PTI code 050

[dave1]

Nortube on your site in the list of PTI codes there is 050 Kennington platform 1 which is shown as not in use.

Was this ever used prior to TBTC or was it for when TBTC was brought in.

I know there was no signalled move back to the siding or loop so was it for a train that was going further than Kennington albeit empty.

[Nortube]

All the PTI codes in the list were those that were originally allocated. I assume that, as they had numbers spare, they allocated numbers for potential future use even though there were never any reversing etc. facilities at that PTI location.

Clapham Common was also provided for in case they re-introduced the crossover. This was one option that was talked about many years ago if they introduced 24hr running. The idea being that many sections of the track would be bi-directional and this would allow engineering work to be carried out on one track whilst still running a service both ways on the other.
Clapham Common N-S = 065
Clapham Common S-N via CX = 127
Clapham Common S-N via City = 137

PTI was introduced on the Northern line during the late the 1980s. The equipment was retrofitted to the existing stock on the Northern line at the time.

On the 95 stock, setting up the PTI also set the on-board dot matrix describer and so setting up 065 would display Clapham Common on the front of the train. As far as I can remember, setting up one of these codes would be treated as a wrong code by the PTI receiving equipment and would normally end up with the “Check destination on front of train” message on the platform DMIs

The only actual passenger reversing point that wasn’t allocated a PTI code was Totteridge, which had a handworked emergency crossover south of the station. The crossover was removed when the new signalling came in.

Kennington platform 1 was the only platform out of the four where a train couldn’t enter the siding via a shunt signal. I assume the thinking was that a SB CX train could go into the siding to reverse or get it out of the way if defective and a NB CX train (from Oval) could be diverted to the siding via platform 3 if required. There was no normal reason why a train would run empty from platform 1 and so the code was not provided for that reason (and probably not recognised by the system as a valid PTI code). I assume that it was for potential use, like Clapham Common, especially handy for optional bi-directional working, as indeed will happen once the Battersea extension is complete. Very forward thinking that around 30+ years ago would never have imagined an extension to Battersea   

[dave1]

Jul 4, 2018 9:18:31 GMT Nortube said:

All the PTI codes in the list were those that were originally allocated. I assume that, as they had numbers spare, they allocated numbers for potential future use even though there were never any reversing etc. facilities at that PTI location.

Clapham Common was also provided for in case they re-introduced the crossover. This was one option that was talked about many years ago if they introduced 24hr running. The idea being that many sections of the track would be bi-directional and this would allow engineering work to be carried out on one track whilst still running a service both ways on the other.
Clapham Common N-S = 065
Clapham Common S-N via CX = 127
Clapham Common S-N via City = 137

PTI was introduced on the Northern line during the late the 1980s. The equipment was retrofitted to the existing stock on the Northern line at the time.

On the 95 stock, setting up the PTI also set the on-board dot matrix describer and so setting up 065 would display Clapham Common on the front of the train. As far as I can remember, setting up one of these codes would be treated as a wrong code by the PTI receiving equipment and would normally end up with the “Check destination on front of train” message on the platform DMIs

The only actual passenger reversing point that wasn’t allocated a PTI code was Totteridge, which had a handworked emergency crossover south of the station. The crossover was removed when the new signalling came in.

Kennington platform 1 was the only platform out of the four where a train couldn’t enter the siding via a shunt signal. I assume the thinking was that a SB CX train could go into the siding to reverse or get it out of the way if defective and a NB CX train (from Oval) could be diverted to the siding via platform 3 if required. There was no normal reason why a train would run empty from platform 1 and so the code was not provided for that reason (and probably not recognised by the system as a valid PTI code). I assume that it was for potential use, like Clapham Common, especially handy for optional bi-directional working, as indeed will happen once the Battersea extension is complete. Very forward thinking that around 30+ years ago would never have imagined an extension to Battersea   

Nortube, Thanks for that I agree whoever thought of the system had the forethought to be able to think ahead something that I don't think would happen today. I suppose Totteridge was omitted because of being a handworked crossover. Over the years I have heard various suggestions that they would signal routes that did not have a signal but with TBTC system coming in fell by the way and I have heard that the TBTC does not like too many points. 

[Nortube]

My understanding was that the Northern line was dictated to as to what could and couldn’t be done, rather than the signalling being created to what was best for the Northern line.

There were many times when the Totteridge crossover would have been useful during shutdowns on the Barnet branch, except that it couldn’t be used because of the time it would take to get everything sorted and trained staff on site.

Obviously there would have been a cost to mechanise the crossover so that it could be controlled like any other crossover, and there would be the annual upkeep cost, but that would be minor compared to the benefits it would give whenever there are problems at High Barnet and the service is suspended from Finchley Central.

The service was suspended for an hour between Finchley Central and High Barnet this evening due to a signal failure at High Barnet. If there was a crossover at Totteridge that may well have allowed for trains to take passengers as far as Totteridge, meaning that only those who wanted High Barnet would have to find alternative transport rather than kicking off everyone at Finchley Central.

The advantage of having a reversing point near a terminus can be seen by how well used Colindale sidings are when there is a problem at Edgware, even if it’s just to reverse a couple of trains due to a temporary shutdown or incident.

My understanding was that Thales said No!

16 siding at Edgware went the same way at Edgware went the same way. 16 siding was a controlled and signalled siding, just like any other move at Edgware. Movement was only between platform 1 and the siding. A train often stabled there at night but, more importantly, as platform 1 had no connection to depot, 16 siding was very convenient for temporarily getting rid of a train from platform 1. My understanding is that Thales said No!

Whilst I don’t know first hand for definite about the reason for the Totteridge crossover and 16 sidings closure, I do know that Thales were serious when they said that it would be much simpler if they didn’t have to include signalling trains direct to Golders Green depot / 4 sidings from Hampstead (a move which means that NB trains do not have to go into the platforms at Golders Green – a very useful move, both for normal stabling, turning trains short, etc.). One important aspect of going direct to GG depot from Hampstead is this is the only way that extra long trains can get into GG depot. It would appear to show that Thales had no real knowledge of how the Northern line ran trains!

I’ve also heard that the thing about the system not liking too many points, but it’s not something that I can understand why it should be so. GG layout was a little complex in the amount of moves that could be carried out, and at the time was controlled via two IMRs, but it’s not that complicated compared to many other railway layouts. It almost seems as if Thales were trying to make it as easy as possible for themselves, or perhaps they were just trying to cut the amount of work down in order to reduce the bid amount for the work.

[dave1]

Jul 4, 2018 20:26:35 GMT Nortube said:

My understanding was that the Northern line was dictated to as to what could and couldn’t be done, rather than the signalling being created to what was best for the Northern line.

There were many times when the Totteridge crossover would have been useful during shutdowns on the Barnet branch, except that it couldn’t be used because of the time it would take to get everything sorted and trained staff on site.

Obviously there would have been a cost to mechanise the crossover so that it could be controlled like any other crossover, and there would be the annual upkeep cost, but that would be minor compared to the benefits it would give whenever there are problems at High Barnet and the service is suspended from Finchley Central.

The service was suspended for an hour between Finchley Central and High Barnet this evening due to a signal failure at High Barnet. If there was a crossover at Totteridge that may well have allowed for trains to take passengers as far as Totteridge, meaning that only those who wanted High Barnet would have to find alternative transport rather than kicking off everyone at Finchley Central.

The advantage of having a reversing point near a terminus can be seen by how well used Colindale sidings are when there is a problem at Edgware, even if it’s just to reverse a couple of trains due to a temporary shutdown or incident.

My understanding was that Thales said No!

16 siding at Edgware went the same way at Edgware went the same way. 16 siding was a controlled and signalled siding, just like any other move at Edgware. Movement was only between platform 1 and the siding. A train often stabled there at night but, more importantly, as platform 1 had no connection to depot, 16 siding was very convenient for temporarily getting rid of a train from platform 1. My understanding is that Thales said No!

Whilst I don’t know first hand for definite about the reason for the Totteridge crossover and 16 sidings closure, I do know that Thales were serious when they said that it would be much simpler if they didn’t have to include signalling trains direct to Golders Green depot / 4 sidings from Hampstead (a move which means that NB trains do not have to go into the platforms at Golders Green – a very useful move, both for normal stabling, turning trains short, etc.). One important aspect of going direct to GG depot from Hampstead is this is the only way that extra long trains can get into GG depot. It would appear to show that Thales had no real knowledge of how the Northern line ran trains!

I’ve also heard that the thing about the system not liking too many points, but it’s not something that I can understand why it should be so. GG layout was a little complex in the amount of moves that could be carried out, and at the time was controlled via two IMRs, but it’s not that complicated compared to many other railway layouts. It almost seems as if Thales were trying to make it as easy as possible for themselves, or perhaps they were just trying to cut the amount of work down in order to reduce the bid amount for the work.

It is a shame as it shows that those who know better are not listened to but I suppose it is to be expected in today's railway as all the people who know how to operate a railway are long gone and they let the likes of Thales dictate like you say.

I know when I saw some photos of Totteridge I thought that Cobourg Street controlled the crossover as the signal aspects seemed to be indicated but I was assured that this was not the case. Doing away with the moves that were there previously is a step back but for the modern railway they let the money do the talking.

I understand the same has happened on the Met/District/H&C prior to their resignalling taking place. All this occurring has had a detrimental effect on the railway with increased speeds and intervals wear and tear on track and trains can be the downfall.

[Nortube]

Totteridge had a cabin code (NT) in the similar naming sequence as the other controlled areas on the Barnet Branch, and this was used on the signals that would protect a reversing train if the ground frame was in use. Cabin code NT was used for Totteridge, and the signals were fairly unique in that the running signal ID was the auto signal number but had NT instead of the normal Axxx or Sxxx.

Totteridge had two ground frames, both NT.
The one at the south of the station (sited on the SB side, just the other side of the road bridge) controlled the N-S crossover south of the station that remained until the resignalling. Moves over the crossover were handsignalled because there were no signals for the move.

The other, on the SB north of the station, controlled the sidings and all pointwork north of the station. When the mainline trains stopped running and the coal yards closed, this ground frame and all pointwork disappeared, the coal / goods yard, like almost everywhere else, becoming a station car park.

The ‘auto’ NT signals had an illuminated A to indicate to the driver that the signal was to be treated as an automatic signal if it remained at danger. The illuminated A was extinguished if the ground frame was in use.

Similar arrangements were in operation at Woodside Park where there was a cossover south of the station and sidings either side of the running line north of the station. The cabin code was NS.

Full details of the signalling arrangements and track layout are shown in the in the diagrams issued by the Underground when they took over the Barnet branch (Northern Heights) and extended from the Northern line terminus at Archway. Harsig has redrawn the diagrams and their excellent clarity shows the full details, including Highgate High level and Highgate Depot:
www.harsig.org/Northern.htm

Harsig has many other line diagrams on his site that are worth looking through.

[dave1]

Jul 6, 2018 11:53:02 GMT Nortube said:

Totteridge had a cabin code (NT) in the similar naming sequence as the other controlled areas on the Barnet Branch, and this was used on the signals that would protect a reversing train if the ground frame was in use. Cabin code NT was used for Totteridge, and the signals were fairly unique in that the running signal ID was the auto signal number but had NT instead of the normal Axxx or Sxxx.

Totteridge had two ground frames, both NT.
The one at the south of the station (sited on the SB side, just the other side of the road bridge) controlled the N-S crossover south of the station that remained until the resignalling. Moves over the crossover were handsignalled because there were no signals for the move.

The other, on the SB north of the station, controlled the sidings and all pointwork north of the station. When the mainline trains stopped running and the coal yards closed, this ground frame and all pointwork disappeared, the coal / goods yard, like almost everywhere else, becoming a station car park.

The ‘auto’ NT signals had an illuminated A to indicate to the driver that the signal was to be treated as an automatic signal if it remained at danger. The illuminated A was extinguished if the ground frame was in use.

Similar arrangements were in operation at Woodside Park where there was a cossover south of the station and sidings either side of the running line north of the station. The cabin code was NS.

Full details of the signalling arrangements and track layout are shown in the in the diagrams issued by the Underground when they took over the Barnet branch (Northern Heights) and extended from the Northern line terminus at Archway. Harsig has redrawn the diagrams and their excellent clarity shows the full details, including Highgate High level and Highgate Depot:
www.harsig.org/Northern.htm

Harsig has many other line diagrams on his site that are worth looking through.

Thanks yes I've seen Harsig's site and I recently bought the yellow peril disc from the SRS.