In 1964 the protected transmitter block at the Schoolhill Chain Home Radar Station south of Aberdeen provided a temporary location for the United Kingdom Warning and Monitoring Organisation’s (UKWMO) Caledonian Sector Control. From October 1st 1964 the UKWMO became a separate executive branch within the home office with the Royal Observer Corps acting as its field force with its network of 1563 underground monitoring posts.
Caledonian Sector Control had been co-located with the ROTOR Caledonian Sector Operations Centre at Barnton Quarry in Edinburgh since 1953. With the demise of the SOC’s, Barnton Quarry became a Regional Seat of Government in the early 1960’s and there was no room for the UKWMO Sector Control so a new site was required. The WW2 Chain Home radar station at Schoolhill had been adapted as part of the Rotor Programme in the early 1950’s but with the introduction of the Type 80 radar it was no longer required. The transmitter block at Schoolhill was available and was acquired by the Home Office as the new Caledonian Sector Control.
Internally it was completely rebuilt; the open walkway between the brick transmitter building and the outer blast wall was roofed over to form a ring corridor with a male and female toilet built within the corridor at either end of the building. The internal partition walls were all removed with a new room layout being built within the shell of the old building. The grassed earth traverse around the building was retained with one entrance through the traverse on the north side and a second entrance on the west side. New ventilation plan, a stand-by generator and water tanks were also added.
Caledonian Sector Control remained at Schoolhill until 1976 when an extension was built to the Royal Observer Corps Group Control at Cragiebarns in Dundee and from that date UKWMO Caledonian Sector Control was co-located within the ROC 28 Group Control.
Grampian Fire Brigade took over the Schoolhill site in 1978, as a training centre for offshore fire fighting on north seas oil rigs. The fire brigade has expanded the site and it is hoped to find a continued training use for the old Chain Home transmitter block.
The building remains in good condition although internally it is damp with the paint peeling badly. Some of the rooms have been used for storage and a number of chairs still remain. There is one entrance through the traverse consists of a single wooden door into the north side of the ring corridor. The purpose of two of the rooms can’t be identified but the large control room is at the south side of the building, with a door into the ring corridor on both sides and a third door incorporating two message hatches into the signals room on the north side. The room has been completely stripped of most original fittings although light fittings around two walls indicate the position of wall mounted maps. A date (1964) on the wall indicates when the building was converted.
The signals room still retains 8 acoustic telephonists’ booths and the kitchen is partially intact with a large wooden kitchen unit, a Butler sink and water heater. Generator, fan and gas filters have been stripped out of the plant room although some metal trunking and electrical switchgear still remains in place.
A long water tank has been suspended from the ceiling in the western side corridor with an ‘L’ shaped female toilet at the north end and a similar male toilet at the opposite end. These retain original fittings including WC cubicles, hand basins, hot water dispensers and in the female toilet, a sanitary towel incinerator. The second entrance is also in the west side corridor consisting of two offset doors through the earth traverse.