A copy of the box diagram in its later form
Introduction:
Spring Vale Sidings Box was on the double-track Stour Valley Line from Wolverhampton High Level to Birmingam New Street. Catchem's Corner was the next box towards Wolverhampton and Deepfields the adjacent box on the Birmingham side. Spring Vale was an L.M.S. standard 'composite' box with a brick locking room and glazed, wooden operating floor. In addition to the Up and Down Main lines, a bi-directional Up and Down Goods Line extended from Spring Vale to Deepfields. There were extensive sidings on both the Up and Down sides of the main lines. The signal box commanded a good view of the steel works on the Up side of the line which gave rise to the box's importance.
The box diagram above shows the arrangement in the later years after changes associated with an ill-starred Steel Terminal built on the down side. Originally, a running crossover with single slip was provided on the Wolverhampton side of the box. After remodelling, motor points 2A/2B and the facing crossover 5/6 provided similar functionality. Originally, access to the Down & Up Goods Loop from the Up Main was via a scissors crossover. Following remodelling, separate crossovers 5/6 and 13A/13B provided similar functionality. The Bonding Diagram below shows the original arrangement.
After electrification of the line, Spring Vale Sidings box struggled on as a Shunt Frame for a few years but, like the steelworks it was built to serve, it has now disappeared.
The Steelworks:
In the early 1950s, I visited the Steelworks on an official tour which started my interest in steelmaking and heavy engineering in general. At the time, the works was universally known as Stewarts and Lloyds but it ended up part of British Steel and was eventually closed. Very little sign of a once-major employer remains.
There was one Blast Furnace, a post-war affair called 'Elizabeth' named after the then-princess, now Queen, Elizabeth. Once 'lit' blast furnaces are kept going as long as possible. A 'campaign' can last 10 - 15 years. The blast furnace produces iron from iron ore in a batch process. Every few hours, the furnace would be 'tapped' to release the new batch of 'blast furnace metal'. Originally, this would be sand-cast into 'pigs', allowed to solidify, then broken up and carried away for further processing which involved melting it again. In an 'Integrated Steel Works', blast furnace metal is kept molten and transferred immediately for further processing. The Spring Vale Works had a number of electric-arc furnaces, used for converting iron into steel.
As British Steel modernised, the more efficient Basic Oxygen Steel process was introduced at certain sites, together with new, larger blast furnaces which, whilst still batch-orientated, had a much larger throughput than 'Elizabeth'. So the Spring Vale works became less economical and closure became inevitable.
Signalling:
The box was provided with an L.M.S. standard lever frame unusally on the track side (because the brick base was 'undercut' due to limited clearance to the siding running behind the box). The lever frame stood about 18 inches above the floor. All the interlocking was contained within the Operating Floor in flat trays protruding to the rear of the frame. The catch handles were 'trigger levers' mounted behind the lever top (similar to old-fashioned car handbrakes). 'Catch Handle Locking' was provided so that, if a lever was locked, it was not possible to squeeze the catch handle against the lever top to release the catch prior to moving the lever. This prevented the signalman from 'taking a swing' at a lever which was locked, minimising the chance of injury. Nonetheless, I always preferred the older L. & N.W.R Webb design where locking was on the lever, not the catch handle. A number of levers in the frame were provided with electric lever locks or circuit controllers.
One feature of L.M.S. frames was that the levers controlling running signals for the main lines were grouped towards the middle of the frame, rather than at each end, so as to minimise the required walking by the signalman. At Spring Vale Sidings, the levers required for an Up Train were thus 20 (Home), 21 (Starter) and 19 (Distants). For a Down train, the "pull" was 35 (Home), 34 (Starter), 36 (Distants) and 37 (Distant).
Signalling at Spring Vale Sidings was upper-quadrant semaphore, wire-operated. The Down Starting Signal (with Catchems Corner Down Inner Distant below) originally had an ususual 'gallows' post but the limited remodelling changed this for a straight post with a 'Shunt Ahead' subsidiary signal below. Note that the lever number for the 'Shunt Ahead' signal was 33 - my diagram incorrectly shows it as 35. Originally, points were all mechanically operated via rodding but the limited re-modelling introduced electric operation of points 2A and 2B.
Absolute block signalling was in use on the main lines, using L&NWR instruments of Fletcher's 'DN' pattern.
The Down and Up Goods Line to Deepfields was worked 'Permissive', using special bi-directional single-line block instruments. Although each instrument had two block indicator needles, only one needle could be used at a time, according to whether the train was 'coming' or 'going'. In addition, the commutator which allowed the block to be set at 'LINE CLEAR', 'TRAIN ON LINE' or, when not in use, 'LINE CLOSED' also included a mechanical reminder device which displayed the total number of trains in the section in a small window.
I'm afraid I never did a detailed signalling diagram before the remodelling, but the diagram above represents Spring Vale in its final years as a block post.
Down Main Signals:
Spring Vale Sidings Down Block Section extended from Deepfields Down Starting Signal to Spring Vale Sidings Down Home Signal (35), just outside the box. 'Station Limits' extended from the Home Signal to the Starting Signal (34).
A Distant Signal is, of course, provided sufficiently far in the rear of the Home Signal to serve as a warning to the driver of an approaching train of adverse stop signals ahead. The location of a Distant Signal depends upon Line Speed, Gradients, Sighting Distance and train braking characteristics. If a Block Section is sufficiently long, the distant signal will be placed on its own post but where Block Sections are shorter (such as along the Stour Valley Line), the Starting Signal of the box in rear would often intervene so a distant arm was placed below the Starting Signal arm. A 'Slot' mechanism on the signal post would prevent the distant arm from coming 'Off' until the Starting Signal had cleared. The lever of the Distant Signal would work the 'Weight Bar' in the Slot mechanism, enabling the Distant Arm to clear once the Starting Signal is cleared. There's a bit more about 'slotting' here. A further Distant Signal would have to be provided under the Home Signal of the box in the rear, similarly 'slotted'.
In fact, Spring Valve Sidings controlled a total of three Distant Signals in the Down direction, all mounted under Deepfields 'stop' signals and 'slotted' by them. Lever 37 operated the weight bar for a Distant Signal 1144 yards from the Home Signal, mounted under Deepfields' Down 'Home 1' signal. You can imagine that getting the weight bar to move correctly at this distance required a certain technique. Lever 36 operated the weight bars for two Distant Signals - 36a (mounted under Deepfields' Down 'Home 2' signal) and 36b (mounted under Deepfields' Down Starting signal).
Up Main Signals:
Spring Vale Sidings Up Block Section extended from Catchems Corner Up Starting Signal to Spring Vale Sidings Up Home Signal (20), from where 'Station Limits' extended from to the Starting Signal 21).
Spring Valve Sidings controlled two Distant Signals in the Up direction, both mounted under Catchems Corner 'stop' signals and 'slotted' by them. Lever 19 operated the weight bar for Distant Signal 19b mounted under Catchems Corner Up Starting Signal. Provided the weight bar came 'off' correctly, a circuit controller applied power to motor-operated Distant Signal 19a mounted under Catchems Corner Up Home Signal. This motor-operated Distant Signal was 1190 yards from Spring Vale Sidings Up Home Signal.
Down and Up Goods Loop & Adjacent Sidings:
The 'third line' on the Deepfields side of Spring Vale Sidings was an up and down permissive block goods line. 'Permissive' meant that a second, or subsequent, goods train could be admitted onto the occupied line. To ensure the co-operation of signalmen at Spring Vale Sidings and Deepfields regarding trains on the Down & Up Goods Loop, stop signals at either end were 'Slotted' (in a similar fashion to slotting of Distant Signals described above) so that both signalmen had to operate their slot lever before the signal cleared. Lever 29 at Spring Vale Sidings worked the slot on the bracket signal allowing Up Trains to proceed to Deepfields. Lever 50 at Spring Vale Sidings worked two slots at Deepfields allowing Up Trains to approach Spring Vale. One slot was on the arm controlling facing movement from the Down Main to the Down & Up Goods; the other controlled the 2-arm miniature semaphore ground signals controlling movements setting-back from the Up Main to the Down & Up Goods.
The 'fourth line' on the Deepfields side of Spring Vale Sidings box gave access to a fan of sidings which extended to Deepfields. There was no block signalling on these sidings and the connection at the Deepfields end was very rarely used.
Typical working:
Whilst some boxes were only open during the daylight hours, Spring Vale Sidings worked three shifts ('Early', 'Late', 'Nights') most of the week.
A lot of the activity was concerned with the through trains. This involved accepting the 'Is Line Clear?' from the box in the rear ("Taking On"), obtaining 'Line Clear' from the box in advance ("Sending On"), clearing the signals in the order Home, Starter finally Distants ("Pulling Off"), observing the train as it passed, sending 'Train Entering Section' ("Section") to the box in advance, ensuring a tail lamp was carried, replacing the signals, giving 'Train Out of Section' ("Knocking Out") to the signal box in rear and waiting for the box in advance to send 'Train Out of Section'. Even this repetitive process could get quite demanding at busy times when trains followed one another on short headways and, of course, trains were being handled in both directions. Once freight trains, requiring to detach or attach wagons, terminate or originate at Spring Vale, were added to the mix, life could be quite hectic.
Signalling Controls:
There's a bit about the electrical signalling controls at Spring Vale Sidings starting here.
References:
For an earlier diagram of the arrangements at Spring Vale Sidings, refer to the Signalling Record Society publication 'British Railways Layout Plans of the 1950's', 'Volume 11: LNWR Lines in the West Midlands' (ISBN: 1 873228 13 9).
For details of the the Stour Valley line in 2005, refer to 'Railway Track Diagrams Book 4: Midlands & North West', Second Edition, published by Trackmaps (ISBN: 0-9549866-0-1). The First Edition of this book was published by Quail in 1988.
[Additional material added January 2010. New links added July 2013]
