Trouble with tunnels: the railway investment legacy

In the first of planned series of historically focused articles, Philip Gale explains how the investment choices of the past continue to affect the railway today

The railway that is operating today is the culmination of many investment decisions stretching back to when the South Eastern Railway (SER) first reached Tonbridge in 1842. Decisions made by railway companies in the 19th and early 20th centuries have a continuing impact on the services we use today by determining the infrastructure of the modern railway: whether tunnels have one track or two, or the motive power of the trains themselves, for example. For the first 125 years those decisions were made by commercial companies who had to – like all businesses – pay a dividend to their investors while providing a service to the public.

The Victorians had a strong faith that private enterprise should develop the railway network and that there should be competition between the different companies. In the long run railway companies needed to make sufficient profits to pay a return to shareholders and to invest in the provision of efficient railway services to the public. In Kent the leading competing companies were South Eastern Railway (SER) and the London and Dover and Chatham Railway (LDCR). This led to the construction of duplicating lines reflected by the fact that Canterbury is still served by two stations, Canterbury West (former SER) and Canterbury East (former LDCR). The results for the shareholders and the travelling public were often less satisfactory, particularly for the SER; an article in The Investors Review published in June 1896 described the company as ‘now almost too weak to turn round and adopt a wise policy. It might become bankrupt in the process; so the best thing to do is to leave it severely alone. Just as none travel by it who can find another route, so none should touch its common stocks.’

The SER had been established in 1836, initially to build a route through Tonbridge to Dover via Ashford and later to construct the Tonbridge to Hastings line which was completed in 1852. These were unprecedented large construction projects requiring for the period enormous amounts of capital; the route from Tunbridge Wells to Bopeep Junction cost over £500,000 to build requiring the careful supervision of the contractors and their costs. This did not happen on the Hastings line which included eight tunnels, some of which were skimpily built with the contractor, Messrs Hoof & Son, insufficiently lining the tunnels with brickwork. In 1855 the Mountfield Tunnel near Robertsbridge collapsed and the subsequent inspection of three tunnels showed that although the railway company was charged by the contractors for six rings of bricks, in fact only four were constructed. The inevitable litigation saw £3500 awarded to the railway company in compensation, but with consequences that still influence today’s rail services.

Reboring the tunnels was too expensive, the repairs consisted of the insertion of two additional rings of brickwork, which resulted in narrowing the width of the tunnel by 18 inches, which in turn led to the line having special rolling stock built to fit into the narrow tunnels; a practice which persisted as the late as the 1950s with the construction of British Rail Class 202 diesel multiple units. Eventually the solution was to replace two tracks through four of the tunnels with a single track namely the Somerhill, Strawberry Hill, Wadhurst and Mountfield Tunnels. The work was mostly undertaken in the mid 1980s in preparation for the electrification of the line. This continues to have consequences for running the line today as trains sometimes have to wait for each other either side of these single line sections: a legacy of poor oversight of the contractors back in the 1840s.

The SER and LDCR competed themselves into mutual exhaustion and in 1899 the two companies amalgamated their train operations while retaining their separate legal identities, to be further reorganised in 1923 to form the Southern Railway as part of a national reorganisation of the industry known as the ‘Grouping’. The new company faced growing competition from roads for both freight and passengers, and made a decision to systematically electrify its suburban routes. There were two major different systems of electrification, 600 volts, third rail direct current collection which we have today pioneered by the London and South Western Railway and alternatively the 6600 volts alternating current collected from wires suspended from overhead gantries developed by the London and Brighton South Coast Railway.

The third rail direct current system was adopted in south east England due to the relatively low cost installation, removing the need for overhead gantries supporting catenary collection of the current, and avoiding the obstruction of the visual sighting of signals. By the 1920s DC motors were reliable, with a good low output at lower speeds, so aiding acceleration, which is important for services with short distances between stations. Furthermore many of the steam hauled railway carriages could be adapted to form trailer carriages for electric multiple units and used much more intensively than before. However, there are some disadvantages for the third rail system, including the danger to staff and trespassers from a live rail, the need for a relay of substations to ensure the voltage is maintained for frequent and fast services, and seasonal hazards such as ice forming on the rails during a hard winter. This was a commercial as much as a technical decision, and the third rail system prevailed as offering the better investment return.

The London suburban lines were the first to be electrified, followed by routes to the coast including the lines to Brighton (1933), Hastings via Lewes (1935) and Portsmouth (1937). The rolling tide of electrification faltered in 1937 when a proposal to electrify the route from Sevenoaks through to Hastings via Tonbridge and Tunbridge Wells was rejected by the Company Board and had to wait until 1986 to be completed. While the electrification of the suburban network had generated new traffic for more long distance routes passing through rural areas, this was a less certain outcome and the return was more likely to be derived from the operational economies that came from abandoning steam locomotives; this may have influenced the Board’s decision in 1937.

At a time of depression the Southern Railway adopted an active investment policy in modernising its infrastructure and services; passenger numbers on the company’s network rose from 236 million in 1923 to 379 million in 1937. An internal company memorandum in 1942 concerning post war electrification proposals observed that the additional £206,000 running costs of operating much more intensive electric train services generated increased receipts of £1,317,000, and ‘Financial results of suburban electrification to the end of 1932 gave a return of 17.75 % on Capital Expenditure’. It also observed – ‘The train service can be immeasurably improved and at the same time the cost per train mile considerably decreased’ citing as an example one man achieving ‘six hours actual running time out of a eight hour shift instead of less than four hours by a set of locomotive men.’ There was a note of corporate self-satisfaction: ‘At the time of amalgamation in 1923, public sentiment towards the Southern Railway was at a very low ebb, due to largely to the effects of the War (sic First World War), whereas, today it is the general opinion that the Southern Railway stands second to none in the service it gives to the Public’.

The railways we use today are shaped by the investment decisions of the 1840s and the inter-war years. Great British Railways, which will have strategic oversight of the railway system if Government plans go ahead, will face some familiar tensions about finding the right level of investment that secures efficient services to the public while being financially viable: a familiar dilemma faced by the railway companies in the past.