Seeing as it's #AdaLovelaceDay18, I thought I'd share a story I came across earlier.

There's a certain male element (and isn't there always) that raised a massive outcry about female characters appearing in historical games. Intersecting on the Venn diagram of misogynist tosspots are another group who get annoyed about female geeks. It's apparently a 'boy' thing.

I have no idea what will happen when these morons discover that in World War Two there was a gang of teenaged female geeks helping to kick the Nazis' collective arse.

Our story is set in Liverpool, home to Western Approaches Command.

In the depths of World War Two, one of the critical battles was that for the North Atlantic. Britain desperately needed food, oil and materiel. Between the ports and the convoys that carried it lay the German u-boats.

The job of Western Approaches was to hunt, destroy and evade those u-boats. They had to muster new weapons, new tactics, and new ways of thinking.

To aid these new ways of thinking, and at a loss as what to do with a TB-affected captain who can't go to sea, the Royal Navy despatched Captain Gilbert Roberts to form a tactical analysis unit.

Roberts had apparently been promised that Western Approaches Tactical Unit would be supplied with the finest men that could be spared.

By the time he arrived in Liverpool the ardour had cooled somewhat. Instead of the promised officers, Roberts was assigned a group of eight Wrens, two of whom were just 17. The closest they'd got to commanding a Royal Navy corvette was presumably a rowing boat on the local lake.

Nonetheless they set to work, quickly working up a set of rules for wargaming so that they could analyse the tactics and counter-moves of the war at sea.

Their first discovery was that the standard response to a u-boat attack - charging about wildly outside the convoy and depth-charging the heck out of anything they found - wasn't much use.

In fact, from what they could see, any u-boats that were being sunk were almost certainly not the boat that had fired the torpedo.

A series of conversations quickly followed that confirmed the most likely explanation. U-boats were motoring into the centre of the convoy to launch their attack, then dropping back to reload.

Amongst the radar clutter and noise of the convoy, the u-boat was hard to spot. Meanwhile the naval escorts were outside the convoy, chasing shadows.

WATU sprang back into action, pulling an all-night session to game the various counter-measures that might be used. Their access to regular deliveries of pizza and Red Bull is unconfirmed. The term "NOOBS" does not appear in despatches.

Still, I suspect most of us recognise ourselves in this situation. The tactic that emerged - codenamed Raspberry after Wren Officer Jean Laidlaw's comment that they were blowing a raspberry to Hitler - was WATUs first solid contribution. It wouldn't be their last.

The biggest contribution was to scale up the wargame and use it to train the captains and officers who would be fighting the war for real.

The gaming room looked absurd - a series of screens and cabinets around a grid square, with officers only able to peer through a slit at the 'ocean' in front of them.

The moves of the attacking u-boats and ships were chalked on the floor. Models represented the allied ships. Orders were passed on slips of paper.

The convoy and escorts had their tracks chalked in white. The u-boats in red. Red filters over the slips meant that allied commanders could only see their own information.

New situations and tactics could be pulled apart, discussed, worked over and taught. The Wrens - fighting these battles day after day - proved invaluable in passing on advice, correcting misconceptions, and handling bruised egos.

One admiral, convinced that a proposed tactic couldn't work, demanded to play the u-boat commander to prove that the u-boats were simply being handled badly.

On the first play through he was confidently working his way to the attack when he was politely informed that he had just been sunk.

After his third consecutive sinking he inspected the screen of the German commander because he suspect foul play.

By the fifth play, still without having got close enough to fire a torpedo he demanded to meet his opponent. The best versions of this tale have it that he wanted to give the officer responsible command of a frigate immediately for their genius.

Roberts had to gently explain that he couldn't possibly do so as they were far too valuable to him. Thus the Royal Navy had to cope without 18 year-old Wren Rating Janet Okell commanding one of his majesty's ships. Shame.

The counter tactic she had devised, however, went straight out into the field. Janet Okell killed more Nazis than any soldier, airman or sailor.

With every WATU success, their access to better and more recent intel was increased. When Captain John Dalison was surprised to see his stern blown off unexpectedly - certainly not a design feature of most escorts - he immediately fetched up at WATU to be debriefed.

Other sources of intel were less formal. One captain knew that the WATU team would wargame through the night if they suspected a new weapon or tactic. He knew this because he was engaged to be married to one of the Wrens.

When his convoy was attacked, he noticed some unusual behaviour and radioed word back to Liverpool immediately so that WATU could work out what was going on.

It was the answer to the missing stern. The unusual behaviour was three u-boats lurking whilst survivors were rescued and doing nothing to attack. A stationary ship was immune to a passive acoustic torpedo, but Dalison, moving at full speed, had had his screws blown off.

As expected, the suspected weapon was wargamed through the night and the new counter-tactic, Step Aside, radioed back to the convoy whilst it was still under attack.

This ability to influence battles as they took place is probably the greatest testament to the abilities of this remarkable group.

By the end of the war WATU comprised 8 men and 36 Wrens, still sinking u-boats as fast as they could find them. Some of their tactics were NATO doctrine to the end of the cold war.

And it all goes to show that one of the things Nazis should really fucking fear is smart war-gaming women who can do maths. And quite right too.

(for more reading on this remarkable story, http://www.professionalwargaming.co.uk/171210WATU-MORS.pdf - or visit Liverpool War Museum @WestApproaches)