Ishikari-class battleship

A preliminary design for Ishikari

141,829 shp

6 x 2 12.7cm/40 Type 89

12 x 1 25mm Type 96

4 x 1 13mm Type 93

Main turrets: 356 mm (14 in)

Barbettes: 356 mm (14 in)

Conning tower: 356 mm (14 in)

Torpedo bulkheads: 76 mm (3 in)

### Aircraft Facilities

Hangars for floatplanes, one heavy-duty crane, and a gunpowder catapult mounted atop the midships turret

The Ishikari-class battleship was a single-ship class of battleship built for the Imperial Japanese Navy immediately before World War II. The Ishikari-class was designed as successor to the aging Kongo-class battleships. Ishikari participated in many actions in the early stages of the war and was sunk during the Naval Battle of Guadalcanal in 1942. Two ships of the class were planned, Ishikari and Oshima, although only Ishikari was ever completed; Oshima was converted into an aircraft carrier beginning in 1942 but was damaged beyond repair in 1945 before the ship was completed.

## Background

The design of the Ishikari-class battleship stemmed from a requirement issued in 1935 seeking a replacement for the old Kongo-class battleships, which at the time were undergoing overhauls to turn them into fast battleships. Through a lengthy design process, including the sketch seen at right, the Ishikari-class ship was born. Two ships were planned initially, with a further two to start work once the Yamato-class ships had been commissioned. However, once the war started, the demand for the Ishikari-class' arguably unorthodox design became less and less and only one ship was ever fully completed.

## Design

Ishikari was initially designed to work alongside the Kongos until enough ships could be produced to fully replace the Kongos. The design was largely modeled after the Fuso-class battleship, with similar dimensions and design innovations. One of the initial designs of the Ishikari is shown at upper right.

The final design was intended to have a displacement of 33,500 tons standard, armed with ten 356mm guns in a very strange arrangement: two twin turrets at the front, and two triple turrets midships and aft. A catapult for launching Kawanishi E7K aircraft was to be mounted atop the midships turret. Top speed was to be 30 knots.

## Description

Ishikari had a length of 228.2 meters overall, a beam of 32 meters, a draft of 9.4 meters, and displaced 33,457 tons at standard load. The crew consisted of 1,690 officers and enlisted men.

Ishikari was planned to receive a refit in 1943 to improve her anti-aircraft and torpedo defenses, as well as reposition the aircraft equipment to a more conventional position. However, the ship was sunk before these modifications could take place.

### **Propulsion**

Ishikari was powered by four geared Kampon turbines, outputting 141,829shp. Fuel came from eight Kampon boilers, allowing the ship a range of 10,000 nautical miles at a cruising speed of 14 knots.

### **Armament**

Ishikari was equipped with ten 14-inch 45-caliber guns in a very odd arrangement. At the front were two twin turrets, one superfiring over the other, and at the midships and aft were two triple turrets at deck level.

Secondary armament consisted of twelve 6.1-inch 60-caliber guns in four triple turrets, two per side. These turrets were positioned alongside the forward and aft conning towers. The guns were very good guns, perhaps some of the best medium-caliber guns Japan ever produced, with extremely tight dispersion and a great rate of fire.

Ishikari also had twelve 5-inch 40-caliber dual-purpose guns in six twin mounts, three per side. These were mounted, on each side, two in the forward half of the ship and one in the rear half. These guns were used on most surface ships Japan built.

Light anti-aircraft armament consisted of twelve 25mm anti-air guns scattered about the deck, as well as four 13mm anti-air guns mounted two each on either side of the ship's bridge.

### **Armor**

Ishikari had a waterline armor belt with a maximum thickness of 356 millimeters thick; this belt was 150 meters long by just over 3.5 meters high. The deck armor consisted of two decks, a 25mm weather deck and a 102mm main deck, for a total deck thickness of 127mm. The main turrets had 356mm of armor on the front. The turret barbettes also had 356mm armor. The 155mm and 127mm secondaries, despite the former having completely enclosed turrets, only had splinter protection of 25mm all-round. The conning tower was, again, armored to 356mm. For torpedo defense, the ship had a 76mm bulkhead.

### **Aircraft**

Ishikari was equipped with a gunpowder catapult atop the midships turret, a collapsible crane for working with both boats and the aircraft she was equipped with, and full hangar capacity for all three of the Kawanishi E7K floatplanes she carried. Plans for a refit in 1943 included adding a second crane purely for aircraft at the stern, with the original crane being relegated to pure boatwork as the catapult also moved to the stern of the ship.