In the hazel nut tree woods by Hoath Lane,straight across from the top of Cornwallis Avenue, & on part of Gillingham golf Course, there was a battery of 4, 4.5" anti aircraft guns. They were deployed during the Summer of 1939 & were in action on very many occasions during the war; only 1/2 a mile away in C.A., we certainly heard them! On a piece of land, to the side of the road that ran between C.A. & Beatty Avenue a Z Battery of 60 twin rocket launchers was installed later in the war. I would say that they had 4" warheads with 3" propulsion tubes. They were manned by the local Home Guard, my Dad being one of them. He was never on duty during the two occasions when they were fired. It seems that, because of the mass of rocket tubes & shrapnel generated, ( even though only 1/2 were fired at a time), they had to be fired out over the Medway estuary, thus falling on the non habitable islands & river. One can only surmise that very few enemy aircraft were ever in the right place at the right time! On the 2nd occasion, we were on our way out one night to the Anderson shelter in the garden when an almighty woooosh, accompanied by the whole sky turning orange! Wowee, I think is the modern term. Initially we didn't know what it was, maybe a stick of bombs? But no explosion & we quickly realised what it was.