Thirsk, LNER.

[Platypus]

Hello all,

I am wondering if anyone has the following book please, "Thirsk, LNER" published 1933 or 1934 by British Westinghouse Brake & Signal Co, York Way, London, England. ( BWB&S Co ). ( If you have, please contact me by Private Message. )

As background, ref "An Illustrated History of Signalling" Michael A Vanns, ( Ian Allan, 1997 ) ISBN 0 7110 2551 7 pp 60,( photo Signal Box ) 61 ( photo Illuminated Diagram and Panel ) 61, 69. Thirsk was part of the LNER's ECML York - Darlington resignalling Thirsk ( 1933 ), Northallerton, Darlington South ( 1939 ), which Scheme required 5 Signal Boxes ( anyone know which the other two were ? ). OS Nock also published a book entitled "British Railway Signalling a survey of fifty years progress" ( Geo Allen & Unwin, 1969 ) SBN 04 625002 6, in which he claims that Thirsk ( pp 89 - 91 ) was the first use by a mainline Signal Box utilizing a Route Setting Panel, Relay Interlocking and an Illuminated Diagram using a row of lights to indicate the route set.

( OS Nock was a Signal Engineer by profession, and he worked at BWB&S Co, later becoming its CEO, and was also along time member, and later President of the IRSE / Institute of Railway Signal Engineers. )

In this instance, the Route Set Switch was superimposed onto , and therefore was part of , the Illuminated Track Diagram. There was one thumb switch for each route, and the thumb switches were grouped in the vicinity of the start of the route to be set up. In later installations, the Route Setting Control Switches were placed on a Panel, or Desk, below the Illuminated Signal Diagram. These route setting switches were later known as OCS / One Control Switch panels. These thumb switches were also used on Signal Control Panels where each switch performed one function only, hence Unilever, or Individual Function Switch / IFS panels.

The LNER Signal Engineer was A.E.Tattersall, later well known as an active IRSE member, and Editor , with TS Lascelles, of "Railway Signalling and Communications, Installation and Maintenance" ( The St Margaret's Technical Press, 1940 )

The York - Northallerton Resignalling Scheme which at this location was also the first use by the LNER of 5 lamp feather route indication, and the use of 4 Aspect signals where the bottom searchlight displayed either a Red, Yellow of Green Light, and the additional top light only displayed a yellow light, thereby enabling Red, Single Yellow, Double Yellow or Green indications as appropriate.In this instance the Double Yellow was necessary to ensure adequate braking distance for the "Silver Jubilee" train. ( Around the same time, the SR introduced a three lamp feather route indicator. )

The LNER generally preferred searchlight signal heads over three or four light signal heads which BR preferred. A searchlight signal has a longer sighting range due to the provision of magnifying lenses within the signal head. A searchlight signal head also requires an operating mechanism to change the coloured filters give the desired signal indication. The net result is a large, heavy signal head which is more expensive than the alternate 3 lamp or 4 lamp multi light signal head that is so familiar, but the multi lamp signal head has a lesser sighting range than the searchlight signal head.

The 1949 AE Tattersall designed Doncaster North and Doncaster South Signal Boxes were unique in utilizing a Rotary Switch with Push Button Route Initiation, known as Sequence Switch, the purpose of which was to reduce the amount of relay interlocking required, as a Rotary Switch can only operate at the point at which it is set, and therefore the other alternate setting points are isolated. Therefore once the Rotary Switch is selected for the required route, the plunger button initiates that set route.

The use of Panel Signal Boxes with Relay Interlockings was intended to improve the control of traffic, extend the area of centralized control, and to reduce the size of the Signal Control system, and thereby reduce the space and cost of large Signal Boxes, and reduce the number of staff required each shift due to a more efficient operating technology. With the passage of time though, whilst the size of the actual operating floor of the new SignalBox reduced, the size of the relay room increased !

It is also noticable how the mechanical boxes lasted a century, the electro mechanical and power boxes lasted around fifty years, the electronic boxes last around twenty years, and recent installations in particular cost a lot of money and time to install, yet their lifespan will be relatively short compared to their predecessors .

Regards, Platypus.

[Platypus]

Hello All,

further to the above, and with reference to the following books, ( A ) "Triumph and Beyond - The East Coast Main Line 1939 - 1959 - Part 1" ( Dr. ) B W L ( Benjamin ) Brooksbank ( 1927 - 2018 ) Challenger Publications, 1997, ISBN 1 899624 21 X ( Chapters 1 - 6 , Appendices A - K, 184 pp ) ; ( B ) "The Route of the Flying Scotsman - Part 2 ofTriumph and Beyond, The East Coast Main Line, 1939 - 1959" , Arcturus Press, 2002, ISBN 0 907322 80 8 , ( Chapters 7 - 12, Index, 178 pp ) ( www.geograph.org.uk/profile/44502 ).

Book ( A ) p19, photo, Thirsk being rebuilt, 1932. Photo, Thirsk Signal Box, 1933. Glasshouse style operating floor mounted above the brick relay room. The Signal Box operating floor is about one third the length of the relay room. The relay room, as built, is well illuminated with natural light through the 11 front windows, which were bricked up as part of the Air Raid Precautions / ARP circa 1939.

The Thirsk, LNER OCS Signal Panel is preserved at the NRM, York, which in many ways is quite a fitting fate for such a historic object.

p36, photo, Northallerton Signal Box, in 1947, looking at the down end of the Signal Box in the Up direction;

p126, photo, Northallerton Signal Box, in the 1950s, looking at the up end of the Signal Box in the Down direction, the signal box being located on the Up side of the railway line.

Book ( B ) Chapter 7.12 York to Darlington, pp 44 - 48.

p45, Thirsk. The 5 Signal Boxes resulting from the Thirsk Resignalling Scheme were Beningbrough, Alne, Sessay Wood ( later renamed Pilmour North ), Otterington and Thirsk .

The first four were partial power signal boxes, presumably the points were mechanically worked, and they could be switched out. Switch In / Switch Out times would be in either the Working Time Table / WTT, or the Sectional Appendix or Addenda to the WTT.

Thirsk was also the first use of Position Light Dwarf Signals on the LNER. ( triangular head showing either two miniature red lights in the horizontal position for Stop, or two miniature lights in the raised up at 45 degrees, one white above one red light, to indicate Proceed at caution. )

p46, Thirsk was the Junction for Leeds via Harrogate line, which closed completely in September, 1959 ( ahead of the Beeching Report, 1963 ! ).

The new Thirsk Signal Box was located on the Down side of the line, north of the station, and it replaced the three pre existing signal boxes at Thirsk.

The York - Darlington section of the ECML was, in North eastern Railway days, and has remained very busy to this day, which is why the NER, LNER, and BR continually upgraded the track arrangements and instituted new signalling schemes, all with the aim of improving traffic flow.

From a signalling history perspective, York - Darlington is a microcosm of changing signalling practice and technology.

Regards, Platypus.

[StevieG]

" .... ref "An Illustrated History of Signalling" Michael A Vanns, ( Ian Allan, 1997 ) ISBN 0 7110 2551 7 pp 60, .... " " .... Thirsk ( pp 89 - 91 ) was the first use by a mainline Signal Box utilizing a Route Setting Panel, Relay Interlocking and an Illuminated Diagram using a row of lights to indicate the route set. .... "

I'm sure I recall reading some considerable time ago, that rather than the original Thirsk panel, it was that at Northallerton (or possibly Hull Paragon) which was the first to use the row of lights method of showing a route set, Platypus.

Without researching to support that, I would've thought in any case, at Thirsk, that other than the OCS route switch positions, if that first ever installation of a completely 'panel' box had some method of indicating route set, that it would have been more likely to be one more rudimentary than the row of lights.

As an example of other methods, the rather later Metro-Vickers/GRS eNtrance-eXit (TP) panels of 1939 onwards, even as late as the 1954/5 example at Potters Bar, did not utilise the familiar chain of white lights, instead leaving signalmen to observe any or all of; -

- illumination of a single white light next to an eXit button, together with

- an eNtrance switch in its Reversed position, and / or
- Normal or Reverse positions of points (if any), indicated on the panel's track diagram,

to identify a complete, or partially remaining, set route.

[Platypus]

Dear StevieG and others,

1 / thank you for your comments, StevieG, it is appreciated.

2 / I understood Hull Paragon to be a miniature lever frame with relay route locking, but lacking a time delay. and with a seperate illuminated diagram,
though I am more than happy for this to be disproven, as I have primarily relied on text, and seen very few time relevant photos.

There was a collision at Hull Paragon due to the signalmen, ( two on shift ) who operated a set of points once the point free light illuminated, but which was later found to happen even though a train was still over, but not necessarily on, the affected points , hence the subsequent use of time delays to ensure that points and signals are cleared prior to re activation.

( When I worked on a NX Panel that replaced a Mechanical Interlocked Frame I previously worked, the time delays encountered on a NX Panel compared to a mechanical frame was quite noticeable, so much so that the WTT had to be redrafted to enable trains to dock and shunt, and still maintain the schedule. )

3 /Thirsk was 1933, Northallerton was 1939.

4 / my understanding is that Thirsk was the first use of a Panel that incorporated both the illuminated diagram and the operating switches on the one Panel as an integrated whole. There were previous Illuminated diagrams, but they were independent of the operating mechanism.

I also understand that the row of lights was more likely to be more spread out than the later postWW2 light rows. The post war units used a small incandescent light about the length of a matchstick which was inserted into a sleeve with thin contacts on each side.

I suspect Thirsk used something akin to a motor vehicle instrument light , so the spacing would need to be wider, and use less lamps, so as to accomodate the required fitting. I also presume that the designers would have to make allowance for the OCS switch and its necessary wiring, and to make room for the Signal Fitters to actually repair it .

I also imagine this to be a big ask in 1933 when control panels by necessity of available technology would be, by todays standards, quite large for the control area in question.

Another consideration is what sort of panels of that time could a comparison be made with ? The designers would be aware of wireless radios, probably have some knowledge of aeroplane instrument panels, or power station control panels. So a lot of effort must have been made to get a design that was suitable for railway use.

5 / I also understand that Thirsk was unique in that subsequent Panels had the operating switches below the illuminated diagram. not within the illuminated diagram that the Thirsk Panel was.

6 / Over the subsequent 50 years there seems to be an ongoing issue with different Panels architecture. For example, OCS Panels , subsequent to Thirsk, used a desk mounted switch panel with an illuminated diagram, and then you had Glasgow in the mid 1960s which was an OCS panel with the switches mounted integrally with the illuminated diagram . However, 1960s installations tend to be long, curved, multi manned designs, and therefore significantly larger than Thirsk.

7 / You also get later eNtranceExit / NX panels where the Push Buttons were integral with the illuminated diagram ( the Swiss Integra designs come to mind ), and yet a newer installation again will have the NX push buttons on a seperate panel to the illuminated diagram above.

8 / on the VR in Australia, Camberwell ( on the Suburban Electrified Ringwood Line ) used a push button version OCS panel with the push buttons on a desk, and the illuminated diagram above it. ( McKenzie&Holland Australia PtyLtd, British Westinghouse B&SCo )

9 / also on the VR, some locations used American GRS electro mechanical frames with illuminated diagrams that used electric bulbs to illuminate track sections in one inch long rectangles which were illuminated white light for a set route, which changed to non illuminated black for train occupied to train passed. Points free lights were above the miniature operating lever.

Thanks again for your comments,

Regards, Platypus.

[StevieG]

Sorry Platypus, I can't agree with several of your comments, but as this is an LNER forum, and not a specialised (and more than UK) signalling one, I think it inappropriate to continue the discussion here.