A Game of Birds and Wolves: The Ingenious Young Women Whose Secret Board Game Helped Win World War II

by Simon Parkin

Gilbert Roberts, a retired British naval officer turned game designer, stepped onto the gangway leading up to the ocean liner, then immediately stopped. If he was not mistaken the man making his way down the plank, labouring under the weight of a suitcase, was Karl Doenitz, a German admiral who, twenty-three days earlier, following the suicide of Adolf Hitler, had become Nazi Germany’s new head of state.

‘Game designer’ was not a job description used by the navy at the time, but this was the nature of the role given to Roberts by Britain’s prime minister, Winston Churchill. He was to create a game that would enable the British to understand why they were losing so many ships to German U-boat attacks. Teamed with a clutch of bright, astute young naval women known as Wrens, many of whom were barely out of school, Roberts had, in the months that followed, restaged countless ocean battles using his game. Through play he had developed anti-U-boat tactics that, once proven, had been taught to thousands of naval officers before they headed to sea.

The plan was simple, and proven. Since the beginning of the war, merchant ships had been ferrying food, fuel and supplies into Britain, an island nation that, without these imports, would go hungry. Sailors knew from the experience of the First World War that the safest way to cross the Atlantic Ocean was to move in convoys, finding safety in numbers. The Royal Navy sent warships to protect them. The ‘escorts’, as these ships were known, carried nothing but men and weapons. They encircled the convoy as it plodded its heavy-laden course, and, like sheepdogs facing down wolves threatening a herd, fended off any enemy attacks. First introduced in 1917, convoys were initially centred on the English Channel, but as the efficacy of the tactic was proven, the system was used to protect ships as they crossed the deep and wide waters of the Atlantic Ocean. Colin’s evacuee ship was just like any other member of the convoy. Except, instead of wood, coal, oil or pork chops, the SS City of Benares carried a cargo of children.

When the U-boat was being hunted by one of the Royal Navy’s attack-dog corvettes (many of which were named, disharmoniously, after English flowers) or destroyers, the sound was akin to lying between the tracks while a goods train thundered overhead. On these ships, the captain’s orders had to be screamed to be heard over the wind. By contrast, as soon as the engines were cut, the U-boat was a whispering realm. Although they did not know it yet, it was here, in the immense deep, that most U-boat crew members would die. Of all the various forces and divisions of air, land or sea, on both sides of the conflict, the U-boat posting had the greatest mortality rate of any in the Second World War. British planes dropped leaflets over Germany, warning potential new recruits that for every one of the 2,000 U-boatmen who were currently living as prisoners of war in Britain, five more had already been killed at sea. Life-insurance companies in neutral countries estimated the average life of a U-boat sailor to be fifty days.7 This was not the hyperbole of propaganda. Of the 39,000 men who went to sea in U-boats during the Second World War, seventy per cent were killed in action. By contrast, only six per cent of those who fought in the British Army died in combat.8 In the early 1940s you were more likely to die on a U-boat than on any other mode of transport in existence.

Colin’s calmness belied his true feelings, familiar to anyone who, as a child, has witnessed an intimate crisis of the adult world: the anxiety that there was something more you should be doing, combined with the bewildered sense that it is neither your place nor responsibility to do so.

The Germans were split into two teams. The Reds played as the Royal Navy. Their side held a pile of tokens to represent the forces at their disposal: twelve battleships, five aircraft carriers, twenty-seven light cruisers and a hundred destroyers.13 The Blues played as the Germans. With tokens representing fifteen torpedo U-boats, two large fleet U-boats, two artillery U-boats, a minelayer, an armoured raider and a single supply ship, they were impossibly outgunned. The rules of the game, which was set four years into the future, at a time when Germany was imagined to again be at war with Britain, were simple. The Red team must use their considerable forces to protect and chaperone five British convoys of merchant ships heading towards Britain from various countries via the Atlantic. Using their sorry fleet of U-boats, the Blue team must stop them.

On multiple fronts Doenitz’s plan to build a sizeable U-boat fleet was frustrated. By the outbreak of war, instead of the 300 U-boats he estimated that he would need, Doenitz had just forty-six craft available for action, a proportion of which would always be in transit or docked for repairs or resupply.

Kretschmer was loath to fire another torpedo to finish the job. His boastful motto was ‘one torpedo, one ship’. Yet dawn approached, and with it the risk of being spotted by an Allied air patrol. Aircraft attack was more feared by U-boatmen than that of an escort vessel, as a well-piloted aircraft could mount an attack on a U-boat before it had a chance to dive to the eighty or so metres required to evade an aircraft-hurled depth charge.

In the five months from June to October 1940, during which the City of Benares was lost, U-boats sank 274 merchant ships and sustained just two losses. By the end of the year the U-boats had sunk more than 1,200 ships, about five years’ worth of construction work in typical peacetime conditions, and more than the rest of the German navy and Luftwaffe combined.

Some crew members took the BdU Zug, an express train reserved for U-boatmen that ran from Nantes through Le Mans and on to the German cities of Bremen, Hamburg and Flensburg, and would be home within two days. Those who chose to remain in France were sent to the U-bootsweiden, luxury hotels or chateaux that had been commandeered to be used as rest camps. These safe havens were far from the ports targeted by Allied bombers, where people were routinely forced to seek shelter, either from bombs or from falling debris from downed planes, whose pirouetting wings seemed as harmless as falling feathers, till their weight was felt through the ground.

Point nine, however, went against the written advice that U-boat captains maintain a minimum distance of 1,000 metres between the U-boat and its target. Kretschmer countered, plainly, that at every given opportunity, torpedoes should be fired at extreme close range. ‘This can only be done’, he wrote, ‘by penetrating the escort’s anti-submarine screen and, at times, getting inside the convoy lanes.’ Having scored three kills in quick succession, Kretschmer knew that there was no more efficient way to cause havoc on a British convoy, causing the escort captains to flounder. ‘This should be the objective of all our attacks,’ he added. In two sentences Kretschmer had outlined a tactic that would, in the months to come, lead to the deaths of thousands of Allied sailors and raise the line on the chart of shipping losses at the Admiralty in London perilously close to the red threshold of starvation. It was a tactic so effective that it would lead to the formation of a British unit staffed by a ragtag crew of women, led by a captain with a life-changing disability, dedicated to its uncovering.

For all the wolfpack’s power and menace, it had one key weakness. In order to organise their U-boats for an attack, the captains needed to communicate at regular intervals, initially to report the sighting of a convoy, and then to invite other boats to join. Even in the midst of battle, requests often came in for U-boats to announce the result of specific attacks, fuel and torpedo stocks and, thanks to those helium-filled condoms, to issue weather reports. These signals, when picked up by Allied shore stations, acted as clues to the U-boats’ whereabouts. By triangulating the signal from two sources, a fairly accurate location could be determined, and the estimated position of the U-boat pinned to the plotting maps around the navy’s various premises.

The novelist Nicholas Monsarrat was a lookout on HMS Campanula, one of a handful of flower-class corvettes deployed as chaperones to the Aguila. One hundred and thirty-five of these chunky, hardy warships were made during the war, thirty-five of which were lost,13 and each was named after a different and equally delicate English garden flower (Bluebell, Zinnia, Hyacinth, Aubretia, Coreopsis). They were notoriously uncomfortable ships but doggedly seaworthy (their sailors were rarely lost overboard14) and, most usefully, presented only a small target to U-boats.

Monsarrat is one of the few who explored, in his fiction, the loss of women’s lives at sea. In The Cruel Sea, his ‘forlorn last try’ to make it as a writer, and the book that subsequently made him a millionaire, one of his characters falls in love with a Wren. The pair’s marriage pledge is thwarted when she is killed after a ferryboat capsizes in a storm, a tentative prodding of his darkest memories of the war at sea.

Technology has a distancing effect on combat. The fist becomes a sword. The sword becomes an arrow. The arrow becomes a trebuchet. The trebuchet becomes a torpedo. The torpedo becomes a nuclear missile. The ICBM becomes, maybe, a clandestine social media campaign, designed to undermine and topple democracies. With each step change the attacker is removed yet farther from the material effects of his actions. At a distance it is harder to properly count the cost. It is, surely, our obligation to count the cost.

Roberts’ naval career continued on a promising, if unorthodox trajectory when, following sorties to fit out Australia’s first aircraft carrier and a trip down the Danube, he was made a game designer for the Royal Navy. In July 1935, a few days after he was promoted to the rank of commander, Roberts joined the tactical school at Portsmouth. Here naval captains and their senior staff played wargames, hyper-evolved military-themed board games staged on floors painted to look like giant chessboards. Distant cousins to commercial board games such as Battleship and Risk, these wargames were intended to explore and rehearse lifelike combat situations, a crucible in which tactics could be tested, analysed, and refined.

Games establish consequence-free realities in which we can explore and experience situations that in actuality are too dangerous, rarefied or consequential. This makes them the ideal sphere in which to experience war.

The best-known sea game is undoubtedly Battleship, variants of which were published by various companies under various names, initially as a pad-and-pencil game in the 1930s. The board-game manufacturer Milton Bradley published its first Battleship-style game in 1943, under the title Broadsides: The Game of Naval Strategy, a title that was distilled to Battleship in 1967. MB Games claims it has no record of who designed or named the game,14 but there were clear commercial precedents.

The origins of Battleship

The company also published a game titled Jutland, similar in rules to the modern game of Battleship. Two players each mark out the position of their warships on a ten-by-ten grid, hidden to their opponent. Once their ships are positioned, each player takes turns to fire a salvo of six missiles at their opponent’s grid, hoping to strike a ship rather than the sea. ‘A lot of skill can be exercised in finding the position of one’s opponent’s ships,’ states the game’s manual, reassuring the reader that this is no game of mere chance. The progenitor of the wargame on which Roberts based his games in Portsmouth was Fred Jane, a failed novelist who, in 1898, published the rules of a boardgame-style naval wargame in the Engineering Journal.16 Later that year, his books, Jane Naval Wargame and Fighting Ships, provided a formal set of rules, scorecards and ship diagrams, which were subsequently adapted by the navy. The game, which used scale ship models, a squared board and even some ping-pong-like bats to fire projectiles, was notable for its flexibility and realism. Jane tested the game aboard warships docked in Portsmouth Harbour and, four years later, a modified version was issued to HM Ships for training. It was a version of the Jane Naval Wargame that Roberts adapted at his posting in Portsmouth, more than three decades later.

The history of Jane’s

His job was dull but vital: ensuring the resupply of ammunition to the escort ships fighting the U-boats in the Atlantic. Estimating how many shells each ship might need on return to port may have been a desk job, but it nevertheless allowed Roberts to live vicariously through his calculations.

While the British could see from intercepted radio transmissions that U-boats were increasingly working together, providing the German vessels with safety in numbers, the specifics of their highly effective tactics could only be guessed at. The Admiralty graph that showed the number of merchant ships the U-boats had sunk each month was drawing close to the threshold of defeat. Pre-war Britain was the recipient of 68 million tons of imports. Usborne revealed to Roberts that this number had now more than halved, to just 26 million tons.18 Desperate to find ways in which to reduce the tonnage of inessential imports, and thereby free up space in the holds of merchant ships, Cabinet Office economists frantically noted that animals were being allowed to ‘eat shipping space… at a rate comparable with the rate at which submarines are destroying it’.19 ‘Unless something was done in the Battle of the Atlantic,’ Roberts was told, ‘we were going to lose [the war], merely because vital food and war supplies would not arrive.’ Moreover, ships were being sunk by U-boats at a faster rate than they could be built,* and the U-boats were now operating principally at night. Churchill was fretfully preoccupied with the situation. A few months earlier he had set up the Battle of the Atlantic Committee, which had focused its attention on the inefficient running of the docks, where weary and disenfranchised workers had been causing those imports that successfully made it to port to pile up on the...

1941 was horrendous in the Battle of the Atlantic

The rescued men were searched, and any documents deemed to be of interest seized. Macintyre’s crew found newspaper and magazine clippings lauding the exploits of the U-boats, which one article termed ‘Sea Wolves’. A sketched drawing was taken from another man. This document was of a different category to the clippings. It showed the crude outline of a convoy with a U-boat attacking from within the columns, a hand-drawn illustration of the tactic that had sent so many people, and hundreds of thousands of tons of food and supplies, to the ocean bed. Here, depicted in a few lines, was the secret to the U-boats’ success.

One unassuming bullet point also mentioned the fact that U-99’s crew had been searched and, among their possessions, an illustration of the point-blank tactics pioneered by Kretschmer had been found. The importance of the document apparently evaded those who read the report. The revelation was neither noted nor communicated to the escort commanders. The three aces were gone, but their pioneering tactic remained in play. Roberts, when he arrived in Liverpool, would have to discover it for himself.

Roberts’ task was threefold: discover the secret of how the U-boats were operating; develop effective countermeasures; and, finally, teach these new tactics to any and every captain who sailed the Atlantic. Tuberculosis may have robbed Roberts of the chance to serve at sea, but it had, in this unlikely way, provided him with an opportunity, one by which he could make his presence felt on every destroyer and corvette on the ocean.

Oblivious to Roberts’ ulterior motives, Walker outlined the tactic. On the order ‘Buttercup’, he explained, all of the escort ships would turn outward from the convoy. They would accelerate to full speed, while letting loose star shells–an explosive that, like a dandelion puffball, released iridescent fragments that hung in the air on a parachute for up to sixty seconds and illuminated the ocean. If a U-boat was sighted, Walker would then mount a dogged pursuit, often ordering up to six of the nine ships in his group to stay with the vessel until it was destroyed.

For Roberts, the exchange vindicated a long-held belief: with careful design, games had the capacity to make experts of amateurs, to instil in players invaluable, potentially life-saving, battle-winning experience.

Finally, there was the introduction of Hedgehog, a bow-mounted anti-submarine weapon that could spray a volley of mortar rounds directly ahead of the ship, toward a suspected U-boat location. The name derived from the weapon’s appearance: the twenty mortar rounds were bunched together at a near-perpendicular angle, giving the appearance of a hedgehog’s spikes. The projectiles were primed to explode not by fuse but on contact, and entered the war just as the U-boat captains had become adept at evading depth charges. By increasing the strength of U-boat hulls so that they could withstand the pressure at 600 feet, a U-boat captain could now listen on the hydrophones for the roar of a warship overhead, and the telltale splash of the depth charges, and immediately increase to full speed, turning sharply while diving. During the time it took for the depth charge to fall, the U-boat would have disappeared. The Hedgehog enabled the explosives to be hurled ahead, while the U-boat was still within ASDIC contact, and before it could turn and dive.18

Hedgehog

June Duncan, whose mother sewed stones into the hem of her daughter’s coat to cheat the Wrens’ minimum weight restriction, was one of WATU’s longest-serving members. After the war she worked as a fashion model for magazines such as Vogue and Harper’s Bazaar. (National Museums Liverpool)