Why Cambridge South was not built with two islands instead of side/island/side platforms

[Maltazer]

2. Why didn't they design the station to have two island platforms? That would have been much more passenger-friendly than what they are actually building, since it would mean all trains in the same direction would depart from the same island, and I would have thought would have been no more expensive either: Fewer platforms to build lifts and other stuff for, and perhaps no need to reroute the existing tracks round a platform.

mods note - split from this thread

Cambridge South new station opening

Look like it on as top story in Cambridge News today all private money as well. I can't post link to story.

www.railforums.co.uk

I asked that during the consultation. The answer was:

"A layout featuring two island platforms in the North location would not be a viable option as it would necessitate reconstruction of the Guided Busway bridge. This would be an expensive operation that would be resisted by Cambridgeshire County Council, who own this asset"

 

[swt_passenger]

Two thoughts watching that video.

[…]

2. Why didn't they design the station to have two island platforms? That would have been much more passenger-friendly than what they are actually building, since it would mean all trains in the same direction would depart from the same island, and I would have thought would have been no more expensive either: Fewer platforms to build lifts and other stuff for, and perhaps no need to reroute the existing tracks round a platform.

It’s discussed way back in the thread. The whole track formation would need to be wider for a longer length, impacting on existing bridges. For passenger access from both sides it would need an extra fourth set of lifts and stairs. Future four tracking south of the station for EWR means the layout will no longer be D/D/U/U but D/U/D/U, ie paired by use.

 

[Magdalia]

Why didn't they design the station to have two island platforms?

Another factor is that two island platforms would have required a bigger land take from Hobsons Park.

 

[alistairlees]

Impressive station - what's less impressive is the screens constantly having London services alternating between Platforms 1 and 2 - often contradicting announcements being made and changing while the train is seconds away from arrival.

I assume its track circuit related and needs ironing out but keep that up and there'll be accidents with people running up and over the bridge (and back).

I hadn't realised that such a stupid design had been used. Island platforms for each direction of travel would have improved the customer experience hugely, as well as giving greater operational flexibility (changing platforms would not matter so much). Fewer platforms is also better for ensuring retail unit success, if they are on the platforms. I would have thought that lessons would have been learned from the poor experience at Redhill platform 0 (last minute changes are stressful / an accident waiting to happen; and there are no facilities at all on platform 0 at Redhill.)

 

[quantinghome]

I hadn't realised that such a stupid design had been used. Island platforms for each direction of travel would have improved the customer experience hugely, as well as giving greater operational flexibility (changing platforms would not matter so much). Fewer platforms is also better for ensuring retail unit success, if they are on the platforms. I would have thought that lessons would have been learned from the poor experience at Redhill platform 0 (last minute changes are stressful / an accident waiting to happen; and there are no facilities at all on platform 0 at Redhill.)

Once EWR is built the entire section from Shepreth Branch Jn to Cambridge station will be four-tracked, with tracks paired by use (for EWR and WAML) not direction. So in the long term there's no point having island platforms.

 

[sharpener]

I hadn't realised that such a stupid design had been used. Island platforms for each direction of travel would have improved the customer experience hugely, as well as giving greater operational flexibility (changing platforms would not matter so much).

Was discussed extensively upthread and/or elsethread. AFAIR having island platforms would have required the outer tracks to spread wider apart and this would have involved more land take.

Once EWR is built the entire section from Shepreth Branch Jn to Cambridge station will be four-tracked, with tracks paired by use (for EWR and WAML) not direction. So in the long term there's no point having island platforms.

True but this will not fix the issue for ppl simply wanting to catch the next train to CBG.

 

[Royston Vasey]

True but this will not fix the issue for ppl simply wanting to catch the next train to CBG.

Yes but pairing by direction would create a ton of conflicting movements either at Shepreth Branch Jn or the Cambridge throat, and undo all the capacity benefits of that four tracking and pairing.

 

[sharpener]

Yes but pairing by direction would create a ton of conflicting movements either at Shepreth Branch Jn or the Cambridge throat, and undo all the capacity benefits of that four tracking and pairing.

Well yes. Except the lovely four tracking and pairing will not be complete until they have replaced Long Road bridge.

Once they had decided on the CMS platform configuration the only way of solving the "next train to CBG" issue would have been to use P2 and P3 as the two down platforms! Obviously not v. practical unless they also built a flyover like Holloway.

None of this solves the problem that traffic from KGX/STP into P7/P8 at CBG has to cross everything that uses P1...P4 somewhere.

 

[wagnaga]

Well yes. Except the lovely four tracking and pairing will not be complete until they have replaced Long Road bridge.

Once they had decided on the CMS platform configuration the only way of solving the "next train to CBG" issue would have been to use P2 and P3 as the two down platforms! Obviously not v. practical unless they also built a flyover like Holloway.

None of this solves the problem that traffic from KGX/STP into P7/P8 at CBG has to cross everything that uses P1...P4 somewhere.

I wonder if this will prove less of an issue than we expect. Taking 1100 hour tomorrow at random nine trains run to Cambridge and only two go from platform 4.

 

[TT-ONR-NRN]

Birmingham International and Woking have a similar number of fast trains to Birmingham New St and London Waterloo each hour split between two side platforms, and they cope fine. I'm sure it won't prove that much of a major issue.

 

[Zomboid]

It's pretty easy to look at the departure board and find out where your need to go. No doubt there will be (should be) a "next train to Cambridge" display to direct people wherever they need to go.