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IoW light rail conversion proposed


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6 hours ago, John M Upton said:

Is there any sign of movement of new 484's coming in or 483's going out yet? 

 

Nope,  there's still plenty to do and I presume they want to make some progress with testing at Eastleigh first.

Edited by Christopher125
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On 14/02/2021 at 19:25, Mike Storey said:

 

But you cannot just weld the rails together!! They have to be stress-treated and laid, with expansion joints (diagonal cuts) at ambient intervals. It would almost certainly also require major re-rerailing and re-sleepering, to absorb the stresses. Plus the track circuits (I presume they have them????) would need significant alteration. So, if you were going to do it, better now than in a piecemeal fashion over many years and many closures. but it can be done, of course, at a price.

 

IIRC at least one heritage railway has taken the step of welding up every other joint (i.e to create 120ft long panels) and has not experienced major problems or been required to stress treat the rails. Although it may sound trivial, the big reduction in the number of bolted rail joints produced considerable maintenance savings as well as a smoother ride.

 

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11 hours ago, phil-b259 said:

 

IIRC at least one heritage railway has taken the step of welding up every other joint (i.e to create 120ft long panels) and has not experienced major problems or been required to stress treat the rails. Although it may sound trivial, the big reduction in the number of bolted rail joints produced considerable maintenance savings as well as a smoother ride.

 

Glow and Warks on the extension from Toddington to Broadway. If you find the extension blog or the heritage blog both cover the welding.

 

Keith

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51 minutes ago, KeithHC said:

Glow and Warks on the extension from Toddington to Broadway. If you find the extension blog or the heritage blog both cover the welding.

 

Keith

The GWSR extension has conventional stressed CWR. There is a video of the stressing here:

 

 

 

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2 hours ago, KeithHC said:

Glow and Warks on the extension from Toddington to Broadway. If you find the extension blog or the heritage blog both cover the welding.

 

Keith


Not quite the same thing - Welding up to 60ft panels to create a 120ft one is very different to several miles of CWR.

Edited by phil-b259
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On 14/02/2021 at 19:25, Mike Storey said:

 

But you cannot just weld the rails together!! They have to be stress-treated and laid, with expansion joints (diagonal cuts) at ambient intervals. It would almost certainly also require major re-rerailing and re-sleepering, to absorb the stresses. Plus the track circuits (I presume they have them????) would need significant alteration. So, if you were going to do it, better now than in a piecemeal fashion over many years and many closures. but it can be done, of course, at a price.

You can. There are considerations, principally the fastening type, but it is possible. There are three sites I converted on Wessex from jointed to CWR. Cut the bolt holes off, installed a closure rail and welded it up, last weld was used as the stress weld. On one location we used the flash butt welder. Adjustment switches, which I assume you mean by expansion joints, are not required in CWR unless at the transition between CWR and Jointed, to protect un-strengthened S&C or at some structures. I discussed with my S&T and E&P colleagues when planning the work, but never had any issues.  
In regards to the IOW, my main concern would be track stability, the ballast, and I use the term loosely, is not ideal for stressed track, it’s mostly shingle and very fluid. The one location of welded track, approaching Lake, is ballasted with proper stone, though the section is more akin to LWR as opposed to CWR. Having conducted an asset assessment on the line last year, CWR does not justify itself on the line. From a maintenance point, it would be a hindrance to it, the jointed system is more that suitable. 

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On 20/03/2021 at 21:50, phil-b259 said:

 

IIRC at least one heritage railway has taken the step of welding up every other joint (i.e to create 120ft long panels) and has not experienced major problems or been required to stress treat the rails. Although it may sound trivial, the big reduction in the number of bolted rail joints produced considerable maintenance savings as well as a smoother ride.

 

The only real down side to 120ft jointed over 60ft jointed is the JCT’s can be affected and the gaps at the jointed ends are more critical in being correct as there is less room for expansion. We have a few locations, and some at 90ft, but most jointed is the standard 60ft. I am aware of one site with 120ft jointed being cut to make it 60ft jointed. 

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12 hours ago, 2251 said:

The GWSR extension has conventional stressed CWR. There is a video of the stressing here:

 

 

 

Great video, shows how wide some gaps need to be to achieve SFT 27. I always like a stressing job, especially through S&C. 
Looks like the sleepers are the SHC fastening type, quickly being eliminated form the mainlines. It’s not uncommon for them to be replaced over a timber site. 

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4 hours ago, Ncarter2 said:

Having conducted an asset assessment on the line last year, CWR does not justify itself on the line. From a maintenance point, it would be a hindrance to it, the jointed system is more that suitable. 

 

Can you say more about what you found? Much is said about how poor the track is compared to the mainland, especially the shingle/gravel ballast, but the 483s clearly didn't help.

 

With track improvements appearing significantly more modest than SWR implied - descoped presumably - it will be interesting to see how the 484s cope and if/how quickly some of the old characteristics return.

Edited by Christopher125
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I am not sure that 60 ft rail lengths have an engineering basis. They are simply the longest lengths which can easily be carried on a single rail vehicle, and came after periods where standard lengths were 23 ft, 27 ft, 30 ft, 45 ft etc. At earlier times it was probably the rolling mills which were the limiting factor.

Jonathan

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One of the considerations I would assume for what to do on the IOW would be to factor in it's isolated nature.  Moving in specialist rail maintenance equipment via ferry would be problematic, so a simpler system that can be done using standard non-rail equipment is likely to be the better choice.

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17 hours ago, Christopher125 said:

 

Can you say more about what you found? Much is said about how poor the track is compared to the mainland, especially the shingle/gravel ballast, but the 483s clearly didn't help.

 

With track improvements appearing significantly more modest than SWR implied - descoped presumably - it will be interesting to see how the 484s cope and if/how quickly some of the old characteristics return.

To be fair, it’s not a badly managed line. The track quality that is quoted as being poor is unfair. The ride quality is poor, that is due to the lack of stability given by the shingle. It does make for a fun ride, especially on the longer sections between stations, but the suspension on the 483’s also had a part to play. Sleeper condition was generally fair, the team that maintains it do a great job, they are proactive and keep on top. There has been a lot of works done. It is wrong to compare it to mainline track, it does not see the use or tonnages. It has its areas of concern like any other place on the mainland, but its controlled and maintained. It’s slowly being modernised, the tunnel has good lubrication devices installed, the S&C is being maintained and weld repaired as necessary. It’s fair to say the pier is very much in need of works, but that is being addressed. I will try and dig out some of the photos I took. What I will say, for an asset as old as it is, with equipment as old as it is, it puts some locations on the mainland to shame. 

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8 hours ago, corneliuslundie said:

I am not sure that 60 ft rail lengths have an engineering basis. They are simply the longest lengths which can easily be carried on a single rail vehicle, and came after periods where standard lengths were 23 ft, 27 ft, 30 ft, 45 ft etc. At earlier times it was probably the rolling mills which were the limiting factor.

Jonathan

Evening Jonathan,

 

I would be very interested to hear your thoughts on why you think that, if you wouldn’t mind sharing them of? 

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10 hours ago, PhilJ W said:

I understood that the shingle ballast is to be replaced by stone. Or has that now been dropped?

I think it’s targeted locations, I can’t see

them replacing near 8 miles of shingle for ballast. Even if they are aiming to, unless the replace the bed as well, the issues of stability will still exist. 

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As I said, rail lengths started much shorter. To give a specific example, the joint RR/GWR which opened in 1875 was laid with 27 ft rails (Inspecting Officer Col Rich's report); unfortunately later the Inspecting Officer usually said "the normal standard of the company" or similar).

Until about the 1930s 45 ft was about the maximum and then 60 ft became the norm - the GWR standardised on it first in 1929 but it later got written into standards. That was certainly at the time the longest that could be shipped on a single wagon. I am sure that if wagons had easily been able to carry 70 or 75 ft lengths they would have become the norm, but there were very few 70 ft vehicles until fairly recently (the GWR carriages were one exception and they were restricted as to where they could run, even on the GWR with its more generous loading gauge).

Then we started welding lengths into longer runs and carrying them on rakes of wagons - one welding site for example was on the old S&M near Shrewsbury. Was 300 ft the norm then?

So while I am sure that 60 ft may have made sense it was constrained by transport, not track engineering considerations. 

Incidentally, there is on RMWeb a discussion of the shortest lengths of rail permissible, which is useful for modellers even though the standards referred to were introduced after the Hither Green accident.

I am no expert on track, and only using what evidence I have seen and I may be making wrong assumptions, but if so I am not sure which.

Jonathan

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1 hour ago, corneliuslundie said:

As I said, rail lengths started much shorter. To give a specific example, the joint RR/GWR which opened in 1875 was laid with 27 ft rails (Inspecting Officer Col Rich's report); unfortunately later the Inspecting Officer usually said "the normal standard of the company" or similar).

Until about the 1930s 45 ft was about the maximum and then 60 ft became the norm - the GWR standardised on it first in 1929 but it later got written into standards. That was certainly at the time the longest that could be shipped on a single wagon. I am sure that if wagons had easily been able to carry 70 or 75 ft lengths they would have become the norm, but there were very few 70 ft vehicles until fairly recently (the GWR carriages were one exception and they were restricted as to where they could run, even on the GWR with its more generous loading gauge).

Then we started welding lengths into longer runs and carrying them on rakes of wagons - one welding site for example was on the old S&M near Shrewsbury. Was 300 ft the norm then?

So while I am sure that 60 ft may have made sense it was constrained by transport, not track engineering considerations. 

Incidentally, there is on RMWeb a discussion of the shortest lengths of rail permissible, which is useful for modellers even though the standards referred to were introduced after the Hither Green accident.

I am no expert on track, and only using what evidence I have seen and I may be making wrong assumptions, but if so I am not sure which.

Jonathan

Hi Jonathan,

Interesting and insightful. Unfortunately for me, I can only go on fairly modern, by comparison, standards. That said, having been subjected to many an old video during numerous training courses, I do believe that there was an engineering basis applied, while I don’t disagree with your statement on using differing lengths in the early days, I do think when 60ft was settled on, there was a form of judgement for it, in addition to the logistical one. The calculations we use today are not much changed from years gone by and days of old. I vaguely remember one the the training videos showing how the LNER completed a relay and working out the gaps required to ensure correct JCT’s were achieved. 
Indeed, JCT’s play a big part these days, and length between joints will affect them. This then affects the CRT’s. Simplistically, 60ft jointed would be preferred to say 120ft, this due to the cumulative room for expansion over more joints. While the longer length offers better ride quality and in theory lowers maintenance cost, it also presents a more challenging engineering risk. Think of it like this, at a set rail temperature, with a set gap in the joints, the JCT will be higher the smaller the length of rail is. This in turn means the CRT will follow suit. So from a modern day perspective, 60ft is preferred. 15ft is the normal minimum rail length that can be installed, however in S&C this can be reduced, there are several locations I know of where the rail length covers 3x sleepers.  
The attached is the best I could find, but it shows what I mean. The gap is 8mm at 10degrees. As each gap reduces to zero you see roughly what temperature that would be at. As you can see, the shorter the rail, the higher the temperature it can handle before the gap closes. This of course is why prior to hot weather, there is a program of works to get the track ready, hot weather preparedness. This will consist of a joint gap survey, calculations being made to assertion JCT’s/CRT’s and then a decision on if rail adjusting is required. If adjusting is undertaken, a further joint gap survey is completed to confirm

the correct gaps have been achieved. 


JCT- joint closure temperature 

CRT-critical rail temperature 

07FFECD7-8E64-472C-B6C4-0337BBB4198A.jpeg

Edited by Ncarter2
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5 hours ago, Ncarter2 said:

To be fair, it’s not a badly managed line. The track quality that is quoted as being poor is unfair. The ride quality is poor, that is due to the lack of stability given by the shingle. It does make for a fun ride, especially on the longer sections between stations, but the suspension on the 483’s also had a part to play. Sleeper condition was generally fair, the team that maintains it do a great job, they are proactive and keep on top. There has been a lot of works done. It is wrong to compare it to mainline track, it does not see the use or tonnages. It has its areas of concern like any other place on the mainland, but its controlled and maintained. It’s slowly being modernised, the tunnel has good lubrication devices installed, the S&C is being maintained and weld repaired as necessary. It’s fair to say the pier is very much in need of works, but that is being addressed. I will try and dig out some of the photos I took. What I will say, for an asset as old as it is, with equipment as old as it is, it puts some locations on the mainland to shame. 

 

That's a fascinating insight, thanks - you could tell the difference shingle ballast makes when it was replaced under Smallbrook Lane last year, like being on a totally different railway.

 

Don't suppose you heard anything about plans for the tunnel? I'd have though that was one section of track they'd be keen to relay given how many times it's flooded, and SWR recently suggested it may need lowering to fit the trains through anyway.

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40 minutes ago, Christopher125 said:

Don't suppose you heard anything about plans for the tunnel? I'd have though that was one section of track they'd be keen to relay given how many times it's flooded, and SWR recently suggested it may need lowering to fit the trains through anyway.

 

That's interesting.

 

Obviously, I might be reading this incorrectly - but it sounds like they've got a tunnel known for flooding - so they're planning on lowering it (which is unlikely to improve the flooding) and running track powered electric trains through it!

 

Even if the trains are powered by batteries through this tunnel, a move like this sounds rather strange, unless they're also improving the drainage.

 

 

Huw.

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7 hours ago, Christopher125 said:

 

That's a fascinating insight, thanks - you could tell the difference shingle ballast makes when it was replaced under Smallbrook Lane last year, like being on a totally different railway.

 

Don't suppose you heard anything about plans for the tunnel? I'd have though that was one section of track they'd be keen to relay given how many times it's flooded, and SWR recently suggested it may need lowering to fit the trains through anyway.

It was a workout walking along it! Myself and a colleague covered the full

line in two days. We were sensible and started at Shanklin so were walking down grade. 
 

I was under the impression the clearance was ok through the tunnel, but I will double check the documents. Surprisingly, the tunnel was not too bad, sleepers and rail both in good condition. You could see previous evidence of water levels on the walls. I’m not sure how often it floods, but given new lubrication units have been sighted with the tunnel itself, I’d be very surprised if the issue is a severe as it has been previously. During my February visit, the weather was very poor, the pier was shut to trains. Unfortunately for me, I then had access to inspect, great as there was no time limit, not so good due to the amount of sea showers I received! 

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