In 1939 the British were unprepared for war.

Suddenly they had to start making weapons in a hurry.

One thing they badly needed was a way to sink enemy ships.

They didn’t have time for the usual months and months of meetings, discussions, testing, and development.

So Major Millis Jefferis was quietly given the task.

He thought they needed a mine frogmen could attach to ships.

It would need to be magnetic.

He’d recently read an article about magnets in “Armchair Scientist” magazine.

So he asked the editor, Stuart Macrae, if he would help him make a magnetic anti-shipping mine.

Macrae was interested but said he needed the editor of “Caravan & Trailer” magazine to help him put it together.

Jefferis said okay and they began work.

To start, they needed a container to hold about 5lb of explosive.

They found the perfect thing in Woolworths: an aluminium washing-up bowl.

They fitted magnets and a lid, but now they needed a timing fuse.

Nothing accurate and dependable existed.

They needed a spring-loaded striker that would be held back until the frogman got clear.

While he thought, Stuart Macrae was sucking aniseed balls.

Aniseed balls are like gobstoppers.

Hard candy that gradually dissolves in the mouth.

And while he thought about what he could use to hold back the detonator, he sucked an aniseed ball.

He needed something to form a barrier between the striker and the explosives and eventually give way, or crumble, or break.

Or dissolve.

Wait a minute: dissolve.

Just the way the aniseed ball he was sucking was dissolving in his mouth.

If it dissolved in his mouth it might dissolve in seawater.

And it did.

Each aniseed ball he tried took 35 minutes to dissolve in seawater.

So Stuart Macrae placed an aniseed ball between the striker and the explosives and he had his detonator.

The problem was, how to keep the detonator waterproof until the frogman attached the mine to the ship.

What could fit over a stiff tube several inches long?

And in a local chemist shop they found the answer: a condom.

Stuart Macrae bought every washing-up bowl, every aniseed ball, and every condom he could find.

That became the “Limpet Mine (mk 1)”

How did it work, this combination of washing-up bowls, aniseed balls, and condoms?

Well, in just one night, 14 Marine Commandoes sank seven Japanese ships using those limpet mines.

For me that’s real creativity.

What I love is none of it was about technology.

They didn’t try to be the first to use the latest thing that had just been developed.

They used what was available to everyone, everywhere.

And they used it to out-think everyone else.

Because they used it in a different way.

Their ‘unfair advantage’ was creativity.


As Jonathan Swift said “The ability to look at something everyone has looked at, and see something no-one else has seen.”