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Post by hellocontrol on Sept 19, 2014 16:26:16 GMT
The easiest way to put it is Dogs on locking bar Cats on cross lock. RT will explain it a lot better than I could ever.
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Post by railtechnician on Sept 19, 2014 21:48:19 GMT
I've had my eyes opened a bit with this thread. How does Epping being an N2M Frame differ from other Frames, what made it a candidate for remote operation? I know how Frames work from the Operating side but the teccy. stuff is beyond me. The Locking Charts might well have been written in Chinese as 99% of the information means nothing to me and in all probability to many others. My previous job before returning to the LU fold was operating a Thames Water Pumping Station, it was converted from steam power in the early 60's with the intention for remote operation. The equipment was in there but never used, much like a lot of the LT 'modernisation' it would seem. Triple expansion steam engine. Wanstead Pumping Station. An N2M frame (as at Ealing Broadway) is an N frame converted for remote operation by compressed air cylinders. It is 'simply' a matter of adding an arm to each shaft such that it can be partially rotated to the left or right by the action of a piston (cylinder). The cylinders are worked by solenoid valves. LT happened to use compressed air but as the great Robert Dell said himself in the paper he presented to the IRSE he could have used solenoids instead of air cylinders. I believe the designation N2M refers to an updated (from original N type) and motorised frame. Ealing Broadway was the only frame of that type that I worked on AFAIR. As a lineman everywhere I worked was 'V' except EBY (EAB if you prefer!) As someone from the operating side you probably know more about locking than you realise! I cleaned every frame on the Picc, every frame on the Jube from Charing Cross to Stanmore as well as Ealing Broadway many times and worked on several others in my early days on Signal New Works but I can't say exactly which parts are 'cats' although I do know what a 'dog' and a 'swing dog' are. I think 'dogs' are what the frame manufacturers officially call tappets and I'm not sure if 'cats' is an LT/LU slang as I haven't seen it crop up on NR signalling webpages. Oh you have to love a steam engine and those found in water pumping stations were so well looked after. Steam engines have always fascinated me alongside the mechanisms, many and varied, that they drove day in day out for decades such as Tower Bridge bascules. I'm an out and out Fred Dibnah fan, he is one of those people that I would have loved to have met and someone who really knew his way around such technology. |
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Post by railtechnician on Sept 19, 2014 22:11:15 GMT
The easiest way to put it is Dogs on locking bar Cats on cross lock. RT will explain it a lot better than I could ever. I'm not sure that I can actually especially when most of my frame experience is on V frames and the cross locks are verticals. I'll have to dig out my locking notes. Just to add to the confusion the basics boil down to ports and tappets which are the proper names, the tappets being the dogs on the locking bars that engage in the ports of the cross slides. Like many aspects of signalling, locking was not taught in detail, just an appreciation of the basics, on the four month signal lineman course that I took. Things are different these days but back then the course was designed to turn out T2S grades predominantly to cover P Way ops, signal failures, point maintenance (4' and chairlocks only), track circuit and delta spread testing, routine and emergency equipment change and of course in depth signalling circuitry. The idea was that once in the grade lineman would be called up to additional courses to cover programme machines, clamplocks, locking and all the other aspects not covered in the T2S course. However, it was literally up to the T2S to teach himself all that he had not been taught by trawling through bookwirings, learning from colleagues and especially discovering such things as 6' point layouts, clamplocks, PM/Cs, lever frames etc etc when doing maintenance and call work. I did get some training in lever frame maintenance after I had spent several years cleaning each one on my 'patch' every six months However, by then I had already taught myself most of what I was going to be taught! |
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Post by hellocontrol on Sept 20, 2014 6:13:35 GMT
I've had my eyes opened a bit with this thread. How does Epping being an N2M Frame differ from other Frames, what made it a candidate for remote operation? I know how Frames work from the Operating side but the teccy. stuff is beyond me. The Locking Charts might well have been written in Chinese as 99% of the information means nothing to me and in all probability to many others. My previous job before returning to the LU fold was operating a Thames Water Pumping Station, it was converted from steam power in the early 60's with the intention for remote operation. The equipment was in there but never used, much like a lot of the LT 'modernisation' it would seem. Triple expansion steam engine. Wanstead Pumping Station. An N2M frame (as at Ealing Broadway) is an N frame converted for remote operation by compressed air cylinders. It is 'simply' a matter of adding an arm to each shaft such that it can be partially rotated to the left or right by the action of a piston (cylinder). The cylinders are worked by solenoid valves. LT happened to use compressed air but as the great Robert Dell said himself in the paper he presented to the IRSE he could have used solenoids instead of air cylinders. I believe the designation N2M refers to an updated (from original N type) and motorised frame. Ealing Broadway was the only frame of that type that I worked on AFAIR. As a lineman everywhere I worked was 'V' except EBY (EAB if you prefer!) As someone from the operating side you probably know more about locking than you realise! I cleaned every frame on the Picc, every frame on the Jube from Charing Cross to Stanmore as well as Ealing Broadway many times and worked on several others in my early days on Signal New Works but I can't say exactly which parts are 'cats' although I do know what a 'dog' and a 'swing dog' are. I think 'dogs' are what the frame manufacturers officially call tappets and I'm not sure if 'cats' is an LT/LU slang as I haven't seen it crop up on NR signalling webpages. Oh you have to love a steam engine and those found in water pumping stations were so well looked after. Steam engines have always fascinated me alongside the mechanisms, many and varied, that they drove day in day out for decades such as Tower Bridge bascules. I'm an out and out Fred Dibnah fan, he is one of those people that I would have loved to have met and someone who really knew his way around such technology. I was always under the impression that air worked N frames were N2 although Ealing Bdy was from the start but all the lists I have seen say it's a N2 not an N2M. I believe that the N2M was a manually operated N which was capable of being converted for remote operation, but you know what LT/LU were like not a lot of standard items more standards in writing. |
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Post by hellocontrol on Sept 20, 2014 6:15:40 GMT
The easiest way to put it is Dogs on locking bar Cats on cross lock. RT will explain it a lot better than I could ever. I'm not sure that I can actually especially when most of my frame experience is on V frames and the cross locks are verticals. I'll have to dig out my locking notes. Just to add to the confusion the basics boil down to ports and tappets which are the proper names, the tappets being the dogs on the locking bars that engage in the ports of the cross slides. Like many aspects of signalling, locking was not taught in detail, just an appreciation of the basics, on the four month signal lineman course that I took. Things are different these days but back then the course was designed to turn out T2S grades predominantly to cover P Way ops, signal failures, point maintenance (4' and chairlocks only), track circuit and delta spread testing, routine and emergency equipment change and of course in depth signalling circuitry. The idea was that once in the grade lineman would be called up to additional courses to cover programme machines, clamplocks, locking and all the other aspects not covered in the T2S course. However, it was literally up to the T2S to teach himself all that he had not been taught by trawling through bookwirings, learning from colleagues and especially discovering such things as 6' point layouts, clamplocks, PM/Cs, lever frames etc etc when doing maintenance and call work. I did get some training in lever frame maintenance after I had spent several years cleaning each one on my 'patch' every six months However, by then I had already taught myself most of what I was going to be taught! When I said you would be able to tell more what I meant was you were qualified to maintain such equipment although I worked in Engineering I never was allowed to touch equipment by myself. |
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Post by railtechnician on Sept 20, 2014 9:23:04 GMT
I have to say that I was always told that EBY frame was an N2 but then the only difference I saw between it and other N frames was the addition of air valves and motors. In which case I have to wonder what the difference between an N and an N2M would be. The backlock circuitry perhaps was different to ensure that levers didn't jam when normalised by air so perhaps an N2M had an LCC contact, as in V frames, but none of the air equipment.
Like everything else signalling no two frames appeared identical, if the mechanical was the same the electrical was different and the air equipment differed with LT potted valves, Martonair valves, of 24v or 50v variety, single or double cylinder motors etc. We were taught that every site was unique and that was certainly my experience although generally frames were much of a muchness in terms of signalling generation e.g. Acton East, Acton West and Ealing Common were similar in generation but varied in non-safety control i.e. Acton West was a slave of Acton East but Ealing Common had a generation of circuitry more related to Kings Cross Picc using Jones relays rather than EGA relays.
In all honesty we seldom knew what type of valve or motor would be needed in an emergency to resolve a frame failure until we got to site to deal with it. Of course I would remember those sites where I fitted particular equipment should I get another call to the same type of failure at the same site but many linemen would not keep their heads full of local knowledge once the days of each lineman having his own small section of railway to maintain were gone. I used to be amazed at what my more senior colleagues at the east end of the Picc didn't know about their local area but then every one of them had once had their own IMR and controlled area to maintain and seldom went elsewhere to do routine maintenance whereas I was predominantly a night TO and routinely worked at every site and on more than one line.
As for touching equipment by oneself one had to know the limit of one's authority, I held a signalling tester license which is generally not issued these days, a more modular approach being taken such that a lineman has to hold several separate licenses (can't recall them now except the maintainer license which was a lesser qualification) as the equivalent of a signalling tester license. The training was also split to into modules that covered all aspects of the job instead of being one long general course (T2S was not the longest, when I did the CET course that turned out to be 29 weeks including one holiday week spent in a call depot!). In my days as a signal lineman DQN32 was where the limits of one's authority were written and we all had to know what we could and could not touch alone, some jobs required a minimum of two supervisors working together and of course most of what we touched required written authority in terms of safety and non-safety AWCs, several hundred copies of which I still have in my IRSE logbook to remind me of the frames that I cleaned, the many trainstops, tripcock testers, inductor rails and safety relays that I changed, the hundreds of ends of points that I maintained etc etc. I had a much wider variety of signalling work than many of my colleagues and worked on all lines over the years but I don't think I really scratched the surface of the subject in what amounted to 10 of my 28 years service in the signal departments.
When it comes to lever frames there are just a handful of people that know them inside out and they are the locking fitters and former locking fitters, a scarce resource there once being only one per New Works depot when I began my career often each having one or two potentially suitable trainees in tow but few making the grade. These days like CETs and AETs the locking fitter grade is also a TO as the three grades were reclassified to be equals back in 1992.
One of my Works Controllers on the Picc was a former locking supervisor and a colleague's father had once been another but they were the only two that I knew in all my years and they both bowed to the knowledge and practical expertise of the locking fitter who was a starred craftsman.
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Post by GentlemanJim on Sept 21, 2014 11:18:06 GMT
Excellent post. If I get bored over the next week sitting by the pool and I think of something I'll pop on for a minute or so, if not I'll catch up with you all in 9 days.
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