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| London Bridge Remodelling 17/10/2012 at 23:26 #36635 | |
GeoffM
6282 posts |
Many of you know that London Bridge has train services that cross each others paths throughout the day. Over the next numerous years there are a number of stageworks to resignal and remodel the entire Metropolitan Junction to New Cross [Gate] area. I can give a rough outline of the stages needed to do this which might be interesting to some. Maybe a magazine's already done it, or will be doing it. Perhaps people can update this thread as time goes by to inform people of the progress. The basic idea is to split the trunk section into four distinct routes:
London Bridge Low Level gets downgraded to six platforms; High Level gains with a total of nine through platforms, mostly bi-directional. The problem is that during all these works, a minimum service level has to be maintained - two tracks to Charing Cross, two to Cannon Street, and six terminal platforms at London Bridge Low Level. Thameslink gets diverted for a while. London Bridge Low Level gets remodelled by taking out platforms 14-16 and using the space to produce two new platforms which are then signed into use. Then 12-13 are taken out and two new platforms put alongside the previous new platforms. 10 and 11 get the same treatment; however 8 and 9 do not get replaced for the low level. The new platforms get letters instead of numbers. Similarly, for the High Level, platforms 5 and 6 get removed, leaving Charing Cross services to run through non-stop. After platform 5/6 is removed, the Up Charing Cross trains get slewed over to the former 5 trackbed. This now leaves room for three new platforms to be built, whereupon the Charing Cross services use the new bridges from Metropolitan Junction to the new platforms and out to lines 5 and 6. The Cannon Street lines then get skewed over towards those new platforms, albeit running through non-stop. This enables platforms 1-3 to be remodelled, after which the Cannon Street lines get reconnected to their original alignment (roughly). There is now a gap between the Charing Cross and Cannon Street platforms, which enables the Thameslink platforms to be built and the rest of the switches and crossings to be put into place. The Thameslink services can now run from Metropolitan Junction on the old viaduct to the new platforms at London Bridge. At Metropolitan Junction, a new double crossover will merge the fast and slow lines and take them over the new bridges to London Bridge. The Slow lines, however, also continue to the old Metropolitan Junction where a double (part triple) track from Blackfriars comes in, and continues on the old alignment to London Bridge. Currently the layout is interlocked using Westpac and SSI technologies; these will be changed to Westlocks during the course of the project. There are numerous other slight realignments, whole sections of line taken out of use for a while, and other modifications too difficult to describe in words, but I hope the above gives some idea of the scale of the project! SimSig Boss Log in to reply The following users said thank you: Class 92, ajax103, cdoward, Philo, andyb0607, TimTamToe |
| London Bridge Remodelling 18/10/2012 at 08:06 #36636 | |
andyb0607
260 posts |
This site shows simplified layouts before and after. Thameslink Blog Not sure how up to date that is as it was posted 4 years back. Log in to reply The following user said thank you: GeoffM |
| London Bridge Remodelling 18/10/2012 at 11:36 #36641 | |
Noisynoel
989 posts |
It's very simplist but basically correct Andy. geoff, you've summed up the latest document I've seen very well, I'll also ad that there are 4 different 'worksites'. Low Level, High Level, Spa Rd & Borough Market. They are all being done by different contractors but must all work at the same pace to ensure that each individual layout change works, for example at one stage 5 Down & 6 Up from New Cross to London Bridge get moved across to where 3 Up & 4 Down are now, but this affects both the Spa Rd worksite and the High leel worksite. Also to make things simplier for everyone, when this happens all the signals on 3/4 will be renumbered as the current signals on 5/6 and the lines renamed 5/6, this means that nothing has to change on the panel other than shoing the relevant crossovers out of use. Noisynoel Log in to reply The following user said thank you: GeoffM |