An Introduction to L&BR Signalling
|Introduction||Original Signalling||Signal Boxes||Ground Frames||Signal Diagrams||Economic FPLs||Detectors||Later Changes|
This page provides a general introduction to the Signalling of the former Lynton and Barnstaple Railway (L&BR). Other pages in RailWest cover specific L&BR signalling topics in more detail - click here for an L&BR Index.
By the time that the L&BR was opened in 1898 railway photography was becoming quite common, so there is a reasonable photographic coverage of the early signalling installations before any significant changes were made. However the signalling was not usually the main focus of any photographer's attention, so much of it appears in pictures only by chance and views of signal-box interiors and equipment are almost non-existent. A small number of official paper records have come to light, but not in sufficient quantity to give more than a brief glimpse into this complex subject. Consequently there remain many gaps in the author's knowledge of L&BR signalling, but it is hoped that the various pages in RailWest will provide a useful reference on the subject.
The L&BR was opened at a relatively late date in terms of railway construction in Great Britain. The whole line was opened at the same time and it was never extended nor subject to major alterations. Consequently it was signalled throughout at the beginning by a single contractor, which meant that the signalling installations all conformed to a consistent style. Unlike some other railways, the L&BR did not have various signalling installations added intermittently over the years by different contractors to different styles. The firm of Evans O'Donnell (EoD) of Chippenham were chosen as the signalling contractor for the L&BR and so all the signalling equipment originally used reflected the practice of that company. After the takeover of the line by the Southern Railway (SR) in 1923 some different equipment did appear as a result of alterations and general maintenance. More information can be found in the separate RailWest page on L&BR Signals.
Evans O'Donnell erected signals and signal-boxes at the two terminal stations at Barnstaple and Lynton, at the intermediate passing-loops at Chelfham, Bratton Fleming, Blackmoor and Woody Bay stations, and also at the level-crossing and passing-loop adjacent to the L&BR's works at Pilton. There was a fairly standard provision of signals across all the installations and further details are given in other RailWest pages about the actual signals and the intermediate station passing-loops. One feature of all the installations was the use of 'economic' Facing Point Locks. The line was regarded as 'Up' to Barnstaple and 'Down' to Lynton and it was divided into six different single-line sections, for which the operating arrangements are described in more detail in a separate page about the Electric Train Tablet (ETT) instruments.
There were two public road level-crossings with gates on the line, both of which came under the control of Pilton signal-box. One crossing was across Pilton Causeway immediately next to the signal-box, while the other one was at Braunton Road (a short distance up the line towards Barnstaple Town station), where a crossing-keeper was provided.
At Barnstaple and Pilton there were elevated signal-boxes (SB) of a similar design. There is plan evidence that it had been intended for the SB at Barnstaple to have a timber superstructure on a stone base, but in fact the SB was built as an all-timber construction. In contrast, it appears that the SB at Pilton was constructed originally as a timber superstructure on a tall masonry base, which subsequently was reduced to little more than a low plinth (possibly circa-1918). Both SBs were equipped with a 9-lever EoD interlocking frame, mounted at the front of the box. At both locations the single-line ETT instruments were housed in the SBs, which probably were manned throughout the day by their duty signalmen.
At the other stations only small platform-level wooden huts of identical design were provided and the photograph shows the former Woody Bay SB (after restoration in 1999); this SB was recorded in the 1935 Sale Catalogue as measuring 6’x5’x7’. (Note the concrete plinth which had been added at some date as a result of timber rot.) In each hut the entrance was a double-door in the front wall, with a 7-lever EoD interlocking frame mounted ‘back-to-track’ against the rear wall. At these stations the single-line ETT instruments were kept in the booking-office; apart from the small size of the 'hut' SBs, this arrangement probably reflected the fact that these SBs were not manned permanently, but merely visited as required by the stationmaster or porter who also acted as signalman.
As well as the SBs and their lever-frames, a small number of uncovered ground-frames (GF) existed on the railway. One GF was located at the Lynton end of Pilton yard and worked the points for the exit from the yard at that end; this GF was unlocked by the tablet for the section to Chelfham. At Blackmoor a new Down Siding was installed shortly after the line was opened and this was worked by an adjacent GF, which may have been unlocked by a key from the main SB lever-frame, but records are conflicting and it appears to have been released by tablet in later years. Each of these GFs contained just a single lever. Between the two level-crossings at Pilton there was a siding to serve a wharf on the River Yeo and in later years (when the siding points faced toward Barnstaple Town) this was also worked by a local GF; however it is unclear whether originally (when the points faced towards Pilton) the siding had its own GF or was worked directly from Pilton signal-box.
In Southern Railway days at least there would have been a signal diagram hung in each SB, showing the layout and numbering of the signals and points worked from its lever-frame. (Although equivalent diagrams may have existed for the GFs as a record for the signal engineer, it would seem unlikely that any copies were displayed at the actual GFs given the simplicity of those installations.) Only one known SR signal diagram copy exists (No 447 for Chelfham), which appears to have been drawn new by the SR in 1923 in a style derived from earlier London & South Western Railway (L&SWR) practice. The author is not aware of any evidence that signal diagrams were displayed in early L&BR days, although it would seem a likely practice, in which case they may have been supplied by Evans O'Donnell as part of their 1898 installation.
The SR allocated a 'roller number' to each SB or GF (so called because the master diagrams were kept on rollers in the drawing office) and the known numbers for L&BR diagrams were as follows:-
The apparently random allocation of numbers was due simply to the fact that the SR allocated some 'spare' numbers from an existing list. (Some of the numbers had been used elsewhere previously and most of them were used again elsewhere after closure of the L&BR.) It will be noted that, although a number was allocated for the GF at Barnstaple Quay, no number is listed for the GF at the Lynton end of Pilton Yard. This may be simply a gap in the surviving records, or an oversight, or perhaps that GF was recorded under the same number as Pilton SB.
The use of 'economic' Facing Point Locks was a feature of the original signalling on the L&BR which merits further comment. It is a requirement of signalling installations for any points over which passenger trains pass in a facing direction to be properly secured to prevent accidental movement under the train. For convenience and ease of operation this is achieved usually by means of a device called a 'Facing Point Lock' (FPL), which usually takes the form of a large bolt located between the rails which engages with a notch in a stretcher bar between the point blades to prevent them moving. Normally a FPL would be operated from the controlling signal-box by a separate lever and rodding from that which worked the points themselves, but as that adds to the cost of a signalling installation some railways (including the L&BR) saved money by using 'economic' FPLs. The basis of an economic FPL was that it was worked by the same lever and rodding as that which worked the associated points, thereby saving money (hence the term 'economic') by avoiding the need for the second lever and additional rodding.
There were a number of different designs of economic FPL used on various UK railways, but in most cases they employed some form of cam mechanism to enable a single movement of the rodding from the signal-box lever to withdraw the bolt, move the points, then re-insert the bolt. Unfortunately it is not known whose pattern of economic FPL was used by the L&BR, because the few available photographs show a design unlike any others known to the author or described elsewhere. Although Evans O'Donnell were the signalling contractors, it would have been quite possible for them to have used under licence some specific item of equipment such an economic FPL which had been patented by another engineer. Because of the narrow gauge used by the L&BR the operating mechanism for their economic FPLs was located outside of the running rails, rather than between them as was normal on standard-gauge lines.
Part of the FPL operating mechanism was the 'lock bar' (sometimes colloquially called a 'fouling bar'), which was a long, narrow bar fixed on hinges to the side of a rail close to the 'toe' of a point. When the FPL lever (or combined FPL+point lever for economic FPLs) was pulled or replaced, then the lock bar was lifted up and then lowered again as the point was locked or unlocked. If a locomotive or item of rolling-stock was stood at the point then its wheels would obstruct the movement of the lock bar, thereby preventing the operation of the FPL. Early FPL installations tended to have the lock bar on the outside face of the rail, where it interacted with the tread of any wheel, but in later years it became the custom to locate locking bars on the inside face of the rail to interact with the wheel flange. Photographic evidence suggests that initially the L&BR's lock bars were on the inside of the rail, but at some later date they were moved to the outside. By the time that the railway closed at least some may have been re-located back to the inside face again.
If there was a facing point in advance of a signal, then the operating wire from the signal-box to that signal would pass through a 'detector' adjacent to that point. The purpose of the detector was to ensure that, when the signal was pulled to the 'off' position, the point was indeed closed fully in the correct position. (Although the lever-frame interlocking prevented the signal lever from being reversed unless the point lever was in the correct position, that was no guarantee that the point itself was properly in the corresponding position.) The detector contained a metal slide, positioned parallel to the track; one end was connected to the wire from the lever, the other end to the wire onward to the signal. At right-angles to that slide would be one or more slides connected to the point's switch blades. Notches were cut in appropriate places in all the slides, such that the signal wire slide was free to move only when the point slides were in the correct position. Usual 'best practice' was to have one slide for the left-hand switch blade of the point, one slide for the right-hand switch blade and one for the FPL. However photographic evidence would suggest that many older installations had only one slide for the two switch blades, especially at points where only one route actually had an associated signal. Furthermore it would appear that points with 'economic' FPLs often did not have a separate FPL slide, probably because it was inherent in the design of the 'economic' mechanism that the FPL had to be in the 'locked' position for the switch blades to be detected as closed.
Most facing points on the L&BR had a signal for one route only, for example a Home signal for the left-hand route at the entrance to a passing-loop, and hence there was only one signal wire slide in the detector. One exception was the point between the main platform and bay platform lines at Lynton, where the Down Home had arms for both routes, so there were two signal slides; clearly only one of those would be free to move at any one time, depending upon the route set at the point. (The other probable exception would have been the point at Pilton leading from the Down Loop into the Yard after the addition of the second arm to the Down Home in 1927.) There are not many good close-up photographs of L&BR detectors, but (apart from the exceptions mentioned with two signal slides) most appear to consist simply of one signal slide and one switch blade slide. Many seem to be covered by some form of 'box' enclosure, although in SR days those at Lynton appeared to have been replaced by an 'open' framework and similar replacements may have occured at other locations. The detector was fixed to a flat rectangular metal plate connected at each end to two of the point's sleepers, with what is believed to have been a rigid adjustable rod connecting the body of the detector to the point's stock rail in order to maintain the correct separation distance necessary for accurate operation of the detector.
During the L&BR's 25 years of independent existence very little of any significance happened on the line that would have required substantial changes to the signalling installations. It was not until a few years into the period of Southern Railway ownership that noticeable changes began to occur:-
© CJL Osment 2003-17
Acknowledgements to the Signalling Record Society for archive information.