Kings Cross Remodelling - what would you have done?

[bramling]

Moderator note - split from this thread :

(3) Kings Cross ‘uncrossed’ Layout/Remodelling - Information and Updates | RailUK Forums (railforums.co.uk)

Feels slightly “wrong” that the equivalent bore in nearby Copenhagen Tunnel isn’t being re-used, though. It could have provided a non-conflicting crossover facility from the up slow line to the low number platforms. I presume there were logistical reasons why this wasn’t pursued. Presumably access for road vehicles to the Belle Isle area also has some value.

 

[SynthD]

I’m curious what could be done, as there’s already the overpass.

 

[edwin_m]

What route was thought up for getting from KX out to Southend? There's no obvious connection I can think of, and surely they wouldn't have been thinking of tunnelling under half of London from the KX area back in those days??

I don't recall the details, but I think there were various options involving new curves, possibly to the Gospel Oak to Barking line.

I’m curious what could be done, as there’s already the overpass.

I guess a new track could branch off the Up Slow north of the flyover but stay on the east side through the empty Copenhagen Tunnel bore to provide a route to the low-numbered platforms. However this might need the flyover to be re-aligned, and there would be no easy way to provide a similarly non-conflicting route in the other direction for a train leaving a low-numbered platform to cross the fasts and reach the Down Slow. Also there's not much need for this sort of route considering that trains on the Slows that don't use the connection to Thameslink have always used the high-numbered platforms.

 

[MarkyT]

I don't recall the details, but I think there were various options involving new curves, possibly to the Gospel Oak to Barking line.

I guess a new track could branch off the Up Slow north of the flyover but stay on the east side through the empty Copenhagen Tunnel bore to provide a route to the low-numbered platforms. However this might need the flyover to be re-aligned, and there would be no easy way to provide a similarly non-conflicting route in the other direction for a train leaving a low-numbered platform to cross the fasts and reach the Down Slow. Also there's not much need for this sort of route considering that trains on the Slows that don't use the connection to Thameslink have always used the high-numbered platforms.

Definitely room for another track to the east of the Holloway Up Slow flyover. Looking at the latest Google Earth aerials, it's clear the alignment and the spare bore have been cleared and used for construction access to the current works. A new single line could plausibly go that way and join the Up Slow & Up Goods further north. The former Up Engine Line, the old diesel depot exit route towards the terminus, could be resurrected, joining the Down Canonbury to allow departures to access the down side, a tight curve hard up against the stadium complex, but I believe still extant as an alignment among the undergrowth. The new bidirectional line could then function as a tidal empty stock line as well as an emergency or engineering bypass to allow other parts of the layout in the area to be closed selectively while traffic continues to flow in both directions. An additional span to widen the bridge for the new track would be required over the A103 just south of the stadium.

 

[Ianno87]

Moderator note - split from this thread :

(3) Kings Cross ‘uncrossed’ Layout/Remodelling - Information and Updates | RailUK Forums (railforums.co.uk)

Feels slightly “wrong” that the equivalent bore in nearby Copenhagen Tunnel isn’t being re-used, though. It could have provided a non-conflicting crossover facility from the up slow line to the low number platforms. I presume there were logistical reasons why this wasn’t pursued. Presumably access for road vehicles to the Belle Isle area also has some value.

The flyover at the north end of Copenhagen Tunnel is in the way.

Given there's not much need to access the main shed from the Slows (as nearly everything goes into Moorgate or Thameslink) there's not much point (and what traffic there is- ECS from Bounds Green etc - can merge "with the flow" on the Up Fast anyway at Holloway).

And once you get into a low numbered platform, it's inevitably highly conflicting to depart back to the Down Slow, which involves crossing everything.

Definitely room for another track to the east of the Holloway Up Slow flyover.

It looks like third bore of Copenhagen is the key maintenance access to the crossovers at Belle Isle. Sticking a track through it may have major impacts on maintainability of those crossovers. (E.g. off memory the Road Rail Vehicle pad is at Holloway).

 

[HST43257]

I’m concerned by the lack of crossovers on the approach to KGX. I understand maintenance cash concerns but are there really enough now to work well?

 

[Ianno87]

I’m concerned by the lack of crossovers on the approach to KGX. I understand maintenance cash concerns but are there really enough now to work well?

How many are really necessary? Most Slow Line stuff goes into Moorgate or Thameslink, do the key is to get from the Fast Lines to/from all platforms and a decent set of parallel moves between arrivals and departures, with the Up Slow Line providing grade separation into the higher platforms for a few arriving trains.

 

[30907]

I’m concerned by the lack of crossovers on the approach to KGX. I understand maintenance cash concerns but are there really enough now to work well?

There are two in the throat itself which would allow full parallel moves - P3/4 and P9/10 share access - but I assume this is a question of track geometry rather than an economy measure.

Those apart, which would you add and why?

 

[Bald Rick]

I’m concerned by the lack of crossovers on the approach to KGX. I understand maintenance cash concerns but are there really enough now to work well?

Yes, plenty. It not a train set!

 

[HST43257]

Those apart, which would you add and why?

An extra crossover from the second track from top to third from top, before the Xover comes into 2nd line from top line.

Earlier access to the 2nd line from bottom from P0

 

[zwk500]

An extra crossover from the second track from top to third from top, before the Xover comes into 2nd line from top line.

Why? It gives you nothing the existing crossover allowing departure from 8 to what was Line C (I guess it'll now be line E? or have they swapped them round?) doesn't already give you
EDIT:That would mean a crossover between different bores of Gasworks tunnels?

Earlier access to the 2nd line from bottom from P0

An earlier crossover would restrict the turnout speed, increasing the junction margin and therefore decreasing the junction capacity.

 

[bramling]

Yes, plenty. It not a train set!

Must admit I am a bit sad to see the current layout go. Given how compact it is, it is a superbly clever design, the throat layout combined with the Belle Isle and Holloway crossovers, plus the Holloway flyover, allows a superb number of useful parallel moves, and with thoughtful and anticipative signalling can be made to flow superbly smoothly.

 

[Bald Rick]

An extra crossover from the second track from top to third from top, before the Xover comes into 2nd line from top line.

Earlier access to the 2nd line from bottom from P0

That’s covered by Holloway Jn, and frankly is only likely to be used in times of disruption. Putting in a second facility to do it is just throwing money down the drain.