Templot Club Archive 2007-2020
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posted: 19 Jun 2007 03:29 from: BTuckey click the date to link to this post click member name to view archived images |
Hi, I have a situation on a planned layout where two tracks split out into four. After the junction, the two straight lines go from ‘Up and Down Main’ into ‘Up and Down Slow’ whilst the two diverging lines become the ‘Up and Down Fast’. This is because the two centre tracks (Up and Down Slow) climb up an incline before crossing over the Up Fast to run into a Terminus. This gives the unusual(?) scenario of the two diverging lines being the high speed ones. If it survives the posting, the track diagram is as follows: --------Up Fast------------ ---Up Fast--------/---------Up Slow----------- ---Down Fast-----\--------Down Slow--------- ---------Down Fast-------- Should I use a regular pair of turnouts (C10) chosen so that the traffic does not have to slow down or slew the line and insert a turnout that has the Terminus route as the switched path. I hope that I have described the scenario clearly enough. Any thoughts gratefully received! Brian |
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posted: 19 Jun 2007 04:42 from: Martin Wynne
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BTuckey wrote:I have a situation on a planned layout where two tracks split out into four. After the junction, the two straight lines go from ‘Up and Down Main’ into ‘Up and Down Slow’ whilst the two diverging lines become the ‘Up and Down Fast’. This is because the two centre tracks (Up and Down Slow) climb up an incline before crossing over the Up Fast to run into a Terminus. This gives the unusual(?) scenario of the two diverging lines being the high speed ones. If it survives the posting, the track diagram is as follows:Hi Brian, Even a C10 will have a significant speed restriction over the diverging road. You would need a very much longer turnout than C10 to be able to regard the diverging road as a "fast" line. The normal practice would be always to have the fast line as the main road of a turnout. So you should try to re-align the lines to achieve this. In other words, in your diagram the facing turnout in the Up lines is a right-hand turnout, the trailing turnout in the Down lines is a left-hand turnout. You may not need to re-align the lines by very much. Try changing to a *curviform* type of V-crossing (important) and then applying negative curving (F6) to a right-hand C10 turnout until it looks very much like a left-hand turnout. If you overlay some straight track for comparison, you will find that you can get very close to the original alignment, with only a slight sideways offset at the exit. If you attach your .box file, we can have a go at finding the neatest looking solution. p.s. I rearranged your diagram using a "code" block ( {} ) in the editor, which uses a fixed-width font which should look correct in all browsers. How it fares in emails is more problematic. regards, Martin. |
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posted: 15 Aug 2007 06:51 from: BTuckey click the date to link to this post click member name to view archived images |
Hi Martin, Many thanks for the initial response and my apologies for not getting back to you. As you know, my PC died and I had to build a new one. To give a little background, I am building a new house with a dedicated railway room of 6.26m by 6.25m. I tried to design a number of possible scenarios but my design skills are dismal. I am an engineer and not an artist and my world is symmetrical with straight lines! I finally settled on a design from the 1960 book; ‘Plans for larger layouts’ by Peco. Having scanned the plan I used Photoshop to scale it to the space available. However, this means that some of the curves are still too tight and the track spacing is too large. The file ‘Layout templates 19 Feb.bgs’ in the file; http://perso.orange.fr/brian.tuckey/Templot files.zip is therefore only a guide. At the bottom of the diagram you can see the junction layout that precipitated this thread and I overlaid track as can be seen from the file; ‘New Layout_07_07_09_0155_32.box’. However, after my initial posting I calculated that the space between the junction and where the terminal track passes over the mainline would produce an unacceptable gradient. I model in P4 so no traction tyres! I therefore produced a second design as can be seen in ‘New Layout rev2_07_07_09_1753_51.box’. I believe that this is more accommodating and provides the height/gradient profile required. I am modelling OHLE so a larger than normal height clearance is necessary. To the left of the junction you can see the return curve which was the topic of an earlier question. Thanks for your help and all suggestions/criticisms are welcome. Cheers, Brian |
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posted: 15 Aug 2007 10:26 from: Martin Wynne
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Hi Brian, brian_tuckey.png  ©Peco Wow! Even after stretching it by 50% the curves are looking tight in P4. The low-level through station can be eased by putting the whole thing on a curve. Does the upper terminus have to be dead straight? You could ease the crossovers in the approach curve by curving that station too. Your junction problem could be solved I think by changing from a burrowing junction to a flying junction. This not only puts the through route on the straight, it also means you can have an easier climbing gradient than the falling gradient (assuming UK left-hand running). I will see how it looks. regards, Martin. |
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posted: 15 Aug 2007 12:09 from: Jim Guthrie
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BTuckey wrote: To give a little background, I am building a new house with a dedicated railway room of 6.26m by 6.25m. I tried to design a number of possible scenarios but my design skills are dismal. I am an engineer and not an artist and my world is symmetrical with straight lines! I finally settled on a design from the 1960 book; ‘Plans for larger layouts’ by Peco. Having scanned the plan I used Photoshop to scale it to the space available. However, this means that some of the curves are still too tight and the track spacing is too large. The file ‘Layout templates 19 Feb.bgs’ in the file; http://perso.orange.fr/brian.tuckey/Templot files.zip is therefore only a guide.Brian, Having a look at the layout plan brings back memories of pipe dreaming as a teenager :-) However, if you are working in P4 I would think that the plan will need a lot of re-working to get radii which are suitable. Before you go too far, can I suggest that you try and have a look at "Historic Railway Modelling" by (the late) David Jenkinson. In this book he describes the thought processes in designing his 7mm scale layout, with various plans. His desired layout was the same basic design as the CJF one, with a largish terminus feeding a continuous run and hidden sidings. I've got the feeling that his layout designs might well reduce to 4mm and give you something which will work in P4. I'm away from home at the moment, so can't get at my copy of the book, but when I get home at the weekend, I can do a quick scan of some of the plans to give you a taste of what he designed. Or maybe someone else who has the book can oblige a bit sooner. Jim. |
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posted: 15 Aug 2007 20:28 from: BTuckey click the date to link to this post click member name to view archived images |
Hi Martin, Many thanks as always for the quick response. Thanks for the suggestion concerning putting the through station on a curve. With respect to the Terminus, no it doesn’t have to be dead straight. I am going to have to pull back the turnout to the ‘goods yard’ anyway as this will become a Freightliner terminal. It will handle quite long trains so the entrance will have to be taken away from the end of the platform. Templot%20master%203.jpg  I am a little puzzled over your suggestion of a ‘burrowing junction’. The big problem is that the area marked by the red box contains three crossing tracks at different levels. If I swop the Terminus line with the upper Main what is the advantage? I still have to maintain a differential height and the distance between the junction and the crossing point has not changed. So the climbing gradient will be the same as the previous falling gradient. In addition, the falling gradient will become a climbing gradient for traffic leaving the Terminus. Jim, Thanks for your input. This plan is very much of a compromise. You may remember my thread, some months ago, asking for assistance with a mainline crossover. The idea was to have two rectangles each comprising of a double track with a series of turnouts to permit routing from one rectangle to another. The general scenario was to have one rectangle with third rail and the other with OHLE. This would provide the ability to change traction on through running trains. In all honesty, I like operational running as much as the construction side of the hobby. I will have the layout running scheduled traffic under computer control (RR&Co) with the operators fitting in manually controlled trains. This means that the operators must obey the signals! Unfortunately, feedback from Martin and Andrew Jukes made me realise that I didn’t have room for the ladder crossovers. Thanks for the information regarding David Jenkinson’s book. I would be most grateful for the scans as my local, French, library is unlikely to have the book! Cheers, Brian |
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| Last edited on 15 Aug 2007 20:44 by BTuckey |
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posted: 15 Aug 2007 21:44 from: Martin Wynne
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BTuckey wrote: I am a little puzzled over your suggestion of a ‘burrowing junction’. The big problem is that the area marked by the red box contains three crossing tracks at different levels. If I swop the Terminus line with the upper Main what is the advantage? I still have to maintain a differential height and the distance between the junction and the crossing point has not changed. So the climbing gradient will be the same as the previous falling gradient. In addition, the falling gradient will become a climbing gradient for traffic leaving the Terminus.Hi Brian, I meant something like this, replacing the burrowing junction with a flying junction: brian_tuckey1.png  The long rising gradient up to the terminus runs from A to B. Departing trains on the falling gradient have a shorter steeper fall from C to D. The through routes are now straight, which I think is what you wanted originally. Unless I've missed something obvious?  regards, Martin. |
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posted: 17 Aug 2007 04:18 from: BTuckey click the date to link to this post click member name to view archived images |
Martin Wynne wrote: The long rising gradient up to the terminus runs from A to B. Departing trains on the falling gradient have a shorter steeper fall from C to D. The through routes are now straight, which I think is what you wanted originally. Ah, I understand now! As they say, a picture is worth a thousand words... It looks as if you have used two different radii for each track. How did you decide on the settings? Cheers. |
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posted: 20 Aug 2007 12:38 from: Jim Guthrie
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BTuckey wrote: Jim,Brian, I haven't forgotten - but when I got home on Saturday I started searching for the book and I haven't found it yet :-) However, when searching for it, I found another book I had lost track off, so there's hope yet that it will turn up. :-) Jim. |
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posted: 23 Oct 2007 01:37 from: richard_t
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Jim Guthrie wrote: Brian, If you've got access to some Model Railway Journal's, David Jenkinson describes the planning behind his "Last Great Project" in some detail in issues: 85, 86, 88, 92 (I'm missing this one  ), 99 and 106. The construction is described in issues: 122 and 124.Richard. |
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posted: 23 Oct 2007 18:22 from: Peter Ayre click the date to link to this post click member name to view archived images |
BTuckey wrote: Thanks for the information regarding David Jenkinson’s book. I would be most grateful for the scans as my local, French, library is unlikely to have the book! Brian, There are some cheap copies of the book in Amazon (.co.uk) market place at £1.89 and with postage to France of £3.75 it would be only £5.64. Just an idea. Also, I tried the link for the jpg and the zip files but the links don't work for me, are they still there or have you removed them? Finally, as with several CJF plans although a good concept (I looked at a 3 level version of this plan) you do have to watch the gradients as you sometimes end up with "train set" gradients. (Think up and over figure of eight). Regards, Peter |
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posted: 23 Oct 2007 18:52 from: Jim Guthrie
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Peter Ayre wrote: BTuckey wrote:Brian,Thanks for the information regarding David Jenkinson’s book. I would be most grateful for the scans as my local, French, library is unlikely to have the book! If you can get the book at that price then that might be best since David Jenkinson does develop the theme of the design through several chapters in the book, with various different versions on the theme, one of which might suit you better than his final plan. So giving you a scan of one of the plans might miss the mark :-) I still haven't found my copy - most annoying :-) Jim. |
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posted: 24 Oct 2007 17:00 from: BTuckey click the date to link to this post click member name to view archived images |
richard_t wrote:
Hi Richard, Many thanks for the above info. Brian |
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posted: 24 Oct 2007 17:28 from: BTuckey click the date to link to this post click member name to view archived images |
Peter Ayre wrote: Brian, Peter, Many thanks for the book information. I will have a look at the Amazon site. Does the book add much to the MRJ articles? Unfortunately, France Telecom has suspended my file area. I have been 'FTPing' the files and FT has informed me that this is a no-no. I have to use their archaic HTML interface which is really only for Blogs. As we all know, 'Customer Service' doesn't translate into French!  With regard to the gradients, thanks to Martin's suggestion, my maximum is a climb of 85mm over 7148mm. I think that this is probably acceptable. Cheers, Brian |
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posted: 24 Oct 2007 17:32 from: BTuckey click the date to link to this post click member name to view archived images |
Jim Guthrie wrote: If you can get the book at that price then that might be best since David Jenkinson does develop the theme of the design through several chapters in the book, with various different versions on the theme, one of which might suit you better than his final plan. So giving you a scan of one of the plans might miss the mark :-) I still haven't found my copy - most annoying :-) Hi Jim, Thanks for your input. I hope you find your copy. Brian |
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posted: 25 Oct 2007 01:16 from: richard_t
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Peter Ayre wrote: BTuckey wrote:Thanks for the information regarding David Jenkinson’s book. I would be most grateful for the scans as my local, French, library is unlikely to have the book! Many thanks for the tip-off; Amazon have one copy less now Richard. |
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