LMS Route: Rugby to Wolverhampton

Kilsby Tunnel: lnwrkt3560

Inside Kilsby tunnel at the bottom of one of the one hundred and sixty feet deep sixty foot diameter ventilation shafts. To the left of the bore is a standard LNWR semaphore distant signal which has been positioned at a level where the crew would have the best possible chance of seeing it.

In response to the above photograph being reproduced in the L&NWR Society's Journal, Richard Foster, Author of 'A Pictorial Record of LNWR Signalling' and three volumes on Birmingham New Street station writes in the letter column in Volume 5 Issue 8, 'A long standing puzzle in my mind has been the distant signal in Kilsby Tunnel which appears on the well-known LNWR postcard from which the December Journal cover picture is presumably a huge blow-up. However, without an obvious explanation I've always put it to one side in the hope that something would turn up to answer the questions, or until I have a bit of free time (some hope!). Anyway, now that the picture is splashed so prominently over the front cover, action has to be taken!'

The main line railways have always disliked placing signals in tunnels, and other than for tunnels approaching main stations, they avoided as far as possible placing stop signals in tunnels, for fairly obvious safety and passenger health (particularly in steam days!) reasons. This is true to this day, and the long signal sections through some long tunnels on busy main lines are becoming capacity constraints. Even distant signals in tunnels were avoided as far as possible. The reasons in steam days are not hard to find; the smoke and steam, often accumulated from earlier trains on busy lines, would obscure the lights, while the forward vision from a steam engine is not good at the best of times, and leaning out for a better view on a train at speed in a tunnel was not generally to be recommended!

The LNW main line was very busy from the earliest times and as is well-known the ‘two-mile’ telegraph was installed between London and Rugby in the 1850s. This gradually transformed itself into the true block system. In practice the inter-signal box distances varied somewhat to fit the locations of stations and other features, but 47 the maximum box-to-box distance south of Rugby was just under 3 miles. Kilsby tunnel was 1 mile 666 yards long, so to maintain the average box-to box distance, something was needed fairly near each end of the tunnel. In the early days, safe traffic working through the tunnel was a problem, and so telegraph posts were established near each end at a very early date, aptly named Kilsby Tunnel South End and Kilsby Tunnel North End (see the L&NWR Society's Journal for June 2005).

New interlocked signal boxes were provided at Kilsby North and South in 1870. North was located immediately north of Bridge 259, which took the old A5 road over the railway just north of the north tunnel mouth. The box was therefore about 250 yards north of the tunnel mouth. It was a simple block post with just a crossover and home and distant signals each way, but this location necessitated the Down distant signal being in the tunnel. The LNW WTT showed North and South boxes as 2 miles 236 yards apart. The south box was therefore about 1100 yards south of the tunnel. With the normal distance between distant and home signals in LNW and LMS days of between about 600 and 900 yards this placed the south Up distant nicely south of the tunnel, although it was located on the wrong side of the line to help drivers see it as they emerged from the tunnel.

The cover photograph therefore shows the Down distant signal for Kilsby Tunnel North Box. This was neatly located in one of the large shafts, which Stephenson had had to make so large to accommodate all the pumping plant needed to dewater the construction workings, as well as to provide access to the tunnel excavation faces. I believe it is the second shaft from the north end.

As can be seen, the signal is a standard LNW semaphore distant, set at about driver’s eye level to maximise the chance of drivers seeing it as they approached through the tunnel. Despite the darkness it was provided with a standard semaphore arm. So to the interesting bit. There are clearly no glasses in the spectacle plate, and although the photo is not too clear, there does not appear to be any sign of balance levers or operating wire (although there appears to be something on the front of the lower part of the signal post). This leads to the conclusion that the signal is fixed at danger, with the signal lamp fitted with a red lens and hence no need for spectacle glasses. This could be plausible as there were quite a few fixed distants around, but this was the premier main line, and everywhere else the signalling was laid out to maximise opportunity to give drivers clear signals throughout and hence for the expresses to travel as fast as possible. But this does not seem to be the case here. If the evidence is correct, drivers would always get the danger signal and have to bring their train under control and down to a speed that would enable them to stop at Kilsby North Home signal, which was only about 250 yards beyond the tunnel mouth and would only come into view as the train emerged from the tunnel. Not an arrangement that one would expect.

The only alternative explanation I can come up with is that there was a working distant signal further on in the tunnel, and this was simply an advance marker to warn drivers to look out for the real one. But one might have thought that a big shaft was the best place for the signal itself. Unfortunately I have not so far found any details of the signalling at Kilsby North at this period, which could have helped. Is anybody able to shed any light on the matter?

In any event, the LNWR eventually decided that it did not like the distant in the tunnel and resolved to do something about it. In October 1914 a new Kilsby Tunnel North signal box was built, located about 600 yards north of the old one, specifically to allow the new Down distant signal to be clear of the tunnel. It was still very close, being located between the tunnel mouth and the A5 road bridge. Interestingly, this signal was provided with co-acting arms, although one might have thought the high top arm would have only been visible once a train emerged from the tunnel. As a result of this the box was inconveniently located a long way from the nearest road bridge. Moving it further north to place it near the next road bridge would have made the tunnel block section too long for efficient traffic working.

Although quite a few references to the main line comment that most freight traffic went via Northampton, this was not entirely true, and a fair amount of freight went via the main line, as evidenced by the provision of long loops at Heyford and between Gayton and Blisworth, to break the otherwise double track section between Roade and Rugby, and minimise the ‘run down’ problems with faster following trains. A Down refuge siding had been provided at Kilsby Tunnel South by 1885, although the box was noted as ‘temporarily closed’ in the July 1896 WTT. The Down refuge was supplemented by construction of a new Up loop and associated new signal box in 1912. This was followed by conversion of the Down refuge siding into a Down loop the following year.

The picture, incidentally, was used in LNWR Postcard Set No 16 ‘Tunnels’, issued in January 1905. Any information or thoughts on the Kilsby Tunnel North Down distant would be most welcome.

Richard D Foster

Stephen Weston writes in the letter column in Volume 6, No 3, December 2009, 'Further to Richard Foster's subsequent letter, I have come across the following, lain Mackenzie, in his youth, travelled around the Rugby district visiting signal boxes. One of these was Kilsby Tunnel North. Subsequently he researched this location and in his book 'Great Central Signalman' (compiled by PJ Wortley) he states an early L&BR signal cabin, 'North End of Kilsby Tunnel Signal Box', was located on the Up side within a stones throw of the tunnel mouth and close by the A5 bridge. A L&BR estates plan shows the box with it’s associated signals; the Down distant was situated within the nearer of the two 60ft diameter ventilation shafts, the Down Home signal 120 feet from the tunnel portal. A crossover was provided. This box was replaced bv a similar cabin on the Down side half a mile closer to Rugby at some unknown date. He suggests that the original down Home provided the mast for the new Down distant signal. Perhaps the slow speeds of the day allowed a good sighting of the shaft signal?'

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