ColHut Posted October 1, 2014 Share Posted October 1, 2014 G'day, I wondered if someone could explain what the numbered black lines along portions of the track were, for example, #8 here http://www.signalbox.org/diagrams.php?id=380 I am guessing they are mechanical locking bars for the points controlled by levers in the signal box but I do not really know. Regards Link to post Share on other sites More sharing options...
micknich2003 Posted October 1, 2014 Share Posted October 1, 2014 You are right, they are Facing Point Locks. Link to post Share on other sites More sharing options...
micknich2003 Posted October 1, 2014 Share Posted October 1, 2014 I have double checked No8, and apart from being a FPL is also a "Clearence Bar" on the Down Bay. Link to post Share on other sites More sharing options...
AberdeenBill Posted October 1, 2014 Share Posted October 1, 2014 The way that the level crossing interferes with the throat of the goods yard would make an interesting model. Bill Link to post Share on other sites More sharing options...
micknich2003 Posted October 1, 2014 Share Posted October 1, 2014 Bill, "Gate Selector for Wheel" is also interesting, and pressumably, because the gates overlap. Mick. Link to post Share on other sites More sharing options...
ColHut Posted October 1, 2014 Author Share Posted October 1, 2014 I have double checked No8, and apart from being a FPL is also a "Clearence Bar" on the Down Bay. So from here (hopefully the same meaning) http://extranet.artc.com.au/docs/eng/signal/procedures/general/SGS01.pdf CLEARANCE BAR A bar fixed alongside the rail and terminating at the clearing point of two converging lines. The clearance bar is interlocked with the points in such a manner that they cannot be moved while a train is passing over or standing on the bar. But why does it have a lever against it in two places? Link to post Share on other sites More sharing options...
micknich2003 Posted October 1, 2014 Share Posted October 1, 2014 No8 lever works both the Clearence Bar, and the Facing Point Lock mechanisiams. Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted October 1, 2014 RMweb Gold Share Posted October 1, 2014 So from here (hopefully the same meaning) http://extranet.artc.com.au/docs/eng/signal/procedures/general/SGS01.pdf CLEARANCE BAR A bar fixed alongside the rail and terminating at the clearing point of two converging lines. The clearance bar is interlocked with the points in such a manner that they cannot be moved while a train is passing over or standing on the bar. But why does it have a lever against it in two places? Strange definition (but then it is from Aus ) there being no such thing in British usage as a 'Clearing Point' between two lines - Clearing Point is of course a term used in block working; the correct term in this situation is 'Fouling Point' . So in many respects the term Fouling Bar is a bit more meaningful as it makes clear that if something is obstructing the Fouling Point (or is not clear of it - hence 'Clearance Bar') the points will be locked and unable to be set for the route which is fouled. In this example, as Mick has explained, Lever No.8 works both the facing point lock bar and the fouling (clearance) bar which makes sense as both would need to be set (down) for a movement through No.7 points into the bay. Thus until such time as the movement is clear of both bars it would be impossible to move Lever No. 8 which would in turn lock crossover No.7 in its normal position. Older photos of the station indicate that the Signalman at Louth North would have had a restricted view of that bay line hence the Fouling (Clearance) Bar. Link to post Share on other sites More sharing options...
micknich2003 Posted October 1, 2014 Share Posted October 1, 2014 I have just done a bit of checking, and it appears the North Eastern Rly did use the expression "Clearance Bar", and again to be different, they painted the associated lever Yellow. Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted October 1, 2014 RMweb Premium Share Posted October 1, 2014 So what's the story with FPL No. 20 and also lever No. 14. I would have thought trains departing from the Down Bay, would have joined the Down Main via points 30, or did they normally exit via points 21, which is actually a double slip. Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted October 1, 2014 RMweb Gold Share Posted October 1, 2014 So what's the story with FPL No. 20 and also lever No. 14. I would have thought trains departing from the Down Bay, would have joined the Down Main via points 30, or did they normally exit via points 21, which is actually a double slip. That one, and the locking bars on 21 & 31 (trailing points) have had me wondering ever since I first looked at the diagram. Presumably some regular propelling of passenger trains into the bay had been allowed for or maybe trains shunted into the bay to attach/detach on a regular basis (not that 46 points have a locking bar!)? Link to post Share on other sites More sharing options...
bécasse Posted October 2, 2014 Share Posted October 2, 2014 Louth South was a GNR box and that company was famously generous with point locks; it wasn't unusual to find them on trailing points. Link to post Share on other sites More sharing options...
ColHut Posted October 2, 2014 Author Share Posted October 2, 2014 In this example, as Mick has explained, Lever No.8 works both the facing point lock bar and the fouling (clearance) bar which makes sense as both would need to be set (down) for a movement through No.7 points into the bay. Thus until such time as the movement is clear of both bars it would be impossible to move Lever No. 8 which would in turn lock crossover No.7 in its normal position. Older photos of the station indicate that the Signalman at Louth North would have had a restricted view of that bay line hence the Fouling (Clearance) Bar. I am not quite getting this. The clearance bars are shown as against 8 (as well as against the FPL) because if the points are fouled by a train bearing on the clearance bars, lever 8 (and consequently 7) cannot be pulled off? Or am I very confused. Regards Link to post Share on other sites More sharing options...
kenw Posted October 2, 2014 Share Posted October 2, 2014 Looking at Louth North, are 20 (and 14) just clearance bars and not FPLs as this can't be a passenger route from this diagram? No flank protection trap point from 'yard' converging towards 21 points; trap point 30 from that line towards bay, trailing end of double slip forming 21 are hand points, as are next facing points towards headshunt (forming double slip with 48, and also direction signals 18 /19 shown as applying to both routes converging on 21 points, so this suggests this is a yard exit and not part of a running line Typo edit Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted October 2, 2014 RMweb Gold Share Posted October 2, 2014 In this example, as Mick has explained, Lever No.8 works both the facing point lock bar and the fouling (clearance) bar which makes sense as both would need to be set (down) for a movement through No.7 points into the bay. Thus until such time as the movement is clear of both bars it would be impossible to move Lever No. 8 which would in turn lock crossover No.7 in its normal position. Older photos of the station indicate that the Signalman at Louth North would have had a restricted view of that bay line hence the Fouling (Clearance) Bar. I am not quite getting this. The clearance bars are shown as against 8 (as well as against the FPL) because if the points are fouled by a train bearing on the clearance bars, lever 8 (and consequently 7) cannot be pulled off? Or am I very confused. Regards I'll try again. Lever No.8 works the facing point lock bar (and the facing point lock - which would be driven off the lock bar) and the fouling/clearance bar. I don't know which way round the lock levers worked but assuming No.8 reversed operated the lock and fouling bars to their 'locked' position the two bars would be down and No. 7 points locked by the bolt of the FPL. In order to unlock the points lever No. 8 would have to be moved to normal in the frame but if a vehicle was standing on either the facing point lock bar or the fouling/clearance bar it would not be possible to move the lever because the presence of the wheel flanges would prevent it from lifting to the unlocked position, hence the points could not be moved. Looking at Louth North, are 20 (and 14) just clearance bars and not FPLs as this can't be a passenger route from this diagram? No flank protection trap point from 'yard' converging towards 21 points; trap point 30 from that line towards bay, trailing end of double slip forming 21 are hand points, as are next facing points towards headshunt (forming double slip with 48, and also direction signals 18 /19 shown as applying to both routes converging on 21 points, so this suggests this is a yard exit and not part of a running line No.14 is most likely a fouling/clearance bar as there is no FPL shown on trap No. 30. No.20 is clearly a point lock bar as that end of 21 has an FPL bolt according to JH's drawing and the same is the case for levers 22 & 31. Interestingly, looking through the drawings on JH's site, Louth South also had facing point locks on many of its trailing point ends (although no lock bars are shown on the drawing as they had clearly been superseded by track circuits and there are no fouling/clearance bars either). Link to post Share on other sites More sharing options...
bécasse Posted October 2, 2014 Share Posted October 2, 2014 Interestingly, looking through the drawings on JH's site, Louth South also had facing point locks on many of its trailing point ends (although no lock bars are shown on the drawing as they had clearly been superseded by track circuits and there are no fouling/clearance bars either). The two boxes at Louth are a wonderful example of why it is so important to understand the fictional history of a proposed model railway when laying out the signalling. Different companies did things in different ways, sometimes very different ways, for all sorts of reasons (often, but by no means always, to save money), and the way that track and signalling was laid out could be as distinctive as the signals themselves. Link to post Share on other sites More sharing options...
ColHut Posted October 3, 2014 Author Share Posted October 3, 2014 Thank you all for your patience. I was confusing the locking bar with a mechanical depression bar I think. I found this discussion helpful too http://forum.signalbox.org/viewtopic.php?f=6&t=6562&view=unread As well as this http://www.irse.org/minorrailways/publicdocuments/PA01%20-%20Mechanically%20Operated%20Points%20v2.pdf Does anyone have a picture or diagram of the two items? Regards Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted October 3, 2014 RMweb Gold Share Posted October 3, 2014 Plenty of facing point locking bar details to be seen here - http://www.google.co.uk/images?q=facing+point+locking+bar&client=safari&rls=en&oe=UTF-8&gfe_rd=cr&hl=en&oq=&gs_l= Link to post Share on other sites More sharing options...
LNERGE Posted October 3, 2014 Share Posted October 3, 2014 Mk1 facing point lock with adjustable stretcher bar.. (don't look at the nuts undone and narrow flangeway) A depression bar that electrically indicates in the box.. The other end of the crossover, both ends have the switch detected by circuit controller not a point detector. Link to post Share on other sites More sharing options...
ColHut Posted October 4, 2014 Author Share Posted October 4, 2014 Outstanding, so the locking bar rocks from side to side! And is pressed down close to the rai by the wheel flange so raising the other side, which then mechanically or electrically prevents the FPL from being taken off? Link to post Share on other sites More sharing options...
Grovenor Posted October 4, 2014 Share Posted October 4, 2014 No, that picture is a depression bar, they were not normally used to lock points but to indicate, electrically, the prescence of vehicles, common at buffer stops as in the pic where track circuits could be unreliable. Lock bars (and clearance/fouling bars) were operated by a lever from the box and rotated parallel with the rails, being below flange level at rest in either position but rising above rail level at mid stroke, hence a vehicle standing over it would prevent the lever being pulled. see this pic from the SMs link in post#18 http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&docid=zznTi218yZu5VM&tbnid=6tAC4sEibetF-M:&ved=0CAcQjRw&url=http%3A%2F%2Fwww.tventon.freeserve.co.uk%2Fpoint2.htm&ei=O7cvVOGfJIbwaOeHgIgJ&bvm=bv.76802529,d.d2s&psig=AFQjCNERu3Uy_mGn3kwGcVstZFSYOQjnSg&ust=1412499615682641 Keith Link to post Share on other sites More sharing options...
micknich2003 Posted October 9, 2014 Share Posted October 9, 2014 The Station Master quiried the expression "Clearance Bar" as can be seen from the attached, the NERly did indeed use such termomonolgy. The signalling plan shows a good example of one in use, and why oweing to the signalman's view being obstructed by "Monkey Bridge" etc. Link to post Share on other sites More sharing options...
Grovenor Posted October 9, 2014 Share Posted October 9, 2014 I see that listing incorrectly describes the function of lever 9. Regards Keith Link to post Share on other sites More sharing options...
ColHut Posted February 21, 2017 Author Share Posted February 21, 2017 Mk1 facing point lock with adjustable stretcher bar.. (don't look at the nuts undone and narrow flangeway)00000164.jpgA depression bar that electrically indicates in the box..00000165.jpgThe other end of the crossover, both ends have the switch detected by circuit controller not a point detector.00000166.jpgApologies for resurrecting this thread. I have just watched a couple of your You Tube videos of FPLs and it was worth a great many words. Thanks for putting them up. regards Link to post Share on other sites More sharing options...
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