Tracks

[whole diary]

[lordgoata]

Hi all,

Popping into Reading on Saturday, I was taking in all the work happening at the new depot area, and noticed that there is a lot of (for want of a better description) raw track, laid out very roughly along a lot of the length of the construction area. Whilst travelling along looking at said track, it suddenly dawned on me how long each piece is.

Then the inevitable question popped into my head ... how the heck does the track get to the railway ?! It looks way too long to fit on a lorry, so I assume it travels by rail, but then thought its too long to go around the bends, surely

I'm intrigued!

[dog box]

Network Rail have a special track dropping off train which is made up of a large number of wagons with a sort of framework to transport and deposit large lengths of track, each length spans many wagon lengths i expect someone wil lbe able to find a photo to post on here

[paul7575]

Continuous welded rail (CWR^▸ (Continuously Welded Rail)) delivery trains are used to move rail to site, and yes the rail does bend round curves - just like the rail that the trains are running on!

I found a video that explains everything about rail delivery, there's a bit of preamble and it gets going about 4 minutes in:

http://www.youtube.com/watch?v=yQDlgmyoGPY

For replacement they'll deliver the new rail either between or alongside the running rails as shown, but for a new job such as at Reading they can drop the rail somewhere alongside the nearest operational track, and then it just gets pulled along the ground to where it is needed.  A track construction machine can then deliver and position the new sleepers, and clip the track onto the sleepers as it goes along.

Interesting video here shows what I mean by new track construction - notice that all there is on the ground ahead is a pair of rails:

http://www.youtube.com/watch?v=piBEReyydBU

Rail is delivered from the steelworks in half lengths IIRC^▸ (if I recall/remember/read correctly), and is welded up into 216m max lengths at Network Rail sites such as at Eastleigh, they have just started a  rail recycling process as well, where they'll cut the defects out of returned CWR and re-weld it into usable 216m lengths for secondary routes.

Paul

[TonyK]

Very true - Tata Steel can supply rail in lengths of 220 metres, or even longer. The maximum length is the length of the delivery train. Going around bends isn't a problem. In lengths like this, without tension, the steel bends easily.

[Boppy]

Hi,

I have another question about tracks that I'm sure lots of people on this forum can answer.

What is the white stuff (looks like paint but may be some thermal compound or something?) that appears to have been applied to the vertical sides of the track at points an don rails around junctions in general.

It appears in various places between Reading and Paddington on my daily commute but I'm guessing is done across the country.

Thanks,

Boppy.

[lordgoata]

Continuous welded rail (CWR^▸ (Continuously Welded Rail)) delivery trains are used to move rail to site, and yes the rail does bend round curves - just like the rail that the trains are running on!

Er yes, I guess in hindsight that was pretty obvious! LOL^▸ (laughing out loud) :-D

Thanks for the info and videos, was very interesting! I could sit and watch them building at Reading all day long, I love seeing how it all develops.

[mjones]

Yes, I'm sure there are a number of us here who find looking at the latest developments at Reading on their way to work more interesting than what they find when they get there!

[BerkshireBugsy]

Hi,

I have another question about tracks that I'm sure lots of people on this forum can answer.

What is the white stuff (looks like paint but may be some thermal compound or something?) that appears to have been applied to the vertical sides of the track at points an don rails around junctions in general.

It appears in various places between Reading and Paddington on my daily commute but I'm guessing is done across the country.

Thanks,

Boppy.

I had noticed this on my journey into reading on the Kennet line and assumed it was something to do with maintenance - we should be told!

[Tim]

Hi,

I have another question about tracks that I'm sure lots of people on this forum can answer.

What is the white stuff (looks like paint but may be some thermal compound or something?) that appears to have been applied to the vertical sides of the track at points an don rails around junctions in general.

It appears in various places between Reading and Paddington on my daily commute but I'm guessing is done across the country.

Thanks,

Boppy.

it is all over the place.  My guess is that it is either:

1) to highlight tripping hazards fro track gangs working at night,  or
2) to reflect the sun and prevent the trackwork heating up, expanding and distorting.

[eightf48544]

1. is near the mark it's all part of the drive towards the 24/7 railway.

As I understand it, it mainly occurs on switches and crossings and is there to alert tamper drivers that they will have to adjust their tamping to accomodate the extra rails.

On the WCML^▸ (West Coast Main Line) the drive towards the 24/7 railway has led to the installation of banks of permanent lights alongside junctions to allow round the clock maintenance. It save having to bring along genrators and stringing lights off poles.

[Boppy]

Thanks for the answer eightf48544!

Boppy.

[Electric train]

The white paint is applied in the summer months to reduce solar heating of the rails, such a simple thing as painting the rail white reduces track circuit faults and other heat stress related failures.  Solar heating is also why some Loc's (location cabinets the boxes that hold track side signaling equipment) have had addition white hats fitted.

[Boppy]

Thanks Electric Train.

Interesting to know that it has such an affect!

[tramway]

In lengths like this, without tension, the steel bends easily.

Possibly not what you were inferring in you comment FTN, but it may be useful for others if there was something readily available regarding pre-tensioning of CWR^▸ (Continuously Welded Rail), which may go some way in explaining the reason behind the speed restriction at Bathampton junction the other week during the warm spell. It was a recently relaid section that may not have been tensioned IIRC^▸ (if I recall/remember/read correctly), and possibly not completely tamped.

It's quite interesting how thermal expasion/contraction is compensated for over large sections of solid rail.

[ellendune]

As I recall (from over 30 years ago) the rail is fixed so that at a temperature that is 2/3 of the way up the accepted temperatuer range, there is no tension or compression.  So at the lower 2/3 of temperatures the rail is in tension (no problem) and at the higher 1/3 of temperatures it moves in to compression (which is when the risk of buckling starts).  This way the extent of compressive forces are limited.  The process of achiveing this is called destressing. 

If my memory iss playing tricks I am sure someone will correct me.  They might also remember the temperatures concerned.