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Post by dave1 on May 13, 2017 15:30:07 GMT
Now what I know about these you could put on the back of a stamp, What is the purpose and how many are there as from what I have been able to find out is sometimes more than one although there was no other information about them. I should have also said that I know that they stopped using them in the way they early IMRs had them.
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Post by Nortube on May 14, 2017 13:01:42 GMT
I've not heard of them (unless I know them under a different name), what are they?
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Post by dave1 on May 14, 2017 14:18:51 GMT
I've not heard of them (unless I know them under a different name), what are they? The best way I can describe and I could be wrong is that they are an early electronic form of locking and conditions have to be met before the circuitry allows the equipment to work. Like I said they stopped using them after a while, don't know when that was but with advances. |
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Post by railtechnician on May 14, 2017 16:05:17 GMT
I've not heard of them (unless I know them under a different name), what are they? An IMR lever operation board (L.O.B.) is exactly that! A L.O.B. is an arrangement of horizontal and vertical equally spaced bars in a grid, the horizontals are the outputs and the verticals are the inputs and 'gates' are placed as required at input/output crosspoints. This is an early form of electronic interlocking found in all the Victoria line IMRs, District/Picc IMRs such as Acton East, Acton West, Ealing Common, Ealing Broadway, Northfields etc. AFAIR a single L.O.B has 24 outputs but I cannot recall how many inputs, that said it is about 2' high and 4' long with a perspex cover allowing the gates (small discrete component screw in modules about 1" by 1" and 1.5" high) to be viewed. In its simplest form an input condition causes an output condition i.e. setting a route into a siding causes a point lever to throw. Of course a single input condition may be looking to set more than one set of points or indeed looking to set one set and ensuring that others cannot be thrown. Whether an input condition causes an output condition or not is determined by other inputs, each input opening a gate or not and the gates on the appropriate lever horizontal either all pass the input to give an output to a lever motor or not. There can be as many as six L.O.B.s (I can't recall seeing more than six) arranged in a suite of 2 high (giving 48 lever outputs) by 3 along. The number required is dependent upon the number of levers in the frame and the number of inputs. I gave points as an example above but the purpose of the L.O.B.(s) is to throw levers N to R and R to N as required to set up a route in the interlocking so any condition set up by control room pushbutton needing to throw a lever will have an input directly or otherwise to the appropriate input bar of the L.O.B. Obviously the larger the lever frame the more L.O.B.s are required to cater for the number of levers and the number of inputs. I think you'd know if you have seen a L.O.B. quite often the appearance is a grid as described above with a row or two of gates arranged in a diagonal left to right and top to bottom and a few 'oddly' positioned gate modules. Of course light bounces off the perspex cover so it is possible to see them at a distance and think nothing of the 'large perspex boxes' with wiring entering top (input conditions) and left (lever feeds) and exiting right (outputs to levers). Active inputs to and outputs from a L.O.B. are usually visible via individual lamps. The L.O.B. drawings are A2 size and found hanging in the light green drawing brackets conveniently hung on support pegs on a wall or pillar in the IMR. What you see is a mechanical drawing of the L.O.B. showing the grid of bars, the gates where the inputs cross the output bars as circuits etc. Somewhere I have pictures of lever operation boards at various IMRs but I have no idea where, they were all digital images and are stored on one of my mothballed old PCs or external HDDs and I don't have the time or inclination to trawl through 20 or 30 devices looking for them. However, I found these photos of parts of a L.O.B, in the gates image you can see the inputs at the top labelled as routes (U). In the other image you can see three gates on one lever bar, all three gates (three different input conditions) have to be open simultaneously for the lever feed on the left hand side to be fed out to the lever on the right hand side. L.O.B. partL.O.B. gates
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Post by dave1 on May 16, 2017 6:40:09 GMT
RT
Thanks for more information my understanding has increased a bit more from the very short notes I have there is mention of 'AND' & 'OR' gates. What replaced these LOBs in later IMRs?
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Post by Nortube on May 17, 2017 11:44:34 GMT
I can't remember seeing these in an IMR, but I have seen them elsewhere (possibly off LU) and also seen photos of similar arrangements (early PC related?)
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Post by railtechnician on May 17, 2017 17:25:08 GMT
I can't remember seeing these in an IMR, but I have seen them elsewhere (possibly off LU) and also seen photos of similar arrangements (early PC related?) Unfortunately I can't find a picture of a whole rack, I'm sure if I could that you would recognise one, those two images I found online are literally about an eighth or a tenth of one L.O.B. |
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Post by railtechnician on May 17, 2017 17:45:44 GMT
RT Thanks for more information my understanding has increased a bit more from the very short notes I have there is mention of 'AND' & 'OR' gates. What replaced these LOBs in later IMRs? On the Central line I believe they used PLCs, they definitely used PLCs on the JLE but on the Met and Jube HP computers, East end of the PIcc from Wood Green to Cockfosters and at Heathrow they used HP rack mounted computers later front ended by PCs. AFAIR almost all IMRs will have had electronic cards, the earlier ones are those you see as shelves of multicoloured cards and the later ones are the shelves of open double sided sandwiched PCBs with the colour code painted on the front edge. The cards are colour coded to indicate function such as AND, OR, Amplifier etc, there are many different card types known by one or two letter designations. Every T.O. should have a list of them in his lineman course notes or a toolbag diagram book that was once issued to signal linemen in the 1960s and 1970s. I have one which I acquired after I retired from a Network Rail engineer who got it from a mate who had been an LT Signal Engineer back in the day. Before electronic cards it was all done with PO 3000 type telephone relays potted in Jones bases originally and later in EGA bases. There are I imagine still thousands of these working on the signalling non-safety side but they must be disappearing apace now. |
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Post by dave1 on May 27, 2017 14:07:46 GMT
RT Thanks for more information my understanding has increased a bit more from the very short notes I have there is mention of 'AND' & 'OR' gates. What replaced these LOBs in later IMRs? On the Central line I believe they used PLCs, they definitely used PLCs on the JLE but on the Met and Jube HP computers, East end of the PIcc from Wood Green to Cockfosters and at Heathrow they used HP rack mounted computers later front ended by PCs. AFAIR almost all IMRs will have had electronic cards, the earlier ones are those you see as shelves of multicoloured cards and the later ones are the shelves of open double sided sandwiched PCBs with the colour code painted on the front edge. The cards are colour coded to indicate function such as AND, OR, Amplifier etc, there are many different card types known by one or two letter designations. Every T.O. should have a list of them in his lineman course notes or a toolbag diagram book that was once issued to signal linemen in the 1960s and 1970s. I have one which I acquired after I retired from a Network Rail engineer who got it from a mate who had been an LT Signal Engineer back in the day. Before electronic cards it was all done with PO 3000 type telephone relays potted in Jones bases originally and later in EGA bases. There are I imagine still thousands of these working on the signalling non-safety side but they must be disappearing apace now. RT Thanks for that interesting how things have changed over the years. |
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Post by railtechnician on May 28, 2017 16:13:34 GMT
On the Central line I believe they used PLCs, they definitely used PLCs on the JLE but on the Met and Jube HP computers, East end of the PIcc from Wood Green to Cockfosters and at Heathrow they used HP rack mounted computers later front ended by PCs. AFAIR almost all IMRs will have had electronic cards, the earlier ones are those you see as shelves of multicoloured cards and the later ones are the shelves of open double sided sandwiched PCBs with the colour code painted on the front edge. The cards are colour coded to indicate function such as AND, OR, Amplifier etc, there are many different card types known by one or two letter designations. Every T.O. should have a list of them in his lineman course notes or a toolbag diagram book that was once issued to signal linemen in the 1960s and 1970s. I have one which I acquired after I retired from a Network Rail engineer who got it from a mate who had been an LT Signal Engineer back in the day. Before electronic cards it was all done with PO 3000 type telephone relays potted in Jones bases originally and later in EGA bases. There are I imagine still thousands of these working on the signalling non-safety side but they must be disappearing apace now. RT Thanks for that interesting how things have changed over the years. You may or may not be surprised to know that everything on a railway changes and yet the oldest technology continues to survive, take points for example, the basic 4' and 6' point layouts still use 100+ year old technology although they are being replaced apace with the new TBTC resignalling coming on stream line by line. Chairlocks, Clamplocks, M63s and other point machines have never fully replaced 4' EP points just as they never fully replaced 6' EP points and in the same vein separately attached GE trainstop valves may still be found in service. Similarly there were/are several generations of lever frame motors and the air valves that operate them. Everywhere one looks on the railway one will still find old technology and because of a mix of generations of individual signalling equipment in the same room even two identical track layouts can have totally different signalling circuits on both the safety and non-safety signalling. Consider the control of an IMR which could be direct wired from a signal cabin or remotely from a signal cabin, regulating room or signal control centre using slow speed scanning, high speed scanning, S2 scanning, DCOS etc. Look at almost any signalling component on the railway and somewhere else on the railway one or more earlier generations of equipment performing the same function could be found. This may not be so for much longer as LUL will wipe away a ton of signalling history as it rolls out TBTC, however, I suspect that by the time all lines have been so resignalled there will be different generations of equipment to be found because technology is always being progressed to improve safety, to use new materials, to reduce necessary maintenance etc. |
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Post by dave1 on Jun 1, 2017 7:05:52 GMT
RT Thanks for that interesting how things have changed over the years. You may or may not be surprised to know that everything on a railway changes and yet the oldest technology continues to survive, take points for example, the basic 4' and 6' point layouts still use 100+ year old technology although they are being replaced apace with the new TBTC resignalling coming on stream line by line. Chairlocks, Clamplocks, M63s and other point machines have never fully replaced 4' EP points just as they never fully replaced 6' EP points and in the same vein separately attached GE trainstop valves may still be found in service. Similarly there were/are several generations of lever frame motors and the air valves that operate them. Everywhere one looks on the railway one will still find old technology and because of a mix of generations of individual signalling equipment in the same room even two identical track layouts can have totally different signalling circuits on both the safety and non-safety signalling. Consider the control of an IMR which could be direct wired from a signal cabin or remotely from a signal cabin, regulating room or signal control centre using slow speed scanning, high speed scanning, S2 scanning, DCOS etc. Look at almost any signalling component on the railway and somewhere else on the railway one or more earlier generations of equipment performing the same function could be found. This may not be so for much longer as LUL will wipe away a ton of signalling history as it rolls out TBTC, however, I suspect that by the time all lines have been so resignalled there will be different generations of equipment to be found because technology is always being progressed to improve safety, to use new materials, to reduce necessary maintenance etc. RT I am not surprised about what you say with all the systems that are in use or out of use, I had to go to Colindale yesterday and I saw all the old signalling still in place and how many years has it been since full TBTC? The railway is strange when you don't see any working signals although the Vic line still has them but the sound of points at Golders Green has gone all now electric. I am sure you are right that when some of today's equipment comes to be changed it will be the same. |
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Post by railtechnician on Jun 1, 2017 13:47:41 GMT
You may or may not be surprised to know that everything on a railway changes and yet the oldest technology continues to survive, take points for example, the basic 4' and 6' point layouts still use 100+ year old technology although they are being replaced apace with the new TBTC resignalling coming on stream line by line. Chairlocks, Clamplocks, M63s and other point machines have never fully replaced 4' EP points just as they never fully replaced 6' EP points and in the same vein separately attached GE trainstop valves may still be found in service. Similarly there were/are several generations of lever frame motors and the air valves that operate them. Everywhere one looks on the railway one will still find old technology and because of a mix of generations of individual signalling equipment in the same room even two identical track layouts can have totally different signalling circuits on both the safety and non-safety signalling. Consider the control of an IMR which could be direct wired from a signal cabin or remotely from a signal cabin, regulating room or signal control centre using slow speed scanning, high speed scanning, S2 scanning, DCOS etc. Look at almost any signalling component on the railway and somewhere else on the railway one or more earlier generations of equipment performing the same function could be found. This may not be so for much longer as LUL will wipe away a ton of signalling history as it rolls out TBTC, however, I suspect that by the time all lines have been so resignalled there will be different generations of equipment to be found because technology is always being progressed to improve safety, to use new materials, to reduce necessary maintenance etc. RT I am not surprised about what you say with all the systems that are in use or out of use, I had to go to Colindale yesterday and I saw all the old signalling still in place and how many years has it been since full TBTC? The railway is strange when you don't see any working signals although the Vic line still has them but the sound of points at Golders Green has gone all now electric. I am sure you are right that when some of today's equipment comes to be changed it will be the same. Cripes, it is many years since I last saw Colindale when we dropped the 'new' Plessey PA cubicle there circa 1981/2 AFAIR. The nearest I got to it after that was in the early 1990s when as a comms CET I was tracing telephone and signal 'thin wire' cabling at Edgware for Signal New Works while Balfour Beatty were remodelling the track layout. It was handy booking on at a temporary signal depot there for a few weeks, Edgware not being far from where I used to live in London and easier to drive to at night than Signal House in Acton Works. |
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Post by fivethirtytwo on Jun 6, 2017 7:34:31 GMT
dave1, all points at Golders Green are still air operated, there are no electric points at Golders.
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Post by dave1 on Jun 6, 2017 9:55:09 GMT
dave1, all points at Golders Green are still air operated, there are no electric points at Golders. I thought that the points were all surelock motors and that the air operated ones had been replaced. I was not in the first car but did not hear the swish of the points. |
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Post by railtechnician on Jun 6, 2017 18:33:10 GMT
dave1, all points at Golders Green are still air operated, there are no electric points at Golders. I thought that the points were all surelock motors and that the air operated ones had been replaced. I was not in the first car but did not hear the swish of the points. Surelock points came to LUL a couple of months after I retired so I have no hands on knowledge of them but AFAIK the point machine does not 'throw' the points instantaneously but rather 'winds' them over. That being the case there would be no 'swish' (or 'bang' to frighten operating staff as the exhausting 'D' valve of a standard 4' layout did at the trackside walkway to Bollo House!). Of course it may be that the video of the surelock machine that I have viewed is of an electrically operated rather than air worked version. |
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