King's Cross remodelling questions

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King's Cross remodelling questions 26/01/2022 at 22:51 #143831
clive
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Two odd comments in the December Modern Railways about the King's Cross remodelling that have left me wondering.

First, it says that the track installed included "31 'A' and 'C' point ends". I don't ever recall coming across the terms 'A' and 'C' before. The information I have shows 31 new points ends, but just numbered in the style 5035 for a turnout or 5012A and 5012B for a crossover. Do these have some special meaning?

Second, it says part of the work was to "move a main sewer on the station approaches which imposed a niggling speed restriction". I can't think of any odd speed restrictions on the approach. Does anyone know what this refers to?

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King's Cross remodelling questions 26/01/2022 at 23:05 #143833
Peter Bennet
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clive in post 143831 said:
Two odd comments in the December Modern Railways about the King's Cross remodelling that have left me wondering.

Second, it says part of the work was to "move a main sewer on the station approaches which imposed a niggling speed restriction". I can't think of any odd speed restrictions on the approach. Does anyone know what this refers to?
I don't think it was an odd speed restriction as such, it was just a speed restriction through the tunnels and they have been able to raise it from 15mph to 20mph and to 25mph in the Down direction.

Peter

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King's Cross remodelling questions 27/01/2022 at 00:17 #143835
Tempest Malice
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clive in post 143831 said:
I don't ever recall coming across the terms 'A' and 'C' before. Do these have some special meaning?
So I had a thought that point radius is often expressed in term of letters (with 'A' for the tightest radius and up to 'J' I think for the highest speed) so at a guess perhaps A and C were the two radii picked for this scheme (though googling around before posting I've found something suggesting they only go down to to 'B' radius which only do 20mph and I thought many at Kings cross are meant to be a bit faster so these letters are probably something other than this)

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King's Cross remodelling questions 27/01/2022 at 09:10 #143836
JamesN
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Typo for ā€˜Sā€™ and ā€˜Cā€™ perhaps?
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King's Cross remodelling questions 27/01/2022 at 12:42 #143839
Jan
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Peter Bennet in post 143833 said:
clive in post 143831 said:
Second, it says part of the work was to "move a main sewer on the station approaches which imposed a niggling speed restriction". I can't think of any odd speed restrictions on the approach. Does anyone know what this refers to?
I don't think it was an odd speed restriction as such, it was just a speed restriction through the tunnels and they have been able to raise it from 15mph to 20mph and to 25mph in the Down direction.

Probably the fact that the 15 mph didn't stop at the last set of points (and would the old points have actually all required a blanket 15 mph limit, or might they in theory possibly have allowed at least 20 mph if it wasn't for the sewer?), but instead extended for a further eight chains (~176 yards/161 m) inside Gasworks Tunnel. This article has a few more details.

Two million people attempt to use Birmingham's magnificent rail network every year, with just over a million of them managing to get further than Smethwick.
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King's Cross remodelling questions 27/01/2022 at 13:24 #143840
DriverCurran
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I am sure I have seen pictures with 8 mph speed boards in place at the exit of at least some of the platforms at Kings Cross. I wonder if this was the odd speed restriction mentioned.

Paul

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King's Cross remodelling questions 27/01/2022 at 13:36 #143841
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DriverCurran in post 143840 said:
I am sure I have seen pictures with 8 mph speed boards in place at the exit of at least some of the platforms at Kings Cross. I wonder if this was the odd speed restriction mentioned.

Paul
8kph would make more sense.

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King's Cross remodelling questions 27/01/2022 at 16:57 #144836
JamesN
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Soton_Speed in post 143841 said:
DriverCurran in post 143840 said:
I am sure I have seen pictures with 8 mph speed boards in place at the exit of at least some of the platforms at Kings Cross. I wonder if this was the odd speed restriction mentioned.

Paul
8kph would make more sense.
No it was definitely 8mph - kph only came into use on UK rail lines in more recent times with Tyne & Wear Metro, DLR, HS1 etc

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King's Cross remodelling questions 27/01/2022 at 23:38 #144855
bill_gensheet
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An 8mph sign

https://www.flickr.com/photos/loose_grip_99/3690605312/in/set-72157594496114232

Recent images seem to be 15 - so changed with the 1978 remodelling ?

Maybe the 8mph was more due to pointwork than sewers ?

Bill

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King's Cross remodelling questions 27/01/2022 at 23:52 #144856
Jan
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Barring any TSRs, the post-1978 layout was definitively 15 mph across the whole throat.
Two million people attempt to use Birmingham's magnificent rail network every year, with just over a million of them managing to get further than Smethwick.
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King's Cross remodelling questions 28/01/2022 at 08:36 #144858
kbarber
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8mph limits abounded in the pre-1978 layout, presumably a function of the limited space for the steam-age tangle that had 'just growed' over many years. All swept away by the 1978 remodelling which, as Jan rightly says, led to a blanket 15mph in the throat.

(Quite how a driver was supposed to observe 8mph, given that most kettles didn't have speedometers anyway, is beyond me. But there we are.)

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King's Cross remodelling questions 28/01/2022 at 09:22 #144859
Soton_Speed
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JamesN in post 144836 said:
No it was definitely 8mph - kph only came into use on UK rail lines in more recent times with Tyne & Wear Metro, DLR, HS1 etc
Agreed. I suppose my point was similar to KBarber's above in that it seems more precise than possible(speed limits normally being in 5mph buckets/increments) and indicates the pressure on the engineers to improve traffic flow in the throat in any way possible.

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King's Cross remodelling questions 28/01/2022 at 11:30 #144862
clive
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JamesN in post 144836 said:
kph only came into use on UK rail lines in more recent times with Tyne & Wear Metro, DLR, HS1 etc
km/h signs are hexagonal (with "kmh" under the number) on the T&W Metro / National Rail joint working sections. Elsewhere on the metro they use the usual black-on-white with red circles, with the numbers in km/h. Indeed, they were doing that when the cut-out sign was still the BR standard. Apparently it was cheaper for the council to get road signs from the depot than to get cut-outs from BR. For the same reason, they used "no entry" or "low flying motorbike" signs for "limit of shunt"; I forget which.

Elsewhere on the national network, km/h signs are white on black.

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King's Cross remodelling questions 28/01/2022 at 11:33 #144863
clive
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Jan in post 143839 said:
Peter Bennet in post 143833 said:
clive in post 143831 said:
Second, it says part of the work was to "move a main sewer on the station approaches which imposed a niggling speed restriction". I can't think of any odd speed restrictions on the approach. Does anyone know what this refers to?
I don't think it was an odd speed restriction as such, it was just a speed restriction through the tunnels and they have been able to raise it from 15mph to 20mph and to 25mph in the Down direction.

Probably the fact that the 15 mph didn't stop at the last set of points (and would the old points have actually all required a blanket 15 mph limit, or might they in theory possibly have allowed at least 20 mph if it wasn't for the sewer?), but instead extended for a further eight chains (~176 yards/161 m) inside Gasworks Tunnel. This article has a few more details.
Aha, thanks. That answers that question, at least.

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King's Cross remodelling questions 30/01/2022 at 11:41 #144909
Harsig
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clive in post 143831 said:
Two odd comments in the December Modern Railways about the King's Cross remodelling that have left me wondering.

First, it says that the track installed included "31 'A' and 'C' point ends". I don't ever recall coming across the terms 'A' and 'C' before. The information I have shows 31 new points ends, but just numbered in the style 5035 for a turnout or 5012A and 5012B for a crossover. Do these have some special meaning?

As you note where two point ends work together, as in a crossover, the points share the same number, suffixed with A or B to distinguish between them. There are some configurations of track layout where three (or more) point ends work together (eg a crossover where one end forms part of a double slip). In this case as before they share the same number with the suffixes A, B & C (&D etc if required) being used. Thus my interpretaion of the statement that the new track included 31 A & C point ends is that 31A points and 31C points are new (or renewed) but that 31B are an unchanged original set of points.

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King's Cross remodelling questions 30/01/2022 at 13:27 #144910
clive
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Harsig in post 144909 said:
clive in post 143831 said:
Two odd comments in the December Modern Railways about the King's Cross remodelling that have left me wondering.

First, it says that the track installed included "31 'A' and 'C' point ends". I don't ever recall coming across the terms 'A' and 'C' before. The information I have shows 31 new points ends, but just numbered in the style 5035 for a turnout or 5012A and 5012B for a crossover. Do these have some special meaning?

As you note where two point ends work together, as in a crossover, the points share the same number, suffixed with A or B to distinguish between them. There are some configurations of track layout where three (or more) point ends work together (eg a crossover where one end forms part of a double slip). In this case as before they share the same number with the suffixes A, B & C (&D etc if required) being used. Thus my interpretaion of the statement that the new track included 31 A & C point ends is that 31A points and 31C points are new (or renewed) but that 31B are an unchanged original set of points.
That's a lovely hypothesis. Unfortunately ...

The points in that area all have four-digit numbers. And absolutely none of them have a C end; they're all singletons or simple crossovers (no switched frogs).

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King's Cross remodelling questions 30/01/2022 at 14:56 #144913
chrisdmadd
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Peter Bennet in post 143833 said:
clive in post 143831 said:
Two odd comments in the December Modern Railways about the King's Cross remodelling that have left me wondering.

Second, it says part of the work was to "move a main sewer on the station approaches which imposed a niggling speed restriction". I can't think of any odd speed restrictions on the approach. Does anyone know what this refers to?
I don't think it was an odd speed restriction as such, it was just a speed restriction through the tunnels and they have been able to raise it from 15mph to 20mph and to 25mph in the Down direction.

Peter
Im not entirely sure where the sewer is but the 15mph started half way through Gasworks tunnel in the old layout, now this tunnel in its entirety is 40mph in the UP and in the down each tunnel has a different speed but ranging from 40-55 mph.

The new layout was supposed to have MPH and KPH speed boards for the fitment of ERTMS but this hasnt happened as yet, however its not far away.

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King's Cross remodelling questions 30/01/2022 at 15:28 #144914
JamesN
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chrisdmadd in post 144913 said:


The new layout was supposed to have MPH and KPH speed boards for the fitment of ERTMS
Is that definitely the case? While the Cambrian ETCS installation uses metric speeds currently, there is a plan to go over to mph for standardisation with the wider network.

The Thameslink and GWML installations still use mph.

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King's Cross remodelling questions 01/02/2022 at 17:35 #144959
chrisdmadd
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JamesN in post 144914 said:
chrisdmadd in post 144913 said:


The new layout was supposed to have MPH and KPH speed boards for the fitment of ERTMS
Is that definitely the case? While the Cambrian ETCS installation uses metric speeds currently, there is a plan to go over to mph for standardisation with the wider network.

The Thameslink and GWML installations still use mph.
Im not sure if they will or not, the route maps network rail provided us showed both speeds im sure. As usual it will be anyones guess as to what will happen and when.

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King's Cross remodelling questions 12/02/2022 at 12:59 #145162
Giantray
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clive in post 144910 said:
Harsig in post 144909 said:
clive in post 143831 said:
Two odd comments in the December Modern Railways about the King's Cross remodelling that have left me wondering.

First, it says that the track installed included "31 'A' and 'C' point ends". I don't ever recall coming across the terms 'A' and 'C' before. The information I have shows 31 new points ends, but just numbered in the style 5035 for a turnout or 5012A and 5012B for a crossover. Do these have some special meaning?

As you note where two point ends work together, as in a crossover, the points share the same number, suffixed with A or B to distinguish between them. There are some configurations of track layout where three (or more) point ends work together (eg a crossover where one end forms part of a double slip). In this case as before they share the same number with the suffixes A, B & C (&D etc if required) being used. Thus my interpretaion of the statement that the new track included 31 A & C point ends is that 31A points and 31C points are new (or renewed) but that 31B are an unchanged original set of points.
That's a lovely hypothesis. Unfortunately ...

The points in that area all have four-digit numbers. And absolutely none of them have a C end; they're all singletons or simple crossovers (no switched frogs).
Indeed, all new Signalling layouts (not recontrolled) now have point ends as a separate numbers. This is to assist in the movement of trains when one end of a crossover fails. The only exception to the individual numbering is with Switch Diamonds(Movable Angles). These will still have an 'A' and a 'B' end as both are required to be moved & set together for a movement to go over them. Under power they cannot be moved individually. I think the 'A' is a typo too and should be an 'S', they are side-by-side on the keyboard afterall.

Retired Professional Railwayman (1981-2023); Pway & S&T (1981-88); Former Signalman/Signaller/ Signalling Trainer (1989-2023) [AB, TCB, Mechanical, NX, WestCad, Hitachi SARS]; Railway Historian (esp.SER, LCDR); Member of The Permanent Way Institution..
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