Major termini/large through stations where entry/exit line speeds could be improved

[brad465]

I was thinking recently at how slow approaches/departures from platforms can not only add to a journey time, but reduces the capacity of key stations, as platforms are technically occupied for longer. Kings Cross also came to mind as an example of where line speeds where enhanced in this way, where the entry and exit speeds were 15mph, but trains can now enter at 20mph and exit at 25mph, while higher 45/55mph speeds now exist through the full length of Gasworks Tunnel. Paddington also has a good 40mph exit speed for most terminal platforms.

Ones that came to mind as having good potential IMO include:

Charing X: 15/20mph? If it were possible to raise to 25/30mph this would help with the intensive platform use. Cannon St is probably not possible due to the tight curve on approach/departure.
London Victoria: Currently 15/20mph, perhaps a remodelling could permit 25mph throughout?
Birmingham New Street: 10mph all lines, could 20mph say be achieved with relatively minimal work?
Liverpool Lime Street: Not sure what the specific speeds are, but with both more electric trains and more powerful ones running, thanks to Chat Moss electrification and 802s on TPE, I'd have thought higher speeds up the cutting are now possible, especially if Edge Hill could be remodelled?

 

[ABB125]

Birmingham New Street: 10mph all lines, could 20mph say be achieved with relatively minimal work?

I seem to remember reading somewhere that higher line speeds are not possible due to modern signalling standards requiring longer overlaps ("safe space" if you go past a red signal) than in the past. Indeed, wasn't the line speed reduced from 15mph during the resignalling a few years ago?
At 10mph you can have very short (or possibly non-existent?) overlaps, which allowed essentially the same usable platform lengths as before the resignalling, but at the newer standards. (And even then I think there were a few shortenings?)

 

[The Planner]

I seem to remember reading somewhere that higher line speeds are not possible due to modern signalling standards requiring longer overlaps ("safe space" if you go past a red signal) than in the past. Indeed, wasn't the line speed reduced from 15mph during the resignalling a few years ago?
At 10mph you can have very short (or possibly non-existent?) overlaps, which allowed essentially the same usable platform lengths as before the resignalling, but at the newer standards. (And even then I think there were a few shortenings?)

No, its always been 10mph. New St has no overlaps. It was meant to go up to 15mph on departure.

 

[devon_belle]

London Victoria: Currently 15/20mph, perhaps a remodelling could permit 25mph throughout?

Would be lovely on the Southern side. I'm not certain what remodelling could be achieved in the space, as there is a road bridge to duck under and then a steep bank on the curve. There's a lot of rattly pointwork, so I don't think they could reasonably be traversed at much speed as it stands. I think a 5 mph improvement in linespeed would not be noticed if many trains are still being signal checked while descending Grosvenor Bank. What could be nice is car markers for when the end of the train has cleared the exit speed restriction, though I suspect most drivers will have the positions burnt into their head by now! I think it is an ambition to upgrade the 5th reversible Southern line to > 20 mph, but that doesn't directly speed up the throat.

I think Waterloo suffers from similar problems due to its geometry. The track is just spaghetti. I did wonder whether the 'fast' lines could be swapped with the 'slow' lines on the SWML as far as Wimbledon, to give expresses a 60 mph (?) run through Clapham Junction, albeit possibly worse speeds through Vauxhall. Sadly the slows would not benefit from having two up platforms at CLJ because of the gap. Unsure if platform lengths at Waterloo are sufficient, and it would probably need new platforms at Earlsfield unless the flyover/diveunder is moved. But I digress, that's probably for another thread.

I think it's great to think about speed improvements, as journeys seem to have become so slow. Hopefully with GBR the need for performance allowance in timetables may be reduced.

 

[swt_passenger]

I think Waterloo suffers from similar problems due to its geometry. The track is just spaghetti. I did wonder whether the 'fast' lines could be swapped with the 'slow' lines on the SWML as far as Wimbledon, to give expresses a 60 mph (?) run through Clapham Junction, albeit possibly worse speeds through Vauxhall. Sadly the slows would not benefit from having two up platforms at CLJ because of the gap. Unsure if platform lengths at Waterloo are sufficient, and it would probably need new platforms at Earlsfield unless the flyover/diveunder is moved. But I digress, that's probably for another thread.

You’re right, the first 6 are 10 x 20m platform lengths at Waterloo and couldn’t accept 12.450 or 10.444 if fast and slow were swapped, and they can’t be easily extended because the throat narrows and is on a tight curve. The flyover at Durnford Road would have to be completely rebuilt to work the other way round, at vast expense. The flyover rebuild would be essential to retain the required change from ‘paired by direction’ to ‘paired by use’. Calls at Earlsfield by up slow trains would then have to cease until you rebuild the missing platform on the embankment as well..

 

[Halifaxlad]

Halifax, as all South bound services have to trudle around the island platform rather than straight through the stations thanks to 1970s/80s remodelling and the removal of P3.

 

[brad465]

Would be lovely on the Southern side. I'm not certain what remodelling could be achieved in the space, as there is a road bridge to duck under and then a steep bank on the curve. There's a lot of rattly pointwork, so I don't think they could reasonably be traversed at much speed as it stands. I think a 5 mph improvement in linespeed would not be noticed if many trains are still being signal checked while descending Grosvenor Bank. What could be nice is car markers for when the end of the train has cleared the exit speed restriction, though I suspect most drivers will have the positions burnt into their head by now! I think it is an ambition to upgrade the 5th reversible Southern line to > 20 mph, but that doesn't directly speed up the throat.

Grosvenor Bank is already 40mph despite the curve and bank. It's 20mph at the bottom by the signals controlling entry to the platforms, then 15mph for some of the platforms themselves where I think remodelling for improved entry/exit should be focused. At the moment I imagine the 40mph can't be easily reached anyway, because of the steep bank combined with the start of the 40 zone being right at the base, so trains can't "get a run at it". If however the exit speed was improved, 40/45mph (45mph is from Grosvenor Bridge) could be reached sooner. Likewise, inbound trains wouldn't have to slow down as much.