Clapham Junction platform 17 lengthening

[mr_jrt]

Random question...passing through CJ platform 17 earlier with time to kill and decided to see how much spare platform was available for when Southern move to 8 car services on the WLL.

...well. In a previous discussion I seem to recall suggesting 8 cars should be easy...and I couldn't have been more wrong! From a base of the existing 4 car service, moving the signal and trap points south buys a car's length on the existing platform that gets you to 5, and at a generous push you might squeeze on another car's worth on the northern end...and that's about it.

So does anyone know what Southern have planned? 2 cars of SDO seems a tad optimistic.

You might squeeze some more platform on the south end, but it seems to me to be a great opportunity to sort out the northern end. It means demolishing some station wall and moving the subway entrance, but behind them it's just greenery and an access road that can be bridged over, enabling them to straighten out the platform and get it to 8 cars easily. You would then be able to straighten out 16 as well as shutting 17 for the bulk of the expansion is perhaps feasible, as you can just slew the lines over as you adjust the platforms. Brief sketch.

 

[Chris125]

You might squeeze some more platform on the south end, but it seems to me to be a great opportunity to sort out the northern end.

I can't see how the extra cost and disruption can be justified, i expect it will just be a simple platform extension with perhaps a realignment of the down line to reduce the curvature - i think NR had a study done into the options which is probably knocking about somewhere.

Chris

 

[swt_passenger]

Interesting question, as this seems to have been missed when Shepherds Bush and Imperial Wharf have been mentioned previously. P14 and 15 are already supposed to be extended during 2013 for 10 car use anyway.

TfL's submission to the CP5 HLOS includes a map of the LO and SN WLL services giving details about platform lengthening needs, and it reckons P16 is already 8 car, and P17 is currently 6 car.

Page 58 of this: http://www.tfl.gov.uk/assets/downloads/Item05-RUP-12-July-2011-HLOS2-recommendations.pdf

 

[mr_jrt]

I can't see how the extra cost and disruption can be justified, i expect it will just be a simple platform extension with perhaps a realignment of the down line to reduce the curvature - i think NR had a study done into the options which is probably knocking about somewhere.

That's the thing though...there's no room to extend north without bridging over something as there's less than a metre at best between the down line and the edge of the bridge/embankment, so no room for more platform, at least not without a horrible Shepherds Bush fiasco again.

The curvature on platform 17 has a huge gap currently with the 20m stock in use...I can see an argument for straightening it out on safety grounds. That doing so would help you easily get to 12 cars on 16/15 offers quite the "synergy" That's 3 issues dealt with in one go:

• Lengthening 17 to 8 cars (and once you clear the curve there's loads of ex-sidings land on the other side of the bridge, so 12 is feasible if ever needed)
• Reducing in curvature leading to smaller gaps between train and platform both on 17 as well as 16
• 16 & 15 can be extended to 12 cars more easily in the future if/when the Southern metro services move to 12 cars.

 

[hwl]

Interesting question, as this seems to have been missed when Shepherds Bush and Imperial Wharf have been mentioned previously. P14 and 15 are already supposed to be extended during 2013 for 10 car use anyway.

TfL's submission to the CP5 HLOS includes a map of the LO and SN WLL services giving details about platform lengthening needs, and it reckons P16 is already 8 car, and P17 is currently 6 car.

Page 58 of this: http://www.tfl.gov.uk/assets/downloads/Item05-RUP-12-July-2011-HLOS2-recommendations.pdf

Extension works on 14, 15, 16 have been going on since late last year. The extension of the P15/16 island involves building over the gap between the 2 bridges over Falcon road and they are currently installing the steel framework there at the moment. Looks like they are going for 12 car platform length (i.e. as long as 12/13 which will be useful during engineering works if the BML fasts are closed.

 

[swt_passenger]

Thanks for the info - I haven't been over that side for a few months now.