facing point lock operation

[The Stationmaster]

This one is worth a read - amazingly short report for such a serious incident

 

What was the Signalman thinking ?

 

http://www.railwaysarchive.co.uk/documents/MoT_Connington1967.pdf

'I want to see a train crash' has been widely suggested over the years.

[John_Hughes]

The Rules clearly required hand points (which of course only existed in sidings) to be correctly set and properly closed before a movement was made over them and the Shunter (or Guard) working them was required to ensure that was the case - Rule 111 in the BR 1950 Rule Book, within Section J of the 1972 Rule Book (where it is even more explicit than in the 1950 book).

 

Indeed, but we all know that most goods guards (my uncle was one) were busy enough without checking up on the shunter doing his job properly, and we've all checked something and forgotten that we've done so - am I really sure I turned the gas off?

 

I suspect that odd mishaps did happen with a couple of errant wagons being grounded as a result, and were duly sorted out without anyone 'official' ever finding out about them. And siding points don't always behave properly anyway - I've seen a few that had to be 'attended to' with a pinch-bar to get the blades right home ;-)

[The Bigbee Line]

The Rules clearly required hand points (which of course only existed in sidings) to be correctly set and properly closed before a movement was made over them and the Shunter (or Guard) working them was required to ensure that was the case - Rule 111 in the BR 1950 Rule Book, within Section J of the 1972 Rule Book (where it is even more explicit than in the 1950 book).

In the 90's there was a derailment of a class 73, the second of a pair of loco's. The shunter was standing holding the point handle and for some unknown reason operated the points between the two locos. He did not intend to cause a derailment and was unable to explain why he pulled the points. I believe in such circumstances you brain is waiting to pull the lever and something triggers the action. I am a great believer in standing away from equipment when your not intending to operate it. Even to the extent of keeping your hands in your pockets. After all you don't keep your finger on the trigger of a gun, unless you intend to fire it Edited March 20, 2015 by The Bigbee Line

[meil]

This one is worth a read - amazingly short report for such a serious incident

 

What was the Signalman thinking ?

 

http://www.railwaysarchive.co.uk/documents/MoT_Connington1967.pdf

Is this the one where the signalman deliberately shorted out the electrical interlock with his signal lamp?

[The Stationmaster]

Is this the one where the signalman deliberately shorted out the electrical interlock with his signal lamp?

It is generally believed that he used an ordinary table knife - I don't know if he ever admitted how he did it although he did, finally, admit to doing it.  The incident demonstrated - above all else - the potential risk, albeit a malicious one, of having locking and particularly electric locking devices mounted above floor level in signalboxes in a way that they could be tampered with.  While I am well aware that it is possible to tamper with sealed releases on FPL levers it is not a particularly easy thing to do and does require the connivance of a Technician and the Signalman and is thus - I'm sure - extremely rare.

[TheSignalEngineer]

............................................  While I am well aware that it is possible to tamper with sealed releases on FPL levers it is not a particularly easy thing to do and does require the connivance of a Technician and the Signalman and is thus - I'm sure - extremely rare.

I've seen it done by the Signalman alone. I won't give away the secret of how he had prepared it but the problem for him was the S&T Inspector was standing next to me when he used it during a frequently occuring TC failure.

 

Later we had an AAM who thought that breaking the glass was a safety risk so suggested that a flexible plastic front should be provided instead.

 

There was also a trick I remember involving a Welwyn release and a poker which enabled the Block circuit to be restored to Normal without cranking the handle for about a minute. It resulted in a mod to the mechanism when it was discovered.

[The Stationmaster]

I've seen it done by the Signalman alone. I won't give away the secret of how he had prepared it but the problem for him was the S&T Inspector was standing next to me when he used it during a frequently occuring TC failure.

 

Later we had an AAM who thought that breaking the glass was a safety risk so suggested that a flexible plastic front should be provided instead.

 

There was also a trick I remember involving a Welwyn release and a poker which enabled the Block circuit to be restored to Normal without cranking the handle for about a minute. It resulted in a mod to the mechanism when it was discovered.

I'd better not mention that I did have a small supply of the glass used in WR releases - but quite legitimately as I had adapted one for use as a 'break the glass' key holder for the ambulance room  (yes, it came from the local S&T Inspector).

[johnw1]

A mechanical switch diamond with FPL's on each switch. A study of the rodding run suggests that the FPL's are worked from one lever

 

 

https://www.flickr.com/photos/pics-by-john/14706658048/

Edited March 22, 2015 by johnw1

[Judge Dread]

I've seen it done by the Signalman alone. I won't give away the secret of how he had prepared it but the problem for him was the S&T Inspector was standing next to me when he used it during a frequently occuring TC failure.

 

Later we had an AAM who thought that breaking the glass was a safety risk so suggested that a flexible plastic front should be provided instead.

 

There was also a trick I remember involving a Welwyn release and a poker which enabled the Block circuit to be restored to Normal without cranking the handle for about a minute. It resulted in a mod to the mechanism when it was discovered.

There was a story in the Hull area that certain signalmen had made for themselves a gadget from "Meccano"  parts which would wind up the Welwyn release very quickly. We were instructed to install all releases from then on close to the block instruments to stop this happening.  

[beast66606]

A mechanical switch diamond with FPL's on each switch. A study of the rodding run suggests that the FPL's are worked from one lever

 

 

https://www.flickr.com/photos/pics-by-john/14706658048/

 

lever 30 - at least they were in 2002

 

[Beatty 139]

I do like the term Brain Fart..... I suffered from this some 20 years ago coming out of a siding protected by a trap point, an experienced shunter, who was operating the ground frame, had such a 'brain fart' decided he had set the road wrongly after calling me forwards, just as the loco was onto of the trap and yes I watched him do it with no way of stopping, worse still a chap was there with a video camera to catch the lot..

People can do the most odd things out of character, hence why we have mechanical systems in place so people think twice and still get it wrong.

[The Stationmaster]

There was a story in the Hull area that certain signalmen had made for themselves a gadget from "Meccano"  parts which would wind up the Welwyn release very quickly. We were instructed to install all releases from then on close to the block instruments to stop this happening.  

The 'best' one I ever saw was made out of track circuit bonding wire and it had a little brass sleeve on the end which you used to wind, sort of like a car starting handle (I understand that one of the S&T Techs was  responsible for making it).

[John_Hughes]

A relief signalman at Pont Llanio on the Aber - Carmarthen line - who needed to catch the last down train to get home, except that he was required to be in the box to return the down starter to Danger after it had left - simply left it set to Danger, boarded the train and leant out of the window so that he could press the broom-handle he was holding onto the signal wire, thus clearing the signal and completely bypassing every single safety procedure.

 

Everyone knew that he was doing it - except presumably the inspectors - and he was never caught.

[40044]

In the late 80's / early 90's there were some hand points that were called switchlocks.  the stretcher bar was done away with and the actual switches operated with a bar that looked like the fletching on an arrow.  A novel design that unlocked, moved then locked the switches in one movement.  I'll try and find some pictures

We had a number of them installed on the most heavily used roads at Arpley. I can only assume that they must have been designed by a member of the breakdown crew as some kind of ploy to keep them in overtime & callout payments. Not seen any in use for a long time now, thankfully.

[Pteremy]

Reviving this thread to ask a related question.

 

Comparing a Western Region signal box diagram with photographic evidence from the late 1950's I can identify the cover plates for the FPLs in the station layout and the separate controls for point and lock. But I cannot see the 'lock bar' supposedly characteristic of GWR FPLs. So my question is, did Western Region practice change after Nationalisation, to adopt simpler version of FPL control? Or could it just be that I don't have a photograph of good enough quality to show the bar(s)?

[TheSignalEngineer]

Reviving this thread to ask a related question.

 

Comparing a Western Region signal box diagram with photographic evidence from the late 1950's I can identify the cover plates for the FPLs in the station layout and the separate controls for point and lock. But I cannot see the 'lock bar' supposedly characteristic of GWR FPLs. So my question is, did Western Region practice change after Nationalisation, to adopt simpler version of FPL control? Or could it just be that I don't have a photograph of good enough quality to show the bar(s)?

The facing point lock bar was provided when there wasn't a track circuit which could lock the FPL lever electrically. Looking at the picture in post #85 above, points 40 are locked by pulling FPL 39. When a train is occupying track circuit T2 Lever 39 cannot be put back to normal to unlock points 40.

 

Are the points in your example covered by track circuits?

[Pteremy]

Thanks for helping. 

 

I have not found anything in writing that says so explicitly. But on the track diagram the points in question have a small cross at right angles to the point V. Does that indicate a track circuit? (There is only one short section with an alphanumeric notation on the diagram - 'V26T' - which I had assumed was some sort of circuit. The other stations on the line are similar, in that there are just one or two isolated sections with this sort of designation.)

 

Otherwise are there any visual clues to look for?

[Siberian Snooper]

Thanks for helping. 

 

I have not found anything in writing that says so explicitly. But on the track diagram the points in question have a small cross at right angles to the point V. Does that indicate a track circuit? (There is only one short section with an alphanumeric notation on the diagram - 'V26T' - which I had assumed was some sort of circuit. The other stations on the line are similar, in that there are just one or two isolated sections with this sort of designation.)

 

Otherwise are there any visual clues to look for?

 

The visual clue is a white diamond on the signal, which indicates to the driver that there is track circuiting. Post 19 in the link below shows a distant with the white diamond.

 

http://www.rmweb.co.uk/community/index.php?/topic/48504-gwr-signals-and-where-they-go/

[TheSignalEngineer]

Thanks for helping. 

 

I have not found anything in writing that says so explicitly. But on the track diagram the points in question have a small cross at right angles to the point V. Does that indicate a track circuit? (There is only one short section with an alphanumeric notation on the diagram - 'V26T' - which I had assumed was some sort of circuit. The other stations on the line are similar, in that there are just one or two isolated sections with this sort of designation.)

 

Otherwise are there any visual clues to look for?

Depending on what type of plan you are looking, on a signalling plan the symbols would be something like this.

 

 

The track circuits would be identified by names such as TA, AAT, T123, etc.

 

Actual presentation details varied slightly between companies and regions, but the standards were laid down in British Standard BS376 Part 1, and now in RSSB standards.

[Pteremy]

Depending on what type of plan you are looking, on a signalling plan the symbols would be something like this.

 

TC and Bar.jpg

 

The track circuits would be identified by names such as TA, AAT, T123, etc.

 

Actual presentation details varied slightly between companies and regions, but the standards were laid down in British Standard BS376 Part 1, and now in RSSB standards.

 

 

Ok so the diagram has features like your upper diagram, but in the late 1950s photos I am not seeing a bar where I expect one.  Will see if i can find some photos with a different perspective on the point.

[Grovenor]

The visual clue is a white diamond on the signal, which indicates to the driver that there is track circuiting. Post 19 in the link below shows a distant with the white diamond.

 

http://www.rmweb.co.uk/community/index.php?/topic/48504-gwr-signals-and-where-they-go/

Assuming you mean this photo the diamond has nothing to do with the Distant signal but is for the home signal above. The diamond is to advise the crew how to obey rule 55 when they are stopped at the signal. Hence not relevant to Distants which do not have stop aspects.

[The Stationmaster]

Reviving this thread to ask a related question.

 

Comparing a Western Region signal box diagram with photographic evidence from the late 1950's I can identify the cover plates for the FPLs in the station layout and the separate controls for point and lock. But I cannot see the 'lock bar' supposedly characteristic of GWR FPLs. So my question is, did Western Region practice change after Nationalisation, to adopt simpler version of FPL control? Or could it just be that I don't have a photograph of good enough quality to show the bar(s)?

 

Depends where it was!  The photo might not show lock bars for the simple reason that the weren't any and the points were locked by a track circuit.  Now look at these photos - they're ona preserved line but teh signalling and standards are basically Western Region and would be similar to those on force in the late 1950s.

 

First a facing point - it has a standard Reading pattern cover over the facing point lock mechanism but no locking bar as it is locked by a track circuit -

 

 

 

Now the relevant signalbox diagram - drawn to more or less Reading DO standards (click on the pic to enlarge it.  The point pictured above is number 19A on the diagram,  and as the diagram is basically to Reading standards the sections of line which are track circuited are coloured black and in this case track circuit AD is the one where this point and point 15A are situtated. As no signals are immediately involved there would be no sign on any signal to indicate that there is a track circuit through these points - track circuit AD is there solely to replace what would otherwise be facing point locking bars on points 15A and 19A.

 

You will also note on the diagram a black rectangle adjacent to the point toe - that rectangle indicates to the Signalman that the point has a facing point lock and shows the appropriate lever number for that FPL.  That is the later Reading Drawing Office standard for indicating an FPL.  The symbols posted above by 'Signal Engineer are the British Standard for signalling plans and what are nowadays known as 'Signal Facilities Drawing' and what were known on the Western Region as 'Locking Sketches'.  Different Drawing offices had different standards for their Region's signalbox diagrams and they didn't necessarily match BS376 but that didn't matter as long as the engineering drawings complied with the standard.

 

 

Hope this has helped clarified what I think you were questioning?

[Siberian Snooper]

Assuming you mean this photo the diamond has nothing to do with the Distant signal but is for the home signal above. The diamond is to advise the crew how to obey rule 55 when they are stopped at the signal. Hence not relevant to Distants which do not have stop aspects.

Sorry, I had scrolled the picture to the point, that I had not noticed the home signal above the distant arm.

[Pteremy]

Depends where it was!  The photo might not show lock bars for the simple reason that the weren't any and the points were locked by a track circuit.  Now look at these photos - they're ona preserved line but teh signalling and standards are basically Western Region and would be similar to those on force in the late 1950s.

 

First a facing point - it has a standard Reading pattern cover over the facing point lock mechanism but no locking bar as it is locked by a track circuit -

 

IMGP6982.jpg

 

 

Now the relevant signalbox diagram - drawn to more or less Reading DO standards (click on the pic to enlarge it.  The point pictured above is number 19A on the diagram,  and as the diagram is basically to Reading standards the sections of line which are track circuited are coloured black and in this case track circuit AD is the one where this point and point 15A are situtated. As no signals are immediately involved there would be no sign on any signal to indicate that there is a track circuit through these points - track circuit AD is there solely to replace what would otherwise be facing point locking bars on points 15A and 19A.

 

You will also note on the diagram a black rectangle adjacent to the point toe - that rectangle indicates to the Signalman that the point has a facing point lock and shows the appropriate lever number for that FPL.  That is the later Reading Drawing Office standard for indicating an FPL.  The symbols posted above by 'Signal Engineer are the British Standard for signalling plans and what are nowadays known as 'Signal Facilities Drawing' and what were known on the Western Region as 'Locking Sketches'.  Different Drawing offices had different standards for their Region's signalbox diagrams and they didn't necessarily match BS376 but that didn't matter as long as the engineering drawings complied with the standard.

 

IMGP6995.jpg

 

Hope this has helped clarified what I think you were questioning?

 

 

Yes, very helpful. I am starting to think that the diagram predates the period I am interested in. It has notes for e.g. sidings taken out of use in 1960's but nothing for track circuitry. 

[Pteremy]

Yes, very helpful. I am starting to think that the diagram predates the period I am interested in. It has notes for e.g. sidings taken out of use in 1960's but nothing for track circuitry. 

 

 

So I am risk of confusing myself even more. I have found a couple of photographs that appear to show some sort of bar, but the other side of the point mechanism, i.e. 'inside' the point itself. Assuming that this is right (and not some sort of optical illusion) a bar in that position, adjacent to a switch blade, must perform a different function?