cctransuk Posted February 6, 2021 Share Posted February 6, 2021 I am about to commence the construction of a layout which will use Peco Code 75 track, at moderate radii, and I need advice concerning platform clearances. The two platform station will, of necessity, be located on a curve; and the outer and inner track radii will be 1000mm.; (the radii will be diverging in order to accommodate a central lay-by track between the two platform tracks). I would very much welcome advice as to the necessary clearance between the outer and inner track centrelines and the adjacent platform edges. The longest coach will be a Hornby ex-LMS Period 1 six-wheeled bogie restaurant car, but the rest of the coaching stock will be BR Mk. 1 or shorter. Alternatively, if anyone is aware of a formula from which such clearances can be calculated, I would love to hear of it! Many thanks in anticipation. John Isherwood. Link to post Share on other sites More sharing options...
RMweb Premium John M Upton Posted February 6, 2021 RMweb Premium Share Posted February 6, 2021 The traditional method for me is to lay the track in its intended position, attach a pen to corner of the longest piece of rolling stock or loco you intend to operate and mark on the 'ground' how far out it will protrude on the curves by running it through. The resultant line is therefore the limit of gauge. 1 1 Link to post Share on other sites More sharing options...
LBRJ Posted February 6, 2021 Share Posted February 6, 2021 The old pencil taped to the middle of the longest coach trick is the only thing that readily springs to mind.... There is going to be a fair old gap on a 3 foot radius curve though. 1 Link to post Share on other sites More sharing options...
DCB Posted February 7, 2021 Share Posted February 7, 2021 (edited) Usually people make platforms too high. They should be 3ft above rail level maximum, 12mm in OO to the top surface. Buffers are 13mm to 14mm, 3ft 3" to 3ft 6" above rail level so no matter what buffer heights you choose, scale Hornby Dublo, Peco etc, or Hornby or Triang about 15mm the platforms should be below the buffer centre line. Once you get that right most coaches have their widest bits above the platform LMS 57ft coaches and GWR Centenaries truss bars hit curved platforms before Mk1 which lack truss bars do. Hornby have locos up to 40mm wide (10 feet) 4mm or a foot wider than the real thing, again they go over the top of scale platforms and hit overly high platforms. A centre lay by sounds like a bad idea, they were pretty rare, Bath GW, Torre, Torquay, Maidstone spring to mind but a simple 2 platform station with a pair of crossovers is more versatile and flexible. For one thing there should be a 6ft way to one side of the centre road and a 10 foot the other. I would go with standard Peco 2" 51mm centres for tracks, but if its straight I would go for 44 or 45mm as it looks much better when seen from the ends and gives 4 to 5mm btween the widest OO RTR trains Edited February 7, 2021 by DavidCBroad 1 1 Link to post Share on other sites More sharing options...
RMweb Gold Harlequin Posted February 7, 2021 RMweb Gold Share Posted February 7, 2021 Templot can sweep out the envelopes of vehicles as they move over curved track. If you have any crossovers between the platforms remember to pay them special attention. Link to post Share on other sites More sharing options...
Philou Posted February 7, 2021 Share Posted February 7, 2021 Agree with what has been mentioned above, though older standards of platform heights show 2' 9" (11mm) above rail height. Mention has been made regarding pencil-at-midpoint and pencil-at-corner regarding clearances for over-hang. Don't forget to use your longest bogie stock that has the greatest distance between bogie centres and the longest overhang beyond the bogies - Class 800 coaching stock springs to mind. Do also check clearances with steam locos at cylinder height - the GWR were generous in this respect and some of their locos could not run everywhere in the UK because of the overall pistons widths. Regarding centres, 44-45mm along straights looks better and allows for clearance - even Cl 800 stock entering onto the main over 3ft radius points (haven't tried with 2ft) cleared other stock on the straight. To cover the widening on curves - you will need to have centres of 50-51mm. IIRC, if you should want to maintain 44-45mm centres, the radius needs to be increased to 11ft! You will need to do some surgery on RTR points to achieve the 44-45mm centres - no such problems of course if you build your own. Here was my approach to surgery on some Peco medium points (any slight sleeper mismatch can be disguised with ballast: and one showing 45mm centres: Cheers, Philip 1 2 Link to post Share on other sites More sharing options...
cctransuk Posted February 7, 2021 Author Share Posted February 7, 2021 7 hours ago, DavidCBroad said: A centre lay by sounds like a bad idea, ..... The problem is that the prototype, Evercreech Junction, had one. John Isherwood. Link to post Share on other sites More sharing options...
cctransuk Posted February 7, 2021 Author Share Posted February 7, 2021 19 hours ago, cctransuk said: I am about to commence the construction of a layout which will use Peco Code 75 track, at moderate radii, and I need advice concerning platform clearances. I have spent the afternoon drawing out diagrams of coaching stock running on a 1000m. radius curve. As anticipated, the ex-LMS period 2 twelve-wheeled restaurant car has the most overhang; I calculate that platform edges at 24mm. from track centreline will allow sufficient clearance. John Isherwood. Link to post Share on other sites More sharing options...
Pete the Elaner Posted February 7, 2021 Share Posted February 7, 2021 5 minutes ago, cctransuk said: I have spent the afternoon drawing out diagrams of coaching stock running on a 1000m. radius curve. As anticipated, the ex-LMS period 2 twelve-wheeled restaurant car has the most overhang; I calculate that platform edges at 24mm. from track centreline will allow sufficient clearance. John Isherwood. As Philou mentioned. don't forget overhang as well as underhang. Since you have mentioned ex-LMS stock, you may well have a Princess to hand. The only vehicles I can think of with more overhang is APT-E's PC1 & PC2. Link to post Share on other sites More sharing options...
cctransuk Posted February 7, 2021 Author Share Posted February 7, 2021 3 hours ago, Pete the Elaner said: As Philou mentioned. don't forget overhang as well as underhang. Since you have mentioned ex-LMS stock, you may well have a Princess to hand. The only vehicles I can think of with more overhang is APT-E's PC1 & PC2. Thanks for that - I'll check my 'SWS-FRS'. John Isherwood. Link to post Share on other sites More sharing options...
Pete the Elaner Posted February 7, 2021 Share Posted February 7, 2021 8 minutes ago, cctransuk said: Thanks for that - I'll check my 'SWS-FRS'. John Isherwood. That should be a little shorter than a Princess. Link to post Share on other sites More sharing options...
cctransuk Posted February 7, 2021 Author Share Posted February 7, 2021 2 minutes ago, Pete the Elaner said: That should be a little shorter than a Princess. As my LMR interest is focussed on the Midland Mainline, and my SWS-FRS was a mere whim purchase, I think it unlikely that a Princess will be added to the stud. John Isherwood. 1 Link to post Share on other sites More sharing options...
Pete the Elaner Posted February 7, 2021 Share Posted February 7, 2021 16 minutes ago, cctransuk said: As my LMR interest is focussed on the Midland Mainline, and my SWS-FRS was a mere whim purchase, I think it unlikely that a Princess will be added to the stud. John Isherwood. I'll be after an SWS if they ever release it in 1946 black. As for Princesses, if your layout is MMR, then they haven't got route clearance. Link to post Share on other sites More sharing options...
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