Kings Cross Thameslink - West Hampstead Lines

[Russel]

An unusual feature of the signalling on the St Pancras Branch back in the Midland era was St. Pancras Tunnel Box, which was built into the wall of the tunnel 46 feet below St. Pancras station. This box was a block post with just four levers and two spares that shortened the signalling sections in the tunnel, so enabling a reduced headway between trains. This lonely and gloomy workplace was apparently accessed from a door set in the wall of the cab rank on the west side of St. Pancras station, behind which a spiral staircase led down to the tunnel and the box.

I assume there is no trace of this, or the access left?

 

[Pigeon]

When St Pancras station was being built the Metropolitan line passed in front and there was a potential plan to continue the widened lines, so a second tunnel was built. In 1930s this was extended west and a junction added (near Ossulston Street / Euston Road), the Met was diverted through it and a similar tunnel built for westbound trains on south side, the original running tunnel is now a concourse (and for many years had short sidings at western end). The Met platforms in the old station were closed when these opened.

The tunnel forks off the tunnel up to Kentish Town and runs under St Pancras forecourt, parallel to the Euston Road and the original Met tunnel, then stops at the boundary of the Midland's land on the east side of the road that runs up the west side of St Pancras station. It was built at the same time as the connecting tunnel as part of the initial work before the main station could be started, to make sure they would never have to dig any of that lot up again.

The Met eastbound was connected to the Up Widened Line just west of the Met station, I think in 1927? Then in the mid-30s (1936?) they knocked a hole through the side of the unused tunnel to the Met and inserted a section of single line from further back along the Met eastbound track to the junction with the Up Widened Line, so that eastbound freight trains on the Met for the Widened Lines could wait in the loop for a path over the WL without blocking the Met. This of course left a stub of tunnel still disused, from where they knocked through up to the actual end of it.

Then a few years later they moved the Met station to its present position. A platform was built alongside the loop line, which was realigned slightly to suit, and this became the Met eastbound line; the original Met was truncated at the eastern end of the station, leaving space for the passenger access; and the westbound line was diverted into a new, smaller, tunnel around the south side. Over the years the original Met tunnel was cut back further, in I think at least 2 stages, and filled up to platform level, for use as passenger concourse, leaving the short stub-end of siding at the western end that is still there. The unused bit of the spare tunnel is of course the bit of tunnel visible off the west end of the eastbound platform.

I have never been able to find any evidence that the spare tunnel was ever extended beyond the Midland's boundary. The name "Ossulston Street Junction" crops up sometimes, but it seems to be yet another of these infuriating instances of spacewarp cartography so common in the naming of railway features. Nothing starts to happen to the track until much closer to St Pancras. To extend the tunnel westwards would have meant digging right across the front of Somers Town goods depot, and the chaos would have left traces. Also, it would have meant excavating right up to the side of the hotel, and I can imagine them being distinctly unwilling to risk disturbing the foundations and bringing that lot down on top of their heads.

What they did was go through the south side of the tunnel leaving a blank end, thus dodging the hotel, and widen the Met tunnel to split off the connection. Then they just repurposed things a bit to turn it into a station. The eastbound track layout today is still remarkably well preserved, following the alignment of the original diverging loop line and then wiggling a bit further sideways just before entering the platform, where they had to realign the loop to get the platform in.

I assume there is no trace of this, or the access left?

It was in the point of the angle where the Hotel Curve tunnel diverges. As far as I know they've not had cause to rebuild that particular bit of tunnel wall since.

 

[Taunton]

I would be interested to know where were the crossovers that allowed the GWR/WR freight trains from Acton Yard to Smithfield, hauled by the condensing 97xx tank locos, to go from the Circle Line onto the Widened Lines. Described above is where part of the unused Widened Lines extension tunnel towards Baker Street was taken for a holding loop for these trains, but that was lost in the 1939 rebuild of Kings Cross Met station. A signalling map on the web shows no connections these trains could then take to clear the Circle Line until Farringdon station.

The detailed OS maps linked above show the Hotel Curve does not define the curvature of the GN hotel (which I thought it did), but passes under and behind it on a different axis.

An interesting map of the tunnels at Kings Cross is here, not only the various routes but also the quite lengthy Piccadilly to Northern tunnel connection (built 1960s?), the long-abandoned north-to-west curved tunnel from the Up GN York Road approach to the westbound Circle Line, which intersected the Hotel Curve, also in tunnel, at right-angles, still there and accounts on the web describe engineers walking it, plus even the Fleet Sewer making an appearance right through the middle of it all!

Tunnels under Kings Cross

Explore IanVisits' 8697 photos on Flickr!

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[swt_passenger]

The detailed OS maps linked above show the Hotel Curve does not define the curvature of the GN hotel (which I thought it did), but passes under and behind it on a different axis.

I’ve pointed this out before, I believe the location of and the curved shape of the Hotel is to match the location of the culverted Fleet River. As you have seen on the maps the railway tunnel basically cuts behind the hotel while clearing the corner of the main trainshed.

An interesting map of the tunnels at Kings Cross is here, not only the various routes but also the quite lengthy Piccadilly to Northern tunnel connection (built 1960s?), the long-abandoned north-to-west curved tunnel from the Up GN York Road approach to the westbound Circle Line, which intersected the Hotel Curve, also in tunnel, at right-angles, still there and accounts on the web describe engineers walking it, plus even the Fleet Sewer making an appearance right through the middle of it all!

We had a thread some years ago which, (after a bit of discussion), confirmed that the north to west ‘Maiden Lane’ curve, (its name on old diagrams), was still accessible on foot from a junction on the York Road curve:

KX Thameslink Old tunnel

This one of the old tunnels from Kings Cross to Moorgate,you can access these tunnels off York way, when were they closed?. And they would come in useful now, as they would be doing to same thing as the new Canal Tunnels at St Pancras International

www.railforums.co.uk

 

[izvor]

We had a thread some years ago which, (after a bit of discussion), confirmed that the north to west ‘Maiden Lane’ curve, (its name on old diagrams), was still accessible on foot from a junction on the York Road curve

I tried to walk it c.1980 after the York Road curve was closed, but a few yards beyond the junction it was full of ballast to within a few feet of the crown of the tunnel arch. In the Hotel Curve I could not see any trace of the intersection, though I did not know exactly where it had been.

 

[John Webb]

An unusual feature of the signalling on the St Pancras Branch back in the Midland era was St. Pancras Tunnel Box, which was built into the wall of the tunnel 46 feet below St. Pancras station. This box was a block post with just four levers and two spares that shortened the signalling sections in the tunnel, so enabling a reduced headway between trains. This lonely and gloomy workplace was apparently accessed from a door set in the wall of the cab rank on the west side of St. Pancras station, behind which a spiral staircase led down to the tunnel and the box.

According to Gough, this box opened in 1869 (21st July) and closed in February 1958, although I believe it wasn't often in use in later days.

 

[swt_passenger]

I tried to walk it c.1980 after the York Road curve was closed, but a few yards beyond the junction it was full of ballast to within a few feet of the crown of the tunnel arch. In the Hotel Curve I could not see any trace of the intersection, though I did not know exactly where it had been.

Yes there were older references to it being filled in from that point, but I think it must have been opened up as an access route when the major works for the various LU alterations (including the northern ticket hall) were underway. That would have been around 2008/9 or earlier?

 

[Rescars]

According to Gough, this box opened in 1869 (21st July) and closed in February 1958, although I believe it wasn't often in use in later days.

It would appear to have been in use during WW2. Apparently the ventilation shaft doubled up as a speaking tube so those at ground level were able to check on the welfare of the signalman following air raids during the Blitz.

 

[izvor]

It would appear to have been in use during WW2. Apparently the ventilation shaft doubled up as a speaking tube so those at ground level were able to check on the welfare of the signalman following air raids during the Blitz.

A poor quality shot of Tunnel Box in 1978, set into an arched recess on the down side (i.e. going uphill!) of the tunnel. It was wrecked by then as you can see. The spiral staircase on the far side of the tracks was still intact but very rickety and I did not venture up. Could hear street traffic noise coming down the shaft. As has been said above, it must have been a horrible place to work.

 

[edwin_m]

I assume there is no trace of this, or the access left?

I believe this is the former cab rank now: https://www.findmeaconference.com/v...-839a-e15d6270f326-hansomloungeafternoont.jpg

(link to image of St Pancras Hotel lounge area)

The door was presumably somewhere in the wall in the background.

 

[Taunton]

Clearly the architectural standards at the top of the speaking tube were not repeated at the bottom!

 

[Rescars]

A poor quality shot of Tunnel Box in 1978, set into an arched recess on the down side (i.e. going uphill!) of the tunnel. It was wrecked by then as you can see. The spiral staircase on the far side of the tracks was still intact but very rickety and I did not venture up. Could hear street traffic noise coming down the shaft. As has been said above, it must have been a horrible place to work.

View attachment 195766

What a workplace indeed! The arched window is a nice touch - shame about the view. The ventilation must have been on overtime if a heavy freight was held on the down line for any length of time. Can't have been too healthy for the footplate crew either for that matter.

 

[bramling]

Yes there were older references to it being filled in from that point, but I think it must have been opened up as an access route when the major works for the various LU alterations (including the northern ticket hall) were underway. That would have been around 2008/9 or earlier?

The Maiden Lane curve is still there, and is nowadays empty. IIRC there are now pumps fitted there. It ends in a solid wall.

My understanding is most of the Hotel Curve was lost when LU built their northern ticket hall. However a section at the south-eastern end survives and now carries utilities. There are two matching pairs of manholes at each end of the open space in front of King’s Cross which give access. I think the Hotel Curve tunnel is owned by LU, whereas the York Road curve tunnel is owned by NR.

I don’t think there’s any trace of the Maiden Lane curve at the Met Line end, the various new tunnels over the years cut through it and obliterated the former connection.

 

[Pigeon]

I don't think there's any trace of the Maiden Lane curve at the Met Line end, the various new tunnels over the years cut through it and obliterated the former connection.

There's a sort of widening of the tunnel on the north side with a gaggle of LOCs in it, which is where the intersection used to be; you can see some indication that the curve used to emerge there once you know to look for it there.

 

[Sad Sprinter]

Further reading about the St Pancras box: https://www.railforums.co.uk/threads/urban-but-isolated-signal-boxes.252835/

 

[swt_passenger]

There's a sort of widening of the tunnel on the north side with a gaggle of LOCs in it, which is where the intersection used to be; you can see some indication that the curve used to emerge there once you know to look for it there.

A photo in a thread back in 2024 shows the way the Maiden Lane is currently blocked off on the ‘inside’ ie looking towards the former crossing of the Hotel Curve, it shows various bits of plumbing presumably for the pumps mentioned in post#43.

Then the next photo is the approach towards that site, curving gently to the right, taken from beyond the junction within the York Rd tunnel:

King's Cross Thameslink, York Road and Maiden Lane curves

I was lucky enough to bag a spot on a tour of these areas today with Branch Line Society, and thought it was only fair if I shared some of the pictures I captured. I've thrown all of the images of value into a Flickr album: https://www.flickr.com/photos/davwheat/albums/72177720322417816/...

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