My thanks to LCT 7074 historian and archaeologist Stephen Fisher for this explanation of the strange pipe-like structure you can see in the picture – the ‘FAM’:
FAM stands for ‘Fast Aerial Mine’, an ‘Unrotated Projectile’: a simple weapon of questionable effectiveness. In essence, a rocket was launched up a launching rail ahead of an aircraft. At a certain altitude, the rocket would deploy a parachute and cable, with the explosive dangling from it, which would slowly float back down to sea level. The unfortunate aircraft was intended to snag the cable on its wing, so detonating the aerial mine. It’s doubtful if 7074 ever fired hers, in training or anger.
HMS Hood certainly had such ‘Unrotated Projectiles’- never used, but one went up by accident while she was alongside in Gibraltar, causing injuries but no inconvenience to the enemy!