SiteName: Portland underground Naval Headquarters and communications centre
Sub Brit site visit 1st September 2004
[Source: Nick Catford]
Today the tunnels remain in extremely good condition. They are lined throughout with steel segments similar to those used on the London Underground and probably made by the same company. There are three different diameters of tunnel, the main access tunnels and most of the rooms are 8' 6" in diameter, the naval operations room and adjacent staff room are about 16' 6" in diameter and the tunnel on the east side of the central complex is 12' 6" in diameter. Most of the rooms have a secondary curved wood fibre board lining although this has now fallen away in places. The tunnels are generally damp with some standing water in the plant room.
Photo:The main eastern access tunnel
Photo by Nick Catford
The tunnels have been largely stripped of all original fixtures and fittings although the ventilation and filtration plant, trunking and electrical control equipment is still in place with ventilation trunking running into some of the rooms. A concrete engine bed indicates the position of the standby generator. Some electrical switchgear remains in place, fixed to the wall just inside the first entrance. WC pans and hand basins are generally still intact and undamaged.
Plan of the whole tunnel complex, the four entrances are indicated E 1 - 4
Plan of the underground headquarters showing current room layout - this dates from 1952.
Surveyed and drawn by Bob Jenner
There is little recorded history of the tunnels. During the 1952 refit most of the internal walls have been stripped out with new breeze block partition walls forming a number of small offices around the central ring structure, these are designated A - Q. A breeze block wall has also been constructed down one side of the main access tunnels, presumably to enclose cables and ventilation trunking.
An underground air-raid shelter was also built into the bank a short
distance inside the entrance to the Dockyard. This has two entrances
going into the hillside for about ten yards, a cross passage still retains
two lines of benches.
For more pictures of the underground headquarters click here
[Source: Nick Catford]