Torpedo: The Complete History of the World's Most Revolutionary Naval Weapon

^{Overflight of Battleship Row. Nevada on the left, obscured by smoke, has been torpedoed and is losing oil. Despite this her captain would decide to try to make a run for the open sea. Ahead of her Arizona has taken one bomb hit. West Virginia and Oklahoma have lost a large amount of oil, and are listing. Oklahoma’s port deck edge is level with the water and she is about to capsize. (NHHC, photo # NH50472)}

^{Ford Island looking south. The white plumes on the left are two more torpedo hits on West Virginia, and the wider, greyish plume on the right is a torpedo hit on Oklahoma. The much larger volume of water thrown up may indicate this to have been a hit from an 18in Type 97 oxygen-fuelled torpedo. Recent evidence suggests that this was fired by the A-Type midget submarine I-16tou. (NHHC, photo # NH50929)}

^{Battleship Row. Nevada is the first battleship, followed by Arizona with Vestal outboard. West Virginia ahead of her, and Oklahoma next in line outboard, have both been torpedoed and begin to list to port, and the ripples caused by the torpedo explosions can still be seen. Oil is spreading from West Virginia. On the right, California has also been torpedoed, and is losing oil. The white smoke in top centre comes from Hickam Field, and the grey smoke to its left from the torpedoed light cruiser Helena moored at 1010 Dock. (NHHC, photo # NH50931)}

^{Second overflight of Battleship Row. Nevada has not yet cast off her moorings. Arizona has blown up and sunk from a bomb hit, Vestal is burning from bomb damage, West Virginia is settling on the bottom, and Oklahoma has capsized. (NHHC, photo # NH50932)}

Of the most serious casualties, Oklahoma was hit by a total of nine torpedoes. Of these, at least eight were the 18in Type 91 aircraft torpedoes. It is just possible that the third torpedo hit was by an 18in Type 97 from the Type-A midget submarine I-16tou. Although all watertight doors had been left open for a captain’s inspection that fateful morning, the sheer number of torpedo hits on the port side had not allowed the ship time to flood progressively and settle upright on the bottom. No amount of counter-flooding could have affected the situation. Ironically, the Japanese pilots had expended a large number of their torpedoes on what was probably the least combat-effective battleship at Pearl.

^{Oklahoma: the sequence of capsizing and finishing upside-down in the harbour mud. (Detail from NHHC, photo # 013719a)}

Oklahoma’s salvage was a difficult and lengthy job, and by the time she was recovered, she was of little use to the fleet. In addition to the severe damage, Oklahoma was handicapped by being one of the last US dreadnoughts to have reciprocating steam engines instead of turbines.

After being hit by just one torpedo, Nevada was attacked by bombers which tried to sink her in the entrance channel. She was hit by five bombs, and was beached, slowly filled and sank. After salvage she was brought into dry dock № 2 on 18 February 1942. Although bulged, Nevada’s bulkhead had held with only slight leaks. The watertight integrity of the ship was preserved, and no significant damage inboard of the TDS was noted. So not only was Nevada the first dreadnought with ‘all or nothing’ armour protection against shellfire, but in her modernised state she also had an effective TDS.

^{Nevada’s torpedo damage, seen from the dry-dock floor. A large section of the torpedo bulge had been blown away. The hole measured 16ft long by 27ft high (4.9m × 8.2m). (USS Nevada Torpedo and Bomb Damage report)}

^{Drawing of Oklahoma’s torpedo damage. This shows the scope of damage discovered when she was in dry dock. Large areas of the bulge have been blown away, several armour plates are missing. and the lower curve of the hull was also crumpled in the capsize and the subsequent operation to roll her upright. (Detail from NHHC, photo # 013719a)}

^{A cross-section of the torpedo damage on Nevada. The TDS was composed of the bulge, which was left void, then two internal spaces filled with oil, then the torpedo bulkhead which had been doubled with 40lb (2.8kg/cm2) nickel steel plate at the time Nevada was modernised. Total width of the TDS was 14ft (4.27m). (USS Nevada Torpedo and Bomb Damage report)}

^{A rare internal view of the torpedo bulkhead of the TDS at the point of torpedo impact. (USS Nevada Torpedo and Bomb Damage report)}

^{West Virginia refloated, entering dry dock on 9 June 1942. (NHHC, photo # NH64491)}

^{Removal of the cofferdam in progress, showing part of the extensive damage to West Virginia’s hull from the multiple torpedo hits, and the armour belt bent inwards. (NHHC, photo # NH 83058)}

West Virginia’s port side had been struck by an estimated five torpedoes, and a sixth had hit and blown off her rudder. Salvage work required the construction of a large cofferdam bolted to the ship’s side. Even when she had been refloated, West Virginia was in a ‘tender’ state and liable to capsize if any leaks had developed. A detailed stability analysis was carried out, and special contingency plans were made for countering any ingress of water, for example from further air attacks. Eventually, however, she was placed in dry dock № 1, where it was found necessary to lower the docking blocks to get her inside.

A curious find was the air vessel of a Japanese Type 91 torpedo found lying on one of West Virginia’s lower decks. The saddest task for the salvage team was the removal of sixty-six bodies of her crew which were found in various areas of the ship. One group of three bodies was discovered in a storeroom, with evidence that they had been still alive on 23 December, when they had died through exhaustion of the oxygen in the air bubble where they were trapped.

The California also required the construction of a large cofferdam and many pumps to refloat her.

The Japanese congratulated themselves on sinking five battleships (Arizona, Oklahoma, West Virginia, California and Nevada) plus the demilitarised Utah, damaging two more (Tennessee and Maryland), badly damaging two cruisers (Helena and Raleigh) and demolishing three destroyers (Shaw, Cassin and Downes), all for the price of twenty-nine aircraft shot down, and five midget subs lost. However, Nagumo’s refusal to launch a follow-up strike left untouched the US Navy’s dry-dock repair facilities which were to accomplish such herculean salvage work. West Virginia, California and Nevada would all be salvaged and repaired to fight again. The Japanese also missed the opportunity to destroy Pearl’s oil fuel tanks, some of which can be seen in the Japanese aerial photos.