Cold War Sites

Havant ROC Monitoring Post

 Created 15-12-2001     Last update 25-05-2002

A Royal Observer Corps (ROC) monitoring post was located on the western edge of Farlington Redoubt. It ceased being operational in September 1991. I won't go into too much detail of what function these posts performed, because there are entire websites and research groups devoted to this topic. Try here for more information. Basically the posts consisted of an underground room - 15 ft by 7 ft 6 in - which could be used to monitor the environment during and after a nuclear strike by the former Soviet Union. The authorities could then assess the damage and fallout situation, issue warnings and decide what level of retaliation to use. There were usually 3 observers on duty at a post at any one time. About 1,500 of these sites were built all around the UK, with a peak staffing quota (pre 1968) of 25,000 people. 

The post on Portsdown was known as "Havant", and was tragically  demolished around 2000 to make way for a phone mast. However the underground portion of it still remains, as it was incorporated into the phone mast site as a secure equipment room. These sites were usually sold off for a couple of thousand pounds, but because this one was in such a prime position it went for 8,000 (late 1990s prices).

There was another similar site in Portsmouth, which was located in an old gun battery at Old Portsmouth. This too has been demolished. 

An ROC post of some type had been in the Havant area since 1926:

1926 First post at  770068 - Southbourne
1937 Resite (west) to 721073 - Post Office roof at Havant
1938 Resite (west) to 692065 - Camp Down
1957 Resite (west) to 685065 - edge of Farlington Redoubt
1968 Installation of underground monitoring post
1991 Monitoring post closed
2000 Site disposed of

Radiation monitoring for Southern England is now carried out by SERMG.


Aerial photo site location    Panoramic photo site location

Grid Ref SU685065

ROC post  - photo by Nick Catford

This is a photo of the site taken in 1998. On the left is the air vent. The pipe sticking out of the ground is Fixed Survey Meter Probe. In the background can be seen the entrance with hatch open.

Copyright Nick Catford - Subterranea Britannica

ROC post  - photo by Nick Catford

Inside the post 1998. On the left is the shaft leading to the surface, with the sump pump in the background. When this post was operational 3 people would have been on duty in here.

Copyright Nick Catford - Subterranea Britannica

Modern day view of the former ROC site

The former location of the ROC post, opened January 1968, closed 1991. Now replaced by a phone mast owned by Millennium Communications.



1969 aerial photo of the ROC post

An aerial photograph taken in 1969, one year after construction, looking west. The HAVANT ROC post sitting on the edge of Farlington Redoubt, is arrowed. Further back is: Dead Man's Copse, the new Crookhorn Pass under construction, and Fort Purbrook.

With thanks to Peter Rogers

ROC post location map

Civil Defence map showing the locations of the ROC monitoring posts around the Portsmouth area. This map is hanging on the wall at the Civil Defence Bunker underneath Fort Widley. I have arrowed the ROC 'HAVANT' site.

ROC post graphic

Graphic showing the underground layout of a typical  ROC monitoring post.

Copyright Derek Wood - author 'Attack Warning Red'


1 Ground zero indicator
2 Survey meter probe unit cover
3 Bomb power indicator baffle plates
4 Air ventilator
5 Pneumatic aerial for radio - so called 'master' posts only
6 Radio set - used in event of telephone breakdown
7 Bomb power indicator
8 ROC fixed survey meter
9 Radio head set
10 Loud speaker telephone
11 Carrier receiver
12 Pump for pneumatic aerial
13 12 volt battery - a charging generator was later added
14 Toilet