Token apparatus - have I got this 'all right'

Discussions of the prototypes and how to model them. Show us how you do it.
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barhamd
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Joined: Sun Jul 20, 2008 2:45 pm

Token apparatus - have I got this 'all right'

Postby barhamd » Tue May 07, 2019 8:10 pm

The web site http://www.trainweb.org/singleline/stour_valley_line/stour_valley_line.htm shows two tokens for the sections of the Stour valley line for Clare. One is a Tyer number 6 token http://www.trainweb.org/singleline/stour_valley_line/cavendish_clare.jpg which is a large brass disk type token for Cavendish to Clare, the other is a Tyer number 9 token http://www.trainweb.org/singleline/stour_valley_line/haverhillnorth_clare.jpg which is more like a key for Clare to Haverhill North. I'm presuming that this dates from after the closure of Stoke-by-Clare box and the 'key' was used to unlock a ground frame there which gave access to the siding.

This arrangement works for me as I've added a fictitious siding to a mill which would have been released by a key on the token.

Looking online I'm seeing pictures for Tyer number 6 equipment https://en.wikipedia.org/wiki/File:Tyer%27s_No._6_Tablet_Instrument-1.JPGand Tyer number 9 http://www.gwr.org.uk/venton/token-apparatus.png

I'm presuming these would both have sat on a table on the rear wall of the box.

Was it common to have two different types of token apparatus in the same box?

Does any of this make any sense?

thanks

David Barham

John Palmer
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Re: Token apparatus - have I got this 'all right'

Postby John Palmer » Wed May 08, 2019 1:02 am

No technical reason to prevent the presence of different types of equipment in any given box.

http://www.trainweb.org/railwest/gen/signal/sl-sdjr.html gives details of the various types in use of the Somerset & Dorset line over its lifetime. In this you can detect a pattern of near-simultaneous changes being made to parts of the network. Thus the Evercreech-Highbridge line is revealed to be a stronghold of Tyers No.3 Electric Train Tablet instruments until about 1952, when their place is mainly taken by WR Electric Key Token instruments. Note, however, that at West Pennard up to 1952 the section to Evercreech Jc North was controlled by a Tyers No.3, but the section to Glastonbury by a Tyers No.1 instrument - apparently the last survivor of such an instrument on the S&D. Similarly, on the Dorset single line sections you can detect a wholesale replacement of No.1 instrumeents by No.6 instruments in 1951, the exception being Templecombe No.2 Jc to Stalbridge, which had acquired a pair of No.6 instruments by 1939 - so giving a 10 year period during which Stalbridge box was equipped with both a No.1 and a No.6 instrument.

These patterns of change suggest to me a formal decision to embark upon a program of equipment replacements covering a series of contiguous single line sections, but if elderly equipment for an individual section became life-expired it might become the subject of ad hoc replacement with equipment of a newer design, and this might have led to No.6 instruments controlling Cavendish-Clare and No.9 Clare-Haverhill at the same date.

In a number of cases the tablet apparatus was originally installed in the station building rather than the signal box, the obvious and notorious example being Abermule.

Incidentally, I'm highly impressed by your 3D printed frame, which seems to have turned out very well save for the loss of a handle on one of your 'spares' - can that be easily remedied?

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Noel
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Re: Token apparatus - have I got this 'all right'

Postby Noel » Wed May 08, 2019 10:42 am

It was also possible in some cases for a box {B} between two others {A & C} to be open for shorter hours than the ones either side. In that case the sections would be A-B-C for part of the day, and A-C for the rest. This required two machines in boxes A and C, one for the short sections A-B and B-C, one for the long section A-C. The GW, which was in its earlier applications inclined to use Webb & Thompson electric train staffs https://signalbox.org/block/lnw.htm, might use the miniature version https://en.wikipedia.org/wiki/Token_(railway_signalling)#/media/File:Electric_Staff_Working.JPG for the long section.

Later they switched to Tyers No. 9 Key Tokens for general use, but not all Webb equipment was replaced; some lasted will into BR days. Where long sections existed or were subsequently set up, they kept, or installed, Webb electric staffs for them. It appears that the instruments for the long section were always different to those for the two short sections, presumably to minimise any risk of confusion. The railways were inclined to keep usable equipment if it was replaced for reasons other than being life expired, and then reuse it, sometimes years later, in other locations.

In this case since the different tokens are for different sections, I would agree with John that the key token is most probably an ad-hoc change for operational reasons or old age.
Regards
Noel

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barhamd
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Re: Token apparatus - have I got this 'all right'

Postby barhamd » Wed May 08, 2019 9:41 pm

John Palmer wrote:No technical reason to prevent the presence of different types of equipment in any given box.

Incidentally, I'm highly impressed by your 3D printed frame, which seems to have turned out very well save for the loss of a handle on one of your 'spares' - can that be easily remedied?


Yep, I noticed the broken handle after taking the photograph and managed to find it on the workbench and reattach with superglue.

David


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