Two St Pancras Platforms

[Firestarter]

Two Platforms at St pancras.
Can any-one tell me why only two through platforms were built at St Pancras lower level. I know Kings cross Thameslink only had two but surely with the GN side planned to join up at St Pancras and the increase of trains especially during the peak it would have made sense too build two additional through platforms. Can anyone tell me if it was even possible to have two additional through platforms/lines built. At the moment we struggle with one broken down train blocking the line, how are we going to cope when the GN join up and a train fails and blocks the line. Lack of vision/ambition me thinks.

All answers on a postcard Lol!!!:

 

[generalvegitable]

I do agree that the route at the moment is overcrowded, and it may need quadrupling to gain maximum capacity

 

[SWT Driver]

I think there were a couple of other tunnels in that area that I read about, but I recall that they were very narrow & quite steeply graded too.

I also seem to remember that they've been used for something else now.

 

[asylumxl]

AFAIK all trains will be funneled through the "Thameslink box"'s two platforms. Yes, pretty stupid right?

 

[SWT Driver]

Two Platforms at St pancras.
Can any-one tell me why only two through platforms were built at St Pancras lower level. I know Kings cross Thameslink only had two but surely with the GN side planned to join up at St Pancras and the increase of trains especially during the peak it would have made sense too build two additional through platforms. Can anyone tell me if it was even possible to have two additional through platforms/lines built. At the moment we struggle with one broken down train blocking the line, how are we going to cope when the GN join up and a train fails and blocks the line. Lack of vision/ambition me thinks.

All answers on a postcard Lol!!!:

Right I've done some digging around the net and found out, there used to be a connection at London Kings Cross, it was called Kings Cross York Road, it used to be used by suburban trains to Moorgate.

http://www.subbrit.org.uk/sb-sites/stations/k/kings_cross_york_road/index.shtml

As the link will show you any chance of using them again is now zero.

 

[Oracle]

York Road platform was unique, in that it was only served by Up trains, and then after going down 'the hole' and connecting with the ex-LMR line, ran to Kings Cross City Widened Lines, and thence to Farringdon. I am not sure if Down Moorgate trains could stop at Kings X CWL as there was I think no suitable platform. Down trains used to call at Kings Cross Suburban as per the photo, stopping on that steeply-graded ascent from Hotel Curve..Kings Cross Suburban Junction I think?

 

[yorksrob]

Yes, a definate tactical error. With various routes converging on one, i'd have thought that a couple of island platforms so that trains could wait for their paths without causing disruption would have been the bare minimum.

 

[A60K]

York Road platform was unique, in that it was only served by Up trains, and then after going down 'the hole' and connecting with the ex-LMR line, ran to Kings Cross City Widened Lines, and thence to Farringdon. I am not sure if Down Moorgate trains could stop at Kings X CWL as there was I think no suitable platform. Down trains used to call at Kings Cross Suburban as per the photo, stopping on that steeply-graded ascent from Hotel Curve..Kings Cross Suburban Junction I think?

There were both southbound and northbound platforms at Kings Cross City Widened Lines - the station that was originally for the Met and Circle lines as well, and following electrification became KX Midland City and later KX Thameslink.

I *think* although can't be certain, that in the 1970s Moorgate to Midland line trains stopped at KX CWL, but that as Moorgate to Great Northern trains stopped at KX suburban (platform 16?) then there was no need to call at the CWL station as well. For trains heading to the Midland there was no equivalent St P suburban for them to call at, Kentish Town being the next station.

Back to the OP's question now! It certainly would have made more sense to have a southbound island at the least in the new station, so that trains could be allocated a little recovery time at St P to allow smooth meshing of the two routes. I can only guess the reason there isn't one is because of foundations of the original station above preventing the junction being south of the platform?

 

[PhilipW]

"Can any-one tell me why only two through platforms were built at St Pancras lower level"

I think the answer is quite simple and can be expressed in one word - "Money"

 

[hairyhandedfool]

I think they didn't include more platforms partly because of money but also because there was little point. Any train calling at St Pancras low level would go on to Farringdon anyway so unless extra platfroms were built there, City and Blackfriars they would all have to funnel into a single track anyway.

What I find laughable is that they want trains to arrive at and depart from the central London stations inside 2 minutes, ready for the next arrival. IMO it's not acheivable on a regular basis.

 

[williamn]

The trains will be automatically operated through central London, which should help.

 

[PhilipW]

There would be a definate adavantage in having two southbound platforms in that in the (likely) event of a ex-Beford traian and an ex-GN train arriving at the same time, they can be held at St Pancras rather than one of them held in the tunnels.

 

[O L Leigh]

A 4-platform station on a 2-platform railway doesn't make any sense and won't increase capacity. All it will do is add complexity from both an operational and construction basis without conferring any benefit. The only time it might have made sense is if some trains pass through non-stop as it would give the chance to "loop" the slow train and allow the fast one to pass through, but nothing will miss SPX.

Even if you had 4 platforms you've still got the bottleneck getting in and out. It's far better just to have 2 through platforms so that trains can get straight in, stop and be right on their way again, just as the Tube does. Increases in capacity will come from shorter headways and faster loading/unloading trains, and I believe both of these issues are currently being addressed.

O L Leigh

 

[PhilipW]

Even if you had 4 platforms you've still got the bottleneck getting in and out.

Not so if there were separate lines from the Bedford/GN junction to the platforms. As I understand it that distance is minimal . With that separation (at least on the southbound lines) no trains will ever be held at signals in the tunnels. The ex-Bedford and ex-GN trains can arrive side-by-side and await their turn to leave for Faringdon in sequence.

 

[O L Leigh]

It doesn't matter about what happens at the northern end if the southern end is still a constricted 2-track railway. It is this that restricts the capacity. All you'll end up with is longer dwell-times while trains wait the road.

O L Leigh

 

[johnb]

Indeed. It doesn't matter from an operational point of view whether a GN train is held in the tunnel or at a dedicated (pre-junction) platform - the latter is mildly nicer for passengers, but not tens of millions of pounds worth of 'nicer'...

 

[PhilipW]

It doesn't matter about what happens at the northern end if the southern end is still a constricted 2-track railway.
O L Leigh

Actually, I do think it matter what happens at the northern end. With 2 southbound platforms
a) No passenger is held up in the tunnels awaiting the station
b) The capacity in the station to hold many more passengers is greatly increased.

From the passenger viewpoint, this is a considerable improvement.

True, I do accept (without argument) that the track capacity has not been increased to accept more trains per hour

 

[O L Leigh]

Actually, I do think it matter what happens at the northern end. With 2 southbound platforms
a) No passenger is held up in the tunnels awaiting the station

Eh...?

Have you travelled into Kings X recently...? Or Liverpool Street? Being "held up in a tunnel" happens to almost every single train but no-one is complaining.

O L Leigh

 

[PhilipW]

Just because many trains now are held up in tunnels at station entrances does not make that practice desirable, especially if given a little foresight it is avoidable.

I am not complaining. I am just expressing my views on the pros/cons of having more than two platformas at St Pancras. Isn't that what this thread was raised for ?

 

[O L Leigh]

Does that justify the construction company having to build a "box" twice the size of the one that is there now? Wasn't it a big enough project as it was? All just so that passengers don't have to wait in the dark...?

Constructing a major rail station underneath Central London with all it's existing underground infrastructure was a big enough job as it was. Cables, pipes and even an underground river all had to be diverted while care had to be taken not to disturb the foundations of the buildings nearby.

In any case, ATO on the central section together with new rolling stock that should hopefully have lots of nice wide doors will ensure that dwell times are short and headways tight enough to fit all the additional services through the pipe. As I said before, the Tube manages it so why not Thameslink. The only potential fly-in-the-ointment is that any stock suitable for the central section is going to be a bit spartan on the longer distance runs.

O L Leigh

 

[PhilipW]

I entirely agree that the project is not worth doing now. I think that we are stuck with 2 platforms forever. I just hope it works as planned

However in years to come when the platforms are crowded and trains are often held awaiting the station, I wonder if the passengers then will reflect to themselves "It's a pity our forefathers never had enough vision when planning this station".

Aren't we all glad now that skimping and scraping were never part of Brunel's vision.

 

[O L Leigh]

I'm just not sure that a "box" big enough to accomodate 4 platforms was ever going to be feasible. As I hinted above, it was a massive project as it was and, given that the southern approaches are never going to be anything other than 2-track, the benefit of the additional platforms are, from an operational perspective, pointless. I'm not even convinced that there is enough room at the northern end for more than 2 tracks. Therefore why bother with all the additional expense and hassle? Unfortunately you can't just drive a mainline railway right through the middle of one of the most congested capital cities in the world.

The key to Thameslink capacity is through-put, as it always has been. The central section has to be operated almost like a Tube line rather than a mainline railway, which means, as I've said a couple of times already, tight headways and short dwell times. Heck, even Crossrail is going to be a 2-track railway and will need to operate in a similarly efficient manner.

O L Leigh

 

[A60K]

The key thing is that it is going to be operated like a tube line. For that to work you need to minimise delays to avoid knock on effects.

I agree it would be virtually impossible to add another platform now, and may have been impossible anyway in the first place.

However, operationally two southbound platforms would have offered significant benefits.

Metro systems generally work better without branches, but taking the tube as an example there are several places where lines converge at a station as Thameslink will do. Many of these have two platform faces of an island available for converging trains, and only a single platform used for diverging: Leytonstone, North Acton, Baker Street (until the Jubilee opened), North Greenwich (no branch yet, but the station is explictly designed for it), Finchley Central. Many other junction stations have two platforms in both directions at junctions: Camden Town, Earl's Court, Acton Town, Kennington, Edgware Road, Harrow. A minority have only one platform, mostly on the sub-surface lines where it would be very expensive to rebuild - or are in low frequency areas such as Woodford or Chalfont.

It certainly does help operating, and is more convenient for the passenger, to have two platforms wherever practical.

 

[O L Leigh]

It certainly does help operating, and is more convenient for the passenger, to have two platforms wherever practical.

Please can someone quantify this for me, because I really don't see the logic.

Where you have converging lines you will inevitably get a bottleneck where traffic density is high. You have to carefully timetable and control your train running to ensure that services don't delay each other. In the event that two trains arrive at the junction at the same time, one will always have to wait. All an extra platform does is move the junction from before the station to after it.

O L Leigh

 

[MCR247]

But with one platform, the chances are, most of the time, your train will depart from platform x , if you are heading to y. Where as, when you have trains coming on after the oher with doors not staying open all that long, its not a great idea, to be standing on the footbridge or whatever to see which platform a train to y comes in on

 

[O L Leigh]

Surely the platforms will simply be "northbound" and "southbound". All that then requires the punters to remember is which side of the Thames they live.

O L Leigh

 

[robertclark125]

A restricting factor in expanding the tunnel was acutally the Victoria Line. When the Vic was being built in the 1960's, part of the tunnel that Thameslink now uses had to be replaced. The tunnel was brick with no inverts or inverts of varying depth. A lenghty section was replaced with concrete, to allow the strucutre to be stable when building the Victoria line below.

Failure to do so could've caused the midland tunnel to collapse.

 

[PhilipW]

Perchance there were to be 2 southbound platforms (which we now all accept will not happen), common sense says that it should be an island platform, so passengers get to both via common escalators/stairs. They just then have to look at the departure boards to decide whether to turn left or right depending where they are going.

If the standard station dwell time is planned as 45 secs, then some trains from one branch may well be in the platform longer awaiting their departure slot if they arrived a little early or the train from the other branch was slightly late.

In these cases I would argue that it has been to the passengers' benefit to have the junction after the station rather than before it. Some people may say the benefit is only slight, but still a benefit.

 

[Snapper]

Yes, a definate tactical error. With various routes converging on one, i'd have thought that a couple of island platforms so that trains could wait for their paths without causing disruption would have been the bare minimum.

Tactical error or cost?

The Thameslink box wasn't cheap and nearly wasn't built in the first place. There's lots of other stretches of the route that are two track, so what would be so clever about providing loops at the most expensive place possible?

 

[yorksrob]

I'd have thought that if a train travelling south from the Finsbury Park direction arrived outside of its slot, it could at least wait at Kings Cross without disrupting services from the Bedford direction. True, it could possibly wait before the junction, but this would cause irritation and potentially an additional delay for passengers waiting to detrain in London. In the opposite direction - admittedley the extra platform is less crucial as trains are only coming from one direction, however, in the event of problems on one route north a train could wait without disrupting services to the other.

In truth, you're correct - cost is the cause. I hope it works as it is otherwise it'll cost much more to rebuild later.