White painted rails

[a98087]

Having seen the local pway lads painting the rails, it is 100% for heat reduction purposes, the paint they use is just standard white emulsion purchased in bulk from the local diy shop

 

Dan

[PenrithBeacon]

Perhaps it's a case of standard practice being rolled out regardless?

I have spent this afternoon indulging in a spot of observation at Preston NU station and noticed that some switches are painted others not. Also that check rail ends are often painted white too.

 

I have my doubts about this practice being done to reduce expansion. Could it not be done just to make the track more visible in poor light?

 

Regards

[Wheatley]

Painting checkrail ends white is for visibility. Painting more than a few inches of anything else is for heat reduction, at least in the UK, as already explained.

[96701]

I have spent this afternoon indulging in a spot of observation at Preston NU station and noticed that some switches are painted others not. Also that check rail ends are often painted white too.

 

I have my doubts about this practice being done to reduce expansion. Could it not be done just to make the track more visible in poor light?

 

Regards

Not all S&C suffers from expansion problems, so there's no need to paint all rails.

[Richard E]

There are long sections of white painted plain rail on the ECML north of Werrington at Peterborough and around Joan Croft between Doncaster and York. The latter covers at least two or three miles or more of running line. It is definitely a heat reduction method, preventing direct sunlight heating the rail quite as much as it otherwise might.

[Derekstuart]

Has anyone thought of having thousands of cheap desk fans lined up against the line (you can get them in Maplins for 9.99)? Alternatively some big sun hats over S&C. Maybe drench them in very cold draught lager (works for me).

 

Sorry for the pee take but I am very much inclined to agree with Mr Southernman. It does sound that perhaps this is not the ideal engineering solution. I'm not advocating going back to jointed track (I'm not advocating anything as I'm not qualified to do so) but I do wonder whether removing expansion gaps and relying on special engineering properties of special steel together with white paint is really a good thing.

[Trog]

Painting checkrail ends white is for visibility. Painting more than a few inches of anything else is for heat reduction, at least in the UK, as already explained.

I have also painted the ends of conductor rails white partly to reduce the risk of people tripping over them. But mostly because the half of a project I was working on was going better than the other half, and I wanted to wind the other sides staff up that while they were struggling we had time to do twee twiddley bits. It worked as once their senior Tech had stopped swearing, they stole the paint and brushes over night to do their side. 

[Trog]

Sorry for the pee take but I am very much inclined to agree with Mr Southernman. It does sound that perhaps this is not the ideal engineering solution. I'm not advocating going back to jointed track (I'm not advocating anything as I'm not qualified to do so) but I do wonder whether removing expansion gaps and relying on special engineering properties of special steel together with white paint is really a good thing.

There is no special steel involved but with the possible exception of switch diamonds which are known to be particularly sensitive to heat. Painting track white should not be needed if the stress state or rail joint gaps are correct, as the track is designed to take the stresses involved in all but the very hottest of exceptional weather.

[phil-b259]

Has anyone thought of having thousands of cheap desk fans lined up against the line (you can get them in Maplins for 9.99)? Alternatively some big sun hats over S&C. Maybe drench them in very cold draught lager (works for me).

 

Sorry for the pee take but I am very much inclined to agree with Mr Southernman. It does sound that perhaps this is not the ideal engineering solution. I'm not advocating going back to jointed track (I'm not advocating anything as I'm not qualified to do so) but I do wonder whether removing expansion gaps and relying on special engineering properties of special steel together with white paint is really a good thing.

 

You are rather missing the issue, as while there are the odd bits of plain line which have been given the white paint treatment about, the bulk of it is applied to points - where it is impossible to prevent the switch (movable) rail from expanding in the heat regardless of they type of steel used.

 

On continuously welded rail, engineers physically stretch the rail to simulate it being heated to 25 degrees (I am not a p-way engineer so may have got the figure wrong) then weald it up at both ends. Further restrain to movement is done by using heavy concrete sleepers and deep ballasting - both techniques which obviously cannot be applied to points.

[Trog]

Points made for use in CWR have heavy cast iron blocks at the heel end containing multiple (at least eight) high tensile bolts connecting the switch and the stock rails together so as to transfer the stress from one rail to the other. This just leaves the short movable length of the switch blade free to expand, hence reducing movement at the switch toe. All other joints in the layout should either be welded or made with TJ or insulating plates again fitted with high tensile bolts which prevent all movement at the joint.

[Wheatley]

It does sound that perhaps this is not the ideal engineering solution.

It's not, but it works and it's cheap, and it can be done quickly. Especially if you're getting continuously berated to reduce delay minutes now, not sometime in the next control period.

 

Likewise locking toilets out of use isn't an ideal solution, or burying defective DMU cabs by coupling the two units the other way round instead of doing proper fault finding because it's needed in traffic in fifteen minutes and woe-betide you if you start the day showing "-1", or flogging 50 year old diesels and coaches around instead of DafT building new trains, or ... or ... or ...

[phil-b259]

Points made for use in CWR have heavy cast iron blocks at the heel end containing multiple (at least eight) high tensile bolts connecting the switch and the stock rails together so as to transfer the stress from one rail to the other. This just leaves the short movable length of the switch blade free to expand, hence reducing movement at the switch toe. All other joints in the layout should either be welded or made with TJ or insulating plates again fitted with high tensile bolts which prevent all movement at the joint.

 

'Reduce' is not the same thing as 'eliminate'. Even your 'reduced movement' can still be a problem at some sites... as many a S&T engineer will attest. White paint is thus a useful tool to have in the box (particularly when dealing with switch diamonds).

[PaulRhB]

While people are bashing NR for a cheap solution that works instantly while relaying can take ages can I also point out the Swiss do the same and more. The Swiss also use very light grey ballast to bury the rail foot in some problem areas to reflect heat especially in sharp curved areas where lots of movement can cause big problems.

The article I read acknowledged it wasn't a long term solution but it was fast and effective in heat waves.

[Zomboid]

It's not, but it works and it's cheap, and it can be done quickly.

The ideal engineering solution is the one which does the job required of it for the lowest overall cost. If that can be achieved 360 days of the year by stressing the rails to a certain level and painting some bits white, then any other solution is going to have to work better for very little extra cost.

 

So perhaps the white emulsion is the best engineering solution. (I'm not a track engineer, so I don't know about that specifically, but I do make a living through being an engineer). Might not look pretty, but when it comes to things like track, I expect it's function over form...

[Peter Kazmierczak]

 

I have also painted the ends of conductor rails white partly to reduce the risk of people tripping over them. But mostly because the half of a project I was working on was going better than the other half, and I wanted to wind the other sides staff up that while they were struggling we had time to do twee twiddley bits. It worked as once their senior Tech had stopped swearing, they stole the paint and brushes over night to do their side.

Painting the ends of conductor rails? Really?

 

Sounds rather dicey to me. 

[Zomboid]

It's fine so long as you use a brush with rubber bristles

[37038]

Having previously been a Senior Technical Officer at Network Rail, I would just like to add a curve-ball....

 

Yes, most white sections of rail are heat-related, but some sites which are at high risk of rail gall / corrosion have been re-railed with coated rails (where the protective layer is white).

 

Little bit more info here: http://www.railengineer.uk/2015/12/28/in-case-you-missed-it-the-end-of-the-line-for-rail-corrosion/

[Pacific231G]

Having previously been a Senior Technical Officer at Network Rail, I would just like to add a curve-ball....

 

Yes, most white sections of rail are heat-related, but some sites which are at high risk of rail gall / corrosion have been re-railed with coated rails (where the protective layer is white).

 

Little bit more info here: http://www.railengineer.uk/2015/12/28/in-case-you-missed-it-the-end-of-the-line-for-rail-corrosion/

Though plugging Tata steel's products this is a fascinating article and does illustrate that, as with most aspects of railway engineering, there's a lot more to it than most of  us lay enthusiasts would ever consider. I'd be very surprised if there wasn't a lot more involved in the adoption of white painting tthan simply slapping on several gallons of white emulsion from B&Q. I did find some product information from an Australian company- whose Solacoat product is mainly used for coating roofs to cool buildings- that has sprayed several hundred kilometres of track in NSW and use a zinc primer including a rust inhibitor.

 

My understanding of the situation is that CWR can be pre-stressed to allow for a certain range of temperature difference and the min-max range chosen will depend on local climatic conditions. Unfortunately extremes of temperature are becoming more common and under direct sunlight the temperature of rail can rise to far higher levels than the general local temperatire.

 

NR say that white painting of rail reduces peak rail temperature by between 5 & 10^o(Coolshield International Pty Ltd, quote 7-12^o in Australian conditions)   It's a simple, effective and cheap solution to a problem  increasingly affecting railways worldwide so I can't see why it would be seen as a "less than ideal engineering solution". As a lapsed engineer simple, effective and cheap sound to me like the hallmarks of good engineering. I'm sure to the uninformed public the idea of blowing sand onto rails to improve adhesion also sounds a bit primitive. . 

 

 

[PenrithBeacon]

Having previously been a Senior Technical Officer at Network Rail, I would just like to add a curve-ball....

 

Yes, most white sections of rail are heat-related, but some sites which are at high risk of rail gall / corrosion have been re-railed with coated rails (where the protective layer is white).

 

Little bit more info here: http://www.railengineer.uk/2015/12/28/in-case-you-missed-it-the-end-of-the-line-for-rail-corrosion/

Interesting! The track layout at Preston NU is basically running North/South although of course that cannot quite be said for the crossovers. That being said the time that the sides of the crossover rails will be in direct sunlight will be pretty small on any given day.

 

The rails in this location are of course at risk of corrosion and I wonder if this product has been used here. I'll probably never know.

 

Also when paint is used for heat protection purposes does it have an unusual composition? It not only has to reflect heat but it also has to be self cleaning and provide protection against corrosion. Track work is not a clean environment and rail is susceptible to corrosion. If the rail corrodes then it will cause spauling of the paint.

 

An interesting problem for an industrial chemist.

[Fat Controller]

Interesting! The track layout at Preston NU is basically running North/South although of course that cannot quite be said for the crossovers. That being said the time that the sides of the crossover rails will be in direct sunlight will be pretty small on any given day.

 

The rails in this location are of course at risk of corrosion and I wonder if this product has been used here. I'll probably never know.

 

Also when paint is used for heat protection purposes does it have an unusual composition? It not only has to reflect heat but it also has to be self cleaning and provide protection against corrosion. Track work is not a clean environment and rail is susceptible to corrosion. If the rail corrodes then it will cause spauling of the paint.

 

An interesting problem for an industrial chemist.

It might be that the track components you saw had been re-used. Someone has mentioned already that the paint used was what is sometimes described as 'wallop'- trade-quality emulsion.

White paint has been used elsewhere on the railways to reduce solar gain: there was a fleet of VDA vans used for Rowntree-Mackintosh chocolate traffic that gained white roofs for this very reason. Apparently, on one occasion, a normal VDA was substituted on a sunny day, and the cargo melted.

[phil-b259]

Track work is not a clean environment and rail is susceptible to corrosion. If the rail corrodes then it will cause spauling of the paint.

 

 

 

Which is why it has to be reapplied every year at the start of the summer. Thing is even dirty white is better than the normal rusty brown when it comes to reflecting sunlight.

[Ian J.]

All my model railway stuff (and pretty much everything else I own) is in a storage container at the moment. The top of the container is wide open to the sun, and it isn't painted white. The heat in the first six to twelve inches on the internal underside can get quite fierce (which is why I've made sure to keep stuff away from it). I think I need to suggest to the storage owner to paint the tops white, but as it would take time and cost money, I suspect he wouldn't do it.

[PenrithBeacon]

Interesting! The track layout at Preston NU is basically running North/South although of course that cannot quite be said for the crossovers. That being said the time that the sides of the crossover rails will be in direct sunlight will be pretty small on any given day.

 

The rails in this location are of course at risk of corrosion and I wonder if this product has been used here. I'll probably never know.

 

Also when paint is used for heat protection purposes does it have an unusual composition? It not only has to reflect heat but it also has to be self cleaning and provide protection against corrosion. Track work is not a clean environment and rail is susceptible to corrosion. If the rail corrodes then it will cause spauling of the paint.

 

An interesting problem for an industrial chemist.

I took a look at my video of Preston last night and then I realised that the white faces I saw on the crossovers where actually facing north and would never get any direct sunlight. I didn't see the other side as I was in a 185 going back to Manchester. The seat was forward facing!

 

The plot thickens or perhaps they really are replacement parts.

[Edwin_m]

I took a look at my video of Preston last night and then I realised that the white faces I saw on the crossovers where actually facing north and would never get any direct sunlight. I didn't see the other side as I was in a 185 going back to Manchester. The seat was forward facing!

 

The plot thickens or perhaps they really are replacement parts.

In summer the sun rises a long way north of due east and sets a long way north of due west.  So east, west or even north facing rail faces could still be exposed to sunlight for periods of many hours, although that light would be somewhat less intense than for south-facing ones. 

[Ken.W]

wasn't the trackwork in Glasgow recently renewed, and if so I would be very concerned if they were checking for cracks already. I would think that the use for heat reduction would be more probable to keep the point work running properly.

That would probably explain why it's been done there. I usually see white painted rails in areas where works such as renewals, balast cleaning etc have recently taken place, so the tracks still not fully consolidated and thus more vulnerable to movement. It's often generally the same areas that have precautionary ESRs imposed during extreme heat conditions