Marine radars on board ships provided the mariner with information on other shipping in the vicinity, together with an image of the adjacent shoreline. It was therefore a natural step for Decca Radar to undertake the development of shore-based radars, which could monitor shipping in sea channels and harbour approaches. In 1951/2 the Company designed, manufactured and demonstrated a prototype Harbour Radar, built around a development of the standard Type 159 Marine Radars Transmitter. The X-band Transmitter/Receiver in combination with a 10-foot half-cheese antenna described a 0.4degree beam.
The first production model of the TYPE 30 series Harbour Radar was sold to the Liverpool Port Authorities to replace out-dated equipment. The TYPE 32 closely followed the TYPE 30 but with a changed antenna to one with a 25 foot aperture. The first system sold to Southampton (1958) included 16 inch fixed coil displays, developed at Tolworth and provided coverage of some 18nm, out to the Nab Tower and up into the harbour of Southampton itself. Other UK installations included a TYPE 30-to-32 up-grade at Gladstone dock Liverpool and another overlooking the Thames Estuary approach to London at Dungeness, (1957). Other installations were at Hythe, Teesport and Leathercotes near Dover. A number of harbour radars were also sold overseas, examples being Freemantle in Australia and Khandla India.
Depicted are the installations of the Harbour Radars TYPE 32 at Southampton (this installation was ‘on’ and ‘in’ Calshot Castle but at a later date the Castle was restored and an updated Type 32 was installed on its own tower). The radar tower at Liverpool is pictured. Also, below, the Seven Display Ops Room at Liverpool, with displays of the 15inch type.