Maximum Turnout Timber length

[Coombe Barton]

I have long believed that the maximum turnout timber length in use was 15ft on the Great Western.

 

First question - is this true? Or was it ever true?

 

Reason for the concern is that I'm building a 3-way turnout to the EM Gauge Society's template, and timbers on that are shown as up to 20 ft 6 in.

 

However I have found from http://www.scalefour.org/history/mrc07.html

 

"Timbers are provided in standard lengths from 8ft 6in, in 6in stages to 15ft 0in. Longer timbers may be provided, but these become increasingly expensive, fragile, difficult to transport and awkward to handle with increasing length. Often two smaller timbers may be half-jointed and bolted together on site to provide the necessary length."

 

So are they:

• that long really?
  
• spliced (and if so where along the length)?
  

Or

• Is the generic diagram incorrect?
  

Could someone throw some light, please.

 

And I looked at the book (title escapes me) on GW turnouts at ExpoEM North intending to buy it at my shopping round, but forgot all about it until I was about 80 miles away driving home.

[TheSignalEngineer]

My old edition of the Permanent Way Institution book 'British Railway Track' shows a table for FB Turnouts with timbers up to 15' long. To qoute part of their text on the subject "...................... Where timbers required would be too long to be handled comfortably, two short timbers may be 'halved' together to form one long one. This consists of cutting out the top half depth of the end of one timber for about 12" in length, and the bottom half of the abutting one for the same length, and placing these two cut portions together one on top of the other. They should be bolted or screwed together"

[buffalo]

David Smith in his GWR Switch and Crossing Practice: A Design Guide for 4mm Modellers said:

Timbers were normally available in lengths from 8'6", (or, previously, 9'0") increasing in steps of 6", up to 30'0"

He also mentions splicing of separate timbers for "...exceptionally long through timbers...in complex pieces of blocked crossing work..." joined as described above by TheSignalEngineer, but with 9"x3"x1/2" steel straps above and below. He also notes that

Recourse to this practice was also necessary during the Second World War and the years immediately following when, because of acute shortages, even timbers of lesser lengths had to be made up this way.

 

Nick

[Western Star]

As an example... consider the timbers under the nose of the crossings in a straight line cross-over. The GWR practice was to block through for the length of the crossings and between the crossings. Hence timbers approaching 17'0" would not be unusual. Set out the templates for such a crossing, with the necessary minimum spacing between the two lines of track, and then measure the length of the blocked through timbers.

 

regards, Graham

[Coombe Barton]

David Smith in his GWR Switch and Crossing Practice: A Design Guide for 4mm Modellers said:

 

That's the one I saw at ExpoEM North and forgot to buy!

[buffalo]

That's the one I saw at ExpoEM North and forgot to buy!

It's well worth having if you build GWR track. Not always easy to find, apparently it is available from the GW study group, but also available from C&L. I'm not sure which page of their web site it is on, but the product code C1665 is mentioned in one of their data sheets. If you enter this code in the 'Product search' box you can find it that way.

 

Nick

[R A Watson]

To help clarify some of the points raised above I have some pictures here of a re-timbering exercise we carried out on the East Somerset Railway a few years ago.

 

 

 

This shows several 20 foot length timbers laid in what is called in the G W practice book "blocking" ie a run of consequetive same length timbers used in S & C work which support complex metalwork.

 

 

Now a look back along the "tanker sidings" towards the turnout from the run round loop which gave access across the running road without the possibility of an accidental movement of a passenger train from main to siding through a facing point. This arrangement was widely used by the G W to both avoid an accidental movement and also the need, and cost, of a facing point lock. Although not specifically shown here there are four more 20 footers directly in front of the photographer which can be seen in part in the foreground. The more eagle eyed reader might notice that the diamond in the middle distance was once a single slip but was reworked by the Western region into a simple diamond by the expedient of the replacement of some parts by plain rail. We subsequently discovered the switch tips discarded in the undergrowth!

 

.

 

A side on view showing the extent of the long timbers running under three running routes, the main line, the crossover, and the siding known as the Cripple Siding. it can be seen from this that any work on, or replacement of, individual timbers raises certain difficulties and why they were only used if other means were impossible.

 

 

And finally a view which shows why we needed to undertake the rebuild, but more importantly if you look to the right hand side of the crossing vee a fish plate can be seen laying on the timber with a line in the timber below it. This is where a repair has been undertaken in the dim and distant past and a short length has been "scarfed" or let in and the stepped joint between the two parts is secured by the use of a fishplate and four chair screws

 

I hope that this helps to answer some of your questions.

[TheAlchemist]

In David Smith's book on Page 81, Chapter 7 Crossing Timbers 1st para. 'Timbers were normally available in lengths from 8'6" (previously 9'-0") increasing in steps of 6", up to 30'-0".'

 

and in 3rd para. 'Up to the mid-1930s standard practice was to align the timbers of a lead squarely to the straight road throughout, . . . . .

 

Titfield Thunderbolt usually has the book.

 

TheAlchemist

[buffalo]

I've obviously been using the invisible ink again

 

Nick

[Coombe Barton]

Thanks to everyone for the replies and book suggestions.

 

Incidentally Amazon is offering the GWR Switch and Crossing Practice: A Design Guide for 4mm Modellers for £31.95 (used) against a new price of £14.95

 

Several sources are advertising this (new) at the real price.

 

Amazon won't be getting my money this time.