DMWD was responsible for a number of devices of varying practicality and success, many of which were based on solid-fuel rocket propulsion. As might be expected of a small, dynamic and highly experimental group, their efforts had mixed results, notable among which were the
Panjandrum rocket-propelled beach defence demolition weapon and
Hajile, a rocket-powered alternative to parachutes for dropping
materiel. A scheme to camouflage bodies of water, used as navigation markers by bombers, was undertaken by a group named the "
Kentucky Minstrels". It involved spreading
coal dust from a ship, ironically named HMS
Persil. The scheme failed due to the actions of the wind and tides, but did produce some confusion when the coal-covered waters were mistaken for tarmac in the blackout. The most successful and significant developments of the department included the
Hedgehog anti-submarine weapon and
Squid anti-submarine mortar, as well as the
Holman Projector, the development of an Army anti-aircraft rocket battery designed to be mountable on naval vessels, and the system of
degaussing used to protect ships against
magnetic mines. Above all, it played an important role in developing parts of the
Mulberry harbour used in the
D-Day landings. Hedgehog was developed after the
29mm spigot mortar anti-tank weapon designed by
Lt-Col Stewart Blacker were shown to the DMWD by
MD1 ("Churchill's Toyshop"). Several experimental weapons were trialled at
Brean Down Fort, a satellite unit of
HMS Birnbeck (Birnbeck pier taken over as a base for DMWD) in
Weston-super-Mare,
North Somerset. Some of the better-known weapons trialled were the seaborne
bouncing bomb, designed specifically to bounce to a target such as across water to avoid
torpedo nets, the
anti-submarine missile AMUCK, and the expendable acoustic emitter designed to confuse noise-seeking torpedoes. ==References==