WATU Wargame Report 2023

On Saturday 6^th May, the Western Approaches Tactical School was once again operational in Derby House for a celebration of the wargaming Wrens of WATU and the 80^th Anniversary of the Battle of the Atlantic. Analysts and wargamers from WATU’s direct-descendant organisations—Dstl, the Maritime Warfare Centre, and HMS Eaglet—took up the roles of WATU Wrens, RN Convoy Escort, and dastardly U-Boats, joined by folks from Defence Academy Shrivenham, US Navy, McGill and York University.

Our WATU Wrens and players were a mix of new wargamers and old hands, men and women, professional and hobby wargamers, serving and retired naval officers, and academics.

The challenge on the Tactical Table was the night of 6^th/7^th May, 1943. A moderate sea, bright moonlight, and intelligence reports of five U-Boats operating in the vicinity of (the entirely fictional) Convoy ONS 506, a slow convoy comprising 12 ships sailing for Halifax. Escort Group B7, consisting of HM Ships D1 (destroyer and Senior Officer Escort), L1 (Black Swan class sloop), and Flower class corvettes P1, P2, P3, and P4, were in Night Escort Six disposition. A substantial wolfpack attack developed at midnight, beginning the game with the torpedoing of the merchant ship in column 3 row 2.

Here’s what the first view-giving looked like, and the same plot from the Wren’s perspective:

The gap in the convoy is our sinking merchant ship. Where could the U-Boat be that fired the torpedo? How many other U-Boats are making an attack? Their tracks are plotted in red pen to hide them from the players. The U-Boat positions are highlighted on the right for clarity, the star is a mischievous shoal of fish.

The first view-giving included the burning wreck of our merchant ship and a surfaced U-Boat sighted at the rear of the convoy. L1 closed for an exchange of gunfire, here is their (and other’s) orders:

Our players had a copy of the relevant parts of the Atlantic Convoy Instructions, including Op: RASPBERRY, which was quickly ordered and developed two asdic contacts at the front of the convoy.

Our Wrens made use of the adjudication tables to decide which of the in-range radar (all of them at this range), asdic and visual contacts to report. Here’s a few turn’s worth of contacts for L1, and a large stack-o-signals:

Oh goodness, there were signals. There were so many signals. WATU had a team of three Wrens and an RN Yeoman handling signals: players handed in signals to be sent, the Wrens copied them to all recipients, and delivered them after some transmission delay. In our game, Lynn O’Donnell handled everything, and our players sent so many signals that we ran out of paper. Here’s a few of them:

While all this was going on, visitors to the museum were grilling Paul and Lt Phil Roberts RNR (Rtd) about the game and the history:

Meanwhile, some familiar faces, and actual submarine warfare officers, were busy plotting the demise of our convoy, upstairs in Admiral Sir Max Horton’s office. While submerged, they didn’t get a look at plot, when surfaced they could peek out the window down onto the plot in the Map Room. Their orders and contacts were sent over the museum’s wifi:

How did our Escort Group do?

It was carnage in the convoy! Six merchant ships lost. But the Escort managed two creditable depth charge attack runs, one of which forced the target to the surface in what was likely to be its death-throes. They also avoided depth charging the shoal of fish (which was mostly down to failing to get an asdic contact rather than good judgement…)

Here is the 1943/2023 edition of the After Action News, hot off the press:

WATU NewsDownload

See also Report of Proceedings from MacKay, RNWR, in command of sloop L1, here.

How realistic was the game?

Well, there are a few reasons why the U-Boats had the upper-hand:

Firstly, in the interests of a fun time for all, our U-Boats all started within 2,000 yards of the convoy. In reality, U-Boats tended not to attack simultaneously like this. Particularly not when using pattern-running torpedoes (as we were), because of the risk of friendly-fire incidents.

Second, we only played 12 minutes of game-time, and an engagement is typically 30 minutes plus. Knowing we were unlikely to play out 20 minutes, we started in-media-res with the U-Boats well inside radar contact range and the extended screen. It’s likely at least some of our U-Boats would have been caught further from the convoy, allowing time for interception before they were able to get off any torpedo shots, which would have improved the score sheet for the convoy somewhat.

Third: the score sheet seems to favour the U-Boats, but one U-Boat was probably not going to survive the next 2 minutes, and the other two were not going to cause too much more trouble for a time. If the game had gone on longer I think we would have seen the tide turning in favour of the Escort.

Finally, the losses seem pretty high, but our convoy was extremely small (for convenience, and for interest—a bigger convoy would mean spending most of the game steaming to get near-enough to contacts to do the fun stuff). The whole point of the convoy system was that the losses were similar regardless of the size of convoy; a bigger convoy would have lost proportionately fewer ships.

In terms of the gameplay: it was certainly a lesson in communication between the Escort players, to co-ordinate a response to contacts without the screen descending into magnet-ball. The outcome of actual attacks were pretty realistic: with a lethal range of only 7 yards, depth charge attacks were about 10% effective. U-Boat kills generally came from hunting to exhaustion, which Escort Groups could not afford to do—this is why Support Groups were introduced in March 1943. We didn’t have enough players and Wrens to support more than six in our Escort, so even if we’d played longer, the chances of killing the submerged U-Boats were small.

The ploting & adjudication rules revision/expansion/better-recreation since the 2018 game made for a much more interesting game: the U-Boat players were thinking about more than just shoot-dive-hide, and there was a passable attempt at RASPBERRY from an Escort group who (with the exception of the Senior Officer Escort) had zero experience of ASW tactics.

I want to thank the Western Approaches Museum for hosting our game and giving us free-run of the Map Room, and about thirty Dstl & MWC folks who took part in the playtest/training games as well as the Big Event. It was pretty special to play a Derby House Principles wargame in the actual Derby House. I had an absolute blast. So did Tom’s U-Boat (har dee har) !

WATU Wargame Returning to Liverpool

It’s the 80^th Anniversary of the Battle of the Atlantic, and back in 1943, the 6^th May marked the turning-point where we stopped losing and started making life so difficult for U-Boats that for a time they withdrew from the Atlantic entirely, and when they returned (in September 1943) they never again had the upper-hand.

So what better time to recreate the Western Approaches Tactical Unit wargame at WAHQ again?

Formed in 1942 to solve the U-Boat problem in the Atlantic, WATU was staffed almost entirely by women, and men unfit for duty at sea through illness and injury. The Wrens came from all walks of life and all across (what was then) the Empire, and were responsible for teaching the Allied navies convoy escort tactics: how to find and sink U-Boats. 

Since the last time we played in 2018, I’ve found WATU Wrens alive and kicking, and learnt a lot more about how the game works, so this time we’re playing with:

Actual pieces from the WATU game:

When WATU demobbed, Cpt Roberts gifted the ships to the Wrens as souvenirs: Leading Wren Helen Coop’s ship has been scanned using photogrammetry, turned into CAD, and lovingly recreated by Ian Greig.

In grey is a test-print with a filament printer, in translucent is a print from a UV-setting resin printer, and one laser-cut from wood, ready for painting:

Actual game chits:

Leading Wren Helen Coop left us a treasure-trove in her scrapbook, including chits from actual WATU wargames played by Cpt Johnny Walker’s support group:

Nothing changes in wargaming: after rolling a 1, Cdr Wemyss would like a new gun crew please :-P

Plotting tools:

In the 2018 game we used a crude movement template to help with plotting, and mostly ignored turning circles. This was partly a simplification to help the players (WATU had the distinct advantage that their players came knowing how to command their ship and plot it on a chart! Our players were liable to try impossible things), and partly due to a lack of data. Since then I’ve found a lot more photos with details of the plot, and hunted down data on period ships which was not easy to find. 

The result is this Rather Excellent [TM] recreation of the plotting protractor, laser-cut by Ian Greig. They work magnificently well and look amazing. Figuring out what they were from a handful of WATU photos might be my favourite bit of wargaming geekery :-)

Side-by-side comparison of the Canadian Tactical Table protractor and our recreation.

Actual adjudication tables (probably):

Chris Carlson dug up some post-war ASW tables which are probably a later version of the WATU adjudication tables. One of the big mysteries of the WATU game has been how all that stuff happened, since the pre-war (1921 & 1929) RN War Game rules are not the WATU game (it’s a fundamentally different game that’s been mistaken for the WATU game by some because it mentions “screens”, but it’s very clearly talking about putting down screens on the plot to screen the surface ships from each other when they’re out of visible contact, not viewing the entire plot from behind a screen to obfuscate the U-Boat tracks on the plot), and the contemporary descriptions forget to mention how you adjudicate an attack. Even these tables don’t really explain how they’re used, but they fit broadly with the assumptions we made for the 2018 game, which is pleasing! 

Well…all except one thing: we used D100s, and it turns out that because dice were too new-fangled (or D100s were hard to come by in 1942, or the Temperance Movement had words), WATU used a 1 to 100 tombola.

I appear to have bought one large enough for Raspberry to go to sea in… stop by WAHQ during the game and you can draw the fate of a U-Boat, Escort, or merchant ship from the adjudication tombola :-)

U-Boat artefacts:

Big Heritage, who run the WAHQ museum, acquired a U-Boat during lockdown, and are busy renovating it and creating a Battle of the Atlantic Museum across the Mersey from WAHQ.

The original plan for this game was for the U-Boat players to play from the actual U-Boat, but the new museum is still a building site, so instead we’re bringing some of the U-Boat artefacts over to WAHQ for the day. Our U-Boat players have been practicing with attack discs to get their firing solution. We’ll see if they’re able to sink anything!

We’re also hoping to make use of the Y-Service teleprinter which has been refurbished to run off a Raspberry Pi, for sending our convoy relevant Engima decrypts.

Come to WAHQ on Saturday 6^th May and you’ll get to:

• Celebrate the remarkable achievements of the WATU Wrens!
• Chat with the direct descendants of WATU about careers in professional wargaming: yes, you can get paid to play board/war/computer games for a living ;-)
• See the WATU game in action, send some signals to the convoy if you’d like.
• Explore the Western Approaches Museum, including their new Wrens exhibition, Leading Wren Helen Coop’s WATU scrapbook, and bits from their newly-acquired U-Boat.
• Say hello to a handful of PAXsims editors :-P
• Delight in a Derby House Principles wargame being played in the actual Derby House that the principles are named for. 

Canadians can also check out the WATU gallery at the Canadian War Museum‘s up-coming wargaming exhibition.

Read more about the Derby House Principles for diversity and inclusion in professional wargaming here.

Holographic Tabletop Gaming

Tilt Five is a table-top holographic projection system. It’s very cool!

How it works:

• An IR camera in the glasses gets tracking data from the dots at the edges of the board
• The glasses get the display output of a PC or android device by USB 
• Two seriously cool micro-projectors in the glasses throw the image at the board
• The retroreflective board throws the image back into the player’s eyes
• There’s also a controller which is tracked by the headset camera. It has a gamepad stick, buttons, and trigger, as well as having its position and rotation tracked in 3D.

That means:

• The player sees the holograms at their in-world distance, rather than being projected onto the inside of the glasses. That makes the holograms actually appear to be in the world, rather than rendered in front of the world with clipping to give the illusion of being rendered “behind” objects. This is a big deal for preventing eye-strain for the player because you get to focus on the object at it’s actual depth. VR headsets and the Hololens force your eyeballs to decouple focus and convergence to maintain the illusion of depth, because everything is rendered an inch from your face.
• You’re not going to see motion sickness like you would in VR. Partly because the real world is still there to keep your vestibular system feeling grounded, but also because the refresh rate on the headset is spectacular (150fps !). A lot of VR-based motion sickness is to do with marginal frame-rate causing an almost-imperceptible lag between tracking and the visuals updating.
• Multiple headsets connected to the same device can view the board at the same time, each getting the view that makes sense for the tracked position of their headset. It’s a shared experience without needing to network the game over multiple devices.
• The retroreflective board means the holograms are bright and the colours vibrant even in a well-lit room, something the Hololens can really struggle with.

What kinda things can you do with it?

That conceptual difference of “it’s a shared experience around a table” is where the Tilt-Five excels. It’s marketed as augmented reality for boardgames and RPGs, sort of like Battle Chess on steroids meets Roll20. You can already buy Catan, Tabletopia, and other Steam Games, and a DnD/RPG sandbox called Battle Map Studio.

Here’s a procedurally-generated island:

It’s particularly suited to a top-down style strategy map view of the world, which makes sense given the boardgame focus in development. 

Here’s a work-in-progress porting Tom Mouat’s 8” hex WW1 trench raid RPG to the Tilt Five: the little dudes are selectable by poking with the wand, and route-plan to a point on the map with a strong preference for staying in cover. You can set them to standing, crouching, or crawling with wand buttons. Guns and baddies TBD ;-)

You can also use the board as a TARDIS-like ‘well’, or window into a 3D world below the table surface that is larger than the board (but only visible through the board).

You’re still able to see and interact with the real world with the glasses on, unlike VR where you’re isolated in your own personal view. You can create a holographic dungeon for use with your physical 28mm miniatures. Or you could hook it up to:

• Drive other projection systems: eg a Google Maps style bird table interface to pull StreetView images to a 360 projection system, using actual Google Maps, or your simulated environment
• Visualise other projection systems: eg a strategy map style view of people in VR, as an alternative perspective to first-person view for over-the-shoulder observation and AAR. It can be maddening directing someone in VR when all you can see is what they’re currently looking at
• Visualise 3D data, photogrammetry, CAD, or provide situational awareness like a 3D HUD

How about a nice game of thermonuclear war?

The multi-headset support means you can make multiplayer games without compromises like split-screen and hot-seat, and without needing to network computers—which is both a skillset all of its own, and an added complication when working at classification.

Is it analytically useful, beyond being very cool?

As someone who makes games for serious purposes, 99% of the time that someone asks “Can you do this in VR?” the correct answer is “Yes…but I don’t think that’s actually useful for you…” stuff isn’t just better because of immersion. Augmented reality is the same: just because you can do a thing does not mean it’s providing more value than a standard monitor or a board-and-counters physical copy of the game.

Compared to a physical game, adding a computer has obvious advantages:

• The computer keeps score, and can show you lots of complex data in ways that gets very messy and complicated if you’re doing things by hand
• Hidden information can exist on the same plot, and we can very easily control who sees what, rather than having to use compromises like a kriegspiel where you can see the blocks but just don’t know what units they are, or maintain two plots and hope they don’t get out of sync
• More intuitive displays of information: you can show dynamic information, like see that a unit is dug-in, firing, or reloading directly with the artwork, rather than having to use abstractions like turning the piece sideways, or this coloured block on a tracker that’s somewhere else on the table. You can also call up context-relevant rules and stats very easily, and without giving away information to the other side about your intention when you start measuring ranges and line of sight.

But these are things that you can achieve on a standard monitor. Can a Tilt Five do more, or differently?

Probably the biggest thing it does is that social aspect: you get all the benefits of four players with their own laptop screens, except that it’s all happening around the same board. All the players are seeing the same game-space but it’s still possible to control individually what they see—I can set the culling masks so that enemy units don’t render for you unless your units have LOS to them, and you get your own user interface which shows only the stats you should know about. Whether this is a competitive or cooperative game, you’re all looking at the same board and able to point out things to each other directly, rather than having to talk someone to pointing their screen in the right direction to see what you’re seeing. 

The other clear advantage is the 3D. It’s very compelling in ways that are hard to convey through 2D captures. The parallax effect is magical. You can share a 3D tabletop setup across physical space with a networked game—instead of having one physical board and distributed players getting only a webcam view of the game, as many of the players as you like can have holographic boards.

In terms of interface, there’s just something more intuitive about being able to crane your head to look at where you want to place a piece and tap the spot with the wand, instead of wrestling with camera position and rotations to get the view to click with a mouse. This might seem like a trivial thing to folks who play a lot of real-time strategy games, but it’s a big barrier to entry for folks who don’t (who are often our customers). I saw this first hand using VR with the Army: give a soldier a VR controller for a shooting game and there’s a “what buttons do I press?” panic; give them a Nerf rifle converted into a VR controller and they visibly relax because they know how to use a gun.

Finally, there’s the wow-factor for communicating with your audience either during the game or in AAR. Sometimes you want to put your data’s best coat and gloves on. Some people equate how good a game looks with how robust its findings are, and will take your recommendations more seriously for being a wizzy hologram. (I know, it makes me sad too.) Sometimes the game needs to feel compelling for people to engage with you, and there is nothing wrong with using cool tech for the engagement value.