Site Records

Site Name: Chancery Lane deep shelter & Kingsway telephone exchange

31 - 33 High Holborn

Sub Brit visit 13th July 1996 & 25th February 2008

Construction supplies for creating the new accommodation were to have been delivered via the existing Central Line station platforms, which would have restricted public shelter provision in the station. In the event, the LPTB would not allow this, so the street entrances had to be used. After this, work proceeded according to plan at Chancery Lane, the orderliness being broken only on 25th November 1944 when a rocket fell just north of the junction of High Holborn and Warwick Place. Minor damage was caused to the shelter entrance at Fulwood Place, without harming the tunnels or shelter below.

A total of some 1,040 staff positions were reserved in the converted shelter and the army was to guard all entrances. Instructions issued in May and June indicate all staff were to enter by way of the Furnival Street entrance, using the station platform access route in emergency only. In the event it seems that little use was made of the premises and then only by ISRB (which arranged for its telephones, teleprinters and furniture to be removed on 8th May 1945). Four days later the Admiralty advised the Home Office in view of the changed situation the accommodation allocated as an alternative headquarters at Chancery Lane was no longer required.

Photo:Stairs linking the shelter tunnels to Chancery Lane Station on the Central Line
Photo by Nick Catford

After the war, Chancery Lane attracted new occupiers. In 1945 it came to attract the attention of the Public Record Office, then located nearby in Chancery Lane itself. The PRO were interested in storing 400 tons of documents in the tube if it could be assured of four years' occupation and this was agreed on 27th June 1945, with London Transport agreeing not to exercise its purchase option.

Under the new occupancy, access to the repository was to be solely by the lift shafts and staircases at either end of the shelter, with the doorway from the lower escalator hall of Chancery Lane tube station to be kept permanently shut at the request of both the PRO and the LPTB. In this way "the shelter would be completely isolated from the tube railway systems and should a fire occur in it, the question of penetration of smoke into the tube will not arise".

An Evening Standard article paints a vivid picture of the shelter and its new occupants:
“For two hours, on January 10, 1946, an Evening Standard reporter trudged around the empty, echoing spaces - now being filled with the Public Records of England. There were 12 of us in the tunnelled labyrinth 200 feet beneath the traffic-jammed thoroughfare of High Holborn; a representative of the Public Record Office, a foreman, five workmen, two watchmen, a liftman, an electrician and myself. Between us we made up the total population of an underground citadel that was built to accommodate 10,000. It was here, during the War, in this top-secret, deep shelter, that thousands of Government executives would have retired to carry on the battle in the event of invasion or super air raids. It was here today that I watched workmen wheeling into the bunk-lined, electric-lit tunnels, loads of Government books and documents which had been `evacuated' to the country during the War. The public records of England are coming back to Town and 500 tons of them will in future be housed in this underground city built to defy bombs. The deep shelter, built at a very high cost, but never required, has been found to be an ideal depository for some of Britain's most important archives.

When war broke out the Public Record Office had to evacuate from Chancery Lane more than 2,000 tons of official books and documents which had accumulated since the days of the Domesday Book nearly 900 years ago. "It was a colossal task," I was told today. "Contents of about 20 miles of shelving had to be transported by lorry to the country. But the job was done - not one book, document or paper was lost or damaged throughout the War." Among the 2,000 tons of documents were 500 tons of
modern departmental records, which were first stored in Canterbury Prison. After the fall of France they were transferred to three depositories in safer parts of the country.

Every day two five-ton lorries, with Public Record Office officials aboard, draw up to the shelter entrance with their loads of records brought from three country depositories - an ecclesiastical training college near Oxford, a ducal castle in the North, and a casualty ward in the Midlands. For two hours today I trudged around the empty, echoing tunnels, 200 feet beneath the road. They seemed to stretch away for miles and possibly they did. I saw the bunk-lined corridors, the control room from which shelterers would have been marshalled, modern kitchens which would have provided hot meals on the cafeteria system, endless rows of stools at the food `bar', and food-storage cupboards which could have stocked sufficient food to withstand a one-year siege.

When fitted with shelving the bunks' steel uprights will make perfect storage receptacles for the official records. Said the Public Record Office official: "We did not choose an underground shelter for safety-first reasons. It is merely that it is available and is ideal for our purpose.” Work on the shelving of the bunks will start soon. It may take months to complete. About 80,000 ft will have to be fitted.”

Although the racking mentioned was installed, the PRO soon exhausted the capacity of the accommodation and beginning in November 1947, had to find additional space shared with other government departments at a number of shelters and certain other shelters were also used for storage of government documents. Typical arrangements put upwards of 400 tons of papers into each shelter, delivered by covered vans at a rate of 5 tons daily. A change of policy by the Ministry in 1951 caused the shelter stores to be cleared again, with all records moved to above-ground archiving at ROF Hayes, Middlesex an ex Royal Ordnance factory.

Photo:Construction of extension in 1952. 15' diameter chamber at base of Furnival Street Shaft. Opening on left leads to the shaft with 7' diameter tube in background.
Copyright photo from BT archives

Two years before the departure of the PRO a new use for the shelter had been identified.  Following the end of WW2, the Government initiated the inevitable post mortem discussions and appraisals of the performance of the Post Office telephone system during the war. Vulnerabilities were recognised and led to an application to the Home Office in 1949 for "special accommodation for the important long-distance terminal apparatus which is the most vulnerable part of the Post Office system and the protection of which would be vital to the country's communications in time of war". Out of this were born broad-ranging plans for new hardened installations across the whole country, of which a new protected trunk exchange was one particular element.

As far as London was concerned, the current terminal was Faraday House in the City and this was "not in the best position nor, indeed, sufficiently protected for its important function". Were this building to be damaged, long-distance communications would be seriously disrupted. The resulting plan was to divert some of Faraday's cables to another London terminal point having some protection located near the existing east-west Post Office cable tunnel and the only suitable location, said the Ministry of Works, was the extreme westerly section (both levels) of the south shelter of the Chancery Lane deep tube shelter.

This was obviously of interest to all government departments and the Home Office indicated it was in agreement with this allocation. The Home Office concurred on 2nd June 1949 although any proposals to earmark further shelter accommodation for purposes other than operational Civil Defence activities would be

resisted except in the most exceptional circumstances. Nonetheless it must have become obvious that 300 feet allocated would be inadequate and the space allocated to the Post Office was doubled to 600ft in July 1949. The Post Office stated its requirements were "so fundamentally important ... for a future war that we dare not risk any delay in the protection of this vital plant".

The original layout of the Chancery Lane shelter was of two parallel tunnels with an intermediate floor to provide two levels in each tunnel. Surface access was by lift and staircase shafts emerging in the old tube station at 31/33 High Holborn and at 38/39 Furnival Street where bomb-damaged premises were demolished to make way. A temporary construction shaft had also been opened in the roadway at the corner of High Holborn and Furnival Street. A staircase also led down to the centre of the shelter from the Central Line station platforms. After the site was taken over by the Post Office one of the first tasks was to extend the tunnel area by building four large-diameter lateral tubes under Staple Inn in the southern sector and it was at this time that the most southerly exit in Tooks Court was constructed.

Another activity was the construction of a goods lift in Furnival Street, allowing delivery of large items of apparatus by road. The alternative method, by rail to the platform of Chancery Lane station, would have disrupted train operations considerably. In any case the LPTB had already established in March 1942, in a letter from their chief legal adviser to the Ministry of Home Security, that, "on the termination of hostilities, the right of access to the shelters through the Board's properties now enjoyed by the Minister and his agents shall cease and access through their properties shall be solely at the discretion of the Board". The war was now long over.

Planning for the installation operations began in early 1950, with construction work starting a year later following the departure of the PRO. The equipment contractor, Siemens Brothers Ltd, began its own planning and manufacture ready for the time when the full access to the new accommodation was to be ready, on 1st July 1952.

Following installation and commissioning the exchange opened to traffic on 30th October 1954, marking a significant milestone in the progress of inland trunk switching mechanisation

in Britain. The new exchange was called Kingsway but known to Post Office staff more generally as TZK (Trunk Zone Exchange Kingsway) or LTK (London Trunk Kingsway).
The exchange was not particularly close to road named Kingsway but this conformed to an established Post Office procedure of giving important facilities names that had a geographical meaning but a deliberately inaccurate guide to their location.

Technically termed a non-director trunk tandem exchange, Kingsway was designed to cater for a maximum of 5,000 trunk circuits and although it was intended primarily as a `through' or tandem unit, part of its capacity was also available for switching calls, referred to as terminal traffic, to and from the London group. In 1956 it gained importance becoming the London terminal of the first Transatlantic telephone cable, TAT 1. This involved a complicated arrangement of equipment at three sites, with several hundred copper `pairs' linking them; the sites were Kingsway itself, the International exchange in Wood Street and the Continental exchange in the Faraday building.

Some notoriety was also gained since the then-famous `hot line' that connected the United States and Russian presidents directly passed through the exchange and this was made a high point of guided tours for visitors.

Photo:Trunk test suite
Photo from BT archives

“A telephone city under London” - That was the dramatic title of an article in the November 1969 issue of ‘Courier’, the newspaper for Post Office employees and indeed it told a remarkable tale. Around the same time the Post Office had taken the press to see its subterranean domain, previously shrouded in the gloom of D Notices and the Official Secrets Act and the marvels of this 12-mile tunnel network were revealed to the public in far more detail than had previously been disclosed.

A city under the city - that is Kingsway trunk exchange, 100 feet beneath the Holborn area of London. Fully self-contained, Kingsway could seal itself off from the rest of London and its 200 Post Office staff could go on working there in comfort and safety. The exchange is air-conditioned, has its own water supply from an artesian well and emergency power from four diesel generators. Fuel tanks hold 22,000 gallons, enough to keep the generators going for six weeks.

Here is all the equipment needed for the automatic routeing of 6,600 trunk lines between London and telephone centres throughout the British Isles. Kingsway deals with 15 per cent of London's trunk traffic, handling about 6,000 calls at once and carrying between 1.4 and 2 million calls every week. The exchange, which went into service in 1954, was on the secret list, until three years ago.

Safety is a religion at the exchange itself and even more importantly, in the deep level tubes housing the cables that run into the trunk exchange. The whole system is wired to give immediate warning of fire or flood. Unlike the exchange, the cable tubes are not air-conditioned and must be evacuated if there is a chance of the air in them becoming foul. The Meteorological Office supplies barometric pressure readings every 12 hours and if the pressure falls below 1,000 millibars the engineer in charge of cable tube maintenance operates the 'clear-out' warning. Lights flash and hooters sound
and everyone working in the tubes must leave immediately.

A two-man patrol walks quickly through the tunnels, to make sure no one is left behind. First aid kits and stretchers are in plentiful supply, and there is oxygen breathing equipment on hand. The cable tubes are also evacuated after a Thames flood warning. At Kingsway, the great bulkhead doors leading to the tubes are shut and the underground city, along with its staff, is sealed off from the world. What's it like to spend your working day, or night, in this underground city? "I've worked here since the scheme opened 15 years ago," said Mr Ken Clark, executive engineer in charge of maintenance. “After a while, you don't notice the noise of the tube trains rumbling above you."

Photo:Standby generators
Photo by Nick Catford

Assistant Executive Engineer (AEE) Jim Barrett is another veteran underground man who enjoys the `deep' life. Jim is one of four AEEs who man the trunk area fault control on a 24-hour rota. "Everything's at our fingertips," said Jim. "Phones and the tannoy system keep us in touch with the staff and our security board shows us, by a system of flashing lights, which doors are being opened between the exchange and the cable tube network."

Kingsway is almost an all-male community. There are just three women -, the canteen staff, headed by Mrs Irene Spalding. In charge of the power plant is Ron Clayson, another underground veteran. Ron's staff of 33 engineers will change a light tube or test one of the huge diesel generators. They also keep the very necessary pumps in good repair. "The air is cleaned and cooled by water," explained Mr Clayson. "Water has to be constantly pumped along the pipes. As for sewage, that has to be pumped up to the sewers. Everything has been done to cut down any feeling of claustrophobia. The canteen has windows looking out on to colourful landscape paintings.”

Kingsway, built to withstand a siege, protects its citizens better than the walls of Troy. There have been no fatal accidents at Kingsway, nor in the cable tubes, no fires, no floods, no suffocation. Kingsway underground men live a healthier and a safer life than their colleagues 100 feet above their heads in choc-a-bloc London.

Click here to continue Chancery Lane deep shelter and Kingsway telephone exchange

Last updated 2nd October 2008
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