GWR Signal Box - Type 7 - drawings / photos

[Western Star]

I wish to build a 7mm model of the GW&GC Jt Rly signal box at West Wycombe station. This box was built in brick with a hip roof in a style known as "Type 7" of which there were several variants (7a... 7b... 7c... 7d) - I believe that the box at West Wycombe was type 7b because the box had an open hearth / brick chimney and ridge tiles / hip hooks (type 7a had lead rolls and terracotta finials... type 7c had a stove and stove pipe).

I have consulted "The Signal Box" (SRS 1986) and "GWR Signalling Practice" (GWSG 2019) which have provided the above details. The SRS website tells me that the box in which I am interested was constructed circa 1905 and to dimensions of 25' x 12' x 11'.

I am looking for architects drawings and/or photos for the box structure of any type 7a or 7b box. I have looked at the Steam Museum website... the NRM website... the Network Rail Archive... and not found any material which relates to the construction of GWR signal boxes.


Anyone any suggestions?

thank you, Graham

[4069]

You will find photos and drawings of the Type 7 in Adrian Vaughan's "Great Western Architecture" pages 334 to 337, and his "Great Western Signalling" page 82. You can also find the real thing well preserved and capable of being inspected at (among other places) Toddington (7b), Winchcombe (7d), Cranmore (7b), Carrog (7a), Llangollen (7a), Kidderminster (7d), Buckfastleigh (7d), Bishops Lydeard (7d), Blue Anchor (7b), and Princes Risborough North (7b).

[ikcdab]

Here are drawings of Blue Anchor and Bishops Lydeard. In case anyone is worried, these are my own copyright.

Bishops Lydeard.pdfBlue Anchor.pdf

[Hal Nail]

On 15/04/2024 at 23:05, 4069 said:

Toddington (7b), Winchcombe (7d), Cranmore (7b), Carrog (7a), Llangollen (7a), Kidderminster (7d), Buckfastleigh (7d), Bishops Lydeard (7d), Blue Anchor (7b), and Princes Risborough North (7b).

How does the classification work? Carrog and Blue Anchor look the same to me (5 × windows), as do Bishops Lydeard, Winchcombe and Toddington (6 x windows)?

 

Edit, just seen the OP has explained this. Were there standard sizes of frames or was each one completely bespoke and the building then juggled to fit (eg by use of the smaller size windows etc)?

 

Edited June 21 by Hal Nail

[RailWest]

Do you mean window frames or lever frames ?

[bécasse]

In broad terms the size of any signal box is determined by the size of the lever frame it has to contain plus other equipment such as gate wheels and token machines. Occasionally site restraints will have an influence on size (or shape or elevation) too. Each company tended to have a range of standard sizes together with window arrangements that went with those sizes. Operational requirements sometimes led to variations, eg windows in the rear wall of a box because there were tracks both sides or to give a clearer view of a level crossing.

[WillCav]

In 'A Pictorial Record of Great Western Signalling' by A Vaughan, OPC 1973 is a table of standard sizes from 1896.

Levers    L x W

15        17' x 12'

23        21' x 12'

33        25' x 12'

41        29' x 12'

51        33' x 12'

61        38' x 13'

71        42' x 13'

79        46' x 13'

89        50' x 14'

97        54' x 14'

107      58' x 14'

117      66' x 14'

127      70' x 15'

135      74' x 15'

145      78' x 15'

155      82' x 16'

165      87' x 16'

175      95' x 16'

185    105' x 16'

Edited June 22 by WillCav
Typo

[5BarVT]

On 22/06/2024 at 10:21, WillCav said:

In 'A Pictorial Record of Great Western Signalling' by A Vaughan, OPC 1973 is a table of standard sizes from 1896.

Not near my copy for a while but I suspect that was for twist type frames with 5+” spacing rather than the 4” spacing of a VT frame.  So potentially smaller for a given number of levers in later years.

Paul.

[WillCav]

1 hour ago, 5BarVT said:

Not near my copy for a while but I suspect that was for twist type frames with 5+” spacing rather than the 4” spacing of a VT frame.  So potentially smaller for a given number of levers in later years.

Paul.

Vaughan says that no later standard has been found and most boxes follow it.

I agree with you that the later 4" lever interval would allow you to have smaller boxes.

Will

[Hal Nail]

On 21/06/2024 at 21:08, bécasse said:

In broad terms the size of any signal box is determined by the size of the lever frame it has to contain plus other equipment such as gate wheels and token machines. Occasionally site restraints will have an influence on size (or shape or elevation) too. Each company tended to have a range of standard sizes together with window arrangements that went with those sizes.

 

My query was prompted by the odd design of Llangollen goods box which has 2 smaller sized windows on one side of the front - which probably reduces it by 6 inches (?) and I wondered why they bothered but I'm not sure how original that is with hindsight.

 

https://tillyweb.biz/gallery/ll/llangollengoods.htm

 

 

Edited June 28 by Hal Nail

[Miss Prism]

I've always felt a 4" lever spacing was ridiculously small.

 

[5BarVT]

2 hours ago, Miss Prism said:

I've always felt a 4" lever spacing was ridiculously small.

Nearly twice the size of 2 1/2” on a Westinghouse L frame.

All about reducing cost (of the building) and walking distance for the signalman.

Paul.

[Miss Prism]

Ah, that's dinky electrical stuff!

[The Stationmaster]

16 hours ago, Miss Prism said:

I've always felt a 4" lever spacing was ridiculously small.

 

Why?  I've worked plenty of Western VT frames. including one with over 100 levers, and have never had any difficulty due to the 4' spacing between levers.  Don't forget that any properly planned frame should not involve any 'pulling between'. (i.e pulling a lever, especially a heavy lever, between two that are already standing reversed).   But I'd go with anything that reduces walking distance but still leaves enough room to do the job as there can be a lot of walking on a single-handed big frame

 

In fact I can't see that it would be much different from a 5" spacing because what matters is where you can put your feet to enable you to get the right swing on your body when pulling any heavier lever.  So even on a 5" spacing you're still going to have a problem if it involves pulling between.

 

BTW I've also worked a (busy) Westinghouse L frame and there's no problem with the spacing (although somebody with very large hands might be a tad uncomfortable?) and it's an ideal frame for a busy 'box requiring quick lever work as you don't need to move very far at all on a relatively short frame that's properly laid out.

[bécasse]

1 hour ago, The Stationmaster said:

BTW I've also worked a (busy) Westinghouse L frame and there's no problem with the spacing (although somebody with very large hands might be a tad uncomfortable?) and it's an ideal frame for a busy 'box requiring quick lever work as you don't need to move very far at all on a relatively short frame that's properly laid out.

 

I worked the middle section of the 1957 L frame at Cannon Street during the evening rush hour on a number of occasions in the early 1960s. I have reasonably large hands but the frame was a total delight to work, I could only manage to work two adjacent levers at once though unlike the regular bobbies who could pull or restore three! The box, with three men on duty at peak hours, was a wonderful example of teamwork, anyone who has watched the BTF "Terminus" about Waterloo will remember the bobbies' calls to each other and it happened in exactly the same way at Cannon Street - I can still hear the call "coming eight to down fast" as the platform starter on 8 was pulled off.

 

Ironically I was only an interested schoolboy at the time, but I was able to satisfy the SM that I knew both the Rule Book and the TCB Block Regulations, and that I could apply a short-circuiting bar and pull a hook-switch (live in those days), and obviously I was supervised by both the SM himself and the bobby whose work I was doing. I rather assume that the SM didn't issue the invite entirely on his own responsibility but had clearance from the DM at least, presumably to attract me ultimately to a railway career (which sort of happened but not in the way they had in mind). I only made one "mistake", pulling off a platform starter perhaps 90 seconds before the TRTS light came up, but that was enough for the driver of the train concerned to ring the box for an explanation. The SM answered the call and put the loudspeaker on so that we could all hear it - "Cannon Street signal box, Station Master speaking" "Oh it's you guv'ner, driver of the 6.24 to Ramsgate here, C60 is showing single yellow before time, what's to do" "We've a trainee on the frame, driver, he won't make that mistake again (nor did he), wait for the right-away from the platform, recheck the aspect and obey all other signals" "right you are guv'ner, wait for the right-away, recheck the aspect, obey everything else, tata".

[Compound2632]

On 22/06/2024 at 10:21, WillCav said:

In 'A Pictorial Record of Great Western Signalling' by A Vaughan, OPC 1973 is a table of standard sizes from 1896.

Levers    L x W

15        17' x 12'

23        21' x 12'

33        25' x 12'

41        29' x 12'

51        33' x 12'

61        38' x 13'

71        42' x 13'

79        46' x 13'

89        50' x 14'

97        54' x 14'

107      58' x 14'

117      66' x 14'

127      70' x 15'

135      74' x 15'

145      78' x 15'

155      82' x 16'

165      87' x 16'

175      95' x 16'

185    105' x 16'

 

I can understand a box needing to be wider if worked by two men, so they can easily pass one another, and wider still for three, and so forth, so does this table tell us how many were expected to be working in a box with a given number of levers? Or is it that more senior signalman, with the greater responsibility of a larger box, were expected to be more portly?

[The Stationmaster]

1 hour ago, Compound2632 said:

 

I can understand a box needing to be wider if worked by two men, so they can easily pass one another, and wider still for three, and so forth, so does this table tell us how many were expected to be working in a box with a given number of levers? Or is it that more senior signalman, with the greater responsibility of a larger box, were expected to be more portly?

Not really until you come to very large frames.   And a lot always depends on how busy the 'box is plus the presence, or not,  of a Booking Boy siting at a desk will take up the same amount of space off teh back wall whether a frame has 80 odd levers or 160.  

 

And the presence of a Booking Boy was more likely than having a second Signalman at many places.  for example Foxhall Jcn had a 76 lever frame and had a Signalman plus a Booking Boy in the war years and for some years after.  But equally I have known frames of over 100 levers which were worked by one man (admittedly with 'skeleton booking' and shorter frames than that which were two handed jobs.