Reviews: Northfleet’s Forgotten Tunnels - Henley’s Second World War Industrial Air-raid Shelters
Northfleet’s Forgotten Tunnels - Henley’s Second World War Industrial Air- raid Shelters. By Victor Smith. 20 pp., illustrated with numerous photographs, diagrams, and maps. Published by the Gravesend Historical Society. ISBN 978 1 9999842 2 9.
Victor Smith is a well-known and respected historian and researcher in the field of defence heritage and his expertise is reflected in this publication. This account of Henley’s shelter first appeared in ‘Subterranea’, the journal of Subterranea [pg352]Britannica, in 2022 and has now been published by the Gravesend Historical Society. The author begins by describing the build up to the conflict with details of the defence strategy and the deployment of anti-aircraft gun batteries in the area with plans of their location and the patrol routes of defending fighter aircraft. A chilling map showed that the Thames corridor was given the highest category in a bombing risk assessment of 1939. The Henley Telegraph Works was in this zone and, complying with a government regulation to provide protection for their staff, constructed a large underground shelter capable of housing 2500 workers.
A series of tunnels were driven into the base of a chalk cliff on the south of the factory site and lined with concrete. The entrances, which were reinforced and had anti-blast walls in front, led to a grid pattern of tunnels 17m (55ft) below ground with a separate entrance via a decontamination centre in case of gas attacks. The tunnels are described in detail including the two separate ventilation systems and the sanitary arrangements using the ubiquitous Elsan chemical toilets. During the war Henley’s did vital work including manufacturing cables, gas masks, rubber tyres for the military vehicles, and parts of the PLUTO pipeline system. When the air-raid siren was sounded the workers would immediately head for the shelter and their allocated seating area. The local industries along the Thames did not get the level of heavy bombing that had been predicted but Henley’s was hit at least once resulting with the unusual sight of banknotes falling from the sky when the pay office was hit. After the war the tunnel complex was considered as a suitable site for a Civil Defence Control Centre but after due consideration a different site was chosen. In 1959 Henley was acquired by AEI Industries and then by the General Electrical Company in 1967 who renamed the site GEC Henley. In the 1970s parts of the tunnels were used as an extension of their engineering drawing office. Subsequently, up to the 1980s, they were used as an assembly area for products of the offshore oil industry. In recent years the factory buildings were cleared and the ground in front of the shelter entrances raised up by material from the excavation of the Crossrail project in London. This area is now a construction site for the building of a new housing estate.
The Henley’s factory was not the only industrial site to have deep shelters and mention is made of existing chalk tunnels to the west being adapted and the large tunnel complex behind the Shorts seaplane factory at Rochester. The publication contains nineteen colour photographs of the tunnels together with six black and white contemporary wartime photographs. As well as plans and maps there are also reproductions of wartime advertisements relating to air raid shelters.
This publication will be of great interest to anyone researching local history and the effect of the second world war on the area with a great deal of information contained within its 20 pages. ‘Henley’s industrial WWII air-raid shelter tunnels at Northfleet Kent’ is available as a free pdf download and there is a limited number of printed copies. Enquire to the secretary of the Gravesend Historical Society, Sandra Soder, via email: sandrasoder@yahoo.co.uk or Victor Smith: victor. defcon1@gmail.com
ROD LEGEAR