The Royal Navy retained the Type 112 into about 1930 and fitted it to B-class destroyers before moving on to later equipment such as the Type 121. Gaps in the visible numbering suggest additional experiments or intermediate designs even where the surviving outline is incomplete. The orderly series contrasts with the more confusing naming associated with some contemporary radar and beacon work. ASDIC evolved through a continuing engineering programme backed by fleet familiarity.
Notable Point · 22:19-23:36
ASDIC was an evolving family of interwar systems
Successive ASDIC types and skipped model numbers reveal sustained development rather than one finished invention suddenly appearing before the war.