Building a 3-throw turnout

Brian Kidman

Member
Location
UK
Hello.

DCC Concepts have pointed me towards Templot. I'm very impressed and inspired by what I've seen so far.

I wish to build a 4mm/00 scale model of Oxted as it was in BR(S) days. I've drawn the track plan and it's clear I shall need to hand-build the S&C.

Oxted had a cramped yard, which included a 3-throw tandem turnout, toe to toe with another turnout. The 3-throw tandem plan on the Templot website is exactly what I need to replicate. One of the challenges is that a couple of the tie-bars pass through the centre switch blades (tricky in 4mm).

Your comment on the website says "difficult to build". This appears to be the key to my entire project, so, can it be done? I'm quite practical and I've bought the tools I need for the job.

Kind regards

Brian
 
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Tony W

Member
Location
North Notts
Hello Brian.
Firstly there appears to be some confusion with your terminology. Three throws and Tandems are slightly different. With a Three throw turnout, the two sets of blades overlap and the tie-bars, properly called stretcher bars, do indeed pass through one of the blades to get at the blade behind. Tandem turnouts have the two sets of blades placed sequentially some distance apart. The answer to your question is that they can be done but the difficulty comes when trying to gauge both sets of switches as there is a double blade thickness where there is usually one, so when the middle road is set, the track will be over gauge for a short distance. I have built several to P4 standards, but I see no reason why they should not be made to work in OO. Probably the most difficult thing is connecting the operating mechanism to the the inner blades of each pair. I should gain some experience of building standard turnouts before attempting one of these. I posted some pictures of Three Throw turnouts on the old forum, if I can find them I will try to post a link for you.
Try this one.

Regards
Tony.
 
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Brian Kidman

Member
Location
UK
Hello Tony
Thank-you very much for your reply with the attached images and for correcting me regarding the terminology. We have a couple of tandem points on the Bluebell Railway and I'd assumed that was the correct term for a 3-way point. However, ours are not of the overlapping blades variety. I can see that building a three-throw would be a challenge - someone suggested to me that I should do it in EM or P4 as there's more clearance between the moving parts. Great idea, but my rolling stock would drop through the gap! The essence of what I'm trying to achieve is that, apart from gauge, it should be as close a possible to the prototype. If I can't build the three-throw I might have to ditch the whole plan, so I want to attempt that first. I believe I understand how the turnout operated in 12" to 1ft scale, but I'm not sure how practical it would be to have the stretcher bars passing through holes in code 75 switch blades. I've attached a photo of the prototype, which was taken by Derek Cross and is the copyright of David Cross.
 

Attachments

  • Derek Cross Oxted (2)_0006.jpg
    Derek Cross Oxted (2)_0006.jpg
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Paul Boyd

Member
Location
Loughborough, UK
If I can't build the three-throw I might have to ditch the whole plan, so I want to attempt that first. I believe I understand how the turnout operated in 12" to 1ft scale, but I'm not sure how practical it would be to have the stretcher bars passing through holes in code 75 switch blades.

Hi Brian

If you’re new to track building, I really would very seriously suggest you don’t start with the three throw or a tandem. They can be tricky even for experienced builders, and frankly I’ve never attempted a three-throw although I have done a few tandems - one of mine is on the Templot website in the “Read all about Templot” page. Start with a straight turnout first, even if the first couple you make are considered exercise pieces. If you dive straight into a three-throw, the experience will likely put you off the whole idea which would be a shame,

Cheers,
Paul
 
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Martin Wynne

Admin
Location
West of the Severn UK
Info
Please do not send requests for help direct to me via email.

Post your questions on the forum where everyone can see them and add helpful replies.
Try this one.

Regards
Tony.

Hi Tony, Brian,

To keep that info visible after the old forum disappears, the new URL will be:

https://85a.uk/templot/archive/topics/topic_2839.php#p19982

But please note that although the above link is working, the text is not yet properly formatted.

The link won't change when it has been formatted (when I have finally got the archive done). :)

p.s. note also that topics which were spread across several pages on the old forum will be a single page in the archive. In some cases this will make for a very long single page.

cheers,

Martin.
 
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