The risk behind Britain's aerial-torpedo tension wire

How extraordinary was the Royal Navy's use of a tension wire for aerial torpedoes?

It was risky and unusual but technically purposeful; careful testing was essential because a wire that failed to part could pull the aircraft into the sea.

The tension wire controlled an aerial torpedo's attitude so that it entered the water belly-first. It then had to break reliably, because the force of the torpedo entering the sea could otherwise drag the aircraft down. Extensive testing was needed to control that risk. Suggested origins include naval familiarity with torpedoes and the handling of heavy boats, but that explanation is challenged because the innovator trained as an observer and navigation officer. The stronger operational incentive was the Royal Navy's interest in night attacks on ships in harbors. A torpedo that initially dived too deeply could still recover in open water, while a confined harbor made shallow entry essential. Taranto and Yokosuka illustrate the harbor targets behind that requirement.