Sonar 2016

Sonar 2016 was a hull-mounted active sonar system of the Royal Navy, in use on Invincible-class aircraft carriers, Leander-class and Type 22 frigates and Type 42 destroyers from 1979. It consisted of a hydraulically roll-stabilised transducer (later fixed with fully electronic stabilisation) in a glass-reinforced plastic dome designated Hull Outfit 29. The system could operate in both active and passive modes, the 5.5-7.5 kHz, 64 stave by 12 element transducer connected to a Ferranti FM1600B computer and a 3-seat display in the warship's Operations Room.[1]

HMS Broadsword, the first ship to be built with Sonar 2016.

Resulting from Naval Staff Requirement NSR7683, Sonar 2016 was first trialled in HMS Matapan in 1973, and from the late 1970s was installed in the newly built Batch 1 Type 22 frigates and Invincible-class carriers, and retrofitted into the three Leander-class frigates converted for Sea Wolf and some Type 42 destroyers. The system was considerably more advanced and computerised than earlier generations, processing signals and displaying them digitally on CRT displays with several classification and tracking features. From 1982 it was gradually replaced by Sonar 2050, which utilised the same transducer but with improved computing and pulse types.

Sonar 2016 used a linear-period FM pulse approximately one second in length, transmitted either horizontally or at a 7-degree negative elevation for convergence zone operation. This pulse type gave good performance in both deep and shallow waters (the latter presenting a challenge due to reverberation). The system could process returns through replica correlation processing, as well as simultaneously processing passive returns and feeding audio to the operators.