Development of the 3" Rocket Launcher Memorial

It's kind of artillery, so...
"Recently, as I was waiting to start a presentation on historical aerial photography at a hotel near Cardigan, I spotted an object placed on a hall-stand, and recognised it as a small replica of a 3” rocket launcher. Intrigued, I picked up the model and read the inscription:

THE ORIGINAL 3” A.A. ROCKET PROJECTOR

DESIGNED IN THE CLIFF HOTEL IN THE SUMMER OF 1940

PRESENTED BY SIR ALWYN CROW C.B.E.

The 3” ground-to-air rocket was a ground-breaking early application of military rocketry. Each projector at the AA battery had a ground crew of two. The missile was fired by a small electrical charge, igniting the 9lb of cordite propellant, to guide the 7ft long rocket, with a 4lb explosive charge in the warhead, towards enemy aircraft.

Although the system wasn’t terribly successful, with only a very few confirmed “kills”, the rocket launchers boosted the morale of the local population. By all accounts, battery salvos generated a tremendous noise as the missiles were sent on their way."
https://rcahmw.gov.uk/rocket-discovery-at-the-cliff-hotel-gwbert/