Radar at Happisburgh

Happisburgh was a good choice and for two other reasons. Firstly it was about half way between similar units at Dunwich in Suffolk and Ingoldmills in Lincolnshire, and secondly it was more or less on a line between Germany and the industrial midlands.

You leave Happisburgh by the coastal road towards Walcott and Bacton, past Blacksmith's Lane on your right. After passing White's Farm on the left a few yards further on is a clump of trees on the right with a field entrance and a pillbox. You have arrived at the site of the first of Happisburgh's two radars. Nothing is now to be seen except a blast wall.

A chain of radars was established in the mid 1930's, the most visible signs of which were 3 or 4 very high steel masts (360 feet) carrying the transmitter aerials. This was called Chain Home (CH). The nearest of these to Happisburgh were at West Beckham in North Norfolk, and at Stoke Holy Cross just south of Norwich. These were high powered and had the ability to detect aircraft at well over 100 miles, but suffered from the disadvantage that they could not see low flying aircraft. Just before the war, the research boffins at Bawdsey were asked for advice. The matter became more pressing when, after war was declared, German aircraft were laying mines from low flying aircraft in the harbours of the east coast and the Thames estuary.

It so happened that Bawdsey had developed a higher frequency radar for coastal defence. Invasion was a possibility, and the new set was designed to detect ships but could also see aircraft flying as low as 500 feet up to 25 miles away.

The Air Ministry purchased twenty four of these units of which Happisburgh was one. They were modified slightly and formed the basis of a new chain called Chain Home Low (CHL). Happisburgh was built at the end of 1939 and was operational at the end of the year. The unit consisted of a number of wooden huts, two of which contained respectively the transmitter and receiver. These were surmounted by a wooden gantry carrying a turntable and an aerial system looking like a very large bedstead which could be turned by an operator in the hut below.

In operation, radar involves sending a short pulse of radio energy as a beam and, if it hits an aircraft or other object, measuring the time it takes for the reflected signal to be received back at the station. When it is remebered that radio waves travel at the speed of light (186,000 miles per second) a very sensitive clock is necessary to measure this time. A cathode ray tube was the answer (much like todays TV picture tube). A spot on the tube can be made to move with incredible speed and can be made to form a complete television picture.

Typically a radar transmitter sends out four hundred short pulses every second, and at the same time as each pulse a spot is made to move from left to right across the centre of a cathode ray tube. As this spot moves at four hundred times every second there is no flicker and the operator sees a steady line. the line is calibrated in miles and the received echo, if any, is superimposed on this line. Thus the operator has the range and, because he knows which way the aerial is pointing, the bearing to the target.

In the beginning this information was passed to the CH at West Beckham, but after a while it was found that this overloaded the system and arrangements were made for all plots to be sent to a filter room at Watnall near Nottingham.

Happisburgh was working 24 hours per day, 7 days a week on a three watch system. The CO was a Flight Sergeant, and the watches were all male airmen. A watch consisted of an NCO and four or five operators and one mechanic all living in civilian billets. One watch was with Miss Cargill at The Rookery, and another with Mrs Giles at the farmhouse next door to the Lighthouse public house. Others were scattered in Walcott and Bacton.

As was common in wartime, very rapid improvements were made to the technical equipment. During 1941 the aerial systems were combined, still with manual turning by an operator sitting in front of the receiver and also a Plan Position Indicator (PPI) was introduced. This display was on the face of a round cathode ray tube (CRT) with the spot forming a line between the centre and the outer edge. The line so formed rotated about the centre, and any echo formed a small sausage glow as the aerial and the line, called a trace, rotated in step with each other. A transparent plastic mask covered the face of the CRT The National Grid was drawn on this mask so that instead of reading a range and bearing, the operator could read off a map reference to Watnall.

During this time experiments were made with fighter aircraft, and it was not long before specialist officer controllers arrived at Happisburgh to control, day or night, aircraft mainly from Coltishall. During they day Spitfires could see the target if pointed in the right direction by the Happisburgh controller who could see friend and foe on his screen. At night the aircraft would be Beaufighters or Mosquitoes who had their own very short range radars on board. It was a bit of a cat and mouse situation and very exciting for the radar crew who could watch and hear everything that was going on. Incidentally, there used to be a telephone kiosk near the cross roads where the coast road to Walcott and the Stalham road meet. As a result of crossed wires it was possible to listen to the radio telephone conversations between the ground radar and aircraft. Alas the kiosk is no more.

Life on duty at Happisburgh was either very boring in bad weather or very exciting in good, but things were to change in 1942. Firstly a group of WAAFs arrived to take the place of the male RAF operators who were posted elsewhere (probably overseas). They were billeted in Pyghtle, a house near the school in Happisburgh. As more girls arrived, Pyghtle was closed as a billet and they were all moved to Norton House in Bacton. Before long there were WAAF cooks, drivers, admin staff, admin officers and even radar mechanics.

The other thing of note brought Happisburgh right up to date with the construction of a new radar about 100 yards from the original unit and closer to the sea. For all the girl crews it was accessed by footpath from Happisburgh One, but the heavy equipment came in by track through Chimney Farm. The low brick building with flat concrete roof is still visible although the internal partitions have been removed together with all the equipment, and it is now used as a store for agricultural purposes. If you look very carefully at the bushes next to the operations block, it is just possible to make out the four concrete blocks which formed the feet at the base of a 185ft wooden tower. This had a motor driven revolving aerial on top which enabled the radar to see further and lower out to sea.

Happisburgh Two, being the more modern of the two units, plotted to Watnall the comings and goings of friendly and foreign aircraft and a few ships which were plotted to Yarmouth. A centimetre height finder was added in 1943. the unit was still operational in 1947 but it is not known when it was closed and the equipment withdrawn.

Happisburgh One on the other hand had no work to do after 1945 and indeed was running down before the end of the war. Many of the girls went away on cookery and other courses to prepare them for civilian life.

If you have been interested in radar at Happisburgh, it is suggested that you should visit the RAF Air Defence Radar Museum at Neatishead. The museum posesses a vast knowledge of radar matters in addition to the displays of equipment. They knidly provided some of the information contained in this article. This is one of the best tourist attractions in Norfolk and is well worth a visit. It is not open every day, but a telephone call to the museum on 01692 631485 will give the opening days and times, or visit www.radarmuseum.co.uk