Clash of Empires World War 2 Japan’s Attack on Pearl Harbor 1941
In this article I’m going to use the Clash Battle System to recreate Japan’s attack on Pearl Harbor Dec 7, 1941. This event ensured that America would become a full participant in the war. Germany and Italy declared war on the U.S. on December 11th. At the Arcadia Conference in Washington on January 1942 the British Prime Minister Winston Churchill and President Roosevelt together with their military advisers devised a strategy which gave priority to the defeat of the Western Axis. After this was achieved then America and Britain would bring to bear overwhelming military force against Japan. From this point on the successful prosecution of the war depended upon the full cooperation of the Allies.
Background
The main impediment to Japanese expansion in the Central Pacific was the presence of the U.S. fleet at Pearl Harbor in Hawaii. Therefore, to prevent any American interference the Japanese Admiral Yamamoto devised a plan for a daring surprise attack upon the U.S. naval base. However, Yamamoto recognized that this attack would have to deliver a complete victory because Japan had little hope of competing with the industrial might of the U.S.A. in a protracted conflict. After neutralizing the mighty U.S. Pacific Fleet, the Japanese planned to seize control of the countries of Southeast Asia which had everything that Japan needed for its war effort i.e., oil, tin, iron and rubber. Once this was achieved Japan planned to protect its new acquisitions by creating an impenetrable defensive perimeter.
Under the command of Admiral Nagumo, the Japanese First Air Fleet consisted of 6 aircraft carriers supported by two battleships, three cruisers, nine destroyers and three submarines. On the 26th of November the fleet left its assembly area in the Kurile Islands and in complete secrecy steamed some 3000 miles to within striking distance of the Hawaiian Islands. A declaration of war was made but it was received too late and a radar detection of the raiders was misidentified and therefore not acted upon. However, the Japanese didn’t have it all their own way as two of their prime targets weren’t present at Pearl Harbor on the day of the attack. These were the aircraft carriers Lexington and the Enterprise that were on manoeuvres in the Pacific.
Early on the morning of the 7th of December 360 Japanese aircraft were launched in two waves. The first wave caught the Americans completely by surprise and torpedo bombers using specially adapted aerial torpedoes that could operate in shallow water sunk four battleships moored along Battleship Row in the Harbor. These were the Arizona, Oklahoma, West Virginia and California. Many other vessels were also badly damaged or sunk. In addition, Japanese bombers targeted five military airfields where the aircraft were out in the open and parked closely together on the ground. Consequently, nearly 200 aircraft were destroyed. The second wave didn’t cause as much damage as the raiders were hampered by smoke and ferocious anti-aircraft gun fire. Nagumo decided not to risk a third wave because he feared a counterattack from the missing U.S. carriers and therefore the harbor installations were left intact.
In fact, Nagumo’s caution and the reluctance to follow up the attack with an amphibious landing may well have cost Japan the war. For now, however, Japan was in the ascendant and America’s unpreparedness for the attack on Pearl Harbour resulted in a major defeat in which more than 3000 American personnel were killed and 18 vessels sunk. The Japanese lost 29 aircraft. Despite the damage caused and the terrible loss of life most of the ships were repaired and the naval base was back to being fully operational within a year. Therefore, the attack only represented a temporary setback for the Pacific Fleet. Nevertheless, immediately after the attack on Pearl Harbour Japan was able to carry out its planned actions in Southeast Asia. This series of offensives 1941-1942 included the capture of the American held Philippines and the conquest of British controlled Malaya along with its so-called impregnable fortress naval base in Singapore. However, America would have its revenge for what President Roosevelt termed a “Day of Infamy” by achieving a decisive victory over the Japanese navy at the Battle of Midway on June 4th, 1942.
Using the Clash of Empires rules the battle strength and capabilities of the combatants can be shown as follows: -
An Airforce unit represents 10 operational aircraft. A unit must lose 75% of aircraft to become ineffective.
The Japanese Strike Force
The Japanese Navy is made up of modern warships whose crew and aviators are expertly trained and well equipped. Therefore, the Japanese Strike Force rolls 2D10 for its Battle Dice (highest scoring die only). The Japanese First Air Fleet consists of 6 aircraft carriers supported by two battleships, three cruisers, nine destroyers and three submarines. In the game Aircraft carriers have a Combat Rating (CR) of ❷, the Battleships ❽, Cruisers ❹ and Destroyers ❷ or ❺ versus Submarines. Submarine CR varies depending upon the target. This gives the Strike Force a combined Fighting Bonus (FB) of +29 although this will only be needed in a big fleet action. The main advantage of aircraft carriers is their ability to launch air raids. Carriers can carry up to 100 aircraft aboard (Fighter bombers, Dive-bombers and Fighters). Japanese carriers are smaller than their American counterparts and can carry up to 80 aircraft. Each carrier can launch a maximum of three air raids. The First and second raids will each be made up of 50% of available aircraft, whereas aircraft launched in the third raid cannot exceed 30% of the carrier’s total compliment and will not have surprise. The most potent Japanese aerial weapon is the Mitsubishi AGM Zero carrier fighter which in the game has a CR of ❷ and +1 to Initiative. Also being used is the Aichi D3A naval Dive-bomber which has a CR of ❶ but due to a lack of manoeuvrability also suffers from a -1 penalty to Initiative. This profile is shared by the Fighter-bomber and Torpedo-bomber with the main difference being their bombing to hit roll. The standard Japanese carrier-based torpedo-bomber is the Nakajima B5N. Zero fighters provide a Combat Air Patrol (CAP) over the Japanese fleet and the target areas. At Pearl Harbor they are used for strafing attacks with their 20-mm cannons and 7.7-mm machine guns especially against airfields. The bombing to hit roll is 1D6 per unit. Fighter bombers will get multiple direct hits on the roll of a 5 and 6 which will cause 300 points of damage. Dive-bombers get multiple direct hits on the roll of 4-5 which will cause 300 points of damage and a critical hit on the roll of 6 which will cause 300 + 1D3 x100 points of damage. Torpedo-bombers will get multiple hits on the roll of 5-6 which will cause 1D6 x150 points of damage. Strafing fighters will cause 1D6 x10 points of damage on the roll of 4-6 on 1D6 per unit. For the attack upon Pearl Harbor the carriers will launch 10 units of Fighter-bombers, 12 units of Dive-bombers, 8 units of Zeros and 4 units of Torpedo-bombers with 4 units of Zeros kept back as a combat air patrol (CAP). The commander of the Japanese First Air Fleet is Admiral Nagumo who, in the game, is rated as Competent and therefore rolls 1D6+1 for Initiative. For the purpose of the attack this information can be simply expressed as follows: Japanese Strike Force. Naval component = N/A. Aircraft: First Air Raid = 18 units (F/brs x5, T/brs x4, D/brs x5 and Fighters x4. Second Air Raid = 17 units (F/brs x5, D/brs x8 and Fighters x4). Bombing to Hit Roll: F/brs 5-6 = 300 hps, D/brs 4-5 = 300 and 6 = 300 +1D3 x100 hps, T/brs 5-6 = 1D6 x150 hps and Fighters 4-6 = 1D6 x10 hps. This is now in an easily accessible form that can be put straight into the Battle Log below.
Pearl Harbor Defenders
The defenders of Pearl Harbour are the American personnel who operate the ships’ anti-aircraft guns during the attack. In addition, there is one Infantry Division stationed on Oahu who have their own anti-aircraft batteries which defend the naval base and the numerous army airfields. The primary targets that the Japanese raiders are going to try and destroy are 7 Battleships anchored in Battleship Row and the 5 military airfields the largest of which is Hicham Field. Secondary targets include 3 cruisers and 2 destroyers which are moored elsewhere in the harbour. Battleships have a hit points value of 1500 each, cruisers 500 and destroyers 250 hit points. Battleships have a Survivability Roll of 5-6 on 1D6. Airfields have a points value of 400 hit points inclusive of aircraft. Hicham Field has 1000 hit points. This information can be simply expressed as follows: Pearl Harbor Defenders. Battleships x7. Total Hit Points = 10500 and Survivability Roll 5-6 on 1D6. Airfields x5. Total Hit Points = 2600. Cruisers x3. Total Hit Points = 1500. Destroyers x2. Total Hit Points = 500.
Scenario pre-set conditions: -
Japanese fleet out of range of land-based radar and undetected by reconnaissance aircraft. Radar detects incoming raiders but misidentified and not acted upon. Therefore, complete surprise achieved and defending aircraft caught on the ground.
Sequence
Bombers shot at by Anti-Aircraft guns over Target Area
Surviving bombers drop bombs
Air Raids (A.A. Guns)
1D6 | B’Ship/AC | Cru. | Dest. | Smaller | Army Div. |
1 | None | None | None | None | None |
2 | 1 | None | None | None | None |
3 | 2 | 1 | None | None | 1 |
4 | 3 | 1 | 1 | None | 2 |
5 | 3 | 2 | 1 | None | 3 |
6 | 4 | 3 | 2 | 1 | 4 |
Number of aircraft shot down
Roll 1D6 for each ship or Army Division able to fire AA guns.
Successful Surprise Attack = -2 First Raid, -1 Second Raid and normal Third Raid.
World War 2 Battle Log
The Japanese Strike Force
Initiative | Battle Dice (Modifier) | No. of Units and CR to Fighting Bonus | Battle Bonus Normal (Enhanced) | Battle Advantage Dice | Total Score |
N/A | N/A | Naval Component = N/A Fighters (CAP) x4 | N/A
| N/A | N/A |
Pearl Harbor Defenders
Initiative | Battle Dice (Modifier) | No. of Units and CR to Fighting Bonus | Battle Bonus Normal (Enhanced) | Battle Advantage Dice | Total Score |
N/A
| N/A | Prime Targets Battleships x7 Airfields x 5 Cruisers x 3 Destroyers x 2 | Total Hit Points 10500 2600 1500 500 | Survivability Roll 5-6 on 1D6 = 1,1,4,3 N/A N/A N/A | Total Damage 5150 2120 N/A N/A
|
Bombing Table (First Air Raid = 18 units)
Japanese Air Group | Target | Bombing to Hit Roll (1D6 per unit) | Scores | AA Gun Losses | Damage |
Grp 1 F/brs x5 | Battleships | 5-6 = 300 points | 6,6,5,4,4 | 5 aircraft | 900 points |
Grp 1 T/brs x4 | Battleships | 5-6 = 1D6 x150 points | 6,5,5,1 (6x150,6x150 and 3x150) | 2 aircraft | 2250 points |
Grp 2 D/brs x5 | Airfields | 4-5 = 300, 6 = 300 +1D3 x100 | 6,4,3,3,2 600 + 1D3 x100 = 300 | 1 aircraft | 900 points |
Grp 3 Fighters x4 | Airfields | Strafing 4-6 = 1D6 x10 | 6,5,4,2 (16x10) | None | 160 points |
Bombing Table (Second Air Raid = 17 units)
Japanese Air Group | Target | Bombing to Hit Roll (1D6 per unit) | Scores | AA Gun Losses | Damage |
Grp 1 F/brs x5 | Airfields | 5-6 = 300 points | 6,5,5,4,3 | 4 aircraft | 900 points |
Grp 2 D/brs x8 | B/ships/Cru | 4-5 = 300, 6 = 300 +1D3 x100 | 6,6,5,4,4,2,1,1 (1500 +1D3 x100 = 200, 1D3 x100 = 300) | 2 aircraft | 2000 (B/ships) |
Grp 3 Fighters x4 | Airfields/Dest | Strafing 4-6 = 1D6 x10 | 5,5,4,2 (16x10) | 3 aircraft | 160 points (Airfields) |
Notes: The two raids result in 3 Battleships sunk, one badly damaged and all five airfields either destroyed or very badly damaged. The Japanese lose 17 aircraft to AA guns.
Sources
Dupuy, R. E. and Dupuy, T. N. 1993: The Collins Encyclopaedia of Military History. Harper Collins Publishers.
Kinzey, B. 2018: Attack on Pearl Harbor Japan Awakens a Sleeping Giant. Detail & Scale.
Mayer, S. L. Various Contributors. 1977: Encyclopaedia of World War II. Hamlyn Publishing Group Limited.
Article Front Page Picture
Pearl Harbor Attack, 1941. Science History Images. After Alamy (IY06688727).
DOWNLOADABLE VERSIONS OF CLASH NOW AVAILABLE IN MY WEBSITE SHOP.
Comments