Combat ships. Cruisers. The last flagship of the lost fleet
Indeed, it was a very remarkable ship. This cruiser was developed as a reconnaissance cruiser, in the course of work it was redesigned into a seaplane carrier cruiser (in principle, the same reconnaissance, but more modern), then the ship was rebuilt into a command ship, and it even became the flagship of the United fleet Empire of Japan.
It is also the last light cruiser of the Japanese fleet to die in World War II.
So, the Oyodo light cruiser.
Japan's naval doctrine before World War II involved replacing the light cruisers that served as leaders of destroyers and submarine flotillas with more modern ships of greater displacement.
Several programs were developed at once, in accordance with which were designed and built, including light cruisers for the Imperial Japanese Navy. It was planned to build 83 warships in the period from 1939 to 1944 inclusive, but the outbreak of the war changed these plans very sharply.
Many projects have been discontinued, rebuilt and postponed. So it happened with the Oyodo-class cruisers. Provision was made for the construction of seven reconnaissance cruisers, but only one was built. Oyodo himself.
Thus "Oyodo" became the last light cruiser built in Japan.
The reconnaissance cruiser project was interesting. We tried several options, from a ship with a displacement of 6 tons without heavy weapons to a very light (600 tons) aircraft carrier and eventually settled on a light cruiser project with a displacement of 16 tons, structurally similar to the Agano-class cruisers, but considerably modified.
These ships were supposed to have a large hangar in the stern for long-range reconnaissance (about them not so long ago was in the "Combat aircraft" cycle), a catapult for launching them and cranes for lifting aboard.
Distinctive details were to be a long cruising range, up to 10 nautical miles at a cruising speed of 000 knots, the ability to carry up to 18 large seaplanes and the most powerful communications. Plus artillery weapons so that you can fight off your colleagues.
It was for these requirements that the project of the cruiser "Oyodo" was created.
The first and last ship of the project was laid down in February 1941, launched in April 1942, and entered service on February 28, 1943. It can be seen that the Japanese were no longer in a hurry. The war consumed all resources.
What happened in the end. As mentioned above, the cruiser was originally planned as a replacement for the old leaders of destroyers and submarines. It was for the sake of the submarines, whose surface speed was in the region of 18 knots, that everything was designed in terms of driving performance.
Power plant
Four TZA "Kampon" with a capacity of 110 hp. set in motion 000 propellers, which gave the ship a maximum speed of 4 knots. The cruising course was as laid down in the project, 35,5 knots. The cruising range at maximum speed was only 18 miles, at a cruising speed of 4 miles.
The fuel stock is 2 tons of oil.
Reservation
Reservation was completely sacrificed for speed and range. The ship had a 60-mm armor belt covering the engine rooms.
The armored deck had a thickness of 30 mm, in the area of the artillery cellars 50 mm. The cellars were covered with 75 mm armor plates in the lateral projection and 40 mm in the frontal projection. The barbets of the guns had an armor thickness of 25 mm.
The conning tower was 40 mm thick at the front and 20 mm at the sides. The towers were 25 mm thick.
It was believed that such a booking scheme would be able to protect the ship from 127-mm shells and bombs of 250 kg and below.
weaponry
The main caliber of the cruiser consisted of 155-mm guns in three-barreled turrets taken from the Mogami cruiser. The Mogami received turrets with 203-mm guns, and it was decided to use turrets with 155-mm guns as weapons on other ships.
Oyodo became such a ship. On it were installed two towers from "Mogami" (out of five) with six 155-mm guns. The towers were installed in the bow as the stern was occupied by the catapult and the seaplane hangar.
The 155-mm Type 3 cannon threw a 55-kg projectile at a range of up to 27 km with an initial speed of 920 m / s. Combat rate of fire was 5 rounds per minute.
The auxiliary caliber consisted of four 100-mm Type 98 double-barreled installations, of the same type as those installed as air defense guns on the Taiho aircraft carrier or Akizuki-class air defense destroyers.

The gun was very fast-firing and with excellent ballistics, but the barrels had to pay for this, which was only 300-400 rounds per barrel, as opposed to 1300-1500 for world analogues.
Small-caliber anti-aircraft artillery, of course, consisted of automatic anti-aircraft guns of 25 mm caliber. Initially, 12 guns (6 x 2 barrels) were installed on the ship. As the upgrades progressed, the number of barrels on the Oyodo was increased to 56, 20 single and 12 triple barrels.
The cruiser did not carry torpedo and mine weapons, which distinguished it from all other Japanese light cruisers.
The main weapons "Oyodo" were supposed to be seaplanes that would collect intelligence information in the interests of the fleet.
To work in this direction, the Kawanishi E15K1 Shiun reconnaissance seaplane was designed.
On the idea of E15K1, due to its very high speed (500 km / h for a seaplane is a lot) and a long range, it could conduct reconnaissance even where aviation the enemy had air superiority.
E15K1 was supposed to replace the plane from the company "Aichi" E13A1 in this position (there was also a story about it recently). The E15K1 turned out to be heavier than its predecessor; to launch it, a 45-meter pneumatic catapult had to be developed, which could launch aircraft every 4 minutes.
However, it was because of E15K1 that the project “didn’t play”. The aircraft turned out to be much slower than expected, was very capricious in service and did not differ in operational reliability.
Initially, Oyodo was equipped with six seaplanes from Kawanishi, but it so happened that the planes were lost very quickly. And because of breakdowns, and because the Americans really controlled the air.
Therefore, in 1944, when the Oyodo was re-profiled into a command ship, the 45-meter catapult was dismantled, a lighter standard 25-meter Type 5 catapult was installed in its place and two Aichi E13A1 seaplanes were placed on the ship.
Already in 1943 it became clear that the Oyodo would not be used as the flagship of the submarine flotillas. Accordingly, the presence on board of a large number of reconnaissance seaplanes that will search for targets and direct submarines at them.
And radars coped with the search for surface ships all the better.
Therefore, it was decided to convert the submarine reconnaissance cruiser into a command ship. A lot of space was freed up in the seaplane hangar, and it was very easy to equip workplaces there.
The modernization was carried out in March 1944 and "Oyodo" from a reconnaissance cruiser finally turned into a command ship.
Instead of a 45-meter catapult, a conventional 25-meter Type 5 catapult and two Aichi E13A1 Reisu seaplanes were installed.
Anti-aircraft armament has been significantly increased. All single 25-mm installations were replaced with triple ones, and two more triple 25-mm assault rifles were installed at the stern near the hangar. The total number of 25 mm barrels after this upgrade was 47 barrels.
The ship received radars to monitor air and surface targets. Radars "Type 21" and "Type 22" were installed on the bow superstructure, "Type 13" on the foremast. And the seaplane hangar became the location of the headquarters and electronic reconnaissance equipment.
This is how the reconnaissance cruiser became the flagship.
In general, the Japanese, unlike many countries of the world, were not the largest and most frightening ships that served as flagships of the fleet. So, in theory, the flagship of the Imperial Navy was supposed to be one of the Yamato-Musashi pair.
However, the flagships in the Imperial Navy were ships that were adapted for such a service and where it was convenient to place the headquarters of the fleets and formations, creating all the conditions for the staff to work.
Combat application

The reconnaissance cruiser was to be baptized by fire in an operation to repel the American invasion of the Aleutian Islands. But the islands fell before a squadron of ships reached them.
"Oyodo" was assigned to the escort formation of the aircraft carriers "Shokaku" and "Zuikaku", based on the island of Truk. The cruiser accompanied convoys with troops and supplies for the garrisons of Rabaul and Kavieng.
Participated in the interception of American ships after the attacks of the Marshall Islands and Wake Island. The interceptions were unsuccessful and Oyodo returned to escort service.
In February 1944 she was converted into a command ship, and in April 1944 she became the flagship of Admiral Toyoda Soemu, commander of the United Fleet.

Work in this role did not require frequent trips to the sea, so Oyodo was mainly located in the metropolis.
The ship took part in the Battle of Cape Engano, rescuing people from the sinking aircraft carrier "Zuikaku".
Further, the cruiser repelled the American invasion of the Philippines as part of Admiral Ozawa's Northern Formation.
On October 25, 1944, the Battle of Cape Engano took place, in which all Japanese aircraft carriers were sunk by US carrier-based aircraft. Participating in the battle, "Oyodo" was hit by a bomb in the boiler room.
After repairs, the cruiser continued transport missions to supply garrisons in the Philippine Islands.
On December 24, 1944, "Oyodo", as part of a detachment of ships from the heavy cruiser "Ashigara" and 7 destroyers, attacked the American troops landing on the island of Mindoro (Philippines).
On December 26, Oyodo came under attack by American B-24 bombers and was hit by two 227 kg bombs. The first bomb hit the armored deck and ricocheted away from it, the second caused light damage, exploding on the port side.
The destroyers sank several amphibious transports with torpedoes, the Japanese ships thwarted the attacks of American torpedo boats with artillery fire, fired at the American positions, but in the end the detachment was forced to leave the base without completing the main task.
On February 7, 1945, Oyodo joins the formation of the battleships Ise and Hyuga with several destroyers to transport strategic materials to Japan. The warships carried gasoline, rubber, tin, tungsten, and oil specialists. The task was completed, the ships successfully returned to Japan.
On March 19, 1945, while at the base in Kure, the cruiser came under an American air raid on the naval arsenal. Three 227-kg bombs hit the Oyodo, and a fire broke out on the ship. The crew dealt with the damage, but the ship took in a lot of water and ran aground off the island of Etajima.
The water was pumped out and the ship was towed to Kura for repairs. The refurbishment was successful and on April 4, the Oyodo was anchored at Etajima. At a position near the island, the ship was in charge of countering American aviation.
On July 24, 1945, Oyodo was again raided by American aircraft. This time the Americans acted very successfully: "Oyodo" received four direct hits with 227 kg bombs and a number of explosions not far from the sides. The fires were extinguished, but the ship received some water.
The cruiser was finished off on July 28, when the bombs caused a divergence of the left side skin. The ship lay down on the starboard side in shallow water.
On November 20, 1945, he was officially removed from the lists of the Navy.
After the end of the war, Oyodo was drained, raised and cut into metal.
It was the last Japanese light cruiser to die in the fighting.
Information