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All across the Great Western territory => Across the West => Topic started by: TaplowGreen on July 15, 2022, 20:39:11



Title: Heatwave July 2022
Post by: TaplowGreen on July 15, 2022, 20:39:11
Things have held up pretty well so far, and (perfect BBQ weather notwithstanding!), I think people will need to be sensible and understanding over the next few days.

Personally I was supposed to have F2F meetings in London early next week but have moved them all to Teams/Zoom.

Stay safe folks.


Title: Re: Heatwave July 2022
Post by: IndustryInsider on July 15, 2022, 20:48:42
Yes, I’m sure we will see quite widespread disruption, especially on Monday when it looks like the 40 degree barrier could well be broken in London and possibly elsewhere - comfortably beating the current UK record.

Might make climate change flavour of the month again mind you, especially if there’s a significant death toll amongst the elderly and also pets and other animals.


Title: Re: Heatwave July 2022
Post by: broadgage on July 15, 2022, 21:26:41
Any reasonable person would expect rail disruption in the expected conditions. My perennial complaint is about disruption during MODERATLY adverse weather.

The forecast temperatures are truly extreme and might well set new records.

Many large London terminals become uncomfortably warm in normal Summer weather and may become dangerously hot in heatwave conditions. I here suggest several ways to reduce the problem.

1) Most retail outlets on stations are air conditioned, as are staff facilities. In many cases the air conditioning equipment rejects the heat to the concourse thereby making it even hotter. I would prohibit any new installations of this type. All new air conditioning equipment must be of a design that removes the heat entirely from the premises, to the outside air

2) When significant volumes of hot water are needed for toilets, catering outlets, and staff facilities, this should be produced by heat pumps that cool the concourse air as they heat the water. Such equipment is readily available and will work more effectively in a hot station than it will outdoors.
Explore the possibilities of using heat pumps to make hot water for nearby hotels or hospitals. Free station cooling !

3) When a glazed roof needs renewal or major repairs, fit semi transparent solar modules instead of plain glass. This reduces solar gain and the electricity produced will displace increasingly expensive grid power.

4) General energy saving measures in both retail units and in areas used by the railway. This is increasingly important with todays energy prices, but remember that all common uses of electricity turn it into heat. Less power used=less heat produced.


Title: Re: Heatwave July 2022
Post by: JayMac on July 15, 2022, 22:23:30
I was planning to go on a mini break somewhere by rail on Sunday for a few days. I've decided to heed the advice not to travel unless necessary. My main concern was Finn. There would've been too much of a risk of him overheating.


Title: Re: Heatwave July 2022
Post by: TaplowGreen on July 16, 2022, 09:32:38
I was planning to go on a mini break somewhere by rail on Sunday for a few days. I've decided to heed the advice not to travel unless necessary. My main concern was Finn. There would've been too much of a risk of him overheating.


Could try Finland instead? (..........I would get my coat, but it's too hot)


Title: Re: Heatwave July 2022
Post by: froome on July 16, 2022, 09:38:31
I wouldn't be surprised if there were many in the south-east who decided to flee the expected heat and head to the far west or north, and by doing so, overwhelmed both the railways and roads.


Title: Re: Heatwave July 2022
Post by: TaplowGreen on July 16, 2022, 10:45:48
First of many I would imagine?

Cancellations to services between Didcot Parkway and Oxford

Due to a rail buckling in the heat between Didcot Parkway and Oxford the line towards Oxford is blocked.
Train services running through these stations will be cancelled or running non stop between Didcot Parkway and Oxford. Appleford, Culham and Radley will not be served. Disruption is expected until 12:00 16/07.


Title: Re: Heatwave July 2022
Post by: IndustryInsider on July 16, 2022, 11:13:04
First of many I would imagine?

Cancellations to services between Didcot Parkway and Oxford

Due to a rail buckling in the heat between Didcot Parkway and Oxford the line towards Oxford is blocked.
Train services running through these stations will be cancelled or running non stop between Didcot Parkway and Oxford. Appleford, Culham and Radley will not be served. Disruption is expected until 12:00 16/07.

Quite probably.  Though it was only for a short time with normal working now resumed.  Another occasion where the new bi-di signalling between Didcot and Oxford came in handy during the closure of the Oxford bound line as at least one train ran through on the other line in the 'wrong' direction.


Title: Re: Heatwave July 2022
Post by: rogerw on July 16, 2022, 11:49:23
I was planning to go on a mini break somewhere by rail on Sunday for a few days. I've decided to heed the advice not to travel unless necessary. My main concern was Finn. There would've been too much of a risk of him overheating.


Could try Finland instead? (..........I would get my coat, but it's too hot)

i know from personal experience that Finland was pretty hot at the beginning of the week


Title: Re: Heatwave July 2022
Post by: TaplowGreen on July 16, 2022, 12:04:33
I was planning to go on a mini break somewhere by rail on Sunday for a few days. I've decided to heed the advice not to travel unless necessary. My main concern was Finn. There would've been too much of a risk of him overheating.


Could try Finland instead? (..........I would get my coat, but it's too hot)

i know from personal experience that Finland was pretty hot at the beginning of the week

I wasn't being entirely serious  ;)


Title: Re: Heatwave July 2022
Post by: JayMac on July 16, 2022, 12:06:56
Finland has it all.


Title: Re: Heatwave July 2022
Post by: bobm on July 16, 2022, 12:10:08
I’m heading to the Isle of Wight where hopefully the sea air will be make it slightly less warm.


Title: Re: Heatwave July 2022
Post by: broadgage on July 16, 2022, 20:30:49
I’m heading to the Isle of Wight where hopefully the sea air will be make it slightly less warm.

Coastal and island locations will almost always be cooler in heatwaves than inland locations. The sea is cooler than the land and air is thereby slightly cooled by passing over the sea. The sea temperature around the Isle of Wight is probably about 15 degrees, much cooler than the air.

In very cold winter weather the position is reversed, very cold air is slightly warmed by passing over the sea which cant be colder than about 3 degrees below zero and is unlikely to go below about 10 degrees.

This is why the UK has a milder climate than other inland places at similar latitudes. The expected temperature of 40 degrees in London is very hot, but a bit less hot than North Africa and Southern Europe over which the air passed on its way to us.


Title: Re: Heatwave July 2022
Post by: REVUpminster on July 17, 2022, 07:28:20
At Paignton yesterday the station staff were loading bottles of water (about 48 shrink wrapped) into the drivers cab of a local train in case of passenger and crew need. Don't know where the water came from unless the 24hr shop opposite the station.


Title: Re: Heatwave July 2022
Post by: TaplowGreen on July 17, 2022, 08:18:11
Latest advice - they've got the date wrong but I guess it's the thought that counts!  ::)


Title: Re: Heatwave July 2022
Post by: CyclingSid on July 17, 2022, 08:45:18
Had a good cycle from Havant, down Hayling Billy Line, Haylimg Ferry, sea front at Southsea, Gosport Ferry and busway  to Fareham. Lovely ride temperatures ok, especially on the ferries. Hayling Ferry was loaded,could have spent the rest of the day going back and forth on the Gosport Ferry.

The only problem was the train back. Lifts out of order at Fareham, humping the bike up and down stairs negated the previous cooling effect. Got a Cardiff train to Southampton, 5 car and relatively empty. Forgot that only one train an hour from Southampton stops at Basingstoke. Train to Winchester with intention of getting the Portsmouth Harbour train to Basingstoke. They then announced lifts out of order at Basingstoke, thought I would wait for the Cross-Country through to Reading, fatal mistake. Cross-Country died at Southampton. So hour and a quarter wait at Winchester and have to hump the bike down more stairs.

Looking at the positive side nice cooling bike ride along the coast, which was cooler than staying in Reading.


Title: Re: Heatwave July 2022
Post by: Timmer on July 17, 2022, 10:36:44
Tomorrow’s cancellations and service alterations due to the hot weather now appearing on Journeycheck.

Few of note so far:
London to Bristol TM reduced to hourly.
London to Cardiff services not running. Hourly Swansea services running.
Didcot to Paddington stopping services reduced to hourly.
Gloucester to Weymouth services terminating and starting at Westbury with Westbury to Weymouth services running separately.
Portsmouth to Cardiff services terminating and starting at Bristol Parkway.
Paddington to Cheltenham services terminating and starting at Swindon.
Cotswolds line services terminating and starting at Oxford.
Reading to Gatwick Airport withdrawn.


Title: Re: Heatwave July 2022
Post by: Timmer on July 17, 2022, 12:16:46
From GWR:

Quote
Amended GWR timetable Monday 18 & Tuesday 19 July

What's happening?
An extreme heat weather warning is in place until Tuesday 19 July, meaning an amended timetable and extended journey times on Monday 18 July and Tuesday 19 July.
 
I'm due to travel on Monday 18 or Tuesday 19 July - what are my options?
We advise to only travel if absolutely necessary on these dates, as heat-related speed restrictions will significantly reduce the timetable we're able to operate. Fewer trains will run, meaning services may be very busy, and journey times will be significantly extended across the network.
 
GWR tickets dated Monday 18 or Tuesday 19 July will be accepted on our services on Wednesday 20 & Thursday 21 July if you're able to defer your journey.
 
If your journey is essential, please check before you travel on the morning of your journey (visit gwr.com/check), and ensure you carry water with you. If you arrive at your destination 15 minutes late or more, you can claim Delay Repay compensation.
 
We're sorry for the inconvenience this will cause.


Title: Re: Heatwave July 2022
Post by: Timmer on July 17, 2022, 17:35:21
London to the Southwest fast services are running via Bristol tomorrow. The semifasts as per usual along the Berks and Hants.


Title: Re: Heatwave July 2022
Post by: broadgage on July 17, 2022, 18:30:47
LNER have announced that no trains will run between London and Leeds or York on Tuesday. Reduced services and delays are to be expected in the extreme conditions, but it seems OTT to run NO services on a major route.


Title: Re: Heatwave July 2022
Post by: TaplowGreen on July 17, 2022, 19:37:01
LNER have announced that no trains will run between London and Leeds or York on Tuesday. Reduced services and delays are to be expected in the extreme conditions, but it seems OTT to run NO services on a major route.

......and if a few ran & a packed train was to break down en route in over 100° heat?

Given the strength of the warnings and the risks involved, even for those in good health, I'd say it's eminently sensible.

The need for business travel is greatly reduced,  and leisure travel does not constitute "absolutely essential" in the conditions anyway.

Stay indoors, stay as cool as possible. Travel on Wednesday.


Title: Re: Heatwave July 2022
Post by: ChrisB on July 17, 2022, 20:50:41
David Horne’s point made on twitter too.

My only question is why NR aren’t being consustent within the red area? Surely this applies across the red area?


Title: Re: Heatwave July 2022
Post by: grahame on July 17, 2022, 20:58:05
David Horne’s point made on twitter too.

My only question is why NR aren’t being consustent within the red area? Surely this applies across the red area?

I'm not sure that the infrastructure design standards and maintenance quality are the same.   Looking at electrification, the east coast mainline in now one of the older, with west coast modernisation and GWR partial electric to Cocklebury Lane and Midland Main Line partials following later.  So perhaps the knitting on the east coast would get baggy and ladder where it'll stay crisp elsewhere?

Public forecasts are amber and red.  In reality, of course, there's no sudden dividing line and is it not likely that some red areas are more red than others when you drill down into Industrial quality (and priced) forecasts which no doubt NR have.


Title: Re: Heatwave July 2022
Post by: bradshaw on July 17, 2022, 21:40:00
This Twitter thread might help explain
https://twitter.com/noeldolphin/status/1548665634698952704?s=21&t=zX28kceqDCMjbuq3JYD8cw


Title: Re: Heatwave July 2022
Post by: ellendune on July 17, 2022, 22:01:36
Public forecasts are amber and red.  In reality, of course, there's no sudden dividing line and is it not likely that some red areas are more red than others when you drill down into Industrial quality (and priced) forecasts which no doubt NR have.

Most of GWR is in amber and all of LNER to York is in Red.  That might be part of the story. 


Title: Re: Heatwave July 2022
Post by: broadgage on July 17, 2022, 22:46:09
I did like the remark "Just stop grumbling, all of you.
It could be worse: it could be snowing.
Just imagine shoveling snow in this heat"


Title: Re: Heatwave July 2022
Post by: grahame on July 18, 2022, 08:23:32
So as I read it:

GWR mainline - 40 degrees
ECML - 38 degrees
Other lines electrified earlier - vague lower figures, sometimes much lower


Title: Re: Heatwave July 2022
Post by: ellendune on July 18, 2022, 08:32:29
So as I read it:

GWR mainline - 40 degrees
ECML - 38 degrees
Other lines electrified earlier - vague lower figures, sometimes much lower

I assume those are the design temperatures. 

A quick look at the weather map suggests typical temperatures in Thames Valley  33-35; typical temperatures on ECML to York 38-39.


Title: Re: Heatwave July 2022
Post by: ChrisB on July 18, 2022, 09:03:19
Don’t forget these figures just relate to the overhead steel wires….there are also the steel tracks that weren’t designed/stressed for these sort of temperatures either.

Nor are the steel boxes that we travel in designed to be sat stationary  on the tracks after sugnal/track failures for hours! Consideration has to be given to this too.

Oh, and this weather is one example where axle counters work better than track circuits which are more likely to fail in this weather than the counters….and we’re replacing the former with latter….


Title: Re: Heatwave July 2022
Post by: Oxonhutch on July 18, 2022, 09:21:35
Had our PW man measuring our rail temperatures yesterday and measured over 37C - air temperature about 30C. Services planned for today and tomorrow cancelled so as not to stress the rails. Apparently, braking and accelerating also adds a considerable heat content to the rails so areas around signals and stations particularly vulnerable.


Title: Re: Heatwave July 2022
Post by: Marlburian on July 18, 2022, 10:37:41
I've been wondering what I would have done today, had I still been based in London (Tilehurst-Paddington-Lambeth North). No problem for me heat wise getting in to the office for 0800. Would I have stayed late waiting for the daytime heat to dissipate? Guess I would have checked the availability of late rush-hour trains. But then the deteriorating COVID situation would have diminished my conscientiousness. Perhaps I would have arranged a visit away from the office on Tuesday or Wednesday (both days might not have been acceptable). Or a couple of days' leave?

I commuted in 1972-73 and can recall the old carriages - eight to a compartment, get on the train at Paddington and tug hard at the two handles on those little windows that were usually closed, musty smell of the upholstery - not to mention that of other passengers after a hot day in London.


Title: Re: Heatwave July 2022
Post by: stuving on July 18, 2022, 10:53:34
Straight track laid to the full current NR standard is stress-free at 27o, and no action is called for until the rail temperature rises by 37 K. So some mitigation may be needed above 59o, and speed restrictions only above 64o.

That's rail temperature, of course, and a number of things can push that well above local air temperature, which itself can be well above a weather-station value. And there are a lot of features (e.g. curves, points, bridges, and uncorrected defects) that can reduce those limits and result in local restrictions.

Series One OLE is designed for an air temperature range of -18-40o. The main factor in this is the adjustment range of the Tensorexes, which is 1 m. The maximum wire run is 750 m (each side of a centre clamp) which combined with the expansion coefficient of the wires gives a temperature range of 74 K. And the maximum wire temperature is, correspondingly, set at 56 o.

The extra heating comes from the sun and from traction current, so running a reduced service or at reduced speed should provide a little extra leeway. However, that effect may be too hard to predict to be useful. There is a separate calculation of maximum current, using the same limit of 56o and an air temperature of 28o. Here the wind speed is critical, as any cooling effect from it allows a large current increase: at 0.45 m/s (1 mph) to 532 A, and at 3 m/s to over 964 A.

Given that there are hundreds of wire runs, and these will be tested today with higher temperatures than they have ever seen, I'd guess that any problems on GWR will arise at those few runs that were set up out of spec, or have been altered without the full setup being repeated. There must be a few out there.


Title: Re: Heatwave July 2022
Post by: jamestheredengine on July 18, 2022, 17:37:08
Looks like something's up with the Severn Tunnel now. The 1348 Paddington to Swansea, which got to Bristol Parkway 128 late, has now been sitting there for 20 minutes. The dreaded "LB" is appearing on Traksy. There's something described as a loco coming the other way now:
https://www.realtimetrains.co.uk/service/gb-nr:59044/2022-07-18/detailed


Title: Re: Heatwave July 2022
Post by: ChrisB on July 18, 2022, 17:51:08
From BBC News (https://www.bbc.co.uk/news/av/world-europe-62213247)

Be grateful this isn't happening here - it's in Spain.....

Quote
Spain heatwave: Moment of shock as train is surrounded by wildfires

Passengers travelling on a Spanish train were alarmed as their train momentarily stopped and wildfires could be seen on both sides of the track.

The footage was captured in the Spanish province of Zamora.

A spokesperson from rail operator Adif told the Associated Press that the passengers were never in danger.

Video in link above.


Title: Re: Heatwave July 2022
Post by: stuving on July 18, 2022, 19:28:16
On the other hand ... a large fire (1000 Ha) south of Avignon has been confidently attributed to sparks from the brakes of a goods train. And, having been brought under control on Friday morning, it has now started up again. The local mayor (of Graveson) has been muttering to himself (and any passing reporter) about suing SNCF.

That line has of course been closed, but it's "only" the old main line to Marseille - not the LGV, and for local trains there are other ways round.


Title: Re: Heatwave July 2022
Post by: broadgage on July 18, 2022, 20:23:58
Some of the large fires near the railway in France and perhaps elsewhere could have been fought from a train.  A train of water tankers can carry a vast amount of water, perhaps a thousand tons as compared to a few tons carried by a fire engine.

Start with say ten tank wagons, and between each pair of tanks place a suitable open topped wagon with sides about 1.2 meters high. Each wagon to contain a couple of portable engine driven fire pumps and two firemen. Connect the pump suction to the tank outlet, and the pump discharge to a short length of standard fire service delivery hose.

Firefighting from the top of the water tankers is obviously not applicable to routes with OHLE, but from a suitable wagon should be ok.


Title: Re: Heatwave July 2022
Post by: Richard Fairhurst on July 18, 2022, 20:48:28
Of all the days... I had a meeting in London today. Both GWR and TfL acquitted themselves splendidly.

Cotswold Line services were starting/terminating at Oxford, which led to the unusual sight (both ways) of a 5-car IET in Platform 2, the bay platform. It fits very snugly!

Elizabeth Line aircon greatly appreciated... I can't imagine trying the Central Line on a day like this.

The morning trains were fairly busy, but the evening was as quiet as the grave - I think I was one of only two people in coach A on the 17.20 out of Paddington.

All services in the evening were limited to 60mph. Trundling along on the fasts at 60mph between Paddington and Reading is a weird feeling.


Title: Re: Heatwave July 2022
Post by: IndustryInsider on July 18, 2022, 22:09:38
Some of the large fires near the railway in France and perhaps elsewhere could have been fought from a train.  A train of water tankers can carry a vast amount of water, perhaps a thousand tons as compared to a few tons carried by a fire engine.

Start with say ten tank wagons, and between each pair of tanks place a suitable open topped wagon with sides about 1.2 meters high. Each wagon to contain a couple of portable engine driven fire pumps and two firemen. Connect the pump suction to the tank outlet, and the pump discharge to a short length of standard fire service delivery hose.

Firefighting from the top of the water tankers is obviously not applicable to routes with OHLE, but from a suitable wagon should be ok.

Wouldn’t only a small percentage of these fires be within reach of hoses on the train?


Title: Re: Heatwave July 2022
Post by: broadgage on July 18, 2022, 23:50:02
Some of the large fires near the railway in France and perhaps elsewhere could have been fought from a train.  A train of water tankers can carry a vast amount of water, perhaps a thousand tons as compared to a few tons carried by a fire engine.

Start with say ten tank wagons, and between each pair of tanks place a suitable open topped wagon with sides about 1.2 meters high. Each wagon to contain a couple of portable engine driven fire pumps and two firemen. Connect the pump suction to the tank outlet, and the pump discharge to a short length of standard fire service delivery hose.

Firefighting from the top of the water tankers is obviously not applicable to routes with OHLE, but from a suitable wagon should be OK.

Wouldn’t only a small percentage of these fires be within reach of hoses on the train?

Yes, But if it keeps the fire away from the railway that could still be most useful. No damage to OHLE, or signalling cables etc.


Title: Re: Heatwave July 2022
Post by: IndustryInsider on July 19, 2022, 00:06:10
I would assume in such cases all the resources go into stopping fires from spreading and preserving life rather than hopefully saving a bit of signalling cable.  Given the speed some fires spread I also don't think I'd like to be one of the firemenfighters stood on the wagon, even if I had a plentiful supply from my hose!

One of your less sensible ideas IMHO, broadgage!


Title: Re: Heatwave July 2022
Post by: stuving on July 19, 2022, 00:34:39
Given the speed some fires spread I also don't think I'd like to be one of the firemenfighters stood on the wagon, even if I had a plentiful supply from my hose!

The same danger exists for those in road vehicles too, where one of the most serious hazards is being surrounded by a fast-moving fire. So in France the front-line vehicles contain a big tank (500 l, in addition to any fire-fighting supply) of water which is sprayed on the outside (and tyres) to keep the inside survivably cool for a few minutes. That works because the risk is from a fast-moving fire, which moves on quickly too.

The only real use I can think of for rail in support of fire-fighting is to bring in water to refill vehicles' tanks.


Title: Re: Heatwave July 2022
Post by: TaplowGreen on July 19, 2022, 04:31:19
Some of the large fires near the railway in France and perhaps elsewhere could have been fought from a train.  A train of water tankers can carry a vast amount of water, perhaps a thousand tons as compared to a few tons carried by a fire engine.

Start with say ten tank wagons, and between each pair of tanks place a suitable open topped wagon with sides about 1.2 meters high. Each wagon to contain a couple of portable engine driven fire pumps and two firemen. Connect the pump suction to the tank outlet, and the pump discharge to a short length of standard fire service delivery hose.

Firefighting from the top of the water tankers is obviously not applicable to routes with OHLE, but from a suitable wagon should be ok.

https://youtu.be/QrrIRr9arkM


Title: Re: Heatwave July 2022
Post by: froome on July 19, 2022, 06:40:10
There have been some phenomenally high overnight temperatures which will have obliterated many local records, particularly in Wales and the west. A minimum of 26 degrees here in Bath by the looks (and feel) of it, and the Met Office site shows minimums of 27 along parts of the west Wales coast. Fortunately here in most of GWR land, we are 'only' likely to reach maximums in the lower 30s today, but the eastern side of the country, and especially the east Midlands, is going to be cooking. I doubt whether anything will be moving there, whether it be by rail, road or foot.

On the subject of transporting water, rail is very efficient at distributing bulky, heavy objects, and should be ideal for moving it around, but obviously suffers from the inflexibility of only reaching certain places, which are unlikely to be where it is needed. And do we have the rolling stock to do it? I'll let you experts answer that for me.

Transporting water by lorry into areas that are savagely hot is likely to end up with the lorry sinking into melted tar, having half destroyed all the roads along the way with its weight.


Title: Re: Heatwave July 2022
Post by: GBM on July 19, 2022, 08:04:57
Thunder, lightning & heavy rain down far West


Title: Re: Heatwave July 2022
Post by: GBM on July 19, 2022, 09:05:49
Cancellations to services between Penzance and St Erth
Due to lightning damaging the signalling system between Penzance and St Erth all lines are blocked.
Train services running to and from these stations may be cancelled, delayed or revised. Disruption is expected until 10:00 19/07.

Alterations to services between St Erth and St Ives
Due to lightning damaging the signalling system disruption is expected until 09:15 19/07.
Train services between St Erth and St Ives have been suspended.

Now updated 10;15
Alterations to services between Penzance and St Erth
Due to lightning damaging the signalling system between Penzance and St Erth fewer trains are able to run on all lines.
Train services running to and from these stations may be delayed or revised. Disruption is expected until 12:00 19/07.


Title: Re: Heatwave July 2022
Post by: stuving on July 19, 2022, 09:28:55
There have been some phenomenally high overnight temperatures which will have obliterated many local records, particularly in Wales and the west. A minimum of 26 degrees here in Bath by the looks (and feel) of it, and the Met Office site shows minimums of 27 along parts of the west Wales coast. Fortunately here in most of GWR land, we are 'only' likely to reach maximums in the lower 30s today, but the eastern side of the country, and especially the east Midlands, is going to be cooking. I doubt whether anything will be moving there, whether it be by rail, road or foot.

The thermometer by the back door of my house said 21o even at 8 am, but that's rather misleading. I had fans set up to pull air into the upstairs rooms, but soon after 8 am they had raised the temperature in one bedroom to 27o.

The back garden is small and surrounded by panel fences, so it acts as a kind of frost hollow - air cooled by the ground (still around 21o at 9 am) and the roof tiles, themselves cooled at night by radiation, fills the "pool" to the top of the fences. Above that the air is a lot hotter at the moment.

There were some other low recorded temperatures last night, even down to 15o at Charlwood, after 36o yesterday - but that's a notorious frost hollow (among weather stations).


Title: Re: Heatwave July 2022
Post by: grahame on July 19, 2022, 09:47:04
from Politics Home (https://www.politicshome.com/news/article/grant-shapps-heatwave-transport-infrastructure-rail-roads-melting)

Quote
Transport Secretary Grant Shapps has admitted it will take “decades” to make road and rail infrastructure able to deal with heatwaves.

On Monday, the UK recorded the hottest night on record, with temperatures failing to drop below 25C, according to the Met office. Temperatures on Tuesday are expected to reach highs of 42C, an all-time record for Britain, compared to an average of 21C for July.

With many train services cancelled or delayed on Monday after tracks buckled in the heat, and flights at Luton airport and at RAF's Brize Norton air base unable to land due to melting runways, Shapps conceded that the UK's transport network cannot cope with extreme heat. Further disruption is expected today.

He estimated it will take “decades, actually, to replace it all”.

”Ditto with Tarmac on the roads,” he told Sky News on Tuesday.

A stunning statement of what - to me at least - seems obvious.  Two questions to be asked:
a) Should we accept a handful of days each year when the railways cannot operate a normal timetable due to stunningly hot weather, just as we do with stunningly cold or wet weather?
b) Climate warming has been going on for years, though it's seemingly only become fashionable to take action on it and on making infrsastructure more robust in recent years.  What have Mr Shapps and his predecessors done to lessen the impact of changing weather on the transport network?


Title: Re: Heatwave July 2022
Post by: TaplowGreen on July 19, 2022, 10:07:30
from Politics Home (https://www.politicshome.com/news/article/grant-shapps-heatwave-transport-infrastructure-rail-roads-melting)

Quote
Transport Secretary Grant Shapps has admitted it will take “decades” to make road and rail infrastructure able to deal with heatwaves.

On Monday, the UK recorded the hottest night on record, with temperatures failing to drop below 25C, according to the Met office. Temperatures on Tuesday are expected to reach highs of 42C, an all-time record for Britain, compared to an average of 21C for July.

With many train services cancelled or delayed on Monday after tracks buckled in the heat, and flights at Luton airport and at RAF's Brize Norton air base unable to land due to melting runways, Shapps conceded that the UK's transport network cannot cope with extreme heat. Further disruption is expected today.

He estimated it will take “decades, actually, to replace it all”.

”Ditto with Tarmac on the roads,” he told Sky News on Tuesday.

A stunning statement of what - to me at least - seems obvious.  Two questions to be asked:
a) Should we accept a handful of days each year when the railways cannot operate a normal timetable due to stunningly hot weather, just as we do with stunningly cold or wet weather?
b) Climate warming has been going on for years, though it's seemingly only become fashionable to take action on it and on making infrsastructure more robust in recent years.  What have Mr Shapps and his predecessors done to lessen the impact of changing weather on the transport network?

a) at least until we see the cost/benefit/practicality of the alternative and understand, in the immortal words of one of our esteemed fellow members........"Oooooooooooos gonna pay for it?"

....I assume, that somewhere amongst the colossal cost of HS2, someone has included weatherproofing it?


Title: Re: Heatwave July 2022
Post by: Electric train on July 19, 2022, 11:05:14
from Politics Home (https://www.politicshome.com/news/article/grant-shapps-heatwave-transport-infrastructure-rail-roads-melting)

Quote
Transport Secretary Grant Shapps has admitted it will take “decades” to make road and rail infrastructure able to deal with heatwaves.

On Monday, the UK recorded the hottest night on record, with temperatures failing to drop below 25C, according to the Met office. Temperatures on Tuesday are expected to reach highs of 42C, an all-time record for Britain, compared to an average of 21C for July.

With many train services cancelled or delayed on Monday after tracks buckled in the heat, and flights at Luton airport and at RAF's Brize Norton air base unable to land due to melting runways, Shapps conceded that the UK's transport network cannot cope with extreme heat. Further disruption is expected today.

He estimated it will take “decades, actually, to replace it all”.

”Ditto with Tarmac on the roads,” he told Sky News on Tuesday.

A stunning statement of what - to me at least - seems obvious.  Two questions to be asked:
a) Should we accept a handful of days each year when the railways cannot operate a normal timetable due to stunningly hot weather, just as we do with stunningly cold or wet weather?
b) Climate warming has been going on for years, though it's seemingly only become fashionable to take action on it and on making infrsastructure more robust in recent years.  What have Mr Shapps and his predecessors done to lessen the impact of changing weather on the transport network?

a) at least until we see the cost/benefit/practicality of the alternative and understand, in the immortal words of one of our esteemed fellow members........"Oooooooooooos gonna pay for it?"

....I assume, that somewhere amongst the colossal cost of HS2, someone has included weatherproofing it?


On the last point about HS2 yes there will be extreme weather resilience (weatherproofing is about IP 54 or IP67 etc) being considered in the design, everything from the one in 50 / 100 year 1962 type snow conditions to flash flooding extreme temperatures both plus and minus.
Resilience of the infrastructure does not mean a full train service or indeed any train service will run in extreme conditions, the resilience measure will include protecting key assets from the impact of extreme weather conditions and recognising other assets will need attention (an example is a Signalling Location Case will be protected from flooding, but track circuits will be up to a certain degree) The resilience plan will include what needs to be done to protect assets, when it is safe and to what level a train service can run, key spare spares to be held as part of the seasonal preparedness plan.

This is also done for existing infrastructure that is why the ECML made the decision to suspended services the NR Region, TOC & FOC will have considered the risks of derailment, dewirement, trains becoming stranded with passengers onboard.

The question do we need to alter our infrastructure for a few days of over 30C air temperatures at the risk it will not handle the sub-zero C ground temperature during the winter


Title: Re: Heatwave July 2022
Post by: ChrisB on July 19, 2022, 12:16:54
We still incur more sub-zero days than days in excess of 30 degrees....


Title: Re: Heatwave July 2022
Post by: grahame on July 19, 2022, 13:31:36
The question do we need to alter our infrastructure for a few days of over 30C air temperatures at the risk it will not handle the sub-zero C ground temperature during the winter.

On the assumption that it has a working range of "n" degrees, we should be considering whether that's -10 to 30, -5 to 35, or 0 to 40 (taking an example of "n" as 40).  And also considering during a period of changeover what the effect is - if we go from a -10 to 30 standard to a 0 to 40 standard, we have a considerable period when it only works 0 to 30.

"Do we need to alter it for over 30C?" ... the answer must be guided by "what happens in higher temperatures".   If it just means the line has to be shut, we probably don't need to alter it.   If it distorts and damages and cost millions to get running again, then perhaps we do need to alter it!


Title: Re: Heatwave July 2022
Post by: ChrisB on July 19, 2022, 13:37:24
Also, we can't keep changing that range frankly - it'll take a decade or so to make changes across the entire rail network, by which time temperature means may have risen. We're already looking at 40 degrees - is that the highest we should plump for? What ranges do France & Spain use for example?


Title: Re: Heatwave July 2022
Post by: GBM on July 19, 2022, 14:53:21
Cancellations to services between Penzance and St Erth
Due to lightning damaging the signalling system between Penzance and St Erth all lines are blocked.
Train services running to and from these stations may be cancelled, delayed or revised. Disruption is expected until 10:00 19/07.

Now updated 10;15
Alterations to services between Penzance and St Erth
Due to lightning damaging the signalling system between Penzance and St Erth fewer trains are able to run on all lines.
Train services running to and from these stations may be delayed or revised. Disruption is expected until 12:00 19/07.

Alterations to services between Penzance and St Erth
Due to lightning damaging the signalling system between Penzance and St Erth fewer trains are able to run on all lines.
Train services running to and from these stations may be delayed or revised. Disruption is expected until 16:00 19/07.

Not quite as easily fixed as first forecast this morning.


Title: Re: Heatwave July 2022
Post by: broadgage on July 19, 2022, 16:08:04
Also, we can't keep changing that range frankly - it'll take a decade or so to make changes across the entire rail network, by which time temperature means may have risen. We're already looking at 40 degrees - is that the highest we should plump for? What ranges do France & Spain use for example?

In my view, all new railway rail infrastructure should be designed for an air temperature of 45 degrees, or a little more than the records set today. Whilst todays temperatures are exceptional, I suspect that they will become more common.
30 degrees is likely to be the new norm in Summer, with over 40 degrees reached if not every year, at least every few years.

And by "infrastructure" I mean not just the track and the OHLE, but also traction current substations, signaling equipment and the power supplies thereto, control rooms and signaling centers including the air conditioning.

Passenger safety also needs consideration. Major urban stations need air conditioned waiting areas, and smaller stations need  open air waiting areas that are shaded from direct sunlight.

Every station with a mains water supply should be provided with drinking water fountains, of a simple traditional design, nothing requiring electricity, smartphones, or apps.

Rolling stock likewise, all new and refurbished rolling stock should in my view be required to operate as normal at up to 40 degrees air temperature, and to cope with up to 50 degrees, though with reduced performance.


Title: Re: Heatwave July 2022
Post by: a-driver on July 19, 2022, 16:22:37

In my view, all new railway rail infrastructure should be designed for an air temperature of 45 degrees, or a little more than the records set today. Whilst todays temperatures are exceptional, I suspect that they will become more common.
30 degrees is likely to be the new norm in Summer, with over 40 degrees reached if not every year, at least every few years.


Wouldn’t that then cause problems in the Winter when it comes to track?  A cold winter would then see the track contract so much it’ll rip itself apart. 


Title: Re: Heatwave July 2022
Post by: ChrisB on July 19, 2022, 16:50:33
From the BBC News rolling page on the heat....

Quote
London Euston trains suspended over cable fire

All trains between London Euston and Milton Keynes have been suspended as emergency services deal with a fire near the track.

The blaze was caused when overhead electric cables came down in Harrow in north London, which Network Rail said was caused by the extreme temperatures.

All services to and from London Euston are suspended until further notice.

James Dean, Network Rail said -
"Please follow our 'do not travel' message today as journeys are being severely impacted. Once the emergency services give us the go-ahead, we will work as fast as we can to restore the railway lines. We're sorry to people impacted and we're working as fast as we can to get things back up and running."


Title: Re: Heatwave July 2022
Post by: broadgage on July 19, 2022, 16:57:36

In my view, all new railway rail infrastructure should be designed for an air temperature of 45 degrees, or a little more than the records set today. Whilst todays temperatures are exceptional, I suspect that they will become more common.
30 degrees is likely to be the new norm in Summer, with over 40 degrees reached if not every year, at least every few years.


Wouldn’t that then cause problems in the Winter when it comes to track?  A cold winter would then see the track contract so much it’ll rip itself apart. 

How do they cope overseas ? Many places have higher Summer temperatures AND lower winter temperatures than does the UK. They have railways.


Title: Re: Heatwave July 2022
Post by: ChrisB on July 19, 2022, 17:04:07
How do they cope overseas ? Many places have higher Summer temperatures AND lower winter temperatures than does the UK. They have railways.

Would you like to name half a dozen?


Title: Re: Heatwave July 2022
Post by: ChrisB on July 19, 2022, 17:12:07
From SWT on twitter (https://twitter.com/NetworkRailWssx/status/1549010541175357441?s=20&t=e2yyOZiGKEVNWNmF-vVcQw) yesterday

Quote
One of the ways the heat can affect our railway. A kink in the tracks was spotted near #Vauxhall earlier today. Our team are working to fix this, and thankfully trains can be re-routed to avoid the affected section, so delays should be minor.

(https://pbs.twimg.com/media/FX8wV4xXoAAnGtV?format=jpg&name=small)


Title: Re: Heatwave July 2022
Post by: broadgage on July 19, 2022, 17:18:11
How do they cope overseas ? Many places have higher Summer temperatures AND lower winter temperatures than does the UK. They have railways.

Would you like to name half a dozen?

France
Ukraine
Central states of the USA.
Russia.
And many other others, generally places well inland and therefore distant from the moderating effect of oceans.


Title: Re: Heatwave July 2022
Post by: ChrisB on July 19, 2022, 17:37:23
The areas that might get 40 degree heat aren’t generally the same areas that get sib-zero. Russia being one….abd generally France.


Title: Re: Heatwave July 2022
Post by: IndustryInsider on July 19, 2022, 17:56:46
The areas that might get 40 degree heat aren’t generally the same areas that get sib-zero. Russia being one….abd generally France.

A combination of that, the less developed and intensive rail services generally in most of those countries and the fact there often is disruption, but we just don’t get to hear about it.

The Clarkson tweet earlier this week springs to mind:  https://www.independent.co.uk/arts-entertainment/tv/news/heatwave-uk-jeremy-clarkson-france-b2125426.html?amp


Title: Re: Heatwave July 2022
Post by: Electric train on July 19, 2022, 18:46:03
How do they cope overseas ? Many places have higher Summer temperatures AND lower winter temperatures than does the UK. They have railways.

Would you like to name half a dozen?

France
Ukraine
Central states of the USA.
Russia.
And many other others, generally places well inland and therefore distant from the moderating effect of oceans.

Most of them have regional difference, you cannot compare due to the size of the USA and Russia to the UK


Title: Re: Heatwave July 2022
Post by: PhilWakely on July 19, 2022, 19:32:54
The areas that might get 40 degree heat aren’t generally the same areas that get sib-zero. Russia being one….abd generally France.

Crossing the Gobi Desert back in May 2012 at about midday..... 
(https://hosting.photobucket.com/images/ww255/PhilWakely/Gobi_Display.JPG)

(I suspect there may have been a fault in the thermometer!)


Title: Re: Heatwave July 2022
Post by: PrestburyRoad on July 19, 2022, 20:31:42

In my view, all new railway rail infrastructure should be designed for an air temperature of 45 degrees, or a little more than the records set today. Whilst todays temperatures are exceptional, I suspect that they will become more common.
30 degrees is likely to be the new norm in Summer, with over 40 degrees reached if not every year, at least every few years.


Wouldn’t that then cause problems in the Winter when it comes to track?  A cold winter would then see the track contract so much it’ll rip itself apart. 

How do they cope overseas ? Many places have higher Summer temperatures AND lower winter temperatures than does the UK. They have railways.

I believe that in some countries with an extremely very high range they have to re-tension the tracks each spring and autumn, so that in the summer the rails are a bit shorter and in the winter a bit longer.  Doing that in the UK would be a lot of work and expense and I doubt it would be funded.


Title: Re: Heatwave July 2022
Post by: onthecushions on July 19, 2022, 23:15:31

I asked a Swedish colleague about this and his reply was that while their railways do have more in the way of snowploughs and resilience etc, it is generally accepted that extreme weather requires compromise in activities rather than complaints. They expect c12 hours of disruption and adapt accordingly. Perhaps our mild climate has led us to believe that we can travel and work quite independently of nature and that its is Government's fault if we can't.

OTC


Title: Re: Heatwave July 2022
Post by: GBM on July 20, 2022, 05:08:27
Is this a first?
05:03 Penzance to London Paddington due 09:55
05:03 Penzance to London Paddington due 09:55 will be started from Plymouth.
It will no longer call at Penzance, Redruth, Truro, St Austell, Bodmin Parkway, Liskeard and Saltash.
This is due to severe weather earlier today.
Will be formed of 2 coaches instead of 5. First class not available.

No trolley then!  :'(


Title: Re: Heatwave July 2022
Post by: JayMac on July 20, 2022, 05:30:16
Is this a first?
05:03 Penzance to London Paddington due 09:55
05:03 Penzance to London Paddington due 09:55 will be started from Plymouth.
It will no longer call at Penzance, Redruth, Truro, St Austell, Bodmin Parkway, Liskeard and Saltash.
This is due to severe weather earlier today.
Will be formed of 2 coaches instead of 5. First class not available.

No trolley then!  :'(

Looks like the original alteration was to run a Class 150 from PNZ to PLY instead of the booked 5 car Class 802. That Class 150 then got cancelled. Due to be 2x 5 car Class 802 onward from PLY. 802011 + 802018 came off Laira around 0530. Sitting at Lipson Jcn currently, waiting for a path into PLY.

Educated guess is yesterday's disruption meant no 802 available at PNZ this morning.


Title: Re: Heatwave July 2022
Post by: grahame on July 21, 2022, 05:23:49
Echo of earlier concerns here - questions of railways in the heat

1. Are the railways able to operate during the heat

2. Are the railways damaged by the heat

From https://www.bbc.co.uk/news/business-62234461

Quote
Repair work is ongoing across the UK's rail network, and Network Rail said it has launched a new taskforce to investigate how the railway can become more resilient in the wake of the heatwave.


Title: Re: Heatwave July 2022
Post by: stuving on July 21, 2022, 11:58:31
Quote
Repair work is ongoing across the UK's rail network, and Network Rail said it has launched a new taskforce to investigate how the railway can become more resilient in the wake of the heatwave.

That task force looks rather like the last one - set up post-Carmont, top report on resilience against climate change in general, but focused on heavy rain rather than heat. I was wanting to look at their final report (which I think came out in March 2021) to see if it did move on to the heat issue, but I can't find it. There is a DfT link to an NR page with that title (Resilience of rail infrastructure: final report (https://www.networkrail.co.uk/who-we-are/our-approach-to-safety/stonehaven)), but it's not got the final report itself. Has anyone seen it?


Title: Re: Heatwave July 2022
Post by: stuving on July 21, 2022, 18:33:00
Quote
Repair work is ongoing across the UK's rail network, and Network Rail said it has launched a new taskforce to investigate how the railway can become more resilient in the wake of the heatwave.

That task force looks rather like the last one - set up post-Carmont, top report on resilience against climate change in general, but focused on heavy rain rather than heat. I was wanting to look at their final report (which I think came out in March 2021) to see if it did move on to the heat issue, but I can't find it. There is a DfT link to an NR page with that title (Resilience of rail infrastructure: final report (https://www.networkrail.co.uk/who-we-are/our-approach-to-safety/stonehaven)), but it's not got the final report itself. Has anyone seen it?

On closer examination, the "update report" listed and linked in that page must be the final report. Maybe they reckoned this subject is too big for any report to claim finality. Certainly in this case, as in the interim report, the top level description says "an assessment of the impact of extreme weather on the resilience and safe performance of the railway". But immediately it starts to limit that to earthworks, and they are at risk from rain more than heatwaves. So another chapter has to be written now ...


Title: Re: Heatwave July 2022
Post by: stuving on July 24, 2022, 19:45:59
Of the two main heat effects, OLE sag is the more tractable. In principle, temperature range is just a  parameter fed into the design process, and if you make it a bit bigger you just get a slightly different set of design rules. The obvious free parameter you can change is the maximum wire run length: on those Series 1 figures, reducing that from 1500 m to 1400 m would allow about 5 degrees more temperature range.

Tensioners with a greater adjustment length might work in some cases, but that increases the along-track movement of the wires. All the things bolted to the wires - registration arms in particular - must be able to cope with this extra movement. I suspect the registration arms would not allow much more than 1 m of movement. For the same increase from 74 to 79 K, a 1 m adjustment has to go up by 65 mm.

As a practical response to the current situation, you could look at any places where loss of tension has happened and work out why. If it's a set-up issue, sort it; if it's a place where the wires get very hot for whatever reason and the wire run is long, split that one into two shorter ones. Then you could have a think about what other key points on the network may see high wire temperatures in a future heatwave. The main difficulty I can see with that is that long main lines without junctions can use mostly maximum-length wire runs, and shortening all those would be costly. 

So is this still a serious issue? Well, Network Rail have been saying this about the problem, which suggests exceeding the temperature range of tensioners isn't common:
Quote
Modern overhead lines, which are used on the majority of Britain’s rail network, are much less affected by hot weather. They have auto-tension systems with balance weights or springs that adjust to different temperatures. But older overhead lines have fixed tension and are more vulnerable.

How we minimise delays caused by overheated power lines

We do this by:

  • Adjusting the height and tension of our older overhead power lines in summer to help prevent sagging.
  • Introducing temporary speed restrictions to minimise the force on the overhead power lines. Speed restrictions reduce the risk of damage and keep services running but they can cause delays. We have to balance the inconvenience of delays against the risk of the greater disruption that would be caused if we need to fully close the line.
  • Replacing old overhead lines with modern, more resilient auto-tension power lines.

What was a surprise there was that there is any fixed wire without tensioners outside sidings and depots. I could only think of Tyne and Wear Metro (1500 V DC), which isn't NR's track except perhaps the bit that's shared. And maybe the fringes of Glasgow Suburban? But not on main lines, you'd hope.

Perhaps surprisingly, SNCF have always struggled in this area, and drooping caténaires are still part of their PR message in hot weather. And that's despite having time to do something about it - I recall hearing of a big programme of uprating tensioners in France (though I can't now find a reference for that).

These are drop weights, and there are several ways of refitting them for a longer travel on the catenary side. I suspect the main problem is with the 1500 V DC  lines, which are heaver and presumably suffer more from traction current heating. And they are concentrated in the hot and sunny south. But even so, you'd have thought that was a fixable problem by now.


Title: Re: Heatwave July 2022
Post by: Electric train on July 24, 2022, 20:02:04
Of the two main heat effects, OLE sag is the more tractable. In principle, temperature range is just a  parameter fed into the design process, and if you make it a bit bigger you just get a slightly different set of design rules. The obvious free parameter you can change is the maximum wire run length: on those Series 1 figures, reducing that from 1500 m to 1400 m would allow about 5 degrees more temperature range.

Tensioners with a greater adjustment length might work in some cases, but that increases the along-track movement of the wires. All the things bolted to the wires - registration arms in particular - must be able to cope with this extra movement. I suspect the registration arms would not allow much more than 1 m of movement. For the same increase from 74 to 79 K, a 1 m adjustment has to go up by 65 mm.

As a practical response to the current situation, you could look at any places where loss of tension has happened and work out why. If it's a set-up issue, sort it; if it's a place where the wires get very hot for whatever reason and the wire run is long, split that one into two shorter ones. Then you could have a think about what other key points on the network may see high wire temperatures in a future heatwave. The main difficulty I can see with that is that long main lines without junctions can use mostly maximum-length wire runs, and shortening all those would be costly. 

So is this still a serious issue? Well, Network Rail have been saying this about the problem, which suggests exceeding the temperature range of tensioners isn't common:
Quote
Modern overhead lines, which are used on the majority of Britain’s rail network, are much less affected by hot weather. They have auto-tension systems with balance weights or springs that adjust to different temperatures. But older overhead lines have fixed tension and are more vulnerable.

How we minimise delays caused by overheated power lines

We do this by:

  • Adjusting the height and tension of our older overhead power lines in summer to help prevent sagging.
  • Introducing temporary speed restrictions to minimise the force on the overhead power lines. Speed restrictions reduce the risk of damage and keep services running but they can cause delays. We have to balance the inconvenience of delays against the risk of the greater disruption that would be caused if we need to fully close the line.
  • Replacing old overhead lines with modern, more resilient auto-tension power lines.

What was a surprise there was that there is any fixed wire without tensioners outside sidings and depots. I could only think of Tyne and Wear Metro (1500 V DC), which isn't NR's track except perhaps the bit that's shared. And maybe the fringes of Glasgow Suburban? But not on main lines, you'd hope.

Perhaps surprisingly, SNCF have always struggled in this area, and drooping caténaires are still part of their PR message in hot weather. And that's despite having time to do something about it - I recall hearing of a big programme of uprating tensioners in France (though I can't now find a reference for that).

These are drop weights, and there are several ways of refitting them for a longer travel on the catenary side. I suspect the main problem is with the 1500 V DC  lines, which are heaver and presumably suffer more from traction current heating. And they are concentrated in the hot and sunny south. But even so, you'd have thought that was a fixable problem by now.

There are a number of factors to be considered with increasing the tension on OLE. 
The registration on curved track will need to be enhanced to accommodate the pull / push of forces.
The actual contact wire alloy may need to be changed
The dynamic uplift will be reduced thereby increasing the wear on the pan and may even put it outside the spec of the pan uplift force
Increased tension on the OLE can lead to more OLE component failures if they have not been changed to accommodate the increase in forces.

There may be some fixed equipment about, if I recall correctly there is a max speed limit of 70 mph on plan line and as low as 40 on radiuses

DC 1500V contact wire is much heavier gauge almost twice that of 25kV


Title: Re: Heatwave July 2022
Post by: BBM on July 24, 2022, 21:29:59
What was a surprise there was that there is any fixed wire without tensioners outside sidings and depots.

Ardwick to Hadfield and Glossop via Guide Bridge still has fixed wire catenary without tensioners which was installed in the 1950s as part of the Woodhead electrification project. The insulators were replaced in the 1980s when the OHLE was changed from 1500V DC to to 25kV AC but no other upgrade work was carried out. Last Monday as a precaution the EMUs were replaced by DMUs but on Tuesday the service had be stopped altogether due to a sagging contact wire at Gorton.


Title: Re: Heatwave July 2022
Post by: stuving on July 25, 2022, 13:36:06
While looking for helpful material about track thermal expansion and its problems, I came across an RAIB accident report which is more useful than all the rest together! This is report 11/2016, "Derailment of a freight train near Langworth, Lincolnshire, 30 June 2015" (https://assets.publishing.service.gov.uk/media/576d3cffe5274a0da9000090/R112016_160627_Langworth.pdf). It's so useful because the accident was a derailment caused by buckled track, and also because RAIB do try very hard to explain technical issues clearly as well as accurately.

The train contained 22 empty diesel fuel tank wagons, of which nine derailed and four rolled over. If they had been full, you'd probably remember it now - as it is you probably didn't even notice at the time.

Most of the report is relevant, but the section of "background information" starting on page 19 has a broader application. However, it isn't a complete primer on "how to manage track to avoid buckling" - it leaves out a lot that is not relevant to this accident. For example, it mentions "adjustment switches" (aka scarf joints) because there are some in the other track, but does not say how they are used in general.


Title: Re: Heatwave July 2022
Post by: paul7575 on July 25, 2022, 18:26:48
Adjustment switches are apparently fitted at the transitions between an area of CWR, and an area of conventional track, or if “non-strengthened” S&C is fitted in an otherwise continuous section of CWR .  (So I assume there’s a type of strengthened S&C which can be stressed.)

It’s just recently been emphasised in RailUK forums that in principle you can have many miles of CWR without any adjustment switches, the way it was explained was “if there were breathers fitted it wouldn’t be continuous”..

Paul


Title: Re: Heatwave July 2022
Post by: TonyK on July 26, 2022, 20:22:54
The areas that might get 40 degree heat aren’t generally the same areas that get sib-zero. Russia being one….abd generally France.

Crossing the Gobi Desert back in May 2012 at about midday..... 
(https://hosting.photobucket.com/images/ww255/PhilWakely/Gobi_Display.JPG)

(I suspect there may have been a fault in the thermometer!)

Not as big a fault as this one:

(https://live.staticflickr.com/65535/52243825795_377f56ac99_c.jpg)

in 32°C Mahon earlier this month. I'm not sure I would trust a medical thermometer supplied by that pharmacist.



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