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Discussion Starter · #1 ·
I will soon start track laying on my new OO layout which will be a double track one round the walls of a room 11ft 6in by 9ft. I can afford to have a minimum radius of about 3ft or 90cm. I think that this will allow trains to pass one another at closer than the standard peco separation of 50mm.

If possible I want to have the prototypical separation which I think scales to 45mm; am I right? Does anyone know whether this radius and separation does allow trains to pass without difficulty?

There will only be one crossover in my track plan involving a single slip and an ordinary point. Has anyone adapted peco points to this separation? Are there any pitfalls to avoid? Thank you for any help that you can give.
 

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'Loosing' three sleepers between Peco large radius points arranged to form a crossover does the trick: that's both of the angled sleepers at the end of the curved road, and one of the straight sleepers behind that, and 'sharing' the other straight sleeper. Should apply to the double slip as well, since they all share the same geometry.

What centres you can use on any pair of curves depends directly on the length of the vehicles you plan to use. If the smaller curve is 3' radius then mk1's should just pass at 45mm centres. That's provided that they are scale width, and there is not much lateral sloppiness on the axles and bogie pivots. Frankly I would do the experiment with the stock you intend using. If there is a problem it's very easy to open the centres slightly on curves, and if using transition curves from straight sections this can be well disguised.
 

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Diagrams in Bob Essary's "Railway Signalling and Track plans", published earlier this year by Ian Allan, show that it was literally a '6ft' between tracks but to the outer faces of the rails, not the inner (flange) faces. This scales to 24mm, not 45mm, but is significantly less than the 34mm that the PECO track gauge gives (for streamline track) between the inner faces of the track. If we allow 2mm for the thickness of the tracks, this gives a Peco spacing of 32mm or a scale 8ft! Why Peco have done this I don't know. Possibly because at the very close scale setting there is too much likelihood of passing trains hitting each other?

But you will need to open out on curves - as 34C says, you need to try your rolling stock out and see what is possible.

Regards,
John Webb
 

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Don't forget that the Peco track setter is for use on their "Narrow Guage" track so the outside faces of the rails would have to be further apart to maintain the scale centres. So Peco is only A foot or there abouts out.
 

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QUOTE If we allow 2mm for the thickness of the tracks, this gives a Peco spacing of 32mm or a scale 8ft! Why Peco have done this I don't know.
And even if you are happy with the Peco spacing (which I am), if you use insulating rail joiners between points in a crossing (which is essential for live frog), even the Peco track spacer is too narrow because it doesn't allow for the thickness of the insulated joiner.

David
 

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I've had this problem recently... try laying a 3 foot radius curve..[your stated minimum], get one of your coaches..a long one, or one with the greatest overhang each end.....and run it round the curve..with a felt tip marker pen held tightly against the inside middle..mark the cut-in on the board...do the same with the pen on one outside corner....this will give you a couple of arcs, which will be the closest you can get to the vehicle alongside.

as long as one arc doesn't cross the arc from an adjacent track.....which will have its arcs closer to the track, as it will be a greater radius....then nothing will contact, coach - wise.

I seem to recall reading somewhere, a long time ago, advice from Peco about adjusting the '6 foot' of their trackwork to a more realistic width......

of course, the prototype could have got this measurement wrong too....which might account for the acute lack of nice brass doorhandles on modern coaching stock?
 

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QUOTE (alastairq @ 28 Aug 2007, 20:50) <{POST_SNAPBACK}>of course, the prototype could have got this measurement wrong too....which might account for the acute lack of nice brass doorhandles on modern coaching stock?

Isn't modern stock a lot longer and slightly wider?

Regards
 

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QUOTE (alastairq @ 29 Aug 2007, 17:09) <{POST_SNAPBACK}>then that DEFINATELY explains the lack of brass door handles!!

That and the fact that you can't open the windows anymore!!

Regards
 

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Hi

You asked: Isn't modern stock a lot longer and slightly wider?

**I believe the widest stock then and now is 9 feet or thereabouts, most in the earler days being 8'6". differences in width were compensated at stations by footboards at each door to keep the coach/platform gap safe.

The minimum gap between the sides passing trains was 2 feet...8mm in 4mm scale/OO. This seems to be consistent with the double track spacing standards. Railways didn't use more space than absolutely needed.

If the model is laid so that this is replicated on the straighter sections, with transition curves which also let the spacing between them slightly diverge through their length to give a wider spacing at the actual main curved area, this will, I think, give the best overall look with safe passing distances.

It really is a strong visual difference that I highly recommend.

I used this "2 feet between trains" rule on my own layout, and as a result the visual difference was so much that actually ended up putting the double track across Ribblehead viaduct first as everyone who used normal Peco track centres who saw it inevitably said "It looks too narrow for double track" and I got tired of explaining it!

Re checking the "safety" of the decision for your layout. Use long coaches such as 67' retaurant cars or long modern coaches AND check with a large loco like a Coronation/Duchess too. When curves tighten, the front of a long loco can actually have a wider "swing" than a coach as the point at which the swing starts is the front driver, which is quite a long way back compared to some coach bogie positions.

Kind Regards

Richard Johnson
 

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Discussion Starter · #11 ·
It is nearly three weeks since I started this thread so I thought that you might like to know the results of an experiment that I did today.

First of all I measured two peco points joined as a crossover and found that the actual centre to centre measurement was not 50mm but nearer to 52mm especially bearing in mind that one must use an insulated joiner with an electrofrog crossover or leave a slight gap. I then discovered that separation could be reduced to about 47mm by 'overlapping' three sleepers of each point. (I found and old Railway Modeller article that explains the best way to do this.) The separation could be reduced further to about 45mm by overlapping four sleepers but this looked too difficult and I felt was going too far.

I then accurately laid a double track curve with an inside radius of 900mm and the outer one 947mm. I found that model 60ft coaches (the largest I use) would pass each other with a gap at the narrowest point of about 2mm. I could just about make them touch by giving them more serious wobble than I think will occur in normal operation. My largest engines, a black five and a royal scot, passed each other and the coaches with much larger gaps so I don't anticipate any problems with these. I have just started laying the track 'for real' and I think that the closer spacing looks good.

Like many others, I assume, I am using my old code 100 track in the fiddle yard. Now I know that you can buy special joiners for the place where the code 100 and code 75 meet but I didn't want to get these as they seem expensive for what they are and I'm a skinflint! I might just solder them together as the position is off-scene anyway, but I also tried an experiment with code 100 joiners on code 75. If you tighten one end of an ordinary code 100 joiner it will nicely grip code 75. Obviously there is a difference in height which could be dealt with by filing down the code 100; I haven't decided on which approach to use on this yet.

I hope that this may be of use to others. Cheers, Robert
 

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I am also way too tight to buy the 'convertor' rail joiners. Simply crushing one end of a code 100 joiner and soldering half a code 75 joiner on top makes a convertor rail joiner that matches the rail heights very closely: a little brute force resolves any small differences.
 

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I have found that the critical part of an oval layout is where the straight track (ST601) joins the curve track - observing two trains running in opposite direction, are most likely to touch at that point.
 

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Discussion Starter · #14 ·
Thank you 34C for the idea. That sounds like the best way to do it. I had already decided to lay the code 75 on top of the other end of a code 100 joiner to solder it as this makes the height correct. Doing this I would have had to be very careful about lateral placing. Your idea is the best of both worlds; you get the height and lateral placing correct automatically.

In answer to double00 I should mention that I don't have any straight portions on my track plan. By the time the 3ft curves have got more gentle through transition curves to be nearly straight it is time to start the transistion getting tighter again to go into the curve at the other end of the 11ft 6in room.
 
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