Midland Signalboxes

by "5-pause-5-pause-5"

I found this article completely by accident in the June 1958 edition of “Trains Illustrated”. It contains a wealth of detail concerning Midland Railway signalling practices and is written by someone who was there. The author clearly attains his expressed wish of “recreating the atmosphere of the Midland signalbox of the 1920s and 1930s”. I suspect that this article is still the copyright of someone. I apologise for the breach. However, I believe that the historical significance of the text justifies the liberty - in any event it isn't as though back issues of Trains Illustrated are readily available!

Swinderby Signal Box viewed from the front three-quarters, looking across the railway with the level crossing gates to the right

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The old Midland Railway in my opinion was a railway of distinction. That distinction was nowhere more apparent than in its signalboxes. Everything about them seemed to have its own individuality, sometimes merely difference from other lines, more often difference allied to improvement.

Take first the outside appearance. Midland signalboxes were pleasingly designed, and were always of made of wood, with the lower half up to floor level finished in horizontal overlapping boarding. Round the front and side there ran a gallery for window cleaning, above which there was a short length of vertical boarding to the foot of the windows in front and up to the eaves at the back of the box. The windows were large, divided into three vertical divisions, and with the top corners chamfered. The slated roof had ends with a slope at the same angle as the front and rear parts, and each end of the roof ridge was enriched by a finial of the same pattern as those on Midland signal posts. Through the roof projected a plain stovepipe. The exterior woodwork was painted a distinctive banana yellow, with the window frames white. The name of the box was displayed on the front below the gallery on a wooden board with iron letters, or sometimes on a blue enamelled sign, near which was a large lamp (oil or gas) fixed to illuminate the large numerals on the tended sides of passing engines, and usually referred to as the "number snatcher". Broad wooden steps, with cast iron treads marked "Midland Railway", led up to the box.

The Midland did not go in for the tall signalboxes so often found on other lines and as a rule the floor of the cabin was no more than 6 to 10 ft. from rail level. Only occasional was a higher box erected, and in a confined location some were constructed with a narrow bottom part broadening out at floor level.

A general feature which would immediately strike visitors from another company was the smallness of the average Midland box, judged by the number of levers in the frame. For this there were several contributory reasons. The Midland made relatively little use of shunting signals or ground discs, and did without them at locations where other companies normally provided them – as, for example, to govern setting back movements into a platform. London Road Junction, Derby, for instance, had no shunting signals for a set-back from the south, although this was a very common movement; there were, however, signals for a set-back from the west, and I had been told that these were only provided after an accident when a man going over the sleeper crossing there at night had with him a bicycle, whose green sidelight was mistaken for a shunter’s hand signal. Another reason for the small frames was that the Midland, contrary to general British signalling practice, worked facing points by the same lever as the facing point lock and locking bar. In some cases, too, there were several point ends on one lever; one example on a complicated lay-out I remember was a lever with three point ends and two bars on it. In any case, Midland lay-outs tended to be smaller than those on other railways, and on the whole of the Midland (not including ex-L.T.S. boxes) there were probably no more than two or three boxes with more than 100 levers. Perhaps some former Midland man can confirm that this was actually so.

Inside a Midland box, the most distinctive feature was the lever frame itself. Instead of the bare levers coming up through slots in the floor, as one usually expects to see on other lines. Midland levers had their lower end enclosed in a cover about two feet high running the length of the frame; the lever pivots were at about floor level, and in consequence the angle of movement was greater than for the usual type with pivot below the floor. This arrangement resulted in levers which seem to stick back into the box a long way when they were pulled over, but they were easy to work, as one’s foot could be placed on the cover to help with the pull, and they seemed more ready to hand when one wanted to put them back. Another advantage of the cover was that it kept out the nasty draught which in other types of frame came up through the spaces where the levers worked.

Midland locking was fixed above floor level inside the casing, on the side away from the signalman, and the top of this part of the casing carried a series of engraved brass plates with the lever descriptions. (In very old frames this information was sometimes set out on a plate on the side of the lever itself). A small brass plate on the front of the lever gave its number and the number of the levers which had to be pulled first to free it.

Midland lever frames had catch-handle locking; if the lever was locked, the catch could not be moved. This locking prevented the chance of a nasty jar to the spine if one tried a hefty pull on a locked lever, but when a lever was pulled the catch had to be well down to release the locking, and it was annoying to have to bump the lever catches after finding that the locking was not released somewhere. This frame was later developed into the standard L.M.S. type, in which larger numbers of levers were used. Some of them must have been hard on the hands, as with catch-handle locking the first grip on the catch has to drive all the locks.

The levers were as usual painted in distinctive colours – green for distant signals (altered to yellow when the distant signal lights were altered in the late 1920s), red for stop signals and ground discs, black for points and white for spares. Somehow one always missed the blue for locking bars. The lever tops had a comfortable grip and were polished; the more faddy men used a cloth when pulling them, but this was not the fetish it was often made out to be by railway writers. Almost all Midland boxes had the levers at the front of the box and it was most unusual for the lever frame to be at the back (I can only remember about five or six instances of the latter arrangement). After the 1923 Grouping the number with frames at the back increased rapidly, and now this layout is standard practice for new work.

If the box was visited by night, the most noticeable thing inside it was the darkness (if you see what I mean). The outside lamp mentioned earlier was used to light the engine numbers, which were recorded for every train, and signalmen developed expertise in remembering the numbers of two double-headed trains simultaneously. These outsize tender numerals were, of course, provided as part of the Train Control system, in which the Midland was one of the pioneers in this country. To help this number recording the box was kept as dark as possible, with just a feeble oil lamp shaded to shine on the train register book. A signalman would sometimes have to take a hand lamp with him to find the right levers at the far end of the frame.

The box floor was covered with a brown linoleum, a great advance on the bare boards of other companies. Newspapers laid down after scrubbing were supposed to keep it clean while it dried and tactful visitors walked on them.

At the back of the box were the train register desk, clock, telephones, telegraph instruments, stove, lockers, and so on. To suit the wooden construction the stove was away from the wall; larger boxes had two stoves, but only one was normally lit at a time. Most of the clocks were of the usual English Dial type with round face and small square case behind, but some were (and still are) delightful specimens of the clockmaker’s art – long case clocks with massive square lead weight, long pendulum, and stately tick.

The block shelf above the levers was typically Midland – dignified and expansive, with a long row of polished brass description plates for bells, block instruments, and other equipment. The bells were of the familiar type with mechanism case below and bell dome on top, supported by a central stalk, like a brass mushroom. Midland bells had a distinctive tone, and one popular standard size had a particularly purposeful and resonant ring, which usually had to be quietened down by wedging a piece of wood between the bell dome and wooden mechanism box. The tapper keys had large knobs to suit the finger and prevent accidental touching of the metal part when ringing (this is only too easy on some companies’ bells, the resultant shock being an impressive demonstration of an induction coil effect). For goods lines the bells usually had taller domes and oval plan form, which gave a peculiar and fascinating tone to the ring, reminiscent of a Norwegian cowbell.

The Midland made extensive use of box-to-box telephones fixed on the block shelf, using the same wire as for the bell; the call signal was two beats on the bell without first calling attention, a signal which has still been kept in the L.M.S. block regulations. These telephones ante-dated the circuit phones, and were provided at a time when normal box-to-box communication was often by telegraph; they are still the usual way of talking to neighbours. The block bell signals and block regulations used by the Midland were based on the standard R.C.H. Rules, without the elaborations found on some other lines. All bell signals were repeated in full, a kind of longhand intended to avoid mistakes.

The block instruments were of the usual modified single needle telegraph instrument type. The top part of the case had a "needle" or pointer in front of a dial with coloured segments. The operating handle worked a commutator inside the lower part of the case, and there was a catch on the accepting instrument for "pegging up", i.e. holding the needle at "line clear" (needle top deflected to right), or to "train on line" (needle top deflected to left).

Where the Midland differed from almost all other lines was in the use of dial signals for routing of trains. For this purpose the block instruments at the offering end were provided with a handle, but without a catch, and battery power to suit. Dial signals, where used, originated at a box to which drivers whistled to indicate their routes. One example, was Bingley Station box, up line, where drivers whistled three for Bradford, but kept silent for Leeds. When the Bingley signalman gave "Train entering Section" to the next box, Hirstwood, he also gave two ticks towards "Train on Line" on the needle for a Leeds train, or three ticks for a Bradford train. Hirstwood replied by repeating the ticks, Bingley gave one tick to the right to acknowledge correctness, and Hirstwood then pegged "Train on Line". (In the rare case of an incorrect acknowledgement of a dial signal, the sender gave one tick to the left; these final ticks were part of the telegraph code). When he offered the train on to Saltaire the Hirstwood signalman gave the routing ticks towards "Line Clear". Acknowledgement was again by repetition, with a final tick for correctness, and then Saltaire pegged "Line Clear". The same procedure was carried out at "Train entering section", and so on from box to box till the diverging point was reached. All this, of course, took time, and the elaborate exchanges seemed almost a ritual. After Grouping other methods, such as block bell or circuit telephone, were adopted for indicating direction.

At most places the block instruments were free of any control, and could be worked at any time (as was the case on most of the lines north of the Thames), but to the Midland goes the credit of devising a system of lock and block which was introduced about 1910, and which was based on a development of the usual Midland block instruments. The offering instrument was almost the same as before, but the accepting instrument had a more massive lower part, with a smaller, stubby operating handle, which was worked clockwise in a rotary motion, once completely round for each train – hence the name of "Rotary Block" given to the system. The handle was vertically upright for "Line Blocked", was turned to four o’clock for "Line Clear", and to eight o’clock for "Train on Line". In operation, "Line Clear" released the starting signal of the rear box (one pull), and once given could only be cancelled by the co-operative action of the two signalmen.

Once "Train on Line" had been pegged, the accepting instrument was locked until the train had run over a treadle fixed just past the home signal, which released a lock and allowed the handle to be turned on to "Line Blocked". "Train on Line" could only be cancelled by breaking a glass cover which gave access to a release button. This glass was later replaced by a linesman, and explanations were then called for. There was also an additional tapper on the accepting instrument to enable dial signals to be received. Other lock and block features were provided, outside the scope of this short description; the net result was to produce a workable lock and block system which could be used easily by men used to the normal instruments.

Rotary Block was fairly extensively used; almost all the four-track sections of Absolute Block were so equipped, as, for example, between St. Pancras and St. Albans and between Leeds and Shipley. In addition it was used in special locations, such as the Settle and Appleby section, and at places with outer home signals (then relatively rare). The Midland considered that this system allowed exemption from Rule 55, which explains why many signals can be seen which are provided with white diamond signs but have not track circuit at them; they are home signals at boxes with Rotary Block.

Unfortunately after the Grouping the L.M.S. adopted a standard "C Class" block without all the features of the Rotary, which in some ways appeared a retrograde step. It must be said in fairness, however, that Rotary Block had some weaknesses and was expensive. More recently Rotary features have been incorporated in an up-to-date form in the "Welwyn Block" of the Eastern Region and of British Railways.

It is now unfortunate but necessary to record that when it came to goods lines, the Midland was as behind the times as it was in front with the Rotary Block. Probably no other British railway had more purely goods lines than the Midland, which were sometimes in long virtually continuous lengths, such as Harpenden Junction to Kettering Junction, or Kilby Bridge (Wigston) to Tapton Junction. The method of signalling these lines was a form of permissive working known as "Telegraph Bells", in which signals were sent on a bell only, with no block instrument or other reminder of the state of the section to aid the signalman (except his entries in the block register). Each train was belled on as it came, the signalman cautioning the driver if the section was occupied. To make matters worse, the same bell was frequently used for both passenger and goods lines at a four-track box, the signals being distinguished by calling attention for those referring to the passenger lines, but not for those concerned with the goods lines. Looking back, it seems incredible that so much traffic was worked in this way with so few accidents; it must have been due to the sterling qualities of the men, for Telegraph Bells lasted until quite recently. A bad accident at Oakley in 1949 due to a misunderstanding on a Telegraph Bell section hastened its decease, and the L.M. Region have recently concluded a programme of providing permissive block working on the ex-Midland goods lines.

There were a number of other instruments on the block shelf of a Midland box – track circuit indicators, block switches, light repeaters, and so on. The track circuit indicators were square wooden boxes with a glass-covered green face and a white centre circle for "track clear", and a red circle for "track occupied". This of course, was, in the days before the smaller indicators now in use, or the illuminated diagram. Signal repeaters were fixed at the front of the block shelf, immediately over the lever concerned. Most Midland boxes had single-needle telegraph instruments, especially on branch lines, but on main lines they were being taken out of use at the time of the Grouping, and telegraphy is now almost extinct amongst Midland signalmen.

Various other Midland features are worth notice. Level crossing gates were worked by a wheel rather like a large bacon slicer, with massive screw gear all plainly visible. At boxes controlling short sections there was a good deal of under bolting, or control of a lever by one worked from another box, usually in connection with distant signals. To show the state of the control, brass circular indicators were fixed on the inside ends walls of the box and there turned down to show their edge when the control was unbolted. Here too were the wire adjusters for the signals.

The Midland had its own way of naming signalboxes. No.1, No.2, etc., was seldom used; instead the place name was employed with such additions as North, South, Station, and so on. Sometimes the naming was ambiguous, as for example "North Stafford Junction" for two different boxes, one at Willington and the other at Burton, only 5 miles apart; another example was "London Road Junction" for three boxes, at Derby, Nottingham, and Leicester. There were also tricky variations such as "Codnor Park Station Junction", which was the next box to "Codnor Park Junction". Usually the nearest town or village gave its name to the box, as for example Sandridge, though in a few cases the name adopted was that of the place to which a diverging branch line ran, e.g. "Melbourne Junction".

The Midland did not go in for power signalling. The only place at which it was tried was a small box at Way and Works Siding, Derby; this was equipped with a power frame on the all-electric Siemens system of the type employed on the G.W.R. at Snow Hill, Birmingham. When this frame was removed in the early 1930s a normal mechanical frame was substituted.

Unlike most other companies, the Midland did not have lads in boxes to keep the block register. In the few boxes where they were found they acted as Control reporters. In some boxes no block register was kept at all. Where there were two men, one was in charge, and the other was a junior assistant.

I hope that I have recreated something of the atmosphere of the Midland box and that my memories of the 1920s and 1930s are not too inaccurate. Summarising these recollections, the average Midland box, tough full of character, was a small affair without modern refinements, and with perhaps only 20 or 30 levers. But it and its neighbours kept the Midland going.

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Dave Harris, Willington, Derby, UK.
Email: dave@derby-signalling.org.uk
Page last updated: Monday, 24 August 2015