FROM THE FILES: End of an era for East Anglian semaphores

• This feature was published in RAIL 858 (published August 1-August 14), and available now on Android, iPad and Kindle.

Re-signalling of the routes between Norwich and Lowestoft and Yarmouth is scheduled for completion during March 2019. Transfer of control to Colchester Area Signalling Centre will mark the end of a great deal of ‘heritage’ signalling on the so-called Wherry Lines.

The changeover will affect 12 signal boxes. Only the swing bridge signal boxes at Reedham, Somerleyton and Oulton Broad will remain operational after the modernisation. The signal boxes at Brundall (Grade II-listed), Cantley, Reedham Junction, Oulton Broad North, Lowestoft, Acle and Yarmouth and the gate boxes at Chapel Road, Lingwood and Strumpshaw level crossings will all close. All the manned gates and the locally controlled lifting barriers at Oulton Broad North will be converted for remote control from Colchester ASC by means of CCTV.

The Wherry Lines are a paradise for lovers of mechanical signalling. Four out of five signals are semaphores, and there are 15 ‘fishtail’ Distant signals. Only Somerleyton and Yarmouth signal boxes don’t control any. In contrast, Brundall, Cantley, Oulton Broad North and Reedham Junction each control two. Due to the short distance between Reedham Junction and Reedham Swing Bridge signal boxes, the latter’s Down Distant signal is located on the same post as Reedham Junction signal box’s section signal. A similar arrangement exists for Oulton Broad North signal box’s Up (towards Norwich) Distant signal, which is mounted below Lowestoft signal box’s Up section signal.

Of particular interest are the Distant signals at Lingwood. They give warning for Chapel Road and Station Road level crossings, situated on either side of Lingwood station. Ever since the protecting stop signals were removed in 1962, the targets and red lamps on the gates act as the stop signals. For Up trains, there is only one Distant signal. This signal will not ‘clear’ until the crossing keeper at Lingwood Station reverses lever 1 and the Chapel Road keeper reverses lever 4.

For trains going towards Yarmouth, there are two Distant signals as a consequence of the close spacing of the Chapel Road and Lingwood Station level crossings; both protecting Distant signals are situated on the Brundall side of Chapel Road level crossing. Chapel Road Distant Signal No. 1 is the first encountered. However, the next Distant signal acts as Chapel Road’s Distant and Lingwood Station’s No. 3. Once again, both gatekeepers need to reverse their respective levers before the signal will clear.

They’re not quite an ‘endangered species’ but semaphore bracket signals are becoming rarer. On the Wherry Lines there are ten. At Lowestoft, the starting signals on island platforms 3 and 4 are mounted on a balanced bracket. Both arms are the same height. In the yard, a bracket with small arms is used to supervise sidings 1 and 2. In contrast, the bracket signals at Brundall, Reedham Junction and Oulton Broad North are ‘stepped’ and control diverging junctions. In each case, the slower speed route diverges to the left and the appropriate signal arm is the lower of the two. The higher arm always applies to the higher speed route.

For various reasons, some bracket signals feature only one arm. At Oulton Broad North, the bracket at the Norwich end of the station seems to be bracketed out to help with sighting. One piece of very recent history involves the bracket signal at the end of Yarmouth’s Platform 2. Before the removal of the track associated with Platform 1 in October, this signal had two arms, like the platform starting signals at Lowestoft.

Cantley’s Down Home Co-acting No. 21 signal is most interesting. Two arms are mounted one above the other on the same post. The higher arm simply repeats the lower. Such arrangements were once commonplace, and frequently installed when signals were obscured. Today, for health and safety reasons, tall signals are being eliminated. The main signal arm is placed at driver’s eye level and, if necessary, a banner repeater is used to give notice of the obstructed signal. Co-acting semaphores are now very rare. Those at Helsby, Greenloaning and Norton South are probably the only other survivors.

The double-track route between Brundall and Lowestoft is currently divided into six Absolute Block (AB) sections. Brundall signal box dates from when the more direct line to Yarmouth opened in 1883. It retains many original features and was Grade II-listed in 2013. The barge boarding and roof ridge tiles are particularly impressive. Re-modelling of the junction will result in the existing double junction being replaced by a single lead, and renewal of the trailing crossover nearer the junction.

Despite being almost as old as Brundall, Cantley signal box is a relatively modest-looking building void of decorative features. Today, with the sidings to the sugar refinery and the trailing crossover long gone, only ten of the 22 levers remain in use. Beside the gated level crossing, the pedestrian wicket gates are worthy of note.

Reedham boasts two signal boxes. Both date from when the route between Reedham and Somerleyton was doubled in 1904. Reedham Junction signal box is used to supervise the unusual layout east of the station. Re-modelling will result in this trackwork being greatly simplified. The junction will be moved 300 metres towards Lowestoft, eliminating the three parallel tracks. Three sets of crossovers and the siding behind the signal box will also be removed.

Reedham and Somerleyton Swing Bridge signal boxes will be retained to operate the swing bridges. Both date from when the bridges were replaced following the re-alignment and doubling of the track in 1904. After re-signalling, the swing bridges signal boxes will need a release from Colchester ASC before the opening sequence can be started. Likewise, after operating the swing bridge, Colchester ASC can’t clear any signals protecting the swing bridges until the interlocking proves the bridge is back in place. For example, the Reedham Swing Bridge signaller must be able to reverse lever 6 before Colchester ASC’s YL8353 signal will clear.

The signal box at Oulton Broad North dates from the doubling of the line onwards into Lowestoft in 1901. Alongside the box is a busy level crossing, on which the gates were replaced by lifting barriers in 1974. The signal box has also controlled the junction with the East Suffolk line ever since Oulton Broad Junction box was decommissioned in 1929.

In 1985, when RETB (Radio Electronic Token Block) was introduced on the East Suffolk Line, control was centred on Saxmundham signal box but Oulton Broad North signal box continued to control the junction and, in addition, became responsible for releasing Oulton Swing Bridge signal box. The station at Oulton Broad South marked the start of RETB working and a sign read ‘Stop and Obtain Radio Token and Permission to Proceed’. However, this was replaced by a two-aspect colour light signal when Track Circuit Block (TCB) working replaced RETB in 2012.

At Lowestoft, the existing three platforms are being retained. The former Platform 1 was taken out of use shortly after the service to Yarmouth was discontinued in 1970. However, the sidings will be rationalized. The signal box dates from when the terminus was enlarged in 1885.

Whereas Lowestoft is controlled exclusively by semaphores, Yarmouth has several colour light signals. These date from when Breydon Junction signal box was abolished. More recently, in October, rationalisation resulted in the loss of Platform 1. However, the station ground frame, allowing locomotives to run-round between platforms 2 and 3, is being retained.

Acle station has the only passing loop on the line between Brundall and Yarmouth. It features a small platform-mounted ex-Great Eastern signal box dating from when the more direct line opened in 1883. Following the closure of the former Midland & Great Northern line via Spalding, the passing loops were extended in 1960 to cater for the diverted Summer Saturday trains. At the same time, TCB working was introduced between Brundall and Breydon Junction. This was extended to Yarmouth after Breydon Junction signal box was abolished in 1977.

Safe working of the single track is achieved by using track circuits at the beginning and end of the single line and direction levers. For example, before the Yarmouth signaller can set up a route towards Acle, the Acle signaller must accept the train by reversing Direction Lever 11 (Red/Brown). This allows the Yarmouth signaller to clear the signals for the departure. Once the train has occupied the single line, the direction lever cannot be returned to the normal position until the track circuits prove the train has vacated it.

The line from Reedham Junction to Yarmouth is single throughout and worked by Tokenless Block. As the name suggests, the time-consuming delivery and collection of tokens is eliminated. Tokenless Block is found in several locations and has regional variations.

Consider a train leaving Yarmouth for Norwich. If the train is scheduled, the Reedham Junction signaller will anticipate this and set the Tokenless Block Instrument to ‘Accept’. Then, when the Yarmouth signaller presses the ‘Offer’ button, the instruments in both signal boxes will change to ‘Train Accepted’. The Yarmouth signaller can now clear the signals. Once the train departs, the instruments will display ‘Train in Section’. When the train leaves the single line at Reedham, the signaller will check the train is ‘complete’. The ‘Train Arrived’ button can then be pressed, and the block indicators will return to ‘Normal’.

At this stage, it is worth looking at the unusual method of working before 1967 on the single line between Reedham Junction and Breydon Junction. Unusually, there wasn’t a passing loop but there was an intermediate signal box at Berney Arms. Most of the time, this box wasn’t manned. Switching out was achieved by reversing the ‘king’ lever. This allowed tablet working to operate between Reedham Junction and Breydon Junction signal boxes. As is usual, a tablet couldn’t be withdrawn by the Reedham signalman until the Breydon signalman accepted the ‘Is Line Clear’ request. Then, after the train had passed through the section, a second train wouldn’t be able to enter the line until the tablet was returned to the tablet machine at Breydon.

However, when Berney Arms signal box was ‘switched in’, it was possible to remove more than one tablet from, say, Reedham Junction’s token machine but it wasn’t possible for the Breydon Junction signalman to remove any until the same number of tokens were returned to the token machine at Breydon Junction.  This was quite safe. It was not possible to signal a train in the opposite direction and the block instruments in Berney Arms signal box kept the trains apart. The system worked very well on Summer Saturdays, when the movement of trains was ‘tidal’; outgoing in the morning and incoming in the afternoon!

Looking at changes over recent years, the Norwich re-signalling was completed in March 1987 when control was transferred to Colchester panel signal box (PSB). However, the impressive array of semaphores was somewhat diminished by the time Norwich Thorpe Junction and Norwich Thorpe Passenger Yard signal boxes closed the previous year. While the transition was taking place, two interim signal boxes were commissioned and later abolished.

Following the Norwich re-signalling, Whitlingham Junction signal box became a fringe box to Colchester PSB. In 2000 it was abolished and Brundall became the new fringe. This was associated with the Railtrack re-signalling of the Cromer and Sheringham lines, and the signal boxes at Wroxham, North Walsham and Cromer were also abolished. At the same time, Absolute Block between Whitlingham Junction and Brundall Junction was replaced by TCB. Towards Cromer, the AB double-track section to Wroxham, and the token-worked single line to Cromer was also replaced by TCB. On the branch to Sheringham, One Train Working with train staff was replaced with a system that didn’t require train staff.

Operation of the re-signalled lines was transferred to a new visual display unit workstation in Trowse Swing Bridge signal box. Before this, Trowse Bridge signal box was primarily concerned with the swing bridge. In addition, there is an emergency ‘eNtrance-eXit’ (N-X) panel covering Norwich station, which replicates Colchester ASC. If required, the Colchester ASC signaller can continue to control the signalling by instructing the Trowse signaller over the telephone.

When re-signalling of the so-called Wherry Lines is commissioned, the signalling will be the responsibility of two new workstations in Colchester ASC. In common with many signal boxes, it has an interesting history. Commissioned in 1983 as Colchester PSB, it metamorphosed into Colchester ASC in 2009. However, it was preceded by a PSB which opened in 1962 in connection with the Great Eastern electrification between Chelmsford to Clacton and Walton-on-the-Naze. By today’s standards, the original PSB was very small and simply amalgamated the roles of two signal boxes. Colchester station signal box was a flat-roofed timber structure, situated at the London end of the station opposite the ex-GER structure it replaced in 1960 - a temporary arrangement needed to facilitate re-modelling around the station. The second casualty, the ex-GER Colchester Junction signal box, controlled the junction between the GE main line and the Clacton routes. Stanway signal box was also abolished but replaced with automatic and semi-automatic signals.

At the same time, Colchester was transformed. The permitted line speed on the main routes was increased from 40 to 90mph. Extra capacity was provided by new platforms. For eastbound trains, a single-sided platform was converted to an island. London-bound services were catered for by creating a long platform, divided into two by offsetting the eastern end to serve as a loop. The dive-under enabling Clacton line trains to pass beneath the GE main line also dates from this time.

The first PSB had a short life. As part of the East Anglia electrification, it was replaced by the existing PSB in 1983. Then, over a four-year period, the PSB replaced 27 signal boxes on the main line towards Norwich and Harwich. Stowmarket signal box was retained and re-classified as a gate box. Now 136 years old, this signal box is used to supervise the adjacent manually controlled barriers by sight, and those at Claydon, Regent Street and Elmswell remotely, by means of CCTV.

As was usual at the time, BR installed an N-X panel. To set up a route, the button associated with the signal at the beginning is pressed, followed by the button adjacent to the signal at the end. If the route is clear and the interlocking doesn’t detect any conflicting movements, the points are set in the correct position and locked. The appropriate signals are then cleared and the route illuminated. White lights are replaced with red ones when the train eventually occupies the section.

Colchester PSB was extended and subsequently renamed Colchester ASC when further re-signalling resulted in the commissioning of three VDU workstations. On the GE main line, the Colchester workstation replaced the London end of the original N-X panel as far as Manningtree. The plan to replace the remainder of the N-X panel with workstations has yet to be implemented.

Also, in 2009, the East Gate workstation replaced East Gate signal box and two sets of manned gates. It controls Colchester Town and the main line as far as Alresford. Later the same year, the Thorpe-le-Soken workstation was commissioned. Thorpe-le-Soken signal box was decommissioned and four manned and gated level crossings converted to remote control by means of CCTV. This workstation presently controls the line beyond Alresford to Walton-on-the-Naze. Due to an overspend, re-signalling stopped short of Clacton. Go and see the classic 1960s ‘searchlight’ signals and the 127-year-old ex-GER signal box at Clacton while you still can. There is still one full-size semaphore signal ‘under the wires’! Re-signalling is provisionally set for December 2019.

Early in the planning stages, it was thought that a workstation for the Ely-Norwich modular re-signalling might be placed in Colchester ASC. In the event, it was installed in Cambridge PSB. Almost certainly, the next workstation to be commissioned in Colchester ASC will control the Lowestoft and Yarmouth Lines.

However, the N-X panel has been reduced in size and several important changes have been made. Following the closure of Westerfield Junction, Derby Road, Trimley and Felixstowe Beach signal boxes in 1999, the N-X panel was extended. More recently, in 2014, the Bacon Factory Curve was added. The double-track connection between Boss Hall Junction and Europa Junction allows freight traffic from Felixstowe to continue northward without reversing. Next year, as part of the Felixstowe branch capacity enhancements, NR is planning to open a new loop at Trimley. The new signals will be controlled from the N-X panel.

On the Cambridge/Ely line via Chippenham Junction, Colchester ASC has fringed with Bury St Edmunds yard signal box ever since it opened. On the line to Ely, Wymondham signal box was replaced by Cambridge PSB when the first modular signalling scheme was introduced in 2012. Towards the Norfolk coast, the original fringe signal box at Whitlingham Junction was replaced by Trowse Swing Bridge signal box in 2000.

East of Ipswich, after Westerfield Junction signal box was abolished, control of the Felixstowe line was taken over by Colchester PSB. At the same time, a fringe box was established with Saxmundham signal box on the East Suffolk line. On the Harwich branch, the original fringe at Parkeston remains to this day. The present signal box replaced an LNER structure in 1987.

Following the commissioning of the two workstations in Colchester ASC, on the line towards Colchester Town, Walton-on-the-Naze and Clacton, the fringe signal box at East Gate Junction was replaced by Clacton. On the Great Eastern main line towards London, the original fringe at Marks Tey was superseded by Liverpool Street Integrated Electronic Control Centre (IECC) in 1997