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Post by londonse on Apr 23, 2011 14:11:50 GMT
Can anyone tell me where the first installation was/is I understand that some locations did not have any spare levers. I know some locations had turn screw handels. Perhaps some kind person has a list.
Note to Mods move this if it's in the wrong location.
Paul
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Post by railtechnician on Apr 23, 2011 14:30:25 GMT
Can anyone tell me where the first installation was/is I understand that some locations did not have any spare levers. I know some locations had turn screw handels. Perhaps some kind person has a list. Note to Mods move this if it's in the wrong location. Paul Well, auto release sites usually have a release lever, AFAIR the only site that I worked at that had auto release without a release lever was Charing Cross Jubilee as all 12 levers were used for points and signals. Sites with release screws were manually operated lever frames. I'm not quite sure what you are asking as there is ambiguity in the question, however, I don't know what the very first auto release site was and I also don't know what the very first site with auto release and without a release lever was. |
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Post by londonse on Apr 23, 2011 14:48:11 GMT
Can anyone tell me where the first installation was/is I understand that some locations did not have any spare levers. I know some locations had turn screw handels. Perhaps some kind person has a list. Note to Mods move this if it's in the wrong location. Paul Well, auto release sites usually have a release lever, AFAIR the only site that I worked at that had auto release without a release lever was Charing Cross Jubilee as all 12 levers were used for points and signals. Sites with release screws were manually operated lever frames. I'm not quite sure what you are asking as there is ambiguity in the question, however, I don't know what the very first auto release site was and I also don't know what the very first site with auto release and without a release lever was. So what you are saying is only sites with V frames have automatic release? The reason I ask is that there are/were some sites on the Northern line where all the levers were used and as they date from the 1950s just wondered how a release was effected. Paul |
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Post by Harsig on Apr 23, 2011 16:02:39 GMT
Firstly I shall define my terms  When referring to an auto release I'm referring to one which is initiated automatically as soon as the signal man returns a signal to danger, if it is approach locked. At some locations the signal is approach locked as soon as it clears even if no train is present. A release lever still may be involved in achieving this release but its operation requires no action from the signalman. When referring to a manual release I mean one where in addition to returning the signal to danger, the signalman must also carry out some other action to operate the release. This may be operation of the release lever or a hand screw or operation of a key switch or button. The latter two may initiate the operation of release lever. Following a cursory scan of my (incomplete) set of signalling notices the earliest reference to Automatic releases I've come across was at Hatton Cross in 1975. There are however some older sites which have subsequently been converted to auto release and not all of these are V -style frames. Many of the older manned signal cabins did not originally have release levers and some did not have any sort of release facility at all. Where release facilities were subsequently provided they, as far as possible used a spare lever to act as a release lever. However if none were available some other means of operating the release would be provided. As an example, Harrow On The Hill, when first opened, in 1948, had no emergency release facilities. These were subsequently provided in 1961. Harrow is a big area and actually consists of three interlockings and so sectional releases were provided. In general at this time an emergency release covered all signals in an interlocking and so if a release was to taken on one signal, all other signals also had to be maintained at danger while the release was taken. With an area as large as Harrow, with multiple running lines, finding a suitable moment to effect a release without causing undue delay might be problematical, hence the provision of separate sectional releases. These divided the area up so only signals in that area need be maintained at danger. The areas were/are Harrow South NB Fast & NB Local Harrow South SB Fast & SB Local Harrow South & Harrow Station Down/NB Main & SB Main/Up Harrow Station NB Fast & NB Local Harrow Station SB Local, SB Uxbridge & Goods Yard (south end) Harrow North NB Local, SB Local & Goods Yard (north end) Harrow North NB Main & SB Main Harrow North NB Uxbridge Those releases listed as Harrow North or Harrow South were each provided with their own release lever in the north and south signal cabins. Thus both cabins each has/had three release levers. In the main (station) cabin there were no spare levers available at the time of installation. Instead a key switch panel was provided, with one key for each of the eight releases listed above. In the cases of the Harrow South and Harrow North releases the key switch just caused the corresponding release lever in the relevant cabin to operate. However for the main (station) cabin releases, the key switch directly initiates the relevant release. Incidentally automatic releases are generally selective. That means the release only applies to the signal concerned and other (non-conflicting) signals can still be cleared while the release is being taken. |
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Post by mrfs42 on Apr 23, 2011 16:47:26 GMT
Do you want to include the 'Welwyn' type releases? Certainly used on the Met&GC and just possibly one of the iterations of Shoreditch before becoming a slave downstairs.
They might also have been used in Met&GW locknblock territory.
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Post by railtechnician on Apr 23, 2011 19:00:19 GMT
Well, auto release sites usually have a release lever, AFAIR the only site that I worked at that had auto release without a release lever was Charing Cross Jubilee as all 12 levers were used for points and signals. Sites with release screws were manually operated lever frames. I'm not quite sure what you are asking as there is ambiguity in the question, however, I don't know what the very first auto release site was and I also don't know what the very first site with auto release and without a release lever was. So what you are saying is only sites with V frames have automatic release? The reason I ask is that there are/were some sites on the Northern line where all the levers were used and as they date from the 1950s just wondered how a release was effected. Paul It depends upon your definition of auto release, I take it to mean an automatic function involving no manual intervention, the situation when the signal lever has returned to the mid position and when the backlock is clear, whether the signal lever has moved from reverse either following the passage of a train or following the 'pulling' of an approach locked route by a signal operator in a control room where no separate release button exists. My definition of auto release fully concurs with that stated by Harsig. Basically auto release is that which is found on later 'V' style frames such as Heathrow, Hatton Cross, Hounslow Central, Hyde Park Corner etc but not at Acton Town East, Acton Town West, Ealing Common, Ealing Broadway, South Harrow etc Platform Keyswitch releases such as found at King's Cross Picc are not auto releases because they are manually initiated. I am not saying that only sites with 'V' style frames have auto release because many of them do not as they require manual intervention in the form of a control room release button. Auto release is a self acting feature of some 'V' style interlockings but I see no reason why it could not exist in modified 'N' style interlockings or other interlockings although I am not aware of any. There are some 'V' style interlockings which despite having a release lever do not have release facilities on all signals and require release of those signals to be effected by a signal lineman, IIRC Acton East IMR has one such signal (can't recall which now), mind you that IMR also has a stick relay on 7s (not usually a feature of 'V' style circuitry) IIRC. Thus I suggested your question was ambiguous! AFAIK the Northern line IMRs that I worked at were all manual release sites, however, I was not a signal lineman when I worked in any of those IMRs. |
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Post by londonse on Apr 24, 2011 8:15:23 GMT
RT I'm sorry if my question came across as ambiguous but I do not have the knowledge of signalling as a lot of the people on here.
Harsig many thanks for the infromative answer the info on Harrow most interesting which leads to a question then if an area was controlled by push buttonand a release was required was there always a release button/switch or was the route self cancelling by pulling the button and if there was a release lever then the same as for Harrow North/South or was there some circuitary if there was no release lever?
MRFS Would you like to expand on Shoreditch?
Paul
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Tom
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Post by Tom on Apr 24, 2011 8:59:10 GMT
I'd agree with Harsig and Railtechnician as to definitions. However, I'd like to differ on the first site and offer the Victoria Line stage 1 sites (Northumberland Park, Walthamstow, Seven Sisters, Finsbury Park and Highbury) as the sites concerned.
Some other locations have also now been converted to a 'Relay auto release' with no release lever, these include Plaistow and Heathrow T123. A similar method is planned for Whitechapel, which will be the first manual cabin with an auto release.
Incidentally, the Central and Waterloo & City lines have a relay based release of a different style, where instead of a common timer to all signals where you cannot start a second release until the first is complete, the timers are individual to the signals and you can have multiple releases running simultaneously.
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Post by londonse on Apr 24, 2011 9:09:58 GMT
I'd agree with Harsig and Railtechnician as to definitions. However, I'd like to differ on the first site and offer the Victoria Line stage 1 sites (Northumberland Park, Walthamstow, Seven Sisters, Finsbury Park and Highbury) as the sites concerned. Some other locations have also now been converted to a 'Relay auto release' with no release lever, these include Plaistow and Heathrow T123. A similar method is planned for Whitechapel, which will be the first manual cabin with an auto release. Incidentally, the Central and Waterloo & City lines have a relay based release of a different style, where instead of a common timer to all signals where you cannot start a second release until the first is complete, the timers are individual to the signals and you can have multiple releases running simultaneously. Tom Many thanks. Paul |
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Post by Harsig on Apr 24, 2011 10:27:30 GMT
Harsig many thanks for the informative answer the info on Harrow most interesting which leads to a question then if an area was controlled by push button and a release was required was there always a release button/switch or was the route self cancelling by pulling the button and if there was a release lever then the same as for Harrow North/South or was there some circuitry if there was no release lever? Paul The answer to your additional question is 'Yes, all of the above'. There is always considerable variation between installations which at first glance may appear similar technically. In practice of course, as different installations are of different ages as time passes ideas evolve on how they should operate leading to different approaches to how certain functions are achieved. Thus, to return to Harrow Cabin, we find that Northwood IMR (and Pinner, when there was an IMR there), is controlled from a push button panel in Harrow Cabin and is provided with a key switch to operate the release. This key switch operates the release lever (No 14) in the IMR. This installation dates from 1962. As an aside the release lever shaft was mechanically coupled to the adjacent lever shaft (numbered 14X rather than 15) in order to provide sufficient electrical contacts for all the release circuits. Down the line at Rayners Lane we find a push button panel for the control of Ruislip Siding IMR and here an auto release is provided such that merely cancelling the route was enough to initiate the release if one was required. Ruislip IMR does have a release lever, No 7. This installation dates from 1975. Doubtless there are or were a few places controlled by push button which had no release lever either. Charing Cross (Jubilee) IMR was probably an example when it was controlled from Finchley Road Cabin. |
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Post by londonse on Apr 24, 2011 10:53:03 GMT
Harsig many thanks for the informative answer the info on Harrow most interesting which leads to a question then if an area was controlled by push button and a release was required was there always a release button/switch or was the route self cancelling by pulling the button and if there was a release lever then the same as for Harrow North/South or was there some circuitry if there was no release lever? Paul The answer to your additional question is 'Yes, all of the above'. There is always considerable variation between installations which at first glance may appear similar technically. In practice of course, as different installations are of different ages as time passes ideas evolve on how they should operate leading to different approaches to how certain functions are achieved. Thus, to return to Harrow Cabin, we find that Northwood IMR (and Pinner, when there was an IMR there), is controlled from a push button panel in Harrow Cabin and is provided with a key switch to operate the release. This key switch operates the release lever (No 14) in the IMR. This installation dates from 1962. As an aside the release lever shaft was mechanically coupled to the adjacent lever shaft (numbered 14X rather than 15) in order to provide sufficient electrical contacts for all the release circuits. Down the line at Rayners Lane we find a push button panel for the control of Ruislip Siding IMR and here an auto release is provided such that merely cancelling the route was enough to initiate the release if one was required. Ruislip IMR does have a release lever, No 7. This installation dates from 1975. Doubtless there are or were a few places controlled by push button which had no release lever either. Charing Cross (Jubilee) IMR was probably an example when it was controlled from Finchley Road Cabin. Harsig Many thanks. Paul |
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Post by railtechnician on Apr 25, 2011 0:18:58 GMT
I'd agree with Harsig and Railtechnician as to definitions. However, I'd like to differ on the first site and offer the Victoria Line stage 1 sites (Northumberland Park, Walthamstow, Seven Sisters, Finsbury Park and Highbury) as the sites concerned. Some other locations have also now been converted to a 'Relay auto release' with no release lever, these include Plaistow and Heathrow T123. A similar method is planned for Whitechapel, which will be the first manual cabin with an auto release. Incidentally, the Central and Waterloo & City lines have a relay based release of a different style, where instead of a common timer to all signals where you cannot start a second release until the first is complete, the timers are individual to the signals and you can have multiple releases running simultaneously. I was aware that Heathrow had been converted as the release lever was required for the new WY7 when T5 was signalled, a former colleague was an installation 'privateer' on that job and the project was in progress when I retired. I had thought that Whitechapel would be gone by now, presumably the District is still some way from being controlled from a single point. I did not know about the independent multiple release facilities on the W&C and Central but I certainly suspected as much for the Central signalling. I recall seeing the 'Q' relay equivalent of the more familiar cubic foot JR and thought it potentially quite self destructive. I understand that additional 'cutoff' circuitry was standard to obviate the possibility of self destruction of such JRs, hence my suspicion with regard to release facilities though I have never seen any CLP bookwirings. |
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Post by Deleted on Apr 25, 2011 8:39:13 GMT
I recall seeing the 'Q' relay equivalent of the more familiar cubic foot JR and thought it potentially quite self destructive. I understand that additional 'cutoff' circuitry was standard to obviate the possibility of self destruction of such JRs, hence my suspicion with regard to release facilities though I have never seen any CLP bookwirings. Yes this is true. Every (mechanical) JR has an associated JSR, although not usually labelled as such. When the JR times out it picks and sticks the JSR, which in turn cuts off the feed to the JR. |
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Post by Deleted on Aug 16, 2011 18:29:03 GMT
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Post by Tom on Aug 16, 2011 20:43:09 GMT
I know the memo you refer to; I don't remember the bit about line speeds however!
The original lever lock circuits for the Victoria Line (IIRC) removed the ALR and UCLR circuits previously used and combined the approach lock, backlock and Delta into a single circuit operating on the (B)L. The JNSR which calls for a release hung off this.
A separate ALR was provided however if a second train could genuinely approach lock the signal before the first train had legitimately lifted the lock, such as multiple homes where the first train would approach lock the 'A' signal before the first had cleared the backlock of the 'C' signal, or where a second train could approach the signal while a backlock timer was running for the first.
The weakness of this 'dead locking' arrangement was that in engineering hours whilst testing a release was needed for every route, and if working the frame manually one had to be ready to fully normalise the signal lever as soon as the lock lifted. This weakness was addressed in the memo by the provision of the (B)LSR circuit.
Certainly working at a deadlock site overnight is a pain, as without lifting the release lever lock there wasn't a way of testing without a forced 2 minute wait! (B)LSR sites are much nicer in that respect, though the circuit design with the Backlock, Approach Lock and suchlike meshed together can be a bit tricky to test, especially when multiple routes are available, as alternative routes are conditioned out rather than the design switching between paths.
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Post by JR 15secs on Aug 17, 2011 10:30:31 GMT
Looking at the yellow peril for Morden & Tooting B (27/62) it states on P606 section 14 That when a release is taken that it will not be possible to lower any signal in the area, and in addition special releases are provided on the NB starting signals Y25/26/27 will be automatically released after 1 minute.
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Post by Deleted on Aug 17, 2011 18:58:21 GMT
Looking at the yellow peril for Morden & Tooting B (27/62) it states on P606 section 14 That when a release is taken that it will not be possible to lower any signal in the area, and in addition special releases are provided on the NB starting signals Y25/26/27 will be automatically released after 1 minute. Interesting. Does the YP say anything else?  |
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Post by Tom on Aug 17, 2011 20:41:14 GMT
Looking at the yellow peril for Morden & Tooting B (27/62) it states on P606 section 14 That when a release is taken that it will not be possible to lower any signal in the area, and in addition special releases are provided on the NB starting signals Y25/26/27 will be automatically released after 1 minute. The auto release bit sounds interesting! Certainly the bit about not being able to clear any signals in the area whilst a release is being taken is pretty standard for an installation of that era. All the signal selection circuits were fed from a special busbar (the JNBX100 bar) which was fed via the release lever normal. As soon as the release lever moves off normal, the feed to the busbar is killed which places all signals to danger. |
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