Jump to content


  • Content Count

  • Joined

  • Last visited

Community Reputation

444 Good

Contact Methods

  • Website URL

Profile Information

  • Location
    East Midlands
  • Interests
    P4, Signalling, Track, Southern EMUs

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. When I first saw this photo, I assumed (given that the auxilliary switch panel has no locking) that the Laird had casually pulled off a random selection of signals simply to demonstrate the working of the LEDs on the repeater panel. I should however, have known better, and I now see that he has carefully selected the maximum possible number of parallel movements as follows:- - North Arrival to Platform 2 (signal 37, could also have had distants 34,35) - South Arrival to Platform 4 (signals 3,8 could also have had distants 1,2) - North Departure, Shunt to Platform 3 (signals 22, 41) - South Departure. Shunt to Platform 5 (signals A, 14, 28) - South Carriage sidings to Loco Sidings (signal 33) So that is five parallel movements, 13 signals off - and not a single lever other than the signal levers needs to be reversed! I think that would consitute a busy day at the office, but I think we came close to that at least once on the last operating day!
  2. Just a couple of further photos of progress on the electric locks. Here is the current pile of work in progress:- Here is one showing the mechanical assembly only to illustrate how alternate locks "point" upwards or downwards to achieve 10mm pitch to enable adjacent levers to be locked. This job was quite a design challenge because of the number of constraints (size, robustness, ease of assembly, availability of suitable off the shelf bits, maintainability etc) but most of all becuase they need to be pretty well 100% dependable - if a lock cannot be released, the job is pretty well stopped and the last thing I want is the Laird and 14 of his burly assistants glaring at me with menaces! As of today, about half of the 42 locks needed for the total of 124 levers in the two frames are complete. Hope that is of interest.
  3. Hello Dave, I think you are too kind! I have a golden rule in this as in all modelling - just copy what the real thing did because the people who really understood this stuff have solved every possible problem years ago. There are a few challenges in this particular job but mostly it comes down to lots and lots of quite simple bits - the challenge being to be efficient enough in the use of space to fit it all in. If there is any clever bit in what I have done, then it lies in the design of the etches and, truth to tell, I was a bit surprised at just how well they worked. Even then I copied what the GW did with their VT locking as it is an extremely well thought out design. And, needless to say, my locos are not one tenth as good as yours! Best Wishes,
  4. Personally, I would build the layout first!! There is more detail on page 36, but here is a copy of one of those photos showing the test frame:- The locks are made using custom-designed etches, home-made PCBs and utilise standard Omron power relays, slightly over-voltaged to provide the umph. They come in various varieties to give the different kinds of lock we need. (combinations of Normal, Reverse, and "Backlock" positions). It has to be said that providing an electrically operated physical lock on levers as small as these (10mm pitch) is by no means easy - particularly making them 110% reliable. We are only doing the locks from the track circuits and block instruments this way yet it still requires around 80 relays just for the 70 lever frame at Junction which has 30 electricly locked levers. If we were trying to do the whole lot electrically we would need another shed to house it all in! Not only that, but each electric lock requires an "Economiser" plunger - like these:- Which means yet more work for an all-electric solution! Based on my (fairly extensive!) experience so far, for frames (say up to 75 levers) such as these, mechanical locking is much "easier" to accomplish than relay locking (not least because of the need to explicitly provide all the reciprocals with a relay design) and if building mechanical locking is beyond one's skillset, or for anything much bigger, I would go a software route - not least because mods are easy! With the advent of Raspberry Pi with cheap-as-chips interface boards, software solutions are pretty simple these days. BUT there is a bottom line here - complex problems are hard work to solve - no matter how you go about it! You got to ENJOY this kind of nonesense - which I do: it is just the right combination of intellectual challenge and bright shiny metal! Cheers,
  5. Excellent photo from the Laird! I think your track is a lot better alingned than the real thing would have been! Not sure the locking would be any easier for a mimic Mike and of course, it is the locking, not the frame which adds the value:- we already have a bank of unlocked switches as you can see in the photo, and they are pretty hard work especialy when the Timetable/Control are putting you under a lot of pressure to run four trains at once! To me, the 'lectrical stuff on these mechanical frames is the most difficult bit - here is the first stage for the Wellington frame... Just the electric locks to fit and wire, then we can play trains... Luckily there are only 10 of them on this frame, but 30-odd at Junction! Best Wishes,
  6. Hello Ian, Almost all of the points had economical FPLs, however, lever 11 is indeed an FPL (on crossover 9) and was probably necessary as 9 has three facing "ends". We discussed if the lever should stand (ie lock) Normal or Reversed - different railways used different practices and some railways changed their standard from time to time. On the Midland, standing Normal seems to have been the general (but perhaps not exclusive) practice. However, in this case - being the only FPL in the frame - and given that we do not know what the reality was, we had to think about it. There is a bit of complication that 13 releases 9 and also locks 10, yet there is a situation where 13,10 and 9 all require to be reversed at the same time (as in the photo) and another parallel route requires 13,12,10 and 9 all to be reversed. It is a close thing, but on balance, it seemed that the layout is slightly easier to work if 11 locks Normal. It has the advantage that the single blue lever in Wellington box, and the solitary blue lever in junction box (working a fouling bar) both work in the same sense. Which the Relief men will like... But I would not like to be dogmatic about wheather it is "right"!!! [now is the moment when someone posts the missing documentary evidence..] Edit:- actually, the photo shows 13,12 and 33 reversed (South Sidings to South Departure) and 9,10,6,8, R (N Arrival to Plat.6). Under this situation, the first points needing to be replaced are 10 or 12, and if 11 stood reversed, then this would necessitate unlocking 11 first to avoid "Push betweens" ie having to replace one lever between 2 which are reversed - a good route to a hernia... Thanks to everyone for the kind words BTW. Best Wishes,
  7. The lever frame for Wellington box is now complete (mechanically) and has passed all the testing I have so far thrown at it. There were a couple of quite important locks missed, but as it happens, they could be provided very easily without dismantling the whole thing. When I first looked at this job, I said I thought it would be fairly straightforward... well, it much of it was, but there are some quite difficult locks as I mentioned in a previous post. In truth, the finished job has quite a lot of metalwork in it:- Part of the complexity comes from the number of possible routes - for example, in this shot, there are 22 out of the total of 53 levers reversed - these represent 4 separate routes, and in the middle, is a continuous run of 8 levers reversed, and they are involved in 3 of the 4 routes. Some of the metal work needs to be a bit ingenious to acheive all of this and here are close-ups of just three of these - in total, there are 15 "loose pieces" (the swinging bits) to provide all the conditional locks. So just the electrical bits to do, then the Laird has a few jobs to do before we can get the thing in service - experience with the City Junction frame has shown just how important some proper locking is to the running of the job! Best wishes,
  8. You are welcome Chris - yes they do it differently elsewhere - the Southern system was unique as it was all based around the Routing Headcodes. I remember it being in use on the Portsmouth Direct in 1969 when as a 14 year old, I used to "help out" at some of the boxes. On Summer weekends, trains not stopping at Havant were 3-1, whilst those which did stop were 1-3. It was down to Idsworth (or Buriton when Rowlands Castle was switched out) to "spot" the headcode and bell the TES accordingly. I remember one occasion when I was on my own in Idsworth, correctly offering Havant a 3-1, but then following up with "2". The bell rang back a very-sternly-chastening "4".- you would never think that a single-stroke bell could speak so eloquently... There was a lot of resentment a couple of years later when the "BR" (ie LMS) bell codes were imposed - at least officially... But by then, traditional signalling between Petersfield and Havant had gone. I do know that at some non-Southern locations, it was the practice to follow-up the Entering Section with a routing description, but there must be other people round here who know a lot more about such things than me... Best Wishes,
  9. Hello there Chris, I am not sure what your understanding was of how the Branch codes were supposed to work but (assuming I am reading it correctly), what you describe here is exactly the "Standard" way of doing it. To me, the Southern had a brilliant way of working in this regard - bearing in mind that it used "routing" and not "Class" headcode discs / lamps on its trains. Sorry if I am telling you what you already know here,and sorry further if it is not relevant to your example, but let me try to describe the logic of how it was supposed to work. Suppose I am signalman in Uddens, and you are Signalman in Wimbourne station. I accept a 3-1 from West Moors followed in due course by a "2" entering section (so main + main). I offer the train to you 3-1 and you accept. As the Train approaches me, I see that it is carrying "Branch" route discs so I send the TES to you as a 4 (Branch). That tells you that the train you have accepted is routing to the Branch at the Junction. So, based on my "4", you offer it forward to Junction as a 1-3 (branch). Junction now knows to set the facing points to the Branch - for a train which he has not seen yet of course. As it passes you, you send the TES as a four (so Branch - Branch). Junction will offer it on down the branch as a 3-1 as it has passed the junction. The beauty of the system of course is that it does not matter how "out of course" the trains become, they always end up correctly routed according to their Headcode. But the system fell down with short sections for which special working was needed! I think that is the sequence you are describing, and I hope that explains how and why it was done. Again sorry if that is all a bit patronising!! But if you had a different understanding, I would be interested to know. Hope that helps! Best Wishes, Howard (Edited for typos!)
  10. Hmm ... can't even write it correctly - should have been 22 Locks 23 Either way, Released by 41 When 23 Normal, (Released by 24 Locks 25, 26 Either way) When 23 Reversed, (Released by 27 Locks 31) When (23,26 Reversed), (Released by 30 Locks 32) When (23,26,29) Reversed. Better check the mechanics are not wrong as well! Cheers,
  11. Correct! Edit:- well done also to Clive Mortimore and 5BarVT for correct entries! The locking on 22 (for the opposing move(s)) is a bit tricky - I "think" it goes something like 22 Locks 23 Either way, Released by 41 When 23 Normal, (Released by 24 Locks 25, 26 Either way) When 23 Reversed, Released by 27 When (23,26 Reversed), (Released by 30 Locks 31,32) When (23,26,29) Reversed. I think fixed Distants approaching termini are something of a "modern" idea (after all, the drivers should know where the buffer stops are to be found!) But there are rather a lot on the approach to Wellington (have a look at the City Junction frame some posts back). But it is a bit of a puzzle why there should be two on each arrival road. My first thought was that the outer distant was to give an indication that any one of the Homes was Off whilst the inner Distant would indicate that it was the "Main" road Home which was off. (and that is how the locking is) But it was also suggested to us that the only reason that there were two levers for each road was simply that four arms were too much for one pull! But that begs the question - why an inner and outer set of arms? On Some Railways, the inner Distant served the function of "Hurry Up" ie - if the driver was checked at the outer distant, but saw the inner distant Off (because of a late line clear for example), he could put steam on knowing that he was clear rather than expecting to be checked at each signal. But at a Terminus? With a 15mph speed limit? So any input based on inside knowledge would be appreciated! Best Wishes,
  12. Meanwhile, the S&T New Works Dept. has got the Wellington Frame assembled. Just the locking bridles to make and fit now then ... Of all the locked frames I have built, this is the first one where I have built the frame, then fitted the locks - previously it has been necessary to push both jobs along at once - I must say it is very nice to be able to try-out various options on a physical frame, a luxury the boys who did this for a living never had. The frame is certainly very well laid-out (even though it does not look like it from a first look at the diagram) From this, the enthusiasts will be able to spot the route "pulled off" above. Ah well. back to the locking design... Best Wishes,
  13. More work in the background... Certain members of the Nottingham Area Group of the Scalefour Society (AKA the Sweatshop), having been busy at the Thursday night meeting for some weeks now; here is the state of play with the Lever Frame for Wellington - just a bit of paint needed... Oh, and the locking to build... For which, here is the preliminary design work... More work for the Sweatshop...
  14. Meanwhile, development of the electric locks themselves is also progressing - here is a quick shot of the first production prototypes fitted to a "spare" frame for testing. The two cocktail sticks are temporary substitutes for the 8BA studding which should be doing the job, but is a bit of a fiddle to do-up and undo! So far, so good - only a further 28 to do... Best Wishes, Howard
  15. Those bushes in the background look almost real Very well done.
  • Create New...