[2] Ranken Darts became obsolete with the advent of the combination of explosive Pomeroy bullets and incendiary ammunition fired from .303 Vickers and Lewis guns mounted on fighter aircraft.
The Ranken dart consisted of a tinplate tube 23cm long, with a cast iron pointed nose at one end, and a plug and three spring loaded arms at the other.
The arms were kept closed in storage by means of a cap, either tin or rubber, which acted as a buffer when the dart was in its dropping tube.
When released, the arms opened up and locked in place to act as a grapnel, thus ensuring that the body entered the fabric.
The Dart contained high explosive, black powder and phosphorus which were ignited when the head penetrated the airship's outer skin.