Thames Valley infrastructure problems causing disruption elsewhere - 2016

[whole diary]

[TaplowGreen]

There is a lot to be said for painting trains white in order to reflect radiant heat and thereby render conditions a LITTLE more tolerable when the air conditioning breaks. Also slightly reduces the energy consumed by cooling.

There was at least one dark green train out there yesterday on which the AC wasn't doing very well ... "34 degrees in each carriage" was comment to me; I was much relieved to be on a 153 which when moving with drop lights open at least had circulating air.

In my experience the chance of a local LTV^▸ (London [and] Thames Valley) service having working aircon is 50/50 at best - to be fair that isn't always helped by people who insist on opening windows....although it's by no means not unknown to get on board on a warm day to find warm air pumping out........

[IndustryInsider]

I'd agree with the 50/50 ratio.  Not particularly impressive but better than the 100% failure rate of the old system.

I'll repeat my annual post to say that the Class 166 air-con is individual to each carriage, so if one carriage is hot, try another - look for the ones with the windows closed if possible.  There's usually at least one carriage per train that's ok.  Set 218 was perfect throughout when I had the pleasure the other day.

[NickB]

Its High Speed Train's (HST^▸ (High Speed Train))'s only for me in this weather.  I'd rather spend extra time in the office or on Paddington concourse and get a later train that has a fighting chance of being decent.

Edit: VickiS - Clarifying Acronym

[Jason]

Due to a speed restriction because of high track temperatures between London Paddington and Reading trains have to run at reduced speed on all lines.
Impact: Train services running to and from these stations may be cancelled or delayed by up to 30 minutes. Disruption is expected until 22:00 19/07.
Customer Advice: <lots>

Due to a fault with the signalling system at Basingstoke the platform 5 line is disrupted.
Impact: Train services running through this station may be delayed by up to 15 minutes. Disruption is expected until 16:00 19/07.

Due to a speed restriction because of high track temperatures between London Paddington and Greenford fewer trains are able to run on some lines.
Impact: Train services running to and from these stations may be cancelled, delayed by up to 15 minutes or revised. Disruption is expected until 22:00 19/07.
Customer Advice: Due to heat related speed restrictions a limited GWR^▸ (Great Western Railway) service is operating between West Ealing and Greenford.

[ChrisB]

GWR^▸ (Great Western Railway) Press Release

Heat speed restrictions to slow passenger journeys home

Stay hydrated and help us keep a lookout for the vulnerable

 

Due to speed restrictions put in place by Network Rail between 1330 and 1900 Tuesday 19 July, GWR is warning customers that journeys are expected to take longer.

 

With rail track temperatures set to exceed 50 degrees in parts of London and the Thames Valley, speed restrictions have been put in place throughout the main junctions into and out of London Paddington.

 

While the vast majority of services are expected to operate as timetabled, journeys may take between 10-15 minutes longer. Customers are advised to check before they travel, to drink plenty of water, and are being asked to help our staff keep a lookout for the more vulnerable making journeys today.

 

A GWR spokesperson said:

 

“With temperatures in London set to exceed 30 degrees, the effect can bring the temperature of the rails to over 50 degrees, and we have been asked by Network Rail to drive more slowly as a result.

 

“We will continue to keep an eye on the situation, alongside Network Rail, and keep you updated throughout the day.”   

 

A spokesperson for Network Rail explained:

 

“Our modern rails are far more resistant to heat expansion and buckling than they used to be.  However, a day this hot affects even our track, so we need to restrict speeds for safety.  Full details are available on our website at networkrail.co.uk/delays explained.”

 

To be able to maintain the train timetable, the following services are expected to be cancelled:

·         All Thames Valley branch lines to remain in branch operation but with no direct London services.
·         London Paddington to Bedwyn and return services will operate between Bedwyn and Reading only
·         London Paddington to Cheltenham Spa and return will operate between Swindon and Cheltenham Spa only
·         London Paddington to Oxford direct (calling Slough, Reading, Didcot and Oxford) and return services are cancelled. Passengers are advised to travel to Didcot for connecting services to Oxford.

Passengers are advised to check their specific journey before they travel.

More links -

http://www.bbc.co.uk/news/uk-england-36836417

http://m.oxfordmail.co.uk/news/14628070.Direct_London_to_Oxford_trains_cancelled_due_to_hot_weather/

https://twitter.com/NetworkRailPAD/status/755357552033095680?s=17

[TaplowGreen]

...........I've just nipped out to the shed, there's a pot of white paint going spare if it'd help? 

[ellendune]

...........I've just nipped out to the shed, there's a pot of white paint going spare if it'd help? 

The flippancy of your remarks suggests to me that you really do not understand the technical aspects of continuous welded rail. 

To stop the rails buckling the rails are put in tension most of the time.  The technical term is that they are de-stressed at a certain temperature. This means that for most of the time they are in tension and for part of the time they are in compression, but not high enough to cause a problem. If you try and touch an object that has been exposed to the hour sun for a long time it is usually considerably hotter than the air around it.  Thus the rail is considerably hotter than even to 30 odd degrees air temperature.

Temperatures of 50 to 55 degrees Celsius are not uncommon (that is too hot to touch for very long without injury).  Painting the rails white has been found to reduce the temperature by between 5 and 10 degrees, so that could be the difference between a speed restriction and no speed restriction!

Apart from the risk of derailment, once a track has buckled you are stuffed until you can get the temperature down sufficiently so that it can be properly de-stressed (in a hot summer period this could be days) after the repair.  So NR^» (Network Rail - home page) takes a cautious approach to avoid buckling.

If the rails were to be stressed any more then the tension that would build up in the winter could lead to other problems so there has to be a compromise.  The only other ways  would be

1) to re-tension the rails every spring and autumn which I would imaging would be prohibitively expensive and would require possessions to do it;
2) Install slab track everywhere (hugely expensive and disruptive to install);
3) Go back to short lengths with fishplate joints with expansion joints - (massive increase in maintenance costs and rail failure and probably speed reductions, also much more noise). 

For further information see this from Network Rail's Website. 

[TonyK]

The flippancy of your remarks suggests to me that you really do not understand the technical aspects of continuous welded rail. 

Sorry Sir.

If you try and touch an object that has been exposed to the hour sun for a long time it is usually considerably hotter than the air around it.

Er. yes. I think so.

[chrisr_75]

...........I've just nipped out to the shed, there's a pot of white paint going spare if it'd help? 

The flippancy of your remarks suggests to me that you really do not understand the technical aspects of continuous welded rail. 

To stop the rails buckling the rails are put in tension most of the time.  The technical term is that they are de-stressed at a certain temperature. This means that for most of the time they are in tension and for part of the time they are in compression, but not high enough to cause a problem. If you try and touch an object that has been exposed to the hour sun for a long time it is usually considerably hotter than the air around it.  Thus the rail is considerably hotter than even to 30 odd degrees air temperature.

Temperatures of 50 to 55 degrees Celsius are not uncommon (that is too hot to touch for very long without injury).  Painting the rails white has been found to reduce the temperature by between 5 and 10 degrees, so that could be the difference between a speed restriction and no speed restriction!

Apart from the risk of derailment, once a track has buckled you are stuffed until you can get the temperature down sufficiently so that it can be properly de-stressed (in a hot summer period this could be days) after the repair.  So NR^» (Network Rail - home page) takes a cautious approach to avoid buckling.

If the rails were to be stressed any more then the tension that would build up in the winter could lead to other problems so there has to be a compromise.  The only other ways  would be

1) to re-tension the rails every spring and autumn which I would imaging would be prohibitively expensive and would require possessions to do it;
2) Install slab track everywhere (hugely expensive and disruptive to install);
3) Go back to short lengths with fishplate joints with expansion joints - (massive increase in maintenance costs and rail failure and probably speed reductions, also much more noise). 

For further information see this from Network Rail's Website. 

Continuous welded rail isn't even painted, so understanding the technicalities of continuous welded rail is completely irrelevant. It's only the point work and crossovers that are painted and mostly only in the GWR^▸ (Great Western Railway) area - I've not seen this elsewhere. IIRC^▸ (if I recall/remember/read correctly) one of our friendly insiders mentioned the reason why the white paint is splashed about earlier in the thread.

[broadgage]

The nearer bits of mainland Europe have a climate broadly similar to ours, and the regions distant from the sea tend to be colder in the winter and hotter in the summer. Yet continental railways seem able to cope with normal summer weather without the frequent and widespread disruption that occurs in the UK^▸ (United Kingdom).

Hot weather DOES sometimes cause disruption in mainland Europe, but only in extreme or exceptional conditions. whereas here we get significant disruption virtually every summer.

It seems a bit like the annual "leaves on the line" fiasco. I am not being flippant and I do have at least a basic understanding of the problem, but it does seem to be largely a UK problem.
In say France or Germany, leaf fall has caused delays but only rarely and in exceptional conditions, here we seem to have significant problems every autumn.

[ChrisB]

And that difference is what the majority don't understand, and hasn't, as far as I can see, bern explained yet in this thread?

Anyone care to elucidate?

[Tim]

any reason CWR^▸ (Continuously Welded Rail) can't be painted white on the sides.   I suspect it would be expensive to paint it in situ.  But my can't Tata steel supply it pre-painted?

[a-driver]

Its fairly commonplace in Australia to paint the rails white, especially between Sydney and Melbourne.  At the hottest times of the day air temperatures can reach into the 40's with high 30's for most of the year.  The same happens in Italy.  Typically a white painted rail is 5 to 10 degrees cooler.

You tend to find point work that is exposed to direct sunlight will be painted white.  Pointwork and point blades are more susceptible to solar gain to the point where point detection can be lost.  This is why they'll tend not to change points where they can so you'll get Greenfords terminating in the West Ealing bay platform and no through trains run between Paddington and Bourne End and Twyford.  This maintains the use of the relief lines. 
Long sections of continuous welded rail has expansion joints to allow for expansion.

High speed lines abroad as well as heavily used freight lines may be constructed using slab track, around four times more expensive than what we use here.  I believe, HS1^▸ (High Speed line 1 - St Pancras to Channel Tunnel) is constructed using slab track.

[Electric train]

  I believe, HS1^▸ (High Speed line 1 - St Pancras to Channel Tunnel) is constructed using slab track.

HS1 is balasted sleepers.  However HS1 does not have as many switches and crossings, its alignment is streighter. Also the density of traffic is less than most mainlies in the UK^▸ (United Kingdom)

[Tim]

  I believe, HS1^▸ (High Speed line 1 - St Pancras to Channel Tunnel) is constructed using slab track.

HS1 is balasted sleepers.  However HS1 does not have as many switches and crossings, its alignment is streighter. Also the density of traffic is less than most mainlies in the UK^▸ (United Kingdom)

I believe that it is better / more heavily ballasted.