Could Island Line joined track be replaced by continuous welded rail?

Meerkat · 16 Sep 2019

Moderator note: Split from https://www.railforums.co.uk/threads/class-484-to-replace-class-483-on-the-island-line.192181/

Will they be rerailing with CWR, and making it less of a mobile trampoline?

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Journeyman · 16 Sep 2019

Meerkat said:
Will they be rerailing with CWR, and making it less of a mobile trampoline?

Didn't someone work out that getting CWR across to the island is pretty much impossible? I think you'd need to weld it into long lengths on the island itself, and I don't know what you'd need to be able to do that.

hooverboy · 16 Sep 2019

Meerkat said:
Will they be rerailing with CWR, and making it less of a mobile trampoline?

probably not.

tightened up,re-ballasted and re-tamped would be the most likely solution.Still jointed but adequate for linespeed upgrade to 60mph.
the live rail also needs a good going over to get rid of any nasty bad contacts- this would probably need checking anyway for insulator ratings/condition etc prior to upping the voltage.

trebor79 · 16 Sep 2019

I read an interesting website a long time ago. The author had been involved in some aspect of the permanent way maintenance and reproduced a professional report. The upshot is that "fixing" it properly would require total replacement, even at formation level as the railways on the island were originally poorly constructed, with the formation being too shallow and substandard materials used, partially due to the difficulty and cost of obtaining decent materials.

swt_passenger · 17 Sep 2019

Journeyman said:
Didn't someone work out that getting CWR across to the island is pretty much impossible? I think you'd need to weld it into long lengths on the island itself, and I don't know what you'd need to be able to do that.

There’s mobile technology that could theoretically do any in-situ welding, an RRV mounted flash butt welder was shown in one of the rail mags a while ago, but as has been said it sounds unlikely they’d be welding rails anyway.

swt_passenger · 17 Sep 2019

trebor79 said:
I read an interesting website a long time ago. The author had been involved in some aspect of the permanent way maintenance and reproduced a professional report. The upshot is that "fixing" it properly would require total replacement, even at formation level as the railways on the island were originally poorly constructed, with the formation being too shallow and substandard materials used, partially due to the difficulty and cost of obtaining decent materials.

The report giving details of ballast problems (amongst other issues), written by Mark Brinton, is linked to in this post in the main island line thread:
https://www.railforums.co.uk/thread...ate-and-the-future.154219/page-3#post-3140932

Chris125 · 17 Sep 2019

There's a section of welded track between Sandown and Lake, renewed after privatisation - the contrast with the rest is pretty remarkable!

DarloRich · 17 Sep 2019

swt_passenger said:
There’s mobile technology that could theoretically do any in-situ welding, an RRV mounted flash butt welder was shown in one of the rail mags a while ago, but as has been said it sounds unlikely they’d be welding rails anyway.

this is exactly how it would be done if required

hwl · 17 Sep 2019

DarloRich said:
this is exactly how it would be done if required

And there is plenty of formation / track bed in the single track locations to enable plenty of rail to be welded up into longer lengths in normal operating hours.

Flash Butt welding the 3rd rail together as well as the running rails will also reduce traction current losses. (There are at least 4 sets of RRV mounted 3rd rail flash butt welding gear)

Dunfanaghy Rd · 17 Sep 2019

With CWR laying out the rails and welding them is the easy bit. CWR needs good ballast, not the Island stuff. The logistics of getting decent stone to the Island and out to site are rather daunting, I would imagine. And getting rid of the spent ballast may be harder still. It won't be any good dropping good stone on a bed of ball bearings, which is what a lot of the current ballast is like, so I'm told.

Pat

Chris125 · 18 Sep 2019

Dunfanaghy Rd said:
With CWR laying out the rails and welding them is the easy bit. CWR needs good ballast, not the Island stuff. The logistics of getting decent stone to the Island and out to site are rather daunting, I would imagine. And getting rid of the spent ballast may be harder still. It won't be any good dropping good stone on a bed of ball bearings, which is what a lot of the current ballast is like, so I'm told.

Pat

I think that may have been an objective of the relaying near Lake, to ascertain the cost of a proper renewal with new ballast and welded track given the logistics involved. I guess the outcome wasn't positive...

MarkyT · 18 Sep 2019

An advantage of welding up at least a proportion of the running and power rail joints would be a likely reduction in the total loop resistance for traction current supply. Voltage drop losses should be reduced thereby. Modern traction control equipment on board should be able to handle supply voltage variations better than the old fashioned kit nonetheless, particularly if the units were also fitted with small battery packs to assist with acceleration and to capture braking energy.

Could Island Line joined track be replaced by continuous welded rail?

Meerkat

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Journeyman

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