The Secret Tunnels of South Heighton
The Eastern Airlock. Before & After 2000.
These pictures show the Eastern Airlock as found in 1994, and after clean-up by the Friends of HMS Forward.
This is the interior of the Eastern airlock beyond which lies the first of three flights of concrete steps emerging in room 16 of the Guinness Trust Holiday Home (later Denton House). This was the principal operational entrance/exit for all personnel who served in the tunnel, and for this reason the 'risers' of the steps were regularly painted with whitewash. The whitewash is today (2000) flaking away from the risers in 1/8th inch (3mm) thick slices.
The Eastern airlock was designed for personnel use only and is therefore only 6 ft (1M80) long. The external blast-proof door, visible (unhinged) in the 1994 view is made of 5/8ths ins (16mm) thick plate steel, weighs some 3 cwt (150 Kg), and has a thick neoprene rubber gas-seal (still pliable in 2009) attached to its periphery on which to close.
An electric extraction fan mounted on a small plinth in the far left corner of the airlock expelled foul air from the adjacent galleries via the circular duct visible above the plinth. The duct continued beyond the airlock, up the stairs and into an under-floor masonry duct beneath the landing at the top of the stairs, and emerged through a 'drain cover' at the foot of a flight of stairs leading to the Observation Post (mock hen-house) by which route the foul air reached the outside atmosphere.
Above the doorway the brickwork is 'perforated' by an airlock-pressure-equalising valve; various conduits for lighting and in-tunnel military communications cables; and three larger in-line provisions for (a) the incoming public electricity supply, (b) the Lamson message tube (seen here), and (c) for internal GTHH telephone extensions and 'alternatively routed' external telephone cables.
Nothing remains of the airlock's internal door or its architrave except the evidence of its former existence.
Finally, the 'sooty' appearance of the walls and step risers is just that - the result of an arson attack, probably pre-1970 before the former Observation Post was demolished.
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All illustrations and text on this site are © 1941-2021 Geoffrey Ellis, or The Friends of HMS Forward, or Nick Catford.