Interlaced turnouts

[David Thorpe]

I'm going to have to make some interlaced turnouts for my 1950s ex-CR goods yard. Does anyone know of any available templates for these? C&L do a NER 1:8 turnout base, but I really want something a bit tighter than that for the goods yard. I'm reluctant to try doctoring the normal society templates as I suspect that that will be more difficult than I initially thought.

DT

[Mark Tatlow]

DaveyT

I am inclined to think that the pregroup company's were rather more flexible with the precise setting out of timber spacings, especially outside of the crossing and switch. Therefore, I would keep the sleepers fairly tight together and otherwise I think you will be right.

There was a picture of a partially interlaced turnout here in case you did not see it: viewtopic.php?f=5&t=1488

[allanferguson]

This might help to give you a feel for it (personally I don't think these things were ever written down in detail -- a lot was left to the ganger on site)

Allan F

Pointwork Falkirk Gmstn.jpg

[John Palmer]

David,

I can't help you much with Caledonian practice, but have developed in Templot some drawings of turnouts with interlaced timbers that reflect North British practice, as revealed by a turnout at Rannoch measured in the 1980's. Unfortunately I have only been working with 1:7 and 1:10 crossing angles, so the angularity and length of lead may be wrong for you. The 1:7's use 12' straight heel switches, the 1:10's use 15' switches. Let me know if you could make use of these. Alternatively, I should able to generate something in .dxf format.

The sleeper pitch on each road of the Rannoch turnout lay in a range between 31" and 36" for sleepers between the heel of the switch and the knuckle. Interlacing commenced immediately beyond the joint of the switches, and extended right through the crossing.

From what little I have observed of Caledonian practice that company seems to have used fewer special chairs at the crossing than did the NBR, but this may just reflect the fact that the CR crossings I have looked at are on turnouts with shorter leads/radii than the NBR pointwork I have seen. For example, I think NB practice would have required and additional two-jaw special chair ahead of the knuckle in the place of the S1 chair shown in Allan's photograph.

[dcockling]

There was an article by Tony Brenchley in the P4 Society's Precision No3 (1972) which you can download from here about building a CR turnout with interlaced timbers.

All the Best
Danny

[timlewis]

I'm about to start building some NER interlaced turnouts for Coldstream, for which I did all the planning in Templot. I actually produced my own templates based on NER information, but I believe that you can download a range of them done by Martin Wynne: you probably need to subscribe to the Templot club forum (which I keep meaning to join).

There's a lot of information (probably too much) in an NERA reproduction document of permanent way standards (you need to be a member to get it I think), and there's a 1 in 7 drawing in NER Record Vol.1.

[David Thorpe]

Thanks for your replies, everyone. I don't have Templot, but I do know someone who has and if necessary I hope to be able to persuade him to run off some suitable templates when I know just what configurations I need. Danny, the article in Precision No. 3 was very helpful particularly as the prototype is in the general geographical area of where my model will be set. John, load of useful information in your post - if my friend with Templot can't help I may be in touch! But I think I've concluded that, as Alan and Mark both remarked, there aren't likely to be any hard and fast rules about this and i doubt very much if anyone will ever be able to come along and say, with any genuine authority, that my efforts at interlaced turnouts are clearly wrong (assuming, of course, that they work!).

DT

[Steve Taylor]

Isn't the NERA P-Way standards reprint an LNER document? I have it somewhere and it is useful for the later stuff and getting your head round timber spacings and chair choice and layout

[randallb]

The NERA document is titled as "Standard Railway Equipment - Permanent Way, 1926" although some of the drawings which it contains are dated '26, '27, '28, & '31.

There are diagrams (No 102 Y, & 103 Y) which are for short timbering for cross over roads - but nothing on interlacing of timbering as evident on the photgraph in the thread.

I had hoped that there might be something in the document that would help in my research for a potential layout of Alston - in some of the photographs of which 'sleepered leads' are clearly evident.

[Penrhos1920]

This is a pre 1906 NER 1:7 loose heal with 12' switch blades that I have drawn in Templot for the Skinningrove Zig-Zags project. Around 1906 the NER changed the sleeper spacing which is why I have had to start from scratch, rather than use the templates already available for the post 1906 spacing.

NER turnout.JPG

[randallb]

Penrhos,

Did you use the shove timber function to get the interlacing - and is it based on published sleeper spacings ? Or is it what looks to be right 'by eye' as it were?

If there are published standards, could you point me in the right direction, please.

cheers

[grovenor-2685]

Somewhere along the way I picked up the attached.
maybe they will help.
Keith

nbr2.png

ner2.png

Interesting that the NBR one shows an alternative single blade switch, and the double blade switch has staggered blade tips.

[allanferguson]

There has been a good deal of discussion about this in various fora in the past, all of which has tended to the conclusion that we don't know. The two drawings submitted by Keith are the only published drawings relating to Scottish practice, and are atypical -- single blade switches or assymetric switches relate, I think, to very early installations, and I have never seen a photograph showing either. There are a number of drawings related to the NER, from which we may infer Scottish practice.

Lindsay Galloway's excellent description in the current S4News of the building of a three way for "Barnton" gives as good an idea of the current state of the art as any. My own practice has been to draw the plan in Templot (or whatever), ignoring the timbering. I then mark the positions at which special chairs are required -- these positions are determined by the geometry of the rails and the standard special chairs, and are shown on the template. I then fit sleepers to support these chairs. Then I fit sleepers in between to support the rails as best practical, bearing in mind the maximum spacing, and the need for packing between them. Also if sleepers are not at right angles to the track, their ability to hold the gauge is compromised.

This has become easier with the availability of many special chairs from Exactoscale.

Incidentally, I did an analysis of sleeper spacings using wheel diameter in broadside views, and these varied between 31" and 47", albeit mostly in yards.

I think my main point is that much of this was done by the ganger on the spot, not by the drawing office, and with sledge hammers, not micrometers -- so we're not going to get a "right" way of doing it.

Allan F

[Penrhos1920]

Penrhos,

Did you use the shove timber function to get the interlacing - and is it based on published sleeper spacings ? Or is it what looks to be right 'by eye' as it were?

If there are published standards, could you point me in the right direction, please.

cheers

Randall,

I'm not sure of the source as I'm only the plotter. I was given a book of NER post 1906 data which I think is NERA track standards. I was also given something else and the info that post 1906 sleeper spacing was 2'6", pre 1906 it was 3'. I'll ask Dave who gave me the info and get back to you.

The sleepers are 'shoved' in Templot when the turnout is on the straight. I was a extra close adjacent lines line to line up the ends on the curved road. You can then adjust the radius of the straight road and the shoved sleepers stay in the correct place. ie once you've got the straight turnout correct, the curved ones only need curving. Although I did find a bug in Templot which I reported on that forum.

[Richard Webster]

Penrhos wrote on 3rd May:-

Randall,
I'm not sure of the source as I'm only the plotter. I was given a book of NER post 1906 data which I think is NERA track standards. I was also given something else and the info that post 1906 sleeper spacing was 2'6", pre 1906 it was 3'. I'll ask Dave who gave me the info and get back to you.

I was very interested to read your posting, but am a little puzzled by your reference to "NER post 1906 data" could this possibly be the NERA publication " NER PW Standards dated April 1912" ? However, if it is dated 1906 then I would be most interested to know more about it.

Also, I was unaware that the sleeper spacing was changed in 1906 and when you have heard from Dave, I will look forward to your next posting.

Regards,

Richard

[randallb]

AH ! Hadn't previously spotted the document you refer to from the NERA publications list - off to their website for me post-haste........

[Richard Webster]

Penrhos,

I wonder if you are now able to respond to my posting on 16th May.

Anything relating to NER permanent way circa 1906 would be of great interest to me.

Regards,

Richard.