Menu
'Whale Head' Chain Home Radar Station
WHALE HEAD
In January 1941 Whale Head Chain Home radar station was under construction (Air Ministry, 1950, 547), and this work was still underway when, on 8 March 1941, a Junkers Ju 88 came from the north east, circled the site an then dived on it, dropping four bombs. Two hit the site, of which one did not explode. The other destroyed four huts, killing one civilian workman and injuring another five. The Ju 88 returned and dived to 500 feet, machine-gunning the site as it approached, before climbing steeply and returning in the direction from which it had come (Hewison, 1990, 329). The station was again attacked on 22 June 1941 when four bombs were dropped on waste ground 50 yards from the station. Fortunately, these caused no damage or casualties. Despite these attacks, work on the construction of the station progressed well and by the end of October 1941 the only outstanding work was the completion of the generators in the main power house (T.N.A. AIR 26/92).
Following the laying of telephone cables and other minor work, Air Ministry Experimental Station Number 51, Whale Head became operational on 29 March 1942 (T.N.A. AIR 26/92). Whale Head was an all-round looking C.H. station, the four lines of shoot being 45°, 135°, 225° and 315°.
The maximum range achieved during April 1942 was 146 miles. On 31 May 1942 Whale Head plotted Hostile 294 for a distance of 160 miles. The aircraft, a Junkers Ju 88, was intercepted and claimed as damaged. The maximum range for May was 167 miles. Hostile activity continued in June, tracking Hostile 251 on the 11th, H.297 on the 12th, H.292 on the 18th and H.285 on the 25th, although none were intercepted. July 1942 saw a maximum range for the month of 182 miles. During October 1942 Whale Head was noted for its outstanding performance in producing height information (T.N.A. AIR 26/92).
During November 1942 a high power amplifier was installed, increasing the transmitter peak output power from 400 to 800 kilowatts. The amplifier was, in fact, capable of much greater output but required a new array, under construction at that time, before the power could be increased beyond 800 kW (T.N.A. AIR 26/92). Mr. Tony Bridgewater, Senior Technical Officer No. 70 (Signals) Wing, recalls that at the time Whale Head was the most powerful station ever built (Mr. Tony Bridgewater, letter to author). One of the receivers was modified to a full R.F.8 form during February 1943, adding to the capabilities of the station. More significantly, the high power aerial array came into use during March 1943 and produced an increase in the station performance (T.N.A. AIR 26/92).
Mr. John Wightman was a Radar Mechanic at Whale Head from May 1943 until November 1944:
Because Sanday was so remote, the Ministry of Food could not economically arrange for the collection of the small output from the farms on the island. Accordingly, the crofters were happy to sell eggs, cheese and butter to us. I had a large screw-top jar of butter which I used to take to meals – reckon I used to get through two weeks civilian rations every day! On evening watch 18.00 to 23.00 and night watch 23.00 to 08.00 we used to cook eggs and chips in the kitchen we had established in T Block. Sometimes I would buy a lobster and cook it before going on watch. Then had a gourmet feast around midnight. A really big lobster cost the equivalent of 15 p., a medium-sized one 12 p. The islanders were great conservationists – they always threw the small ones back ...
The transmitter hall in T Block was about 40 feet by 20 feet. One night the plaster ceiling, an estimated 2 tons, fell down. Fortunately the mechanic was in another part of the building or he would have been, at the least, seriously injured. Apparently, during construction the concrete of the inner, flat roof had been insufficiently ‘keyed’, hence the fall. The station went off the air because plaster blocked cooling fan intakes and the tilt switches cut off the power. The stand-by equipment was equally affected. From memory I think the station was off for less than an hour, but it took us a week to clean up the mess.
At the power station, the diesels had governors to maintain engine speed and hence voltage. The governors were chain driven and one evening when load was high, the chain on the engine in use broke ... the cause was probably metal fatigue in the chain ... The load caused the Blackstone to slow down so that voltage dropped from the usual 220 to 240 volts a.c. to about 170 volts. The megawatt P.A. would not operate with low primary voltage on its power supply so the power supply to the big amplifiers was fitted with an ‘undervolt’ relay. This dropped out as it was designed to do, and thus the main component of the load was removed from the power line. Now the diesel started to race and generator output rose to well over 300 volts as fuses in remaining circuits started blowing. The diesel mechanic on duty got everything shut down and ran up the other generator. The whole episode took probably a little over ten seconds but it took us a full week to repair the damage done to the radar gear. We were back on the air in a few minutes with the stand-by equipment and in fact the transmitter in use had suffered no damage. Fortunately the spare R.F.7 in R Block was off and could be brought into use, but the operational one was badly damaged. Fuses were really designed to protect against short circuit of capacitors and not voltage surges, so there were multifarious obscure faults in the receiving circuits (Mr. John Wightman, letters to author).
Whale Head was equipped with a searchlight for the purpose of directing lost aircraft to the nearest suitable airfield. It was first used on 18 November 1943 to direct a Sunderland flying boat from Sullom Voe to a safe landing at Alness (T.N.A. AIR 26/92).
Further improvement was made to Whale Head with the installation of a megawatt amplifier driven by an M.B.2 transmitter, constructed by staff at Headquarters No. 70 (Signals) Wing, between 11 and 25 February 1942. This equipment proved its worth on 30 May 1944 when a Junkers Ju 88 was shot down mainly as a result of the height information from Whale Head. The station passed heights of 24,000 feet; the hostile was intercepted at 23,000 feet (T.N.A. AIR 26/92).
Preparations were made during June 1945 for observations to be made on the effect of the solar eclipse on 9 July on ionospheric scatter, principally modifications to one of the R.F.8 receivers to provide a 400 mile range on the tube. The observations were carried out from 1 to 16 July and indicated that there was no noticeable decrease in scatter during the eclipse, but that it did decline towards sunset every day (T.N.A. AIR 26/92).
Whale Head C.H. ceased operating at 4.30 p.m. on 15 March 1946 due to the closure of No. 13 Group Filter Room (T.N.A. AIR 26/93).
