S&DJR Signals

Introduction

Information on the earliest forms of signals on the Somerset & Dorset Joint Railway (S&DJR) is virtually non-existent, but it has been suggested that the Somerset Central Railway (SCR) used disc-and-crossbar signals similar to those of the Bristol & Exeter Railway, whilst the Dorset Central Railway (DCR) used disc signals similar to those of the London & South Western Railway. The 1864 S&DJR Rule Book contains illustrations of the former type only and certainly an example existed on the old DCR at Spetisbury until 1901, although it may have been moved there from elsewhere. The familiar semaphore signal probably first arrived on the S&DJR in large numbers with the opening of the Bath Extension in 1874 and the rest of these notes deal with the subsequent period. Some suitable illustrations can be found in "A Pictorial Record of Southern Signals" by GA Pryer (referenced in this page as 'PRSS').

Signal Posts

Three main materials were used: wood, steel lattice and old rails. The Bath Extension probably was equipped throughout originally with wooden posts, which were surmounted by a ball-and-spike type finial. By about 1900 the metal lattice post had come into use and this was identical to the L&SWR pattern, as was the finial (PRSS Fig 15). There were a few examples of lattice posts with ball-and-spike finials (similar to those used on wooden posts), but it is not known if these were original or later replacements. Signal posts constructed from old rails were a common sight on the Southern Railway (SR), but it is not often realised that this method of construction was neither invented by, nor exclusive to, the SR as the S&DJR had erected a considerable number of rail-built posts prior to the 1923 Grouping of the railways of Great Britain.

The S&DJR appear to have been using rail-built posts by about 1900-05, but it has not been possible to establish a precise starting date. It is possible also that this type of construction may have been superseded prior to the Grouping, as at least one S&DJR rail-built post is known to have been replaced by a lattice post prior to 1923. Exactly when the SR started using rail-built posts seems unclear, but their first widespread use appears to have been on the Wimbledon-Sutton line in 1929 (when they were described as "a novel idea"), so the SR pattern may have begun to appear on the S&DJR in the early 1930s.

The method of construction varied between the two Companies. The S&DJR pattern normally consisted of two rails bolted tightly together, so that at a distance they appeared to be a single rail and sometimes are erroneously described as such in photograph captions, even though the heads of the bolts holding together the two rails can be seen. Although the two-rail method provides better strength, it appears that some examples did have only a single rail. The SR type had two rails, held about 9" apart by spacers in an elongated 'H' pattern. S&DJR-pattern posts were erected with the rail web at right-angles to the track, while the SR type had the rail web parallel to the track.

The S&DJR-pattern rail-post signals had a cruciform finial, of which at least two designs are known, and also there were differences in the fixing arrangements. Some surviving finials have a single bracket projecting from the bottom, suggesting that it was located between two rails for bolting through, whilst others have a pair of brackets apparently to go either side of a single rail - these differences may just be discernible in some photographs. The SR pattern had a low, pyramid-shaped finial. The rail-post signals built by the S&DJR had lower-quadrant (LQ) arms, although a few were converted to upper-quadrant (UQ) arms in later years. Apart from one known example with a LQ arm, all the SR rail-built posts on the S&DJR seem to have had UQ arms.

For rail-built bracket signals the S&DJR design appears to have been similar to straight posts, although the dolls may have been only single rails - possible because of their short length or the need to reduce weight on the bracket. In the SR design the main post was often more substantial, with at least four rails, but the individual dolls were always lattice in order to reduce the weight.

A solitary example is known of a concrete post. In 1960 two examples of British Railways (Western Region) tubular steel posts were erected at Midford, and another example was installed at Masbury at an unknown date. In March 1966 a short BR(WR) tubular doll was fitted to an existing bracket signal at Highbridge as part of the alterations to retain the line to Bason Bridge for milk traffic. It is possible that there may have been other BR(WR) installations which have escaped the photographic record.

Signal Arms

Signals arms originally were made from wood in a LQ pattern similar to that used by the L&SWR, but in SR days onwards metal UQ replacements appeared, usually with the distinctive horizontal corrugations which were provided to give greater strength to the sheet metal arm. UQ arms were used mainly on the SR-type rail-built posts and on lattice posts; a few examples were known on the S&DJR-type rail-built posts, and only one on a wooden post. Metal LQ arms of the BR(WR) style were fitted to the few BR(WR) tubular post signals that were installed in the 1960s.

Stop arms were painted red with a vertical stripe on the front, white with a black stripe on the rear. No specific information is available on the early style of distant arms but probably this followed the general British development. Originally identical to stop arms, from 1872 distant arms were distinguished by a V-notch cut in the end and later the white stripe was replaced by a white chevron; the rear appears to have retained a stripe even when the front changed to a chevron.

From about 1925/7 onwards all distant arms would have been re-painted in the new standard of yellow with a black chevron on the front and white with a black chevron on the rear. Spectacle plates originally displayed red and white, but the white was replaced by green by about 1895. On distant signals the red aspect was superseded by yellow at the same that the arms were repainted yellow.

In later years a few examples appeared of main signal arms which had a large ring fixed to their front face. Although this style had been used extensively by the S&DJR for subsidiary arms, the use for main arms was limited and confined to signals controlling movements to or from goods lines. All known S&DJR examples are listed in RailWest in a separate Register of ringed arms.

Subsidiary Signals

S&DJR 'Calling On' and 'Shunt Ahead' signals took the form of a full-size arm painted red with a white spot, surmounted by a black ring, the reverse being painted white with a black spot (PRSS Plate 81). In the SR period a few appear to have been renewed as a LQ arm, painted red with a broad horizontal white band and bearing a large 'C' or 'S' on their face; the reverse was painted white with a broad horizontal black band. In later years some were renewed as smaller UQ arms painted in the same style; some of these bore a large 'S' on their face while others had an indicator attached to the post which, when the arm was 'off', showed an illuminated 'C', 'S' or 'W' to denote their function ("Calling On', 'Shunt Ahead' or 'Warning'). In such cases the main arm was renewed also as an UQ arm. All known examples are listed in RailWest in a separate Register of ringed arms.

Wrong-Road Signals

For 'wrong direction' movements over running lines a particular 'wrong-road' signal was used which had a full-size arm in the shape of an elongated 'X', often referred to as a "bow-tie" arm. This pattern was peculiar to installations by the signalling contractors Stevens and was not unique to the S&DJR, but sadly it is often described incorrectly as such in many books. Although the 'wrong road' signal is perhaps the most well-known aspect of S&DJR signalling, only five examples are known to have existed on the line (PRSS Plate 83). More details can be found in a separate RailWest page.

Ground Signals

These were originally of the Stevens 'flap' type (PRSS Plate 79). In due course the S&DJR started to use the 'miniature semaphore' type and there is a reference to this pattern being used as early as 1910. From SR days onwards many ground signals were replaced by the standard SR Westinghouse 'half-disc' pattern (PRSS Fig 20), but there were also a few examples of the 'miniature semaphore' type used specifically where 'yellow' arms were required (PRSS Plate 87). In BR days two of the ground signals at Midsomer Norton were replaced by examples of the BR(WR) pattern ground signal (with full disc), and a further example was fitted onto an existing bracket signal at Highbridge during layout alterations in 1965. It is possible that there may have been other BR(WR) installations which have escaped the photographic record.


Stevens 'Flap'		Miniature Semaphore		Westinghouse Half-Disc

Motor-worked Signals

With very few exceptions, all the signals on the S&DJR were worked mechanically in the traditional manner, by means of wire runs from a mechanical lever-frame in the controlling signal-box or ground-frame. One exception existed at Templecombe No 2 Junction signal-box, which gained a motor-worked Down Distant in 1933 after it took over the work of the closed Templecombe No 3 Junction signal-box. Another exception arrived in 1958, when alterations at the neighbouring Lamyatt and Bruton Road ground-frames (two level-crossings between Evercreech Junction and Cole) provided a motor-worked Up Distant that was controlled by both ground-frames.

There was also two examples of electrically-worked 'banner repeaters' on the S&DJR in later years. One example was at Evercreech Junction, just north of bridge 107, and was installed at some unknown date between 1930 and 1949 to repeat the North signal-box's Down Main Outer Home signal. The other example was on the goods line between the 'B' and 'C' signal-boxes at Highbridge in BR days, but again the exact date of installation is not known.