1941, Wednesday 14 May;
Park had been driven there in his Humber Super Snipe, with Wing Commander Pearce as company, leaving the city, heading northeast along the Bukit Timah Road, past the turning for the MacRitchie reservoir and the as yet unfinished General Headquarters at Sime Road, then the Singapore Turf Club and race course, and under the railway bridge, all the while climbing up to the highlands. At the little village of Bukit Timah, the road turned north, meandering alongside the railway line. Just outside the village, they turned off and the road quickly became a narrow, gravelled lane, with passing bays for oncoming traffic. The Humber crept along up the hill in a low gear, dappled sunlight filtering through the jungle canopy lighting her way.
They’d come to see first-hand, a demonstration of the first working AMES, 250 TRU, here on Bukit Timah hill, the highest point on Singapore Island. She was a transportable unit, so had only took several days to set up, but had been waiting on extensive building works. A trail up the hill had been extended and improved into the gravel road to allow good access to the site, numerous buildings had been constructed for equipment and accommodation, and two 120ft towers, built of hardwood, erected for the aerials.
The AMES Mk 9 series TRU was the overseas alternative to the Chain Home radar, able to locate an aircraft at 30,000 ft out to a range of 120 miles, range decreasing as aircraft height lessened, only 70 miles at 10,000 ft, and was blind below 3,000 ft. However, newer units named MRU’s, mounted on Crossley trucks, using metal 105-foot aerials were now being produced, offering similar performance, with some of these earmarked for Malaya. Another two units were being installed at Kota Bharu, 243, and 244 at Kedah Peak, a 3,800 ft limestone outcrop overlooking the village of Gurun, and a keystone of any defence there. This unit had originally been planned for being sited up on Penang Hill, which overlooks Georgetown, but that site would take a lot longer to develop, so Kedah Peak would do for now.
These units weren’t the only ones to arrive, another four COL (Chain Overseas Low) stations, 511 to 514 had arrived in March, but were all static, and, like 244 TRU, needed extensive work, carving radar stations out of virgin jungle, with no local facilities present. Although their works were prioritised, they wouldn’t be ready until September. 511 and 512 were allocated to Singapore, 511, at Bukit Chunang, on the south east tip of Malaya and 512 at Tanjong Kupang, over on the south west, while 513 would serve Penang, and 514 would serve the Port of Swettenham. COL units were capable of detecting low flying aircraft, range about 80 miles for aircraft at 5000 feet, and about 15-35 miles for aircraft at 500 feet. They could also detect ships at sea, a Motor Torpedo Boat up to 15,000 yds (8.5 miles), and a Destroyer 35,000 yds (nearly 20 miles), which provided a useful aid to coastal defence. For higher flying aircraft they had a range of possibly up to 150 miles for aircraft at 20,000 feet, but will lose them quicker than TRU/MRU stations as aircraft fly closer, while maintaining height. Further fixed stations of both types were planned to be built both on the eastern and western coastlines, again needing extensive preparative site works before being installed.
So here they were, both Park and Pearce stood behind the operators, the Flight Lieutenant, CO of the station, waiting nervously nearby. The expected trial time arrived, the equipment was switched on and the system began to start up, valves warming, the transmitter began sending out electromagnetic waves, the receiver patiently waiting on a reflection. The scope came alive, a horizontal green line, an electron beam drawing a line left to right, refreshed 25 times a second, presenting a shaky tight squiggle of a line to the human eye. At the left end a large downward spike presented, the large transmitted pulse, and close by a much smaller downward spike, which the Flight Lt was quick to point out was the refection of the Cathay Building in the city. The rest of the line was clear of any further spikes, but presented as a squiggle which he explained was radar noise, or grass, as they called it in the trade.
They sat or stood waiting, a tension in the air, and then there it was, a blip, a bit bigger than the Cathay blip. Contact sir, called out the leading operator, as both operators began working, trying to calculate a bearing, height and range, the blip steady on the scope, over half way across the screen. Single aircraft, bearing 275 degrees, height 8,000 feet, range 60 miles. They watched, as gradually the blip moved, the operators recalculating, plotting the aircraft flying across them, while a third aircraftsman called on the designated telephone line back to Katong to report the contact.
Park turned to the Wing Commander, “well done Pearce, your chaps have done a fine job.” In his mind’s eye he could see the new Filter Room at Katong, RAF blue uniforms, manning a switchboard, writing down on signal pads the information to be passed to another uniform, who had nowhere yet to go. The accompanying Fighter Operations room was still incomplete, another six weeks they reckoned, But Park wanted to see this bit up and running, and was quietly more than satisfied with the results.
His smile remained on his face as he sat in the back of the Humber on the return journey, while Pearce explained how tomorrow’s exercise, a Blenheim of 27 Squadron, equipped with an AI Mk IV radar set, would try a daylight intercept of a second Blenheim, only using the radar unit installed in the aircraft to locate it.
