[motto]

One of the contributors to the Australian Shooters Journal was an ammunition tester during WW2 and has referred to some of his activities in his articles for the magazine. He worked in South Australia and for one of the tests they used a huge flat area in which they fired vertically so as to recover the projectiles with as little damage as possible. I think it was on the coast somewhere. Perhaps they were doing something similar at Ajax
As regards electrical firing. In this instance it probably refers to remote firing of the weapon as most artillery and probably all was percussion ignition. Electrically ignited munitions have been around since the late 1800s but were to my knowledge confined to shipboard or fixed shore installations.
David