Facing point locks
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Facing point locks
I recently joined a local model club and asked if there was anything I could do to help with one of their layouts, I was invited to make covers for facing point locks to extend the lovely work done with point rodding (that even spans baseboard joints).
Foolishly I thought this would be straightforward...
Surprisingly I found it difficult to find all the information I would like - published info seems to cover bits of systems rather than complete installations, so I have some questions.
The first is about usage, mostly obvious but I have one area about which I am uncertain. The layout is set on the Western Region in the 1950s and is a branch terminus with one main platform face with an engine release crossover near the end of the platform and the buffer stop at the end of the platform. The platform is relatively short so after running round the train has to be set back over the crossover towards the buffer stop. As I understand things, there would have to be a point lock on the platform road as there would be a facing point under a departing train. I haven’t yet measured it, but I expect there will not be room for a typical lock bar and a loco between the toe of the point and the buffer stop, so it will be necessary to fit a lock bar within the point. Am I right?
Does anyone know of a location where there is still such an installation that I could inspect close up?
Foolishly I thought this would be straightforward...
Surprisingly I found it difficult to find all the information I would like - published info seems to cover bits of systems rather than complete installations, so I have some questions.
The first is about usage, mostly obvious but I have one area about which I am uncertain. The layout is set on the Western Region in the 1950s and is a branch terminus with one main platform face with an engine release crossover near the end of the platform and the buffer stop at the end of the platform. The platform is relatively short so after running round the train has to be set back over the crossover towards the buffer stop. As I understand things, there would have to be a point lock on the platform road as there would be a facing point under a departing train. I haven’t yet measured it, but I expect there will not be room for a typical lock bar and a loco between the toe of the point and the buffer stop, so it will be necessary to fit a lock bar within the point. Am I right?
Does anyone know of a location where there is still such an installation that I could inspect close up?
Regards,
Andrew Nummelin
Andrew Nummelin
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Re: Facing point locks
You might expect to find a FPL lock there but in practice lots of real locations didn't have one, however the interlocking would not have allowed the crossover to be anything other than normal when either the starter or the home was pulled off. The single passenger carriage bogie that would pass over the crossover point would do so at a very low speed.
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Re: Facing point locks
Detector bars to stopo the point being changed during set back?
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Re: Facing point locks
Just to confirm what Becasse has said, when I was researching the signalling for Bodmin (45 years ago!), I discovered that it was not the practice of the GWR to put an FPL on the engine release crossover. However (again, as Becasse has observed), the interlocking would not have allowed the Home signal to be pulled off unless this crossover was set Normal, and pulling off the Home signal would therefore have the effect of back-locking the point lever for the crossover. The same would also apply to the platform Starting signal.
I believe that the practice of other companies may have been different in this regard, but God's Wonderful Railway always was a law unto itself.
[P.S. In response to Gordon's point, I am not aware of the GWR using a detector bar in this situation. This would, as Gordon has suggested, have meant that a setting back move was effectively unprotected, but with no passengers on board and the move being made at very slow speed, presumably the GWR was not bothered about this.]
I believe that the practice of other companies may have been different in this regard, but God's Wonderful Railway always was a law unto itself.
[P.S. In response to Gordon's point, I am not aware of the GWR using a detector bar in this situation. This would, as Gordon has suggested, have meant that a setting back move was effectively unprotected, but with no passengers on board and the move being made at very slow speed, presumably the GWR was not bothered about this.]
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Re: Facing point locks
martin goodall wrote:the interlocking would not have allowed the Home signal to be pulled off unless this crossover was set Normal, and pulling off the Home signal would therefore have the effect of back-locking the point lever for the crossover.
Hi Martin,
The purpose of an FPL is nothing to do with interlocking with the signals.
It is to prevent the switch blades from physically moving under traffic. FPLs are required where service passenger trains travel over facing switch blades. This would only apply to a release crossover if the coaches were pushed back up to the buffers after running round.
Often the platform does not extend past the release crossover. But if it does, and it is desired to start a long passenger train from the buffers, it would be necessary to clip the release switch blades.
p.s. non-passenger coaching stock and empty stock movements don't count.
cheers,
Martin.
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Re: Facing point locks
Andrew,
There is a facing point lock associated with the loco run round at the end of the main platform at Minehead on the West Somerset the last time I was there. It is worked from a ground frame. Normally the loco has to round forward and the run round the coaches.
Dave
There is a facing point lock associated with the loco run round at the end of the main platform at Minehead on the West Somerset the last time I was there. It is worked from a ground frame. Normally the loco has to round forward and the run round the coaches.
Dave
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Re: Facing point locks
Martin Wynne wrote:
The purpose of an FPL is nothing to do with interlocking with the signals.
Yes. I was aware of that. (But the signal box interlocking also provided the protection referred to.)
The GWR did not put an FPL on this point, even where a passenger train would stand over the facing point and the end of the train would run over that facing point when departing. What the Railway Inspectorate made of this is anyone's guess. But the GWR definitely did not lock this point, except through the normal locking in the signal box lever frame.
If you don't believe me, ask an ex-GWR/BR(WR) signal engineer, as I did. (As I pointed out, other companies appear to have adopted a different approach.)
The current position at Minehead no doubt reflects modern practice, and is presumably now insisted on by the HSE.
[On reflection, GWR practice may have been based on the assumption that an outgoing passenger train, having stopped short of the engine release crossover, or having been propelled away from this crossover for running round, would not then be propelled back over it before departure. But there could be no guarantee of this; hence, presumably, the current practice at Minehead, and perhaps also on other preserved lines. There was certainly no FPL on this point at Bodmin, but it would be interesting to see if this point has now acquired an FPL under the auspices of the Bodmin and Wenford Railway.]
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Re: Facing point locks
martin goodall wrote:But the GWR definitely did not lock this point, except through the normal locking in the signal box lever frame.
That doesn't lock the points, it locks the lever in the frame. Flexibility in the rodding means the points can still move a fraction.
If you don't believe me
Of course I believe you.
The Railway Inspectorate presumably expected the points to be clipped for such a move.
Martin.
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Re: Facing point locks
We shouldn't overlook the fact that we are talking about about a 1/76-size model here.
The question was: Does the point at the Down end of an engine release crossover on a model of a GWR branch line terminus need an FPL and lockbar (and an FPL cover)?
The answer to that question is "No."
The question was: Does the point at the Down end of an engine release crossover on a model of a GWR branch line terminus need an FPL and lockbar (and an FPL cover)?
The answer to that question is "No."
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Re: Facing point locks
Martin Wynne wrote:
The Railway Inspectorate presumably expected the points to be clipped for such a move.
No, Martin, they clearly didn't given the number of places where such points existed without any FPLs or detection - and not just on the GWR either.
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Re: Facing point locks
bécasse wrote:Martin Wynne wrote:The Railway Inspectorate presumably expected the points to be clipped for such a move.
No, Martin, they clearly didn't given the number of places where such points existed without any FPLs or detection - and not just on the GWR either.
Such places can obviously exist in profusion. The question is whether loaded passenger trains were actually run over them? Quite often the platform does not extend as far as the release crossover. Even if it does, after running-round it would require an extra positioning move to push the coaches up to the buffers. Not very convenient for waiting passengers and the loading of vans, etc., to have to wait while the engine runs round and moves the coaches. Especially if it stops to take water in the process.
Martin.
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Re: Facing point locks
Martin Wynne wrote:bécasse wrote:Martin Wynne wrote:The Railway Inspectorate presumably expected the points to be clipped for such a move.
No, Martin, they clearly didn't given the number of places where such points existed without any FPLs or detection - and not just on the GWR either.
Such places can obviously exist in profusion. The question is whether loaded passenger trains were actually run over them? Quite often the platform does not extend as far as the release crossover. Even if it does, after running-round it would require an extra positioning move to push the coaches up to the buffers. Not very convenient for waiting passengers and the loading of vans, etc., to have to wait while the engine runs round and moves the coaches. Especially if it stops to take water in the process.
Martin.
The carriages would certainly have been pushed back towards the stops sometimes (perhaps most of the time) at some locations, I doubt whether more than one bogie would have been beyond the tip of the point blades and the fact that the bogie had been propelled through them in the trailing direction proved that they were normal. When the train started the bogie would have passed over the blades at perhaps a couple of miles per hour and the point (or its controlling lever frame) would have been locked normal before the starting signal could be pulled off. I agree that that would have been insufficient for any point passed over at any sort of speed, even 15 mph when as a minimum detection would have been required, but at less than walking pace ...... After all if the guard felt anything wrong as the train pulled away, he would have dropped the handle and the train would have stopped before any significant damage was done.
In my experience, Inspecting Officers were reasonable (and responsible) human beings who were concerned about safe working, not about ticking every little box.
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Re: Facing point locks
bécasse wrote:...they clearly didn't given the number of places where such points existed without any FPLs or detection - and not just on the GWR either.
Dalmellington, G&SWR. Not only was there no FPL, the loco release points were hand points. There are plenty of published photos of all dates of the waiting-to-depart train standing over them pushed right up to the buffers. To the best of my knowledge it remained like that until closure in 1964.
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Re: Facing point locks
I agree with Martin, on GW practice, the crossover at the buffer stop end was not locked with a FPL. Just looking at Clevedon signalling diagram which conforms that. However Portishead with the new box (1954) does show FPL at the buffer stop end.
If there was an FPL on that crossover, there would not have been a locking bar to answer the OP's original question. There isn't one at Bodmin in 2012 (my last visit there).
If there was an FPL on that crossover, there would not have been a locking bar to answer the OP's original question. There isn't one at Bodmin in 2012 (my last visit there).
Tim V
(Not all railways in Somerset went to Dorset)
(Not all railways in Somerset went to Dorset)
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Re: Facing point locks
Martin Wynne wrote:martin goodall wrote:the interlocking would not have allowed the Home signal to be pulled off unless this crossover was set Normal, and pulling off the Home signal would therefore have the effect of back-locking the point lever for the crossover.
Hi Martin,
The purpose of an FPL is nothing to do with interlocking with the signals.
It is to prevent the switch blades from physically moving under traffic. FPLs are required where service passenger trains travel over facing switch blades. This would only apply to a release crossover if the coaches were pushed back up to the buffers after running round.
Often the platform does not extend past the release crossover. But if it does, and it is desired to start a long passenger train from the buffers, it would be necessary to clip the release switch blades.
p.s. non-passenger coaching stock and empty stock movements don't count.
cheers,
Martin.
This is precisely what we have to do at Llanfair Caereinion in these circumstances on the rare occasions this occurs. Even though only one or two wheelsets may be beyond the tips of the switches the blades must be clipped.
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Re: Facing point locks
david_g wrote:This is precisely what we have to do at Llanfair Caereinion in these circumstances on the rare occasions this occurs. Even though only one or two wheelsets may be beyond the tips of the switches the blades must be clipped.
+1
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Re: Facing point locks
What happens now on preservation and what happened in the past are not the same. In the past the majority of release crosovers did not have FPLs, no doubt there were a few but they would have been the exceptions.
There are lots of box diagrams on line for those who want to check. And they would not have been clipping the points either.
There are lots of box diagrams on line for those who want to check. And they would not have been clipping the points either.
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Re: Facing point locks
Not GWR, but I can offer Burnham-on-Sea (S&DJR) as another location where passenger-carrying vehicles made facing movements over an engine release crossover not fitted with a FPL. The crossover in question was located two carriage lengths distant from the western end of Burnham's excursion platform, and there is photographic evidence of excursions embarking passengers for departure with at least one carriage positioned over or beyond the facing switch.
If the clipping of unbolted points prior to a facing movement by passenger-carrying vehicles is nowadays regarded as obligatory then this appears to reflect a change in what is treated as acceptable operating practice. Recall that in the lead-up to the 1915 accident at Quintinshill the down local train was propelled through an unbolted crossover, and that at the subsequent BoT inquiry it became apparent that such a practice was commonplace and one that attracted no adverse comment.
At Highbridge, the GWR-controlled connection from the down Bristol & Exeter line to the S&D was devoid of any FPL. Inevitably this meant that the passage of any excursion from the GW line to the S&D involved a facing movement by the entire train over unbolted points. It would be interesting to discover whether it was the practice to clip those points when such a manoeuvre was carried out.
If the clipping of unbolted points prior to a facing movement by passenger-carrying vehicles is nowadays regarded as obligatory then this appears to reflect a change in what is treated as acceptable operating practice. Recall that in the lead-up to the 1915 accident at Quintinshill the down local train was propelled through an unbolted crossover, and that at the subsequent BoT inquiry it became apparent that such a practice was commonplace and one that attracted no adverse comment.
At Highbridge, the GWR-controlled connection from the down Bristol & Exeter line to the S&D was devoid of any FPL. Inevitably this meant that the passage of any excursion from the GW line to the S&D involved a facing movement by the entire train over unbolted points. It would be interesting to discover whether it was the practice to clip those points when such a manoeuvre was carried out.
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Re: Facing point locks
John Palmer wrote:If the clipping of unbolted points prior to a facing movement by passenger-carrying vehicles is nowadays regarded as obligatory then this appears to reflect a change in what is treated as acceptable operating practice.
I recall an incident at Worcester Shrub Hill some years ago where we were all turfed off a DMU so that it could change platforms over an unbolted crossover. This was deemed quicker than fetching clips from the signal box and applying them. I can't remember the operating upset which made this necessary. We all trooped over the footbridge and rejoined our belongings on the train. I recall some mutterings from fellow passengers.
Martin.
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Re: Facing point locks
Historically, the Railway Inspectorate had the power to insist on the appropriate safety measures being incorporated in 'new works', because such new lines, new stations, new junctions or other new facilities could not be opened or used until they had been formally approved by an appointed officer of the Inspectorate.
The Inspectorate's powers over existing lines and facilities was limited, except where new legislation was introduced which was of general application, in which case all companies then had to change their equipment and operating practices in order comply with the new rules by the stipulated date.
However, this left quite a lot of old equipment and existing operating practices undisturbed, and while the BoT/MoT could issue recommendations, there was little that could be done to persuade companies to adopt 'best practice' (except under legal compulsion of the type mentioned above). But accident reports were one means by which pressure could be brought to bear to encourage improved practices and equipment.
This general approach no doubt explains the widespread practice of omitting an FPL from the engine release crossover. And in the 'good old days' (pre-WW2) companies certainly wouldn't have wasted time and effort faffing about clipping the points in question.
Things began to change with WW2 and Nationalisation, and a rather more up-to-date approach to such matters gradually began to be taken, but it was still a slow process, and there were plenty of examples of the older more relaxed approach for a long time after 1948.
When modelling earlier periods, we need to bear in mind that equipment and operating practices may have differed from the way things are done nowadays.
The Inspectorate's powers over existing lines and facilities was limited, except where new legislation was introduced which was of general application, in which case all companies then had to change their equipment and operating practices in order comply with the new rules by the stipulated date.
However, this left quite a lot of old equipment and existing operating practices undisturbed, and while the BoT/MoT could issue recommendations, there was little that could be done to persuade companies to adopt 'best practice' (except under legal compulsion of the type mentioned above). But accident reports were one means by which pressure could be brought to bear to encourage improved practices and equipment.
This general approach no doubt explains the widespread practice of omitting an FPL from the engine release crossover. And in the 'good old days' (pre-WW2) companies certainly wouldn't have wasted time and effort faffing about clipping the points in question.
Things began to change with WW2 and Nationalisation, and a rather more up-to-date approach to such matters gradually began to be taken, but it was still a slow process, and there were plenty of examples of the older more relaxed approach for a long time after 1948.
When modelling earlier periods, we need to bear in mind that equipment and operating practices may have differed from the way things are done nowadays.
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Facing point locks
Gents,
Thanks for the fascinating discussion, it was very informative.
Yesterday evening I went down to the club to trial fit my first attempt at making a FPL cover and found out that the club layout had been derived from the track plan of Dowlais Central for which a signalling diagram (date uncertain) had been found: there was no FPL for the engine release crossover.
Digging through old photos I found a couple showing short trains being left clear of the crossover but also two showing passenger trains over the crossover, one was pre-grouping and the other was a DMU (that I think did not run regular services).
Now all I'm expected to do is to make the locking mechanism - fortunately a working version has not been requested!
Thanks for the fascinating discussion, it was very informative.
Yesterday evening I went down to the club to trial fit my first attempt at making a FPL cover and found out that the club layout had been derived from the track plan of Dowlais Central for which a signalling diagram (date uncertain) had been found: there was no FPL for the engine release crossover.
Digging through old photos I found a couple showing short trains being left clear of the crossover but also two showing passenger trains over the crossover, one was pre-grouping and the other was a DMU (that I think did not run regular services).
Now all I'm expected to do is to make the locking mechanism - fortunately a working version has not been requested!
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Regards,
Andrew Nummelin
Andrew Nummelin
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Re: Facing point locks
For inspiration, here is Blue Anchor in 1975.
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Tim V
(Not all railways in Somerset went to Dorset)
(Not all railways in Somerset went to Dorset)
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Re: Facing point locks
andrewnummelin wrote:Digging through old photos I found a couple showing short trains being left clear of the crossover but also two showing passenger trains over the crossover, one was pre-grouping and the other was a DMU (that I think did not run regular services).
I can offer you one from 1950, with the two [still chocolate and cream] bogie coaches pushed back right to the stops - Branch Line Byways, Ian L Wright
Regards
Noel
Noel
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Re: Facing point locks
And here, bucking the trend, is Staines (GW).
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Tim V
(Not all railways in Somerset went to Dorset)
(Not all railways in Somerset went to Dorset)
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Re: Facing point locks
Taken after the layout was altered post withdrawal of the passenger service. The point is clearly worked by the two-lever ground frame to the left but I'm not sure why both levers seem to work something, it clearly isn't a classic FPL as there is no locking bar and I can't think that the neck is track-circuited.
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