Wednesday, 22 November 2017

Denmark Strait Scenario Notes: 24th May 1941 (Wargame) - Quite a big post

Scenario specific details/notes to self on playing The Battle of the Denmark Strait:

Contact: Set-up: 05:35 24/5/41
KM Bismarck and Prince Eugen sailing at 28 knots on course bearing 220 degrees

The German lead in (see below, but not quite the final set-up, PE leading Bismarck following):

Range between RN and KM when smoke first detected: 34,000 yards (17 nautical miles)

Note: German hydrophones on the KM Prince Eugen picked up the approach of two ships while "over the horizon". Lutjens believed them to be additional shadowing cruisers and was amazed to discover two RN capitol ships bearing down on them. One identified as HMS Hood. This was the worst case scenario wargamed by the Germans as despite her age they knew they could not out run the Hood. In fact Admiral Holland in HMS Hood had asked Captain Leach in HMS Prince of Wales if she could make more speed. To which the reply was, "not without damaging her", The crew report HMS Prince of Wales was "rattling herself to pieces" as it was while she tried to keep up with the Hood (28knots). In effect HMS Prince of Wales was still very much "working up" (with civilian contractors and dockyard hands aboard).

HMS Hood and HMS Prince of Wales sailing at 28 knots on course bearing 240 degrees
At 05:38 turn of 40 degrees to 280 degrees course heading
At 05:49 turn of 20 degrees to 300 degrees course heading

The British set-up (see below):

Both fleets are on converging courses. The KM are moving away from the Greenland ice shelf being shadowed by HMS Suffolk and HMS Norfolk under the command of Vice Admiral Wade Walker RN. The HMS Hood and HMS Prince of Wales under the command of Admiral Holland are intercepting. The screen force of four destroyers are still to the east of the BCF (Battle Cruiser Force).

Note [Other RN Forces, HMS Suffolk and HMS Norfolk, plus the BCF screening destroyers (4)]: In this scenario both the shadowing cruisers and destroyers play no active part other than after a certain time limit they would have to be factored in as ready to engage. The Germans (KM) needs to have "won" by that point.

At 05:53 HMS Hood opens fire on Prince Eugen at extreme range, historically 26,500 yards, nearly over the horizon shooting.

The range is converted from inches to cm is 106 (so4cm per 1000 yards) due to the constrained playing area (this makes the ships appear overly large in context - maybe 1/6000 would be a better representation?)

HMS Hood (leading) and HMS Prince of Wales (astern at 80 degrees) are in a quartered formation (see below, given the large size of the ship in proportion to sea space this is done more for visual effect than simulation accuracy):

Because X and Y turrets on HMS Hood and Y turret on HMS Prince of Wales historically could not bear the German fleet is pushed some 12" in from the 'table edge' (apologies for mixing imperial and metric measurements) placing it slightly ahead of the British BCF (Battle Cruiser Force). The angle between the two fleets should be 80 degrees with the Germans slightly ahead, enough to mask the British rear turrets from firing.

Note [British Erroneous Targeting]: Historically HMS Hood fired first and she was targeting the wrong ship (KM Prince Eugen). The reason for this being that the shadowing cruisers had last seen KM Bismarck leading the German formation and it was assumed that this was still the case. However Bismarck had discharged her main battery at the cruisers and in so doing so "knocked out" her own radar. The KM Prince Eugen therefore took the lead.

Note [German Command and Control "Freeze" and Poor British Gunnery Mechanism on HMS Hood]: The British fire from HMS Hood is a freebie as historically Lutjens froze giving no orders to return fire. owever given the antiquated WWI Dreyer fire control system on HMS Hood only a roll of "0" on a d10 would hit (GQII WWI Gunnery Rule). The first opening salvo from HMS Hood misses much to the consternation or relief to the crew of the KM Prince Eugen. In fact Holland (in the Hod realised by observation of the Prince of Wales he was shooting at the wrong ship and ordered "shift to second ship" but this order historically did not come into effect as the Hood blew up. To simulate this lag HMS Hood has to fire on the Prince Eugen  for the first three turns. If Hood makes a radical turn of 45 degrees or more her Dreyer gunnery tables need time to recompute, so she suffers -10% chance of hitting for that turn (as the Dreyer tables were poor when the rate of change varies greatly, strictly speaking this could apply if the target was changing course and speed to but I am trying to keep it 'relatively' simple).

Note: [The "Weather Gauge" disadvantages the British.] HMS Hood and HMS Prince of Wales were running into a heavy sea and the light advantage was to the German favour (dark horizon and silhouetting the RN). In particular HMS Prince of Wales (and all KGV class ships) were very "green" and took in lots of water over their forecastle. "A" turret was ankle deep in icy water for the whole battle. Hence British Gunnery is reduced by 10% in its chance to hit.   

Note: ["Crack" German Gunnery] "Until" the first successful straddle the Germans gain a 10% modifier chance to hit a British ship. This is to reflect the initial sharpness of the German guns on the day of the battle as they straddles their targets almost immediately.

Note: [HMS Prince of Wales erratic gunnery, "teething problems"] Due to her status of "reporting for duty" but in fact was not fully yet worked up HMS Prince of Wales has gunnery problems. At the time of the battle she had never initiated a full broadside. Something always broke. The quadruple 14" gun turrets were the problem. The RN did not solve these problems in KGV class battleships until mid 1943. Hence when HMS Prince of Wales hits a d6 is rolled:

1: 50% of armament boxes
2: 100% of armament boxes
3: 100% of armament boxes
4: 100% of armament boxes
5: 100% of armament boxes
6: 100% of armament boxes

On reflection this might be actually "too" generous?

Firing begins and something of interest almost immediately happens. HMS Hood is straddled by the Bismarck losing a turret and a hull box plus a "critical" is rolled (see below, will history come alive"?):

With bated breath we see extensive boiler room damage and she is reduced to half speed (6cm) becoming an annoying blocking hazard to HMS Prince of Wales (see below)

More smoke is added for aesthetic purposes (see below):

Heavy blows indeed against the RN on the first turn. No hits were landed on Germans in return. Holland (in HMS Hood) performs a radical turn towards the enemy to allow HMS Prince of Wales to fire this turn and pass by her next turn. This allows HMS Hoods "T" to be crossed by both the KM Eugen and KM Bismarck (see below):

The Germans look Teutonic and menacing, while in the distance smoke is belching from HMS Hood (see below):

The ships move and fire again. HMS Hood this time lays into the KM Eugen, despite the adverse weather gauge and her old RN 15" gun she takes two hull boxes and halves her speed in return (down to 6cm). KM Bismarck suffers from good gunnery from HMS Prince of Wales, losing a turret and a hull box (see below, note RED indicates visible damage to the enemy [such as a destroyed turret], BLACK not so obvious damage that is not disclosed to the enemy or simple no damage but a straddle):

Hoods "T"has been well and truly crossed. She is punished losing another turret [A] and taking another hill damage reducing her speed further (3cm). HMS Prince of Wales however is cleared for action (see below):

More damage on the KM Prince Eugen sees HMS Hood take out an eight inch turret (see below, note both German ships have been reduced to 6cm and HMS Prince of Wales is making steady progress to cross the Germans "T" in the not so distant future):

HMS Hood is hammered. More critical damage to her boilers stops her in the water and she is reduced to a single forward turret firing. The German battle line however has been hammered. KM Prince Eugen is really only a threat with respect to her torpedoes and Bismarck has just to say got two functioning main turrets. The (erratic) gunnery from the Prince of Wales is hurting (see below, the poor battered Hood):

HMS Prince of Wales finally bring the KM Bismark to her knees reducing her to 3cm speed. There is no way she can either become a commerce raider or even realistically escape additional units of the RN. Especially as HMS Prince of Wales is untouched (albeit with implicit gunnery problems). KM Eugen cannot escape either. The game is called a RN victory. The German ships do not have enough umpf left (see below, the broken and battered HMS Hood lies to the top left, but the unbroken HMS Prince of Wales steams off to the right ready to administer the "coup de grace"):

Additional smoke is now seem from HMS Suffolk and HMS Norfolk closing. The KM Prince Eugen is their target. Admiral Holland issues a visual lamp order to the destroyer escort which now arrives on the scene: "Execute torpedo attack on German Battleship Bismarck". Her fate is sealed.

An enjoyable play test. A few things were played wrong on the night but corrected in hindsight. Nothing that would have changed the outcome of the above.

Final Rule Notes:
Basic GQII: Multiple ships firing at same target, 2nd+ ships -10% to hit target
House Rule: If your ship is straddled then it is -10% chance to hit (being put off by shell splashes)

Result: Comprehensive RN Victory

HMS Hood should be "salvageable" although perhaps a constructive loss
The KM Bismarck and KM Prince Eugen look "doomed" their loss of speed being the biggest factor that weighs against them. They are now targets for destroyers, cruisers, submarines, swordfish and that is not to mention the fully functioning HMS Prince of Wales. In addition HMS King George V in accompaniment of  HMS Repulse with HMS Victorious will soon be within striking range.

It makes the events of the battle all the more fascinating and thought provoking given the catastrophic loss of HMS Hood.


David Crook said...

Hi Geordie,

Excellent report old chap and one that almost had me reaching for Ludovic Kennedy's book on the Bismarck (I have a few others but that was the nearest to hand!).

The last time I fought this (also using GQ1/2)the result was Hood sunk, POW and Bismarck battered beyond belief and the Prinz Eugen had no armament boxes left but could still rattle along at full speed.

The whole operation is a fascinating one and makes for a great campaign exercise.

Very well done sir!

All the best,


Geordie an Exiled FoG said...

Cheers David,

IMHO the GQII stats for HMS Hood make her an excellent WWI ship but do not age her in comparison to the BAs in WWII

One key issue that did not come out in the re-fight was the fact that for Hood's old 15" guns to work she had to get into the 59" (or in my case cm) range band to punch through BA armour vertically. That was because PoW did a good job at hammering the Bismarck.

All interesting stuff indeed ;)

I want to get another tabletop run-out before we take it to the Stockton Battleground Wargames Show this Saturday 25th November (shameless plug).

TO ALL: If you are at the show please come along and have a chat. Opinions welcome .. and wargamers have a few ;)

Ian Robinson said...

Excellent post, and I can't wait to restage this with you. Rerunning the same scenario to get an average result would be interesting, rather like the study Neill MacKay's group at the University of York did for Dogger Bank & Jutland.

Paul Liddle said...

Smashing game, wish I could go to Stockton but I have to go to work.

Stryker said...

I agree - excellent report on a fascinating encounter. If you played it ten times I wonder if you'd ever get anywhere near the same result twice!

Geordie an Exiled FoG said...

My good friend Renko showed me this nice Uou Tube video of a new game called Atlantic Fleet:

This is The Battle of the Denmark Strait
The ships look really nice!

Geordie an Exiled FoG said...

I hope to get through another dry run before the Show and a couple during the game

I hope to mix the display with 1/3000 and tactical 1/1200 displays

Geordie an Exiled FoG said...

Cheers Ian, I am getting excited ;)