Flat Bottom S&C

[Bob Reid]

With a view to constructing turnouts with flat bottomed rail and using Templates from Colin Craig (assuming that the turnouts are flat bottom rail on wooden timbers and constructed post 1965), is there any ready way to identify the standard turnout type and size used from photographs by counting say - the number of sleepers between the tip of the switch blades and the nose of the crossing vee?

 

The (clearly) two different sized turnouts shown in this picture are typically what I'm trying to identify before purchasing the correct templates.

 

http://davids.railwa...et/p827512.html

 

This may have already been asked for or supplied on RMweb however is there anywhere online or does anyone have, the prototype details for these standard turnouts that I could use for trying to identify the type and size?

 

Many thanks

[Bob Reid]

Bump......

[lyneux]

Hi Bob,

 

I'm trying to do the same thing. I figured out that the best/easiest way to do this is to work out the angle of the crossing vee from an aerial photograph.

 

I used Google maps to locate the target turnout and to provide an aerial shot, then I did a screen capture to create an image file on my hard disk. I then imported this into a drawing package (any will do, but I use Omni Graffle on the Mac). Rotate the image until one side of the vee is aligned to to the grid of the drawing package. Then use the drawing package to draw a line parallel to one side of the crossing vee. Make sure that when you create lines they "snap to" the grid of the drawing package. Create another line parallel to the other side of the vee (this is done by eye).

 

By this stage you should have something looking like this:

 

 

 

Then remove the original image and you should now be able to count the number of grid squares in either direction:

 

 

 

In this case, it was 20 squares by 2, giving a 1 in 10 crossing V angle.

 

Guy

[griffgriff]

Hi Bob,

 

I'm trying to do the same thing. I figured out that the best/easiest way to do this is to work out the angle of the crossing vee from an aerial photograph.

 

I used Google maps to locate the target turnout and to provide an aerial shot, then I did a screen capture to create an image file on my hard disk. I then imported this into a drawing package (any will do, but I use Omni Graffle on the Mac). Rotate the image until one side of the vee is aligned to to the grid of the drawing package. Then use the drawing package to draw a line parallel to one side of the crossing vee. Make sure that when you create lines they "snap to" the grid of the drawing package. Create another line parallel to the other side of the vee (this is done by eye).

 

By this stage you should have something looking like this:

 

 

Then remove the original image and you should now be able to count the number of grid squares in either direction:

 

 

 

In this case, it was 20 squares by 2, giving a 1 in 10 crossing V angle.

 

Guy

 

Just a thought but sat images are not necessarily taken from directly above so surely there is a risk of parallax error if calculating angles angles from pictures in this way - this is more pronounced further away from the centre of the image.

[Bob Reid]

Many thanks Guy. I've tried a similar approach using an map of the location in earlier times (and with a different track layout) and overlaying it in Autocad with lines equating to known points of reference that are aligned with the turnout. In this case, the bore of the tunnel and the edge of Platform 2, both of which remained relatively unaltered by the later station layout changes;

 

 

 

With this approach the angle of the crossing vee was 5^o giving a slope of 1:11.43 so I'd probably be safe enough to use a template for a 1:12 turnout. There is course some error even in that method in that I'm depending on the accuracy of the mapping however for my purposes it'll suffice.

 

Unfortunately in the case of Queen Street some eejit plonked a car park right over the turnout which is now sub-surface;

 

 

Thanks again.

[craigwelsh]

Not sure about FB but BH p&c had angles down to a 1/4. ie 1:8, 1:8 1/4, 1:8 1/2 etc so you'll be averaging it in any case.

[Bob Reid]

Not sure about FB but BH p&c had angles down to a 1/4. ie 1:8, 1:8 1/4, 1:8 1/2 etc so you'll be averaging it in any case.

 

Cheers Craig. I'll be playing about with it on Templot with different angles however I needed something to start off with. Mind you the pre-66 layout looked considerably more interesting and an fortunately all BH plain track and S&C and less "rationalised"

[Scottish Modeller]

Cheers Craig. I'll be playing about with it on Templot with different angles however I needed something to start off with. Mind you the pre-66 layout looked considerably more interesting and an fortunately all BH plain track and S&C and less "rationalised"

 

Hi Bob,

 

You are following the same process as the Scottish DEMU team did about 3 years ago!

 

We were looking at doing F/B S&C but there wasn't a lot of help or info available.

 

However - things are different now!

 

See attached list of drawings.

 

Gives a good idea of what you should be looking for to fit in with preparing to Templot the trackplan.

 

Hope this gives you some ideas....

 

Thanks

Drawing Index.pdf

[Bob Reid]

Thanks Phil. How far did the DEMU team get with it?

 

I have to say whilst the list is clearly exhaustive it's down to the Nth degree however it kind of makes the pre-66 version even more attractive. That said, I guess it's down to the level of accuracy / closeness to prototype that you're looking for. I'd personally settle for something more generic from the likes of Colin Craig.

[Scottish Modeller]

Thanks Phil. How far did the DEMU team get with it?

 

I have to say whilst the list is clearly exhaustive it's down to the Nth degree however it kind of makes the pre-66 version even more attractive. That said, I guess it's down to the level of accuracy / closeness to prototype that you're looking for. I'd personally settle for something more generic from the likes of Colin Craig.

Hi Bob,

 

I managed to (sort of) build 3 12.5 turnouts.

 

On test they looked good but worked terribly. Whether or not this was down to the actual construction, my workmanship or what - I don't know.

 

As that was the situation - we gave up and hoped that things would improve in the future.

 

Now - Things have improved, but only a bit.

 

How?

 

A full range of drawings of the real thing are available now - but only if you can find the right person with access.

 

Some layouts are now starting to feature hand built concrete sleeper turnouts - it's just a case of finding them.

 

It's possible that, due to the interest shown, one of the current track manufacturers 'may' be looking into producing something, but exactly what - we don't know.

 

Peco have already jumped in with the Concrete sleepered medium point. However, it's no more than a nice gesture realy as it still does not address any of the reasons that people build there own. It's not based on any real bit of S&C - just something from the existing Peco range with the sleepers changed from wood.

 

That makes it exactly what the opposite of what the majority of modern modellers asked them to do!

 

So - that's where we are at present - all the trackwork built and nothing to link it all up!

 

I'll be having a go at some more concrete sleepered stuff - probably over next winter.

 

Thanks

[martin_wynne]

is there any ready way to identify the standard turnout type and size used from photographs

Hi Bob,

 

See: http://www.templot.com/martweb/info_files/gimp_track.htm

 

regards,

 

Martin.

[Bob Reid]

Many thanks Martin. I've never managed to master the intricacies if the Gimp package (that's me rather than the package itself) so I've been ploughing on with a combination of the packages that I know, namely Photoshop and Autocad with the help of the Google Earth images and a map from an earlier period/track layout and combining the knowns - the physical constraints of the layout and the fixed dimensions between the platforms and of course the track gauge.

 

On Google Earth, the image is pretty well taken directly overhead on the centre lines in this image, and by scaling in Autocad, overlaid the rail outlines to the track gauge thus;

 

 

 

From this I managed to identify that two of the turnouts had vee angles of 9^o (1 in 6.3) and one each of 7^o (1 in 8.1) & 6^o (1 in 9.5)

 

When positioned and combined over the separately scaled original map (albeit with the earlier track layout) it has fitted in nicely with those platform edges that remained relatively unaltered and those that were altered as a result of the changes in 1966.

 

This is the combined image;

 

 

 

Once I've added the remaining three points the "intent" (providing I've worked this all out properly) is to output the track outline as a DXF file for importing into Templot. That's the theory anyway!

 

Late Note; It's not the dimensions or the "rough" track layout that bother me, it's the identification of the types of turnout used (installed in 1966) and what components I require that can be readily sourced to give a half decent representation of the real thing!

[martin_wynne]

It's not the dimensions or the "rough" track layout that bother me, it's the identification of the types of turnout used (installed in 1966) and what components I require that can be readily sourced to give a half decent representation of the real thing!

Hi Bob,

 

The vertical 1432mm designs available in the Colin Craig templates were first used in 1968 (according to BRT4), so for a 1966 installation I think you should be looking at the previous BS-113A inclined 1435mm designs with curved switches. These are all available pre-set in Templot. Crossing angles were made in 1/4 unit steps from 1:4 to 1:9, then in 1/2 unit steps to 1:12, then in full unit steps to 1:21.

 

p.s. I'm sure you are aware of the amazingly detailed old town plan maps available on the NLS site: NLS 1893 map Glasgow Queen Street

 

regards,

 

Martin.

[Bomag]

I was a PW engineer in RCE Anglia in the late 1980's (although I spent most of it doing plain line).

 

At that time we had a range of standard designs with both inclined rail (1435mm) and vertical rail (1438mm) versions - the later were more common and went AV to GV, SGV and HV (slowest to fastest). The nosing would be 1 in 8 for an AV to 1 in 12 for a GV. Points were made to order at Chesterton Junction (Cambridge) with refurbished parts or Castleton in Mancheter for new parts. From the standard designs you would specify curveture of the mainline (if relavent) and they would fabricate the switch for you and it would magicly appear on site!

 

If you had something more complicated with switches and crossing running into each other as per Queen Street above each element would be designed (at that stage on either a very slow comptuter or hand) and then combined for the final design to be checked before fabrication. You could get some very comlipcated designs with shared sleepers etc. The current comuter systems seem to come up with more stand alone elements, easier to fabricate and install but not quite as professional.

 

There is PDF of at least the SGV floating around but I unfortunately don't have a copy.

[Bob Reid]

Many thanks Martin - had a quick glance at Templot this morning as suggested so I've something to at least make a start with. (p.s. It was the map from the NLS site that I've been using for the background image - a least a composite image of the two maps)

 

Thanks Bomag, there's fortunately quite a few photo's taken at different angles that'll help ascertain what was constructed a combination as opposed to a single turnout in it's own right, and certainly in some it's more obvious where for example the crossing timbers were shared. If any has the PDF you mention I'd certainly appreciate a copy to at least see what chairs etc. were typically used.