are increased.
- We check the stability of the track each winter and strengthen any weaknesses before the summer arrives; typically this includes replenishing the ballast that surrounds the sleepers, and re-tensing (stretching) continuously welded rails.
- We plan to avoid work that will disturb the stability of the track during the summer as this increases the chance of a track buckle, though sometimes it cannot be avoided.
- We paint at-risk rails white so they absorb less heat, reducing rail temperatures. Typically a painted rail will be five to ten degrees cooler than an unpainted rail.
- We have also introduced sprinkler systems to cool rail temperatures at key junctions and during trials these have reduced temperatures by four degrees in ten minutes.
- We are continually enhancing our measures for calculating rail temperatures, including installing probes that give us instant alerts when track temperatures rise.
- On very hot days when high rail temperatures are widespread, we impose speed restrictions at vulnerable locations; slower trains exert lower forces on the track, reducing the risk of buckling.
The briefing note also addresses future solutions and discusses the use of slab track rather than ballasted systems.
“Some countries use ‘slab track’ where track is laid on reinforced concrete slabs rather than on sleepers and ballast, preventing tracks from buckling,” it said. But the installation cost of slab track is typically four times that of track laid on sleepers and ballast. “Even taking into account the savings in maintenance and disruption costs, it's hard to make a business case for slab track, though we are working with suppliers to see how we can get the costs down,” said Network Rail.
Tell us what you think – have your say below or email [email protected]