Cambridge (Central) station post East West Rail

[William3000]

With construction work on Cambridge South station now underway, changes to the southern throat to Cambridge (Central) are proposed to allow for 4 tracking as far as Purbeck Road.

The current layout at Cambridge seems quite inefficient and despite 8 platforms is not far away from being at capacity at many times of the day. My understanding is that as part of the East West rail proposals there are plans for 2 or possibly 3 new platforms on the eastern side of the station, which would provide at least 6 through platforms. Looking at google maps I wonder whether there is sufficient room to add a bay immediately south of platform 7 with a narrower single faced platform running southwards from there opposite platforms 1,2, and 3. It seems to me that to really increase capacity there would need to be considerable track route upgrades to the southern throat of the station - be interested in what others think.

 

[mr_jrt]

I suspect they would prefer a topic like this to be in the speculative section of the forum. You may find your previous posts in there if they were also in a similar vein.

 

[zwk500]

There may be room for a 150m platform (so 6x23m would just about squeeze in), but the additional crossing moves would be a real nightmare to fit in without stuffing the timetable.

If EWR are planning on building new platforms (and they probably are) then the sidings will need to be replaced, although there's currently a massive question mark over whether EWR will get to cambridge at all. I believe if they do get there the plan is to 4-track from Shepreth branch Junction (not sure how they'd pair them) and remodel the south end. I do agree though that if you want major capacity increases at Cambridge you do need major work at the southern end.

 

[Magdalia]

Operation of the old part of Cambridge station (platforms 1-6) is very constrained by 21st century signalling rules, designed to reduce the risk of SPADs leading to collisions. These featured in the recent discussion here:

Very late platform change at Cambridge

A few days before Christmas I was waiting at Cambridge (central) for a northbound train to Cambridge North, shown to be at platform 1. There was a southbound (to Stansted) cross country train due a couple of minutes before from platform 4. These are actually 2 ends of a long platform with an...

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One of the advantages of the island (platforms 7 and 8) is the long overlaps that comply with those 21st century signalling rules. The extra platform that you propose would chuck that advantage into the bin.

 

[mr_jrt]

I used to commute through Cambridge and mused quite a bit whilst hanging around the station. The main building is listed (AIUI), but I did wonder if it would be possible to jack it up and move it away from the tracks to enable you to turn 1 & 4 into an island, or even a bit further and end up with all the bays as through platforms. I'm sure if the will was there it could be done, but I doubt it would ever wash its face financially. An entertaining mental picture nevertheless.

You'll never get more than 4 tracks under Hills Road, so any solution has to limit itself to that. As I understand it the lines will be paired by direction, so any use of the bays will incur quite the crossing penalty. You might be able to improve things by restricting 1/4/7 to northbound use, and 8 (and any new 9/10) to southbound use.

Could use of the bays be done away with if more ran to Cambridge North to turn back there instead?

 

[Magdalia]

I used to commute through Cambridge and mused quite a bit whilst hanging around the station. The main building is listed (AIUI), but I did wonder if it would be possible to jack it up and move it away from the tracks to enable you to turn 1 & 4 into an island, or even a bit further and end up with all the bays as through platforms. I'm sure if the will was there it could be done, but I doubt it would ever wash its face financially. An entertaining mental picture nevertheless.

A long while ago I had an even more barmy idea, inspired by a visit to Limerick Junction. That was to have a line through the old steam shed, past the old Station Hotel and out through the Coalfields. Trains could then use the bays at the "wrong" end of the station in the style of the Limerick-Rosslare.

You'll never get more than 4 tracks under Hills Road, so any solution has to limit itself to that. As I understand it the lines will be paired by direction, so any use of the bays will incur quite the crossing penalty. You might be able to improve things by restricting 1/4/7 to northbound use, and 8 (and any new 9/10) to southbound use.

Could use of the bays be done away with if more ran to Cambridge North to turn back there instead?

A bit more seriously, most use of the south end bays (platforms 2 and 3) is now trains coming from and going to the GN. I do hanker after a 4 track layout that allows up trains from platforms 2 and 3 going towards Foxton to avoid any conflicting moves with down trains coming from Shelford and heading into any of the through platforms.

 

[Brubulus]

Platforms 2 and 3 are only used by 1tph off peak and 2tph in the peak because they aren't long enough for 12 car 700s but would be long enough for any EWR rolling stock so EWR stock . Another idea would be to turn P1 into a 12 car bay for the Brighton services plus building another bay by putting a track to the south of p7 and extending p8. Having more than 3 usable through platforms at Cambridge is going to be extremely expensive so if they can't fit all through services the Cambridge North terminators might need to be cut back. Regarding track layout having 2 tracks for GN and 2 for WA seems like a good idea.

 

[mr_jrt]

Could the new island platform be lengthened to provide a pair of additional platforms? More old musing, but I wondered at the time they announced it if they could emulate 1&4 on both sides of the new island to squeeze in more platforms, sharing the platform through line by adding another double crossover slightly north of the current one, and using one of the freight through lines on the other side of it for the same. I would imagine they wouldn't want to introduce something like that nowadays. It would enable them to be used for terminating services from either direction without blocking through services, though.

 

[cle]

There is definitely room at North for another platform. The odd extra service could go there. I’d think EWR go into the current WA bays (shorter trains, right side of the pairs), and those Liv St services all go through p4 to North, and back through p8.

If there was also another island, or even a side ‘9’ - one would hope that the main 1/4 could be made to operate like a normal through platform - vs the splitting and scissor moves.