The assembly of Kido Butai

22 Nov 1941 (X-16)
Groups of gunmetal grey ships gather in Hitokappu Bay in the Kurile Islands, the northern most group of the islands that make up Japan. Far away from population centres and any prying eyes, a fleet gathers in secret. Each of them flies the naval ensign of the Imperial Japanese Navy, a Rising Sun, offset to the lanyard side.

9 destroyers (DD), the fast, manoeuvrable ships with notoriously short legs (range) built to escort their larger cousins guard a pair each of heavy cruisers (CA) and battleships (BB). 7 of them of the new Kagero-class, the largest and most modern class of destroyers the IJN had at that point in time. The CAs Tone and Chikuma are representative of the workhorses of any naval fleet, fast enough to put themselves into and out of harm’s way, armored and heavily armed enough to see off all but the heaviest warships, the CAs are armed with main batteries sporting 8 x 20cm guns. The battleships Hiei and Kirishima, are even more well protected and more heavily armed with 8 x 35.6cm guns, they represent the modern day first rate ships of the line.

Impressive as this collection of ships was, they were subservient to the real power of this fleet. 6 ships, each with a full-length flat deck built to launch and land aircraft were the centrepiece. Their names would soon go down in history. Just 38 years after the Wright Brothers’ first flight and 23 years after HMS Argus became the first ship to launch and recover aircraft, the 6 aircraft carriers of the 1st Air Fleet (also known at various times as Kido Butai or Mobile Force) were the world’s largest aircraft carrier group. From the decks of these 6 aircraft carriers (CV) flew nearly 400 combat aircraft. A mixture of fighters, torpedo/level bombers and dive bombers that fought as one cohesive unit, it’s size and strength would not be surpassed until 1944, when the US Navy’s Fast Carrier Task Groups came to dominate the Pacific.

In one of the ironies of war, the IJN’s air arm had depended heavily on the Royal Navy in its formative years. Royal Navy pilots had not only trained their IJN counterparts but had also provided technical know how when it came to the design and operation of naval aircraft and aircraft carriers. The lessons the IJN had absorbed in the 1920s and honed over China in the 1930s would soon be put into practice against a modern naval power.

The carriers were named Akagi, Kaga, Hiryu, Soryu, Shokaku and Zuikaku. The first two were originally to have been built as a battlecruiser and battleship respectively but were completed as CVs due to restrictions imposed by the Washington Naval Treaty. Their names would reflect this, battlecruisers were named after mountains, thus Akagi, named for a volcano in the Kanto region. Kaga as a battleship was named after a province. Their relatively slower top speeds as compared to their counterparts would also reflect their heritage.

The second pair, Soryu and Hiryu, were sister ships, built from the ground up as CVs and fairly new, completed in 1937 and 1939 respectively. Carriers would have some form of flying creature in their name. Thus, Hiryu (Flying Dragon) and Soryu (Blue Dragon). Together these 4 ships made up Carrier Divisions 1 (Akagi and Kaga) and 2 (Soryu and Hiryu). Their crews and aircrew were the varsity of the IJN’s naval air arm, having trained and operated together for years.

The last pair, Shokaku (Flying Crane) and Zuikaku (Auspicious Crane) formed Carrier Division 5 and were only commissioned just a few months ago, in August and September 1941 respectively. They were large, modern and had the endurance to complete their upcoming mission without refuelling, unlike the Soryu and Hiryu. Their aircrews, like the ship crew were fresh and unblooded. Their first combat mission would also be their shakedown cruise.

Nov 1941 Hitokappu Bay. Photograph taken from the deck of Akagi, From left to right, Kaga nearest and directly astern, Shokaku and Zuikaku are furthest from camera. Hiryu and Soryu closer to camera.

Nov 1941 Hitokappu Bay. Akagi.

23 Nov 1941 Hitokappu Bay. From left to right, Kirishima, a merchantman converted to a fleet oiler, Kaga and Hiei (partially covered by Kaga)