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G.N. signalling Moorgate line

Unread postPosted: Fri Apr 21, 2017 9:50 am
by scarpa
The G. N. was responsible for building the underground line from Drayton Park to Moorgate about the turn of the century. Is there any information on the type of signalling installed and location of signalboxes ,power frame types .Were trainstops employed .Were steam engines banned from the tunnels, condensing type?

Re: G.N. signalling Moorgate line

Unread postPosted: Fri Apr 21, 2017 10:00 am
by davidwoodcock
It ran from Finsbury Park (underground) via Drayton Park to Moorgate when it was built - and it was built by a private company, which admittedly had aspirations of linking with the Great Northern but was thwarted by that company. It sold out to the Metropolitan Railway which operated it until the LPTB was formed. It had a central conductor rail but I am not certain about the signalling.

Re: G.N. signalling Moorgate line

Unread postPosted: Fri Apr 21, 2017 3:12 pm
by Harsig
H. Rayner Wilson's 'Power Railway Signalling' has a description of the original signalling on this line (Pages 180 to 183) (Part 1B if you have the Peter Kay reprint)
The equipment was provided by Spagnoletti and Co. Two aspect colour light signals were provided (with the red aspect above the green). Signal boxes were provided at all the stations. However to quote: 'Signal boxes with attendant signalmen, are provided at each station. These men are not necessary for signalling purposes, and they do not interfere at all with the operation of the signals, but they are useful for booking the passage of the trains and watching that all is right, whilst their presence would be extremely useful in case of emergency. All the relays and operating mechanism, too are in the signal boxes so that the men keep them under constant observation.'
Train detection was by means of track circuits, reinforced with what are described as treadles located between 350 and 400 feet in advance of signals. These worked by completing and electrical circuit when they came into contact with a special brush mounted on the rear vehicle of the train.
Where points existed (Finsbury Park, Drayton Park and Moorgate) these were worked mechanically from lever frames, these frames also controlling the signals in the area.

Re: G.N. signalling Moorgate line

Unread postPosted: Sat Apr 22, 2017 12:07 pm
by scarpa
Thankyou for the replies. If 2 aspect colour light signals were used ,and the line opened in 1904 these would predate the Liverpool overhead railway where it is claimed colour light signals were among the first installed.The red aspect was the top aspect ,were they provided by the same company. Is there any record how the rolling stock was moved onto the line.Was there a connection at Drayton Park? Were trainstops in use on the Moorgate line.

Re: G.N. signalling Moorgate line

Unread postPosted: Mon May 1, 2017 10:52 pm
by tjc
I believe there was a form of trainstop, but can't remember the details.

Re: G.N. signalling Moorgate line

Unread postPosted: Tue May 9, 2017 10:06 am
by StevieG
Hopefully I can add to the info. in previous posts, trusting that what follows is reasonably accurate and that none contradicts the Raynar Wilson descriptions.

Two Non-signalling items
There was a connection between the GN&CR and the rail 'outside world' from the early days scarpa : It was not the one more familiar to some, dropping from the GN / LNER's Highbury Vale / Gillespie Road sidings and passing under the Finsbury Park / Canonbury Junction line to connect with the ex-Great Northern & City Railway's southbound line at the north end of Drayton Park station, but was instead a short but steep incline connecting off the westernmost siding in DP depot and rising to connect with a road(s) in the south end of Ashburton Grove sidings, not far from Finsbury Park No.1 signal box.
After being later severed at the top end, the track was nevertheless partly retained as a very short siding.

Also, the original arrangement of the two traction current rails was unusual, in that neither were sited anywhere in the 'six-foot', instead both ran outside the running rails, one on each side.
LT changed this arrangement to their standard four-rail configuration in 1939.

But regarding the signalling, in "The Big Tube - An Illustrated History of London's Great Northern & City Railway" (1976, London Transport), J Graeme Bruce variously wrote :

"The system actually provided the first automatic-type signalling arrangement for a tube railway. The signal displays had no moving parts but provided red and green aspects.
A treadle, which was struck by a brush carried on the last bogie, was placed about 400 ft. beyond each signal. Until this treadle was struck the signal in rear did not clear."

"Signalmen were required only at the terminal stations, Finsbury Park and Moorgate, Drayton Park cabin being opened only when required for shunting and dividing trains.

This was the first railway in England not to be operated by the well tried absolute block system requiring signalmen to pass each train from the protection of one to the other. A type of train stop was also installed at the inner home signals protecting the terminal junctions. The trip consisted of a wire loop suspended from the tunnel roof which made contact with a trigger on the car roof. This loop was energized at traction voltage when a danger signal was displayed. If a train proceeded past the signal at danger this loop came in contact with a device in the car energizing an electro-pneumatic valve which applied the brakes.
This device was ingenious and worked reasonably well but was not 'fail safe'. Similar devices, permanently energized, were provided at the ends of the platforms beyond the normal stopping mark to reduce the impact of a train hitting the buffers on an overrun.
The Board of Trade Inspecting Officers were not satisfied that the system was sufficiently safe and required the provision of track circuits to monitor the signal aspects. The opening date was, in fact, postponed until the alterations were made."

"The exit control signals at Drayton Park depot were semaphores worked by electric motors. This equipment was also of a pioneer design which subsequently provided the basis for future siding control signals generally."

I am not at all sure of the precise meaning which those last few words of the final sentence refer to.

Re: G.N. signalling Moorgate line

Unread postPosted: Tue May 9, 2017 11:49 am
by Chris Osment
"...This was the first railway in England not to be operated by the well tried absolute block system requiring signalmen to pass each train from the protection of one to the other...."

Surely a rather wide-of-the mark statement, given that most early railways started without "the well tried absolute block system"? Even in the 20th Century railways such as the Swansea & Mumbles ran quite safely without any signalmen :-)

Re: G.N. signalling Moorgate line

Unread postPosted: Wed May 10, 2017 5:41 am
by scarpa
Thankyou everyone who did research on this subject .

Re: G.N. signalling Moorgate line

Unread postPosted: Thu May 11, 2017 1:41 pm
Little bit late to the party, but I do have copies of original GN&C diagrams and wiring charts (somewhere, digitally).