2 Group HQ, which was co-located with the Metropolitan Area UKWMO Sector Control, is located to the rear of the TA Centre alongside the railway line. The TA centre itself closed in 1999 and the site is due to be sold to the local council for redevelopment. The main TA building will be retained for community use but the future for the rest of the site is undecided.
The protected blockhouse is of the standard two level surface design and is clad in local brick. In the 1970’s, as the centre was co-located with the UKWMO Sector Control, a new larger control room was built on the west side of the blockhouse and a new brick built administration block was added in the 1990’s butting onto the south face with the emergency exit from the bunker coming out inside the administration building
The layout of the protected HQ follows the usual pattern with a recessed porch in the north wall giving access to the filter room to the right and the main blast protected entrance on the left. Having entered the main door, the decontamination room is straight ahead and this still retains its shower and sink and a door though into the dressing room. Turning right inside the main blast door is the main north - south spine corridor entered through a double air lock. Mains electricity is still connected to the bunker but only a few of the lights work. The first room on the right is the filtration and ventilation plant room. All the ventilation plant and compressors and filters appear in good order and the room is clean and tidy. At the back of the room, double doors lead into the generator room. The TA removed the generator in the 1990’s although all the electrical control racks for it are still in situ. A new wooden door has been inserted into the far wall for easy access, the TA have used the room for storage. Back in the main corridor the next room on the right is the original control room, which would have had a balcony above. The balcony has been floored over although an emergency escape hatch and ladder has been installed up to it. A prefabricated room has been constructed in the well area and a doorway has been added in the back wall leading through into the new control room; this is now bricked up. A door leads from the control room into the ‘Data Room’, which still retains a sign on the door, and another door leads out into the BT equipment room, which still retains some of its original racking and wiring. A second door at the other end of the room leads back into the main corridor where stairs lead up to what would have been the control room balcony.
The balcony itself is intact and there are several telephones mounted on the wall and the position of the Bomb Power Indicator and Fixed Survey meter are clearly visible in a bay. There are also a number of papers relating to INTEX 91, NATO’s international nuclear burst and fallout exercise held on 20/21 April 1991. Two other rooms are to be found on this level, one is the tank room and the other the ‘Radio Equipment Room’ that still has a sign on the door. Inside is a large metal rack of electrical equipment, possibly part of AWDREY (Atomic Weapon Detection Recognition and Estimation of Yield). A number of large lead acid car batteries lie on the floor and there are several thick coaxial cables coming from the radio mast protruding from one wall.
Back in the spine corridor, the last two rooms on the right are the canteen and kitchen. The canteen has a seized lifting serving hatch from the kitchen and another blocked way through to the new control room. The kitchen still retains all of its equipment including a large cooker. On the opposite side of the spine corridor are the male and female dormitories now stripped of their beds and filled with Dexion racking and the male and female toilets which are intact but disconnected from the water supply.
The only access to the new control room is from the outside where a new wooden double door has been inserted into the four foot thick north wall. The control room itself is a large (about 50' X 30') rectangular room with the controller’s office protruding from the centre of the west wall. Two of the original control tables are still in place. This room, the old control room and the control rooms are all painted dark blue. The new control room has been used by the TA for storage and there is empty Dexion shelving along two walls.
The bunker contains many of its original signs on doors and walls and generally seems to be in good condition with no sign of water ingress. A fixed aerial mast still remains between the bunker and the railway line and the usual instrument mountings are still to be found on the roof, the BPI pipe retaining its baffle plates. There is a 6 foot high metal table in the centre of the roof with a thick metal pipe coming up into the middle of it with a number of coaxial cables protruding from it. This appeared at first to be a siren table but may have been a mounting for the AWDREY equipment.
Horsham was the Royal Observer Corps' No.2 Group HQ, and the UKWMO Metropolitan Sector HQ.