LSWR turnout timbering; length increase intervals?

[essdee]

A query for LSWR PW specialists, please,

As a SW Circle member, I have benefitted enormously from the recent re-printing in the Journal of Peter Bedding's overview of the development of LSWR switch and crossing practice. Allied to some earlier correspondence I had with the late Derek Genzel, this has given a firm foundation for planning my turnouts, which are of 1891 and 1902 geometry.

However, an apparent anomaly has arisen, concerning the interval by which turnout timbering increased towards the heel of the turnout:

1) Bedding (p.497), in a general non-date-specific reference, comments: 'Drawings indicate that timbers were extended in 12" stages'.

2) In contrast, Genzel, in a derived drawing (pers.com, but apparently intended for a non-published Society Digest feature, and based on official LSWR switch and crossing plans) of a LSWR 1902 era 1:6 turnout, shows the timbering increasing in 6" intervals, after an initial12" leap from 9 to 10ft.

3) TimberTracks do a specific LSWR 1:7 turnout (T4B7LSWR), which duly shows the 'Bedding' 12" step in the increase of timber lengths.

4) In contrast, TimberTracks' non-LSWR-specific turnout for a 1:8 angle (T4B8) displays a 6" step increase. The timbering intervals are also very different, and I assume that these are probably REA spacings?

At this point my limited knowledge of LSWR PW work runs out, and I trust that someone else of LSWR (Southwark Bridge, perhaps!?) persuasion can clarify the position. Derek Genzel clearly had a deep knowledge of LSWR trackage as well as did Peter Bedding, but I wonder if the former's use of a 6" interval in turnout timber lengths for a pre-Group LSWR situation might be a lapse, importing a feature that only developed 'under REA rules'?

Many thanks for any advice, PW buffs!

Steve D.

[grovenor-2685]

I thought I had seen some LSWR drawings in our digest but looking its only a single slip, it does go in 12" steps but that may or may not carry over to simple turnouts.
That drawing is said to be based on an original LSWR drawing from the Southwest circle, are there no other drawings from the same source?

[essdee]

Thanks Keith,

I have seen and used the single slip drawing to prepare my own double slip version - original by Bob Bourne I think, lovely job. Quite possible that there is a Circle resource, but at moment time is at a premium, and I wanted to check if someone already knows the answer, before I have to go delving....!

Steve D.

[ted.stephens]

I am not aware of any drawings showing the timbering pattern between switch and crossing so took a look at some old photos. One difficulty is that track before 1905 tended to be covered in with ballast, so you can't see the timbers.

In the book "London and South Western Railway Miscellany", John Scott-Morgan, published by OPC, there are two examples for the era you are interested in, pages 25 and 26. According to their captions both views are taken at Clapham Junction around 1907/8.

Turnoput 1.jpg

Turnoput 2.jpg

The upper picture has quite an untidy appearance with timber ends on the main line road looking distinctly ragged. The lower picture shows timbers that vary in length, probably in 6 inch steps, but there is distinct step at the Y timber (two in front of the crossing nose), circa 1ft.

Interesting challenge to model the somewhat random pattern of timber placements.

[Philip Hall]

Also noticeable is the very sharp lead into the check rails...

Philip

[Winander]

Also noticeable is the very sharp lead into the check rails...

And the wing rails. It was a feature of early track and the check rail would be quite short compared to 20thC

[bécasse]

The timbers would have been of varying width, 10" standard and 12" and 14" specially for pointwork. The wider timbers are required because the chairs sit at an angle on them. It isn't impossible that the 10" timbers were available in 6" step lengths but that the 12" and 14" were only available in whole foot lengths. The wider timbers were disproportionately expensive, one of the reasons why some railways (eg the LNWR) used interlaced timbering to a considerable extent in pointwork.

[Jol Wilkinson]

I am not sure to what extent the LNWR used interlaced timbering in pointwork. The attached shows that some was used but not always.

LNWR track drawings.pdf

[ted.stephens]

To add detail to Philip's point ...

Here are the arrangements for LSWR 1908 track. Check gap is 1 3/4 in, opening at end is 3 1/2 in. The rail has a set in it which is why it looks so sharp in the photo. For REA track, post 1923, the set was replaced by a radius bend so is not so noticeable.

LSWR Check Rail 10ft 6in.jpg

LSWR Check Rail 15ft.jpg

LSWR Check Rail Usage.jpg

To add detail to becasse point...

The 1908 drawings for a No 3 switch show 14" by 7" for the timber under the switch tip, followed by 12" by 6" timbers for the rest of the switch.

LSWR No3 Switch Timbers.jpg

For crossings, again 1908, Y timber is 12" x 6"; X, A and B timbers are 14" x 7"; C timber 12" x 6".

LSWR Crossing Timbers.jpg

All images are snips from drawings available from The South Western Circle, http://www.lswr.org

[Martin Wynne]

Interesting challenge to model the somewhat random pattern of timber placements.

Templot has a timber randomizing function:





That's at real > timbering > timbering data... menu item.

It is easy to overdo it. The twist randomizing is really only for narrow-gauge crazy track, because it will upset the switch geometry.

Hold down the F12 key to watch the timbers dance.

That's the control template. Be sure to store a background template and save the BOX file for future reference, before printing a template or 3D export. Because there is no way to repeat a particular arrangement at a later date.

Martin.