Elephant&Castle speed control

[Deleted]

Hello everyone, this is my first post on this forum. You may know me better as "G Force" on other forums.

When trains approach the pre-NB platform at Elephant&Castle there is what appears to be a speed control signal (or at least a trainstop), which considerably slows down the time it takes for a train to enter the NB platform as opposed to the ex-SB platform (by over 20 seconds). I have a few questions about this:-

Was this signal in use when the Bakerloo ran 34tph many years ago, or was it installed when the line was resignalled post Jubilee Line?

Is the signal there to protect the points to the south of the platform, or to protect any trains that could be stabled in the overrun?

Would either having the points in normal position heading into the crossover instead of the overrun, or only using the signal when a train is in the overrun, allow for a higher speed entry to the NB platform?

[Admin Team]

Welcome to this forum, and i certainly recognise the 'name' from elsewhere!

One of our regular contributors is a veritable fount of knowledge on the B/loo signalling and I'm sure he'll be along some time in the near future with your answer.

Meantime, happy posting!

[Tom]

Been to Birmingham - Just got back!

At the moment, I can't say off the top of my head if it was there pre-resignalling or not. Will do some hunting around though...

[Phil]

I am assured by Q8 that it was NOT there in the '70s, i.e.not before the resignalling

[Deleted]

After a bit of research I turned up some info on the existing arrangements at B&R that BAET posted elsewhere.

tom said:

E&C, a favourite location of mine!
The signals on the southbound are as follows
BR3 (Lambeth North Starter)
A325 (Speed Controlled by PF Position Detector operated for 4.5 sec)
BS210 (Speed Controlled)
BS21 (with route indicator).

BS21 controls the junction, but BS210 protects it and is the signal installed for headway purposes.

As you say, if BS21 is at danger, an approaching train will get a speed check at BS210 (which will clear with PJ track occupied for 4.5 seconds or PH Position Detector having been operated for 15 seconds), then be allowed to draw forward to BS21 at reduced speed.

I'm fairly certain this is the way the site operates, but I've only got a site plan and extracts from the bookwiring to go by.

tom said:

Once BS210 is at danger, the points can still move.
BS210 was originally planned to be an Auto signal, which would have been A327.

The operation of the points is connected to BS21. Once 21's signal lever is reversed, it will mechanically lock the point levers, likewise if a train overruns BS21 at danger the points will be electrically locked (no feed to the point valves).

I presume that G Force is asking about BS210, the signal which Q8 states was not present during the days of 34tph on the B&R scissors.

[Deleted]

I think BS210 is the speed control signal before the crossover home signal BS21. I'm referring to the speed control signal/trainstop located at the entrance to the NB platform, which is located after the crossover for an incoming train.

[Deleted]

stephenk said:

I think BS210 is the speed control signal before the crossover home signal BS21. I'm referring to the speed control signal/trainstop located at the entrance to the NB platform, which is located after the crossover for an incoming train.

Oh.

www.anorakheaven.com/photos/e&c02.jpg seems to show the reason why a policeman would be present in the n/b platform but not the s/b platform.

[Deleted]

theonekea said:

stephenk said:

I think BS210 is the speed control signal before the crossover home signal BS21. I'm referring to the speed control signal/trainstop located at the entrance to the NB platform, which is located after the crossover for an incoming train.

Oh.

www.anorakheaven.com/photos/e&c02.jpg seems to show the reason why a policeman would be present in the n/b platform but not the s/b platform.

I can see why it's needed (as there is little overrun between the South end of the platform and the start of the sidings crossover or stabled train), I'm just wondering if it was there when the line ran 34tph, due its negative effect on the time it takes to get a train into the pre-NB platform compared to the ex-SB platform.

I can't see any evidence of it on the signalling diagram in the picture you linked.

[Deleted]

stephenk said:

theonekea said:

Oh.

www.anorakheaven.com/photos/e&c02.jpg seems to show the reason why a policeman would be present in the n/b platform but not the s/b platform.

I can see why it's needed (as there is little overrun between the South end of the platform and the start of the sidings crossover or stabled train), I'm just wondering if it was there when the line ran 34tph, due its negative effect on the time it takes to get a train into the pre-NB platform compared to the ex-SB platform.

Indeed. The policeman is undoubtedly there to prevent a SPAD on the dummy into the sidings, as a SPAD might result in either hitting the train in the siding or a derailment on the crossover.

stephenk said:

I can't see any evidence of it on the signalling diagram in the picture you linked.

Makes sense - the resignalling at B&R which took that frame out of use probably added the policeman.

[DWS]

All the speed controlled trainstops in terminal stations were fitted after the crash at Moorgate (Northern City Line). Before then trains could run into a terminal station at faster speed, it did not occur to the Signal Eneginners that a train would not overrun a terminal station.

[Tom]

Indeed Q8 is correct but as DWS points out before the 70's no-one would think twice about not providing a speed controlled trainstop.

In 1974 a speed controlled trainstop was added to both the NB and SB sidings, but the platforms didn't have any until 1991. The one Stephen is thinking of is 301V which is set up to lower at 10mph, and it protects the NB siding. There is a similar one in the SB platform (401V which protects 28B points and is set up for 40kph.

[Deleted]

tom said:

Indeed Q8 is correct but as DWS points out before the 70's no-one would think twice about not providing a speed controlled trainstop.

In 1974 a speed controlled trainstop was added to both the NB and SB sidings, but the platforms didn't have any until 1991. The one Stephen is thinking of is 301V which is set up to lower at 10mph, and it protects the NB siding. There is a similar one in the SB platform (401V which protects 28B points and is set up for 40kph.

Thanks, that answers my question ;D

[Phil]

Another input from Q8

"Will you reiterate to them once more that the signal at E & C Bakerloo was NOT there in the 70's. The one they are talking about is the sentry AFTER the scissors xover in the northbound platform."

[q8]

Now let me explian about this E & C signal doodah that started this thread. In the 70's when you left Lambeth North you came round the bend approaching E & C and you got a repeater on the left followed by two home signals also on the left. If there were trains in both Elephant platforms both of these were red of course. Depending on which northbound platform starter was clear you then either remained where you were or were allowed up to the second and last home which had the 'abour' lights on it.

By that I mean if the southbound platform starter was 'off' for him to leave you stayed at the first home. If it were the northbound starter clear you got let up to the second one. This was obviously a safety measure for the southbound platform and any train leaving via the scissors Xover.

Now as to the reason for the sentry at the entrance to the northbound platform [which was NOT there in my day] it may be because the northbound siding is shorter than the southbound by some 70ft and consequently a train stabled down there is nearer to the platform. Hence the need for the northbound one to be slower.

[Deleted]

q8 said:

Now let me explian about this E & C signal doodah that started this thread. In the 70's when you left Lambeth North you came round the bend approaching E & C and you got a repeater on the left followed by two home signals also on the left.

www.anorakheaven.com/photos/e&c02.jpg shows the signals on the 'bottom' of the representation of the track. Does that mean the draftsman thought the signals were on the right?

q8 said:

If there were trains in both Elephant platforms both of these were red of course. Depending on which northbound platform starter was clear you then either remained where you were or were allowed up to the second and last home which had the 'abour' lights on it.

BS10?

q8 said:

By that I mean if the southbound platform starter was 'off' for him to leave you stayed at the first home. If it were the northbound starter clear you got let up to the second one. This was obviously a safety measure for the southbound platform and any train leaving via the scissors Xover.

Interesting. It seems then that the 'outer' home (which looks like A355 - needs more Harsig) is the primary headway signal and provides the full overlap for the scissors crossover.

q8 said:

Now as to the reason for the sentry at the entrance to the northbound platform [which was NOT there in my day] it may be because the northbound siding is shorter than the southbound by some 70ft and consequently a train stabled down there is nearer to the platform. Hence the need for the northbound one to be slower.

Indeed. I suspected as much, especially with the points so close to the dummy for the northbound siding.

[q8]

I bow to the diagram in the picture TOK. You see how memory fades in old age. I thought they were on the left but as you see I was wrong. [can't see the repeater on the diagram though]

[Tom]

q8 said:

Now as to the reason for the sentry at the entrance to the northbound platform [which was NOT there in my day] it may be because the northbound siding is shorter than the southbound by some 70ft and consequently a train stabled down there is nearer to the platform. Hence the need for the northbound one to be slower.

But it wouldn't have been there in the 70s anyway - nobody thought about protecting trains in terminal stations before 1974 at the earliest and no mods were carried out until 1976.

[Tom]

theonekea said:

Does that mean the draftsman thought the signals were on the right?

Draftsman?? Signalling Design Engineer please (Illuminated Diagrams are part of our responsibility - I've never had to mod one, though a colleague did produce the diagram in Rayners Lane Cabin.

Interesting. It seems then that the 'outer' home (which looks like A355 - needs more Harsig) is the primary headway signal and provides the full overlap for the scissors crossover.

It is A355. I can't remember from the Headway Curve what the overlap details were, but IIRC A355 is where the present A325 is (roughly). The present A325 is provided for both Headway Reduction and round-the-bend purposes.

BS1 protected the crossover in the same way that BS210 does now (BTW, BS210 is still shown on the Headway Curve with it's original designation of A327!!)

[Deleted]

q8 said:

Now let me explian about this E & C signal doodah that started this thread. In the 70's when you left Lambeth North you came round the bend approaching E & C and you got a repeater on the left followed by two home signals also on the left. If there were trains in both Elephant platforms both of these were red of course. Depending on which northbound platform starter was clear you then either remained where you were or were allowed up to the second and last home which had the 'abour' lights on it. By that I mean if the southbound platform starter was 'off' for him to leave you stayed at the first home. If it were the northbound starter clear you got let up to the second one. This was obviously a safety measure for the southbound platform and any train leaving via the scissors Xover.

Thanks for you input Q8. It sounds like quite an interesting arrangement with the two home signals, instead of the now more common speed signal followed by home signal arrangement. In the days of the Bakerloo running up to 34tph, was the run into Elephant&Castle usually straight in, or was queuing to get through the crossover more common?

The operations at Elephant&Castle must have been quite tight during rush hours in the days before the Jubilee. Any delays in closing the doors and departing after a green light was given must have delayed the service behind! But was the reversing arrangements at Elephant&Castle the limiting factor in running the line reliably, or was it other factors such as junction operations at Baker St (e.g trains arriving out of order), or excessive dwell times at busy stations such as Oxford Circus?

[Deleted]

According to MAC Horne's "The Bakerloo Line", in 1948 the city section of the Bakerloo was running 36 tph. The limiting factor was the arrangement at E&C: even with "stepping back" it took two minutes to reverse a train.

This was a major reason for LT's enthusiasm for extending to Camberwell: it would be easier and less disruptive to build a new 3-platform terminal than to add a platform at E&C.

In the end, of course, the problem was solved by the Jubilee.

[Deleted]

I wonder if reversing part of that 36tph via the sidings was ever considered - it seems to me that balancing the ability to clear the s/b platform more rapidly against having to tip out the entire train before going to the siding would have to be weighed.

[Deleted]

sydneynick said:

According to MAC Horne's "The Bakerloo Line", in 1948 the city section of the Bakerloo was running 36 tph. The limiting factor was the arrangement at E&C: even with "stepping back" it took two minutes to reverse a train.

It actually would have taken approx 85 secs to for a train to leave a platform and the next to arrive in that platform. (This is based on existing times for trains reversing in the ex-SB platform, the NB now having the restrictive speed control). If even headways were being operated at 34tph, this would allow 85sec dwells for the drivers to step back, and 20seconds of door closing time and operating margin before any delays occured to trains behind. It may have been the case that uneven headways were operated out of Elephant&Castle to ease things a bit (under the present signalling the starter in the pre-NB platform can clear just 70secs after the previous departure).

This was a major reason for LT's enthusiasm for extending to Camberwell: it would be easier and less disruptive to build a new 3-platform terminal than to add a platform at E&C.

I'm interested to know if this three platform terminus at Camberwell was designed to be built at deep level, cut and cover, or on the surface? A deep level 3 platform terminus would be most interesting! Post-Moorgate, most dead end three platform termini actually have lower reversing capacities than two platform termini with overruns.

[Deleted]

Any three-platform deep-level terminus would most likely have a layour similar to Uxbridge (MW), unless someone was smart and (a) connected one platform to the approaches with a flying junction, or (b) used a flying terminus, which doesn't need three platforms and can reverse 40tph with proper overruns ;D

[q8]

Thanks for you input Q8. It sounds like quite an interesting arrangement with the two home signals, instead of the now more common speed signal followed by home signal arrangement. In the days of the Bakerloo running up to 34tph, was the run into Elephant&Castle usually straight in, or was queuing to get through the crossover more common?

The operations at Elephant&Castle must have been quite tight during rush hours in the days before the Jubilee. Any delays in closing the doors and departing after a green light was given must have delayed the service behind! But was the reversing arrangements at Elephant&Castle the limiting factor in running the line reliably, or was it other factors such as junction operations at Baker St (e.g trains arriving out of order), or excessive dwell times at busy stations such as Oxford Circus?

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I'll answer these two questions now. E&C worked like clockwork in the 70's peak and off peak. Stepping back was in force in the peak and a train would be in and out in 4 minutes. [Except when yours truly forgot to push the damn 'RCC' plunger] There was a bit longer off peak but you still got a train leave in 6 mins. You were rarely kept waiting at the homes for more that a minutes or so and sometimes off-peak you got a straight run in

Incidentally on the diagram photo provided by TOK you can see the visuals for the RCC plungers at the bottom. [the triangles]

[q8]

I wonder if reversing part of that 36tph via the sidings was ever considered - it seems to me that balancing the ability to clear the s/b platform more rapidly against having to tip out the entire train before going to the siding would have to be weighed.
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Would not have worked TOK. The southbound siding was reserved for dud trains if unable to take them to Neasden empty straight away or to put a train in that had no crew relief and was cancelled as a result.

[Deleted]

theonekea said:

Any three-platform deep-level terminus would most likely have a layour similar to Uxbridge (MW), unless someone was smart and (a) connected one platform to the approaches with a flying junction, or (b) used a flying terminus, which doesn't need three platforms and can reverse 40tph with proper overruns ;D

I would disagree about an Uxbridge style layout. You have to remember that deep level stations in London have a separate tube for each platform. Thus for island platforms at deep level, the track seperation is substantially larger than for surface island platforms. This track speration then increases the size of the crossover, with negative impacts on capacity. A Stratford (Jubilee) layout would be better for capacity, as there is only one island platform instead of two at Uxbridge.

3 platform termini with overruns only have a smallish increase in realistic maximum capacity over a 2 platform terminus with similar overruns. However 3 platform termini can operate the same frequency with much better reliability and longer dwell time (and thus delay catch up time) than a 2 platform terminus.

The big problem with 3 platform termini is that people can end up on the wrong platform. This happened to me recently at Morden, where I was directed to platforms 4/5 by the DMIs, only for a train to depart in front of me, thus I had to go back up the stairs and over to platforms 2/3. Now this isn't a problem for an elite athelete such as myself, but for a disabled or elderly person, or someone with heavy luggage or kids, its a bit of a problem!