WATU wargame report

On September 8, volunteers from the Defence Science and Technology Laboratory, the Royal Navy, the Royal Canadian Navy, and PAXsims paid homage to what may have been the most consequential wargaming of World War Two: the work of the Western Approaches Tactical Unit. WATU contributed greatly the development of anti-submarine tactics, and also taught more than five thousand British and allied escort officers during the war. Most of those wargamers were women too.

The event was hosted by the Western Approaches war museum and held in the map room of the wartime headquarters of Western Approaches Command: an underground bunker beneath the Exchange Building (Derby House) in Liverpool. During the war, WATU had operated from an upper floor.

Setting up the plotting map. The screens on the right prevent the escort commanders from seeing the map, except when permitted to peek through small visors. Red filters in these prevent them from seeing the U-boat tracks.

The plot viewed through the visor. U-boat tracks are not visible.

The screen from above, with the tables for the escort commanders beyond.

Nefarious U-boat commander Tom Mouat (Defence Academy of the UK/PAXsims).

Some of our lovely simulated Wrens.

Pre-game briefing.

The WATU wargame underway. The convoy, escort, and U-boat positions are being plotted on the floor, while escort commanders plan their next moves beyond the screens.

The game started with U-305 (U1 on the plotting floor, commanded by your scribe) having penetrated the escort screen on the surface at night, and attacking from within the convoy. One ship went down, and I ordered my vessel to submerge to periscope depth and to turn slightly to run under the convoy.

Meanwhile, U-501 (U2) approached on the surface from outside the screen, hoping to attack while the escorts were distracted.

The U-boat commanders smile as they celebrate their first sinking of a merchantman.

Alas—or fortunately, depending on your perspective—it wasn’t to be so. As soon as the first ship was hit, HMCS Ottawa (L3) made a high-speed dash into the convoy and ran straight into the still-submerging U1, which it had not yet spotted. The damage was enough to force U1 to the surface. I ordered my submarine to run close alongside the Canadian destroyer, hoping her guns would not be able to depress sufficiently to engage my much smaller vessel. My own 88mm deck gun fired into the escort at close range and I also fired a spread of my remaining bow torpedos at the damaged HMS Starling (L1) as she approached to assist. However, soon U1 began to sink. I ordered the Enigma machine and codebooks thrown overboard and we abandoned ship.

Image of a WWII WATU wargame in progress. Note the plotting of the convoy, escorts, and submarines on the floor, as well as the screens.

WWII WATU wargame in progress. Wrens point out ships and current situation for officers viewing through screen.

Meanwhile, U2 fired a spread of torpedos into the convoy, sinking one freighter. Its lookouts failed to notice a Royal Navy destroyer (O1) bearing down her through the dark night until it was almost too late, however. Fregattenkapitän Mouat ordered a crash dive, which was soon followed by the thunderous explosions of depth charges overhead. With a drive shaft damaged, the wily Moaut ordered that oil be vented and rubbish discharged through the torpedo tubes to suggest his vessel had been destroyed. HMS Vanquisher was having none of that, however, and continued to drop depth charges. U2 would eventually be sunk with all hands.

U1 sunk, U2 under attack.

As this was ongoing, U3 (Brynen) approached from the front of the convoy submerged, while U4 (Mouat) proceeded on the surface well ahead of the convoy to report its location to Kriegsmarine headquarters back in Germany. These transmissions were picked up by HF/DF (High Frequency Direction Finding), and minutes later U4 itself was spotted on radar by HMCS Orillia (P1). Mouat turned slowly, and then proceeded south at top speed, hoping thereby to draw off escorts before eventually submerging and doubling back.

U3 continued to creep forward, until it was within 1500 yards of the convoy. It then fired two pairs of torpedoes from its forward tubes. A short while later hydrophones reported more explosions as two merchantmen were hit. The wolfpack had now sunk four ships in the convoy, and damaged two escorts.

The plot. U4 (bottom) has just begun its dash south with escorts in pursuit. The white markers indicate the depth charges dropped by O1 on U2, while U3 is nearby, having just fired torpedoes and turned.

…and there we had to finish as the day came to an end.

We all had a terrific time, and the 130 visitors who passed through the museum while the wargame was underway seemed to find it all very interesting too. It was particularly gratifying to meet with the daughter and granddaughter of wartime wargaming WATU Wren officer Laura Janet Howes.

The daughter (right) of WRNS officer Laura Janet Howes poses with a card summarizing her mother’s wartime career.

The commander of HMS Vanquisher points to the last resting place of U2.

Enormous thanks are due to the Dstl team that made this all happen, and especially Sally Davis and Paul Strong. Emma Stringfellow (Big Heritage) and the rest of the Western Approaches museum staff were terrific hosts, happily putting up with twenty or so of us moving things around, talking loudly, and even playing ASDIC noises and dive alarms. The screens produced by Alfred Chow (Maker of Things) were perfect for the task. Steve Cowan recreated the HMS Tactician/WATU crest, which was emblazoned on the shirts of many of the wargaming crew, and on commemorative mugs available in the Western Approaches gift shop.

I would like to personally thank Cmdr Jeffrey McRae (Royal Canadian Navy) for joining with the Royal Navy to mark the occasion, taking on the role of an escort commander (HMCS St Croix). Some five hundred Canadian naval officers were among those trained by WATU during WWII, and a similar tactical training unit (modelled on WATU) was established in Halifax in 1943.

The WATU wargame is an excellent tool for teaching about wargaming, operations, research, the Battle of the Atlantic, and the contribution of women during WWII. Visitor after visitor expressed how interesting it was, and how analysis, gaming, and outthinking an opponent all converged in the kind of work WATU did. I certainly hope this becomes at annual event at the museum, and the Dstl and RN volunteers who made it happen are able to organize similar events elsewhere in the UK.

The Dstl/RN/RCN/Defence Academy/PAXsims crew, including nefarious U-boat captains Mouat and Brynen.

Finally, if you are in or visiting the Liverpool area, go and see the Western Approaches museum (where, for a limited time, you can get your very own HMS Tactician/WATU mug). They’ve done a terrific job rennovating the facility, and it is well worth a trip.

RN officers demonstrate appropriate protocol for carrying a simulated Wren.

We had a great time with these folks ! https://t.co/3Xp93iFwIM

— Western Approaches (@WestApproaches) September 9, 2018