Signal Levers - a question

Discussion in 'Running Your Trains' started by Wolseley, Nov 9, 2019.

  1. Wolseley

    Wolseley Full Member

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    Sep 30, 2017
    I am in the process of wiring up all the points and signals on my layout. Now I know that, as it is a double oval with a reversing loop the layout of the track is not something you would find on a real railway, but I do want to get certain details prototypically correct and there is one thing that I want to make sure of before I get much further.

    In spite of my Great Great Grandfather and one of my Great Grandfather's brothers both being signalmen on the North British Railway, I find myself unsure as to whether or not I have something right. In relation to the point levers, does the signalman pull the lever towards himself to indicate the line is clear and away from himself to stop a train (or move a distant to the caution position) or is it the other way around?
  2. York Paul

    York Paul Staff Member Moderator

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    Aug 20, 2017
    The simplest way I can answer your question Wolseley is to describe the lever functioning as thus:- the normal position for any lever is "back in the frame" e.g not pulled, when a lever is reversed (pulled towards the signalman) then it is reversed and thus a locking / unlocking action of other levers occurs.

    So let us imagine a set of points which we shall number 7 for this description, the normal lie of 7 points will mean the lever (number7) is back in the frame, to reverse the point so a train can travel onto of from the other line 7 points are reversed in the frame. Now this action we see has a relationship with the signals; described as thus:- for simplicity sake of this conversation (for the purposes of medeling) signals are of two types, these are signals which read through a set of points in the facing direction and signals which read through the points in a trailing direction... ignore the Distant, Home and Starter signals for this conversation as it gets too complicated.

    Now facing points are where the direction of trains travel through points from the switch blade end and trailing points are where trains travel through from the crossing (frog) end, facing points are fitted with an FPL (facing point lock) which is a bolt plunger which prevents point blades from moving when pulled... so for this description the FPL is number 8. Thus with 7 points normal 8 FPL lever when reversed in the frame will lock 7 point and then release the respective signal which we shall number as 6, this now means a train is clear to travel in a forward direction through the points. However if a train is required to travel in a trailing direction (from the turnout side of the points) then another signal is needed, this one we shall number as 9.

    So the sequence of lever pulling for a train to travel through the points in a trailing direction is as thus:- signalman puts 7 points in reverse and leaves 8 FPL in the normal position, he then places 9 lever into reverse which clears the signal to green and also locks both 6,7 and 8 levers in their respective positions in the lever frame so these levers cannot be pulled in error.

    Finally the lever colours are as thus :- red is signals, black is points and blue is FPL, distant levers are yellow. There are other colour combinations but for this description it is not necessary to discuss.

    Some modelers I have noticed become confused when modeling their signal box interiors and painting the levers in haphazard manner, the correct combination would be as follows :- Distant, Home signal, Points, Facing Point Lock, Start signal, so from left to right in order in the lever frame for a train traveling through points in a facing direction we would see levers coloured, yellow, red, black, blue, red. Trains traveling in a training direction from right to left the lever colours in the frame would continue as thus :- red, black, blue, red, yellow. So the complete colour combination for all levers would be, yellow, red, red, black, blue, red, red, yellow.

    From this layout combination of levers it will be noted that all the point and lock levers are located in the centre and all signals located to the left of the signalman have their respective levers located in the left hand side of the frame and signals to the right of the signalman are located in the right hand side of the frame, this ordering is done this way to create a logical sequencing.
    Andy_Sollis likes this.
  3. Sol

    Sol Full Member

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    Mar 13, 2016
    I guess then the advantage of CTC over the old style signal boxes rears its head

    One of my modelling mates here in South Aust is a Senior Train Controller & they control turnouts etc from many many miles away, even in a different State.
    jakesdad13 and Toto like this.
  4. Echidna

    Echidna Full Member

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    Oct 15, 2016

    Hello All,

    as a retired signalman, and not wishing to be excessively pedantic, there are more variations in the layout of an interlocked frame than York Paul has indicated. Assuming you are standing in front of the frame, which is located between yourself and the front windows, and to your left is the Down Line ( coming from the London ) and to your right is the Up Line ( going to London ) , the "typical" ( generic ) Signal Box layout where the Signal Box is roughly half way between the Down and the Up direction of your location, the following sequence is the more usual. ( There are exceptions ! )

    From your left to your right would be Down arriving Signals, Up departing Signals, Lock Bars, Points, Shunting signals, Points, Lock Bars, Down departing Signals, Up arriving Signals.

    As a generalisation, the frame was set up so that signals to your left were operated by levers to the left of the frame, and signals to your right were operated by levers to the right of the frame. Most mechanical Signal Boxes had the interlocked frame at the front of the Signal Box so that you looked along and over the frame to observe the passage of the train. ( You needed to do this to ensure the train had arrived complete with tail lamp, and to also look out for anything wrong with the train, such as dragging ropes or chains for example. )

    From the mid 1920s, some new Signal Boxes on the LNER and the SR, placed the frame at the rear of the signal box, thereby giving the signalman a clear view of the passing traffic. As Miniature Lever Frames and Signal Control Panels entered service, they were generally also located to the rear of the Signal Box. These early electrically activated ( and some pneumatic versions as well ) were quite bulky, and the only practical way of allowing the signalman to observe the passing traffic was to place this equipment to the rear of the Signal Box.

    Distant signal levers were originally painted Red, then Green, and generally not painted yellow till after WW2, so all signal levers are normally red. Lock Bars are Blue, though some mechanical points which incorporated the Facing Point Lock mechanism ( FPL ) within the point operating mechanism ( rare ) had a top half Blue and a bottom half Black operating lever.

    Alternatively, a top half Light Blue and a bottom half Black, is a Cross Lock lever, which works in conjunction with an adjacent Signal Box. ( May also be called a Control Lever. )

    Black colour levers operated points and ground frame releases, and White levers were spare. Some locations also had a top half White, bottom half Black lever ( magpie ) which is known as a Pilot lever, the purpose of which is to confirm a selected route, and usually the result of a colour light signal replacing two previous mechanical shunt signals. This was done to maintain the existing interlocking arrangements, without requiring a re locking exercise to accomodate one signal post change.

    Where Shunt signals ( disc, dwarf, miniature arm, or position light signals ) were utilized, the Red signal lever were usually placed within the group of Black point levers.

    Blue Lock Bars, depending on the interlocked frame design, the "Normal" position is equally likely to be Reverse or Out of the Frame ( as opposed to In the Frame ),
    this being the case for Westinghouse, and McKenzie & Holland Pattern frames. The reason being the sliding lock of the FPL in the field has to engage as a cross lock, and by moving the Blue Lock Bar levering the frame, the cross lock in the field is removed to unlock, and free the points to be moved.

    Gate wheels and Wicket Gates, or Wicket Gate Locks, were Brown in the UK, though Black in Australia ( and probably elsewhere ).

    Intermediate Block Posts / IBP remotely operated from an adjacent Signal Box became a popular economy measure between the wars, and more so after 1945. In this case one lever, top half Red, bottom half Yellow, when reversed, placed the IBP colour signals to Proceed, and which reverted to Caution / Stop after the passage of the train. In later installations an Individual Function Switch / IFS or Unilever Control Panel for remote control was placed on the Block Shelf.

    Some locations also had Signal Box operated Platform Indicators, this utilized a top half Red, bottom half Black lever.

    Ground Frames / GF also had two possible variations, in that some had the Switch In Switch Out Lever Normal ( in the frame ) when switched out; and therefore Reversed ( out of the frame ) when switched in. ( LNWR, NSWGR ). Alternatively, the opposite could also apply ( VR ). In either case, there was a visual cue to the railway employee of the status of the GF.

    Best wishes and regards, Echidna.
    Peter Cross and York Paul like this.

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