Japanese Radar Station On Tai Mo Shan
At the end of the Second World War, the returning British forces found a Japanese radar station on the top of Tai Mo Shan. This discovery highlighted the technical strength of the Japanese military.
The theory behind radar had been established in the 1920’s with developments in Britain, US, USSR and Japan. However, whereas the British and Americans military recognised the opportunity this technology could deliver the Japanese military could see little merit. Development did continue in Japan, notably by Nippon Electric Company (NEC) and Toshiba based on information gained from captured US and British military equipment and with assistance from Germany.
By early 1944 the first effective system was put into service, the Tachi-3. This system had a transmitter operating at 3.75 m (80 MHz), and produced about 50-kW peak power, with 1- to 2-ms pulse width and 1- or 2-kHz PRF. The transmitter was designed for enclosure in an underground shelter. It used a Yagi antenna that was rigidly mounted above the shelter and the entire unit could be rotated in azimuth. By phasing the antenna elements, some elevation change could be attained. The receiver for Tachi-3 was located in another underground shelter about 30-m distance from the transmitter. Four dipole antennas were mounted on orthogonal arms, and the shelter and antennas rotated to scan in azimuth. The maximum range was about 40 km. NEC built some 150 of these sets. This is likely to be the system installed on Tai Mo Shan or the later version, the Tachi-6.
The radar facility was built between 1942 and 1943 using Prisoner of War labour. In addition to the radar there were placements for anti-aircraft guns. The location of the facility was established from RAF aerial photos in 1945 and the installation was demolished after the liberation of Hong Kong.
The site of the buildings is still visible on the Tai Mo Shan hillside but all other evidence has been lost with the passage of time.
- Government report “Photographs Of Japanese Radar Site On Tai Mo Shan”, Public Records Office, HKRS169-2-193
- Wikipedia http://en.wikipedia.org/wiki/Radar_in_World_War_II#Japan
- Wikipedia http://en.wikipedia.org/wiki/History_of_radar
- The HK Institute of Surveys, Special issue to commemorate the 70th Anniversary of the Battle of Hong Kong, 8 December to 25 December 1941, http://www.hkis.org.hk/hkis/general/journal/SBEvol21b.pdf
- Short Survey of Japanese Radar Volume II 11 November 1945, www.dtic.mil/dtic/tr/fulltext/u2/895892.pdf
Related Indhhk articles: The website contains many articles related to the Japanese occupation of Hong Kong during WW2. These can be found in the index.