Operational instruments of the Royal Observer Corps
The Royal Observer Corps (ROC) was a civil defence organisation operating in the United Kingdom between October 1925 and 31 December 1995, when the Corps' civilian volunteers were stood down. (ROC headquarters staff at RAF Bentley Priory stood down on 31 March 1996). Composed mainly of civilian spare-time volunteers, ROC personnel wore a Royal Air Force (RAF) style uniform and latterly came under the administrative control of RAF Strike Command and the operational control of the Home Office. Civilian volunteers were trained and administered by a small cadre of professional full-time officers under the command of the Commandant Royal Observer Corps; a serving RAF Air Commodore.
Royal Observer Corps
In the early 1960s, when the nuclear reporting role building programme was in full swing, the ROC post at Windsor relocated to the cellar beneath the Brunswick Tower and a partial monitoring room was excavated under the garden in front of the tower's base. The BPI (Bomb Power Indicator) and FSM (Fixed Survey Meter) instrument fittings on the lawn were clearly visible to the many tourists visiting the castle, although few would have realised their significance. The GZI (Ground Zero Indicator) was mounted on top of the tower's battlements involving an exhausting climb of several hundred circular stone steps and 400 feet in each direction. The observers at the Windsor post were unique in the country in not having to provide their own food during exercises. Instead, they received hot meals, brought by royal footman, from the castle kitchens. Twelve months after the ROC post was closed, the Brunswick Tower was the starting point and seat of the 1992 Windsor Castle fire and was substantially damaged.