The Branch Line Society


Blackpool Line Signal Box Visits
Friday 5th May 2017

Report by John Cowburn

The Preston to Blackpool North line is currently controlled by five traditional signal boxes between Salwick and Blackpool, with the remainder supervised by Preston Power Signal Box (PSB). The forthcoming electrification will finally bring about the demise of the manual boxes and, with a total line block for re-signalling and electrification work being scheduled from 11 Nov 2017, this visit was quickly oversubscribed. Member Andrew Gardiner has kindly provided links and to photographs taken on earlier official visits to the boxes described.

The group of twelve members met at Blackpool North station at 10.00 and, after introductions and a safety briefing, made their way to Blackpool North No.2 box, which stands on the north side of the station throat between the eight platforms [since reduced to four: P3, 4, 5 & 6] and still extensive carriage sidings. It is a Lancashire and Yorkshire (L&Y) box with an L&Y frame, both dating from 1896. While it has (as does each box on the line) replacement UPVC windows and a false ceiling, it retains much character both internally and externally, including elderly if not original wooden name-boards on each gable. The box is partitioned at each end but is still substantial. The original 120 lever frame now runs only from numbers 11-90; some of these have been removed but around half remain in use. Most of the layout is mechanically worked; all (then) 8 remaining platforms having mechanical semaphore starting signals. The current station was originally the 'excursion platforms' so, in earlier days, the box would only have been open during the 'season', unusual for one of this size. It still has a platform bell.

Blackpool North No.2 signal box (the only one there now) and Carriage Sidings on 4 Sep from the platform end. The sidings were unusually occupied in the day due to Northern industrial action. This scene is to change dramatically this winter.
[© Richard Putley 2017]

In contrast, the points and signals at the east end of the layout, where No.2 box took over the role of the former Blackpool North No.1 in 2011 (the latter having been 'switched out' since 2007), are electrically worked. The Up Main Section signal is a motor worked semaphore and Down Main Home 1 a two aspect (red and yellow) colour light. Unusually for a terminus station, these two signals have working distant signals associated with them. Approaching Down trains are presented with a twoaspect colour light distant (signal 21) which can be cleared if a route has been set up into the platform using Down Main Home 1 (signal 22) and Down Main Home 2 (signal 23). Main signal 23 and calling on arm 24 below it give access to each platform, the display on the theatre route indicator and associated block shelf indicator being governed by the lie of the points. Departing trains from all except P1 encounter two closely spaced semaphores, the platform starting signal being closely followed by one of the mechanically worked semaphore 'homes' (as described on the lever plates), each of which has an electrically worked semaphore distant on the same post. The distant is for the electrically worked Up Main Section signal (65) and has no separate lever in the frame. Note: For Down trains, the signaller clears signal 23 before 22 (the opposite of standard practice) as once lever 22 is reversed, it is not possible to change the route into a different platform; clearing 23 first therefore proves the route.

Blackpool North No.2 signal box - a detailed close up.
[© Richard Putley 2017]

Despite its name, Carleton Crossing signal box is a block post which happens to control an adjacent barrier level crossing. It is a very small L&NWR box, with a twelve lever L&Y frame, both dated 1924. Only four levers remain in use, a home and distant semaphore in each direction, which means that there are no 'station limits'. There is no gate release lever, as the home signals are released by the 'crossing clear' button on the barrier control pedestal (as well as 'Line Clear' on the block). The Down distant, underneath and slotted with Poulton No3's section signal, is electrically worked but the Up distant is mechanical, an inverted v-shaped 'pull plate' being provided on the end of the frame to allow the signaller to apply enough force to clear it. The distance to the signal means that the signaller typically has to adjust the tension in the signal wire several times per day as temperatures rise and fall.

On 4 Sep (a strike day) Northern ran Burnley Central and Manchester Airport services.
[© Richard Putley 2017]

Unusually the box has a non-illuminated track diagram; track circuits are provided but their occupation is shown on 'banner repeater style' indicators on the block shelf. Trains are signalled under normal absolute block working in the Up direction but in the Down direction, due to the short length of the section, rather than waiting to receive 'train entering section' from Poulton No.3, trains are offered on to Blackpool North No.2 when an annunciator indicates the arrival of the train in Poulton platform.

Next was Poulton No.3 signal box (there were once five boxes here) an L&Y box dating from 1896 which is located in the 'V' of the former junction between the Blackpool North and the Fleetwood routes, west of the attractive station. As well as controlling the junction (the signaller reminded us that originally the Fleetwood line was the 'main' line and the later route to Blackpool the 'branch'), the box was at the end of the fast lines (CA 9 Dec 1973) which were both located south of the platform lines. The Fleetwood line was cut back from Wyre Dock Jn to Burn Naze from 14 Jul 1970 and even this has been OOU for many years (the last freight train was in Apr 1999) and is now rusted black. A few weeks prior to the visit, the junction was plain lined, though passive provision for later reconnection will apparently be included in the re-signalling. Thus the substantial box, still with an increasingly unusual wooden staircase, is now reduced to controlling the Up and Down lines with not even a crossover.

The box has an 1896 L&Y 74 lever frame, with a few levers missing and many now white (spare), two of which are locked in the 'reversed' position. There are also a small number of 'interlocking levers' which are painted white at the top and either red or black at the bottom depending on their former use. Of the signals still in use, most are mechanical semaphores with two homes and a starter on the Down and a home and starter on the Up. The Up distant, as at Carleton Crossing, is a mechanically worked semaphore. The clearing point is thus 440 yards beyond the Up Main Home which in turn means that Poulton cannot send 'train out of section' to Carleton until trains have departed from the station. Lever 74 for the distant is also provided with a 'pull plate' to assist the signaller.

Back in the early 1980s there were two signal boxes between Poulton and Kirkham, Singleton which was normally open and Weeton (between Singleton and Kirkham) which was opened only on the busiest summer or illuminations Saturdays and bank holidays. Each of these boxes unusually had two distant and two home signals on each line, in an arrangement that your scribe seems to recall being locally referred to as 'double block'. Trawling the web in 2017, it seems the term 'double block' was used to describe a way of working to keep fast trains two block sections apart where distances between boxes were short, eg with double-headed class 50 hauled expresses on parts of the WCML prior to re-signalling. However, the system at Weeton and Singleton, in contrast, was a semaphore version of today's use of colour light Intermediate Block (IB) signals to break up a section. This arrangement allowed a train to be accepted from the box in rear under normal regulations, and the first distant and home to be cleared while the second home and distant (the latter on the same post as the first home) remained at danger and caution respectively due to line occupation ahead. This in turn allowed trains to approach at full speed giving a high line capacity on an intensively worked absolute block worked railway; even then, at busy times trains would sometimes be checked at most signals.

After first Weeton (closed 24 Jul 1993) and then Singleton (closed 13 Dec 1997) were abolished, colour light IB signals were installed between Poulton and Kirkham to avoid a significant loss of line capacity. In the Up direction, the two IB signals are controlled by levers 68 and 67 in Poulton No.3 box, the latter being the section signal for the absolute block worked section to Kirkham. Both boxes were observed to use the IB sections to group bell codes and reduce the time spent at the block instruments; as long as the sections ahead are clear, once the train has passed the box in the rear but before it reaches the three-aspect signal which acts as the 'distant' for the final IB signal, it can be offered on, accepted and train entering section sent and repeated in one long barrage of bells!

The inappropriately named Kirkham North Junction signal box is located at the west end of the Kirkham station layout at the point of convergence of the former fast and slow lines from Preston and the divergence of the closed direct line (CA 13 Feb 1967) to Blackpool Central and the still open but now singled Blackpool South line. (Blackpool South to St Annes-on- the-Sea was singled 7 Mar 1982, and from there to Kirkham & Wesham on 20 Nov 1983.) In recent years about a mile of the Blackpool Central direct route gave access to the former Kirkham civil engineer's tip, which is still shown on the box diagram, but now heavily overgrown and partly lifted. The box and frame are both of L&Y vintage and date from 1903. Though not partitioned, the box now has a shortened frame; originally this had 105 levers but now only 30 to 88 remain, with gaps, including where 81 to 85 would have been. The box is the only one on the line to retain an outside balcony, apparently replaced relatively recently.

In contrast to the signalling further west, all main signals here are colour lights, and the box also now controls three IB signals at Bradkirk, Weeton and Preese Hall on the Down line to Poulton. Even with these, the line still operates at capacity at certain times of the day and the signaller on duty remarked that his personal record was 11 trains on his illuminated box diagram; others have apparently achieved even more. The box controlled the fast lines which avoided the station until their abolition on 9 Apr 2017; however, these were not much faster than the slow lines through the platforms as at the east end of the station (Kirkham South Jn) the fast lines were the diverging route, while at the west end the slow lines were the diverging route. This combination meant that that any non-stop train had to slow down whichever route it took.

The box supervises the Blackpool South branch (officially the 'Up and Down Lytham') via a system of one train working. A train going onto the single line occupies and clears three track circuits in order. The interlocking then prevents any other train being signalled onto the line until the same three track circuits have been occupied and cleared in the reverse order. The remainder of the branch is not track circuited which means that the signaller has no visual indication of the where the train is.

The branch passes close to the end of Blackpool Airport runway near Squires Gate station and, should an incident occur, the airport control tower would contact the Kirkham signaller via the public telephone network. To allow the signaller to be able to advise the approximate position of trains in the area, drivers on the branch have to contact the signaller prior to departing St Annes in the Down direction and Blackpool South in the Up. For a train to leave the branch, before clearing main running signal 67, the signaller must also reverse the lever for ground disc 71, known as a 'running dummy'.

Salwick No.2 signal box is the oldest on the line, with both box and frame being of Railway Signal Co. design, built for the L&Y and commissioned in 1889. It is located on the north side of the line, to the east of the sparsely served but still open station. The now removed fast lines were adjacent to the box, so it is set back some way to the north of the remaining running lines. The box would have originally been named simply 'Salwick' and only acquired its current designation on the opening of Salwick No1 box during WW2 with the establishment of the adjacent Springfields munitions factory, subsequently used to manufacture Magnox nuclear fuel rods (but no longer does so as Magnox is now obsolete other than in North Korea). The original 30 lever frame was extended in 1942 but levers 29 and 30 have been removed leaving 33 in the frame, lettered/numbered A to E and 1 to 28. Salwick No1 box was abolished on 3 Feb 1973 when No2 box became the fringe to Preston PSB. Recently the Down loop and sidings were lifted, further rationalisation prior to electrification and resignalling, leaving just Up and Down running lines. Remarkably the box still sports a genuine maroon (BR London Midland style) enamel name board 'SALWICK NO 2' (the 'O' is large) above the door and a similar smaller 'PRIVATE' sign at a lower level to its right.

West of Kirkham, absolute block with BR standard instruments reigns supreme, but to the east the line is controlled by Track Circuit Block (TCB). Salwick communicates with Preston PSB by a train describer but Kirkham and Salwick describe trains to each other with standard 'is line clear for' bell codes rung using tappers and bells formed of the bottom sections of BR standard block instruments and then simply send trains forward. The branch passenger bell code of '1-3' is used for trains to and from the Blackpool South branch. 'Train entering section' and 'train out of section' bell codes are not used and neither are block indicators nor a train describer. Only three levers remain in use, each controlling a colour light stop signal (two on the Up and one on the Down) and the distant function of the preceding three-aspect colour light; the levers are accordingly painted red and yellow. Once a train has cleared the overlap of the next signal, levers are generally 're-stroked' (put back into the frame and immediately cleared again) for the next train, with the track circuiting taking care of the signal aspects.

Finally was Preston PSB, opened in 1972 in anticipation of the extension of the West Coast Main Line electrification to Scotland. Its BR (LMR) design is typical of its period and it is located on the west side of the main line adjacent to Fylde Jn, with DMU (and now EMU) stabling sidings in front of it. The box retains its original control area, which is broadly the WCML from just south of Balshaw Lane Jn to just north of Carnforth, the Preston to Manchester line as far as Adlington, the East Lancashire line to Brierfield, over Copy Pit to Hall Royd Jn, the Calder Valley line between Littleborough and Hebden Bridge and the Blackburn to Bolton line. To these have more recently been added the reinstated Todmorden curve and the Morecambe branch, which have been incorporated into the existing panel.

The Westinghouse 'Entrance - Exit' ('NX') panel consists of five straight sections arranged in an arc, covering from left to right (1) the Calder Valley line as well as the East Lancs lines beyond Blackburn, (2) Blackburn to Bamber Bridge and Bromley Cross plus Adlington and Balshaw Lane to Farington Jn, (3) Bamber Bridge and Farington Jn to the PSB including Preston station, (4) Maudland Viaduct Jn to Salwick and Lancaster and (5) Lancaster to Morecambe and Carnforth. Four grade 7 signallers are on duty 24/7 with their supervisor and a 'meal break relief' on days. One signaller controls the West Coast north of Preston (ie most of panels 4 & 5), one the West Coast south of Preston, the third the East Lancs lines and the last Preston Station, with the signallers responsible for train regulation.

The boundaries between the control areas are notional and, where possible, are located in areas of automatic control to allow trains to flow from one panel to the next. As no CCTV operated level crossings were incorporated into the panel, a number of former signal boxes survived as gate boxes to supervise those crossings that were not automated. Two remain, at Towneley and Bamber Bridge, but in 2013 control of the crossings at Hest Bank and Bolton-le-Sands moved from the former Hest Bank gate box to the new level crossing workstation in the PSB staffed by a Grade 1 crossing keeper. This workstation also controls the crossing at Bare Lane on the Morecambe branch since the closure of the adjacent box in 2012 on the transfer of the line to the PSB.

In a short visit, few of the nuances of such a large box can be appreciated, but an example is the 'slot' light on the panel under signal PN56 at Farington Curve Jn and the associated unusual method of operation of the single line to the fringe box on the Ormskirk line at Midge Hall. When the line was singled south of Midge Hall on 28 Jun 1970, electric key token working was introduced between Midge Hall and the passing loop at Rufford but the section to the north across Farington Moss was left as double track operated by TCB. By June 1983, due to the condition of the track, this latter section was also singled but the box at Midge Hall, key token working to its south and TCB working of the remaining single line to its north were retained. Midge Hall was left as a very rare example of a signal box on a single line without a passing loop. So that only one train is allowed onto the single line at once, Preston first sets the route onto the branch alerting Midge Hall to obtain a token for the section to Rufford. With a token withdrawn from the machine, Midge Hall can reverse its slot lever (No.18) which in turn allows signal PN56 to clear and the slot light under signal PN56 on the panel to light.

Control of the Calder Valley section is due to be lost in the not too distant future but Preston PSB is likely to be around for a good number of years yet. In contrast the manual boxes visited are all due to close on 11 Nov this year. Thanks to Barnaby Clark for organising the visit, Christian Wyatt of NR for hosting it and all the signallers for being so welcoming despite the forthcoming abolition of their boxes. A £300 donation was made to NR's chosen charity, Barnardo's, in recognition of the facilities provided. Thanks to Melvin Teale, Ian Smith, Nick Jones and Andrew Gardiner for assistance with this report. Historical signal box data is from Peter Kay's Signalling Atlas and Signal Box Directory. A recent article about the line:

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