The 'Naval Bombardment of Japan' was a programme of shore bombardments, targeting Japanese industrial facilities and urban centres, by warships of the British, New Zealand and US navies during the last weeks of the World War II (14 July/9 August 1945).

Most of the bombardments were undertaken by battleships and cruisers, and caused heavy damage to several of the targeted factories as well as nearby civilian areas. A major goal of the attacks was to provoke the Japanese military into committing some of its reserve force of aircraft into battle. However, the Japanese did not attempt to attack the Allied bombardment forces, and none of the involved warships suffered any damage.

The major bombardments began on 14 and 15 July 1945, when US Navy warships attacked the cities of Kamaishi and Muroran. The next attack was made by a joint US and British force against Hitachi during the night of 17/18 July. Groups of cruisers and destroyers subsequently shelled the Nojima Saki area on 18 July, and Shionomisaki on the night of 24/25 July. On 29 July, US and British warships attacked Hamamatsu, and on the night of 30/31 several US destroyers shelled Shimizu. The final bombardment took place on 9 August, when Kamaishi was attacked again by US, British and New Zealand warships. Two US Navy submarines conducted small-scale attacks during June and July 1945, and one of the submarines also landed a small raiding party.

The Allied naval bombardments disrupted industrial production in the cities targeted, and convinced many Japanese civilians that the war was lost. Up to 1,739 Japanese were killed in the attacks, and about 1,497 were wounded. The only Allied casualties were 32 Allied prisoners of war killed in the bombardments of Kamaishi.

By the middle of 1945, cities and industrial facilities in the Japanese home islands were under sustained attack by elements of the US Army Air Forces flying the new Boeing B-29 Superfortress four-engined heavy bombers based on bases in he newly recaptured Mariana islands group. Attacks by Allied submarines and surface ships had also cut most of the Japan’s trade and logistic routes, and US Navy aircraft carrier task groups had raided locations in the home islands on several occasions. Shortages of fuel had confined most of the Imperial Japanese navy’s surviving warships to port and forced them and the Imperial Japanese army air force to hold its air units in reserve against the Allied invasion that was expected late in the year. Before the war, the Japanese military had assessed that coastal artillery was no longer suited to the country’s circumstances and, as a result, only a few strategic ports were protected by artillery capable of engaging enemy warships, and most of these guns were of relatively small calibre.

During the Pacific War, the US Navy’s fast battleships had been employed mainly to escort the groups of aircraft carriers that formed the main striking strength of Admiral Chester W. Nimitz’s US Pacific Fleet. They had also occasionally bombarded Japanese positions near the shore and had fought some actions with Japanese warships. Allied naval commanders now decided to use battleships to conduct a series of attacks against Japanese coastal cities from the middle of 1945. It was hoped that the Japanese military would respond to these bombardments by attacking the Allied forces with the aircraft that were being held in reserve, thereby exposing these aircraft to destruction by Allied fighter aircraft. However, the Japanese Imperial General Headquarters had anticipated that the Allies would conduct bombardments and other operations for this very purpose, and had therefore decided to not attack naval forces operating off Japan. Instead, the aircraft would remain in reserve until Allied landing operations in the home islands began.

On 1 July 1945, Admiral William F. Halsey’s US 3^rd Fleet sortied from Leyte Gulf in the Philippine islands group to attack the Japanese home islands. Halsey’s plans included the use of battleships and cruisers to bombard military facilities and factories. To prepare for these attacks, US Navy submarines sailed into Japan’s inshore waters to search for naval mines. B-29 Superfortress and Consolidated B-24 Liberator four-engined aircraft also conducted photo-reconnaissance flights over much of Japan in search of airfields and facilities which could be attacked by the 3^rd Fleet.

The 3^rd Fleet’s main component, Task Force 38 began to attack targets in Japan on 10 July under the command of Vice Admiral John S. McCain. On this day, aircraft operating from the task force’s fleet and light carriers attacked facilities around Tokyo. Task Force 38 then sailed to the north, and on 14 July began raids on Hokkaido and the northern part Honshu. These areas lay beyond the range of the B-29 bombers, and had at that point not been attacked. The US aircraft met little opposition, and sank 11 warships and 20 merchant ships. Another eight warships and 21 merchant ships were damaged, and the carrierborne aircraft claimed the destruction of 25 Japanese aircraft.

The first Allied bombardment of a Japanese coastal town came on 14 July in conjunction with the air attacks on Hokkaido and the northern part of Honshu. A bombardment group commanded by Rear Admiral John F. Shafroth, designated Task Unit 34.8.1 was detached from Task Force 38 to attack the iron works at Kamaishi in the northern part of Honshu. At the time the city had a population of 40,000 and the iron works were among the largest in Japan, though for shortages of coking coal and other raw materials, they were running at less than half their maximum capacity. Allied prisoners of war had been assigned to work at the Nippon Steel Company, and were housed in two camps in Kamaishi.

TU 34.8.1 comprised the battleships South Dakota, Indiana and Massachusetts as well as the heavy cruisers Quincy and Chicago, and nine destroyers. The bombardment group opened fire on the iron works at 12.10 from a range of 29,000 yards (26520 m). The ships then moved closer to the city, but did not cross the 100-fathom line as no minesweepers were available to clear the area of mines. The bombardment lasted more than two hours, during which time the force made six passes across the mouth of Kamaishi’s harbour and fired 802 16-in (406.4-mm), 728 8-in (203.2-mm) shells and 825 5-in (127-mm) shells. While most of these projectiles landed within the grounds of the iron works, the concussion from their explosions caused kitchen fires to break out across Kamaishi. The resulting smoke prevented US Navy aircraft from being able to support or spot for the warships, which continued to fire accurately on predetermined targets. No Japanese aircraft or coastal guns responded. Allied aircraft photographed the iron works following the attack, but photo interpreters underestimated the extent to which they had been damaged. This was one of the first times that the US forces had used aerial photography to assess damage from a naval bombardment, and the interpreters placed too much weight on the fact that none of the iron works' buildings had been destroyed. The Allies learned after the war had ended that the iron works had been extensively damaged and forced to cease production for a period. This resulted in a loss of the equivalent of four weeks of pig iron production and 2.5 months of coke production. The attack destroyed 1,460 houses in the city, and killed 424 civilians. A total of 28 Japanese naval personnel also perished when their 'Type 28' submarine chaser was sunk in Kamaishi harbour. Five Allied prisoners of war were killed by the bombardment.

On the night of 14/15 July, another bombardment unit was detached from Task Force 38 to attack Muroran on the south-eastern coast of Hokkaido. This TU 34.8.2 was commanded by Rear Admiral Oscar C. Badger and comprised the battleships Iowa, Missouri and Wisconsin, the light cruisers Atlanta and Dayton, and eight destroyers. Halsey accompanied this force on board Missouri. The targets of this attack were the Japan Steel Company’s facilities and the Wanishi Iron Works. On the same night, a force of four cruisers and six destroyers cruised along Honshu’s eastern coast to attack Japanese shipping, but located no targets.

TU 34.8.2’s bombardment began at dawn on 15 July. The three battleships fired 860 16-in (4406.4-mm) shells at the city at ranges between 28,000 and 32,000 yards (25,605 and 29260 m). Aerial observation and spotting of damage was made difficult by hazy conditions, and only 170 shells landed within the grounds of the two plants. Nevertheless, considerable damage was inflicted on the industrial facilities, resulting in the loss of 2.5 months of coke production and a slightly shorter loss of pig iron production. Damage to buildings across the city was also extensive. As with the bombardment of Kamaishi, photo interpreters underestimated the scale of the damage. TU 34.8.2 was highly vulnerable to air attack throughout the period of more than six hours in which it was visible from the shore of Hokkaido, and Halsey later wrote that these were the longest hours of his life. The failure of the Japanese to attack his ships convinced Halsey that they were preserving aircraft for use against the Allied invasion force. On 15 July, aircraft flying from Task Force 38’s carriers struck again at Hokkaido and the northern part of Honshu, devastating the fleet of ships that carried coal between the two islands.

The attacks on Hokkaido and the northern part of Honshu ended on 15 July, and Task Force 38 left the Japanese coast to refuel and rendezvous with the main body of the British Pacific Fleet, which was designated Task Force 37. On the morning of 17 July, the US and British carriers attacked targets to the north of Tokyo. Later that day, Badger’s TU 34.8.2 detached from the carrier force to bombard targets around the city of Hitachi, about 80 miles (130 km) to the north-east of Tokyo. TU 34.8.2 and comprised the battleships Iowa, Missouri, Wisconsin, North Carolina, Alabama and the British King George V, the light cruisers Atlanta and Dayton, and eight US and two British destroyers. King George V and her two escorts sailed astern of the US force, and operated independently. Halsey again accompanied this force on board Missouri.

The bombardment of the Hitachi area took place on the night of 17/18 July. Rain and fog made target location difficult and prevented spotting aircraft from flying, but several carrier aircraft flew protective patrols over the bombardment force. The Allied warships opened fire at 23.10 and aimed at their targets using radar and the LORAN radio navigation system. The attackers targeted nine industrial facilities, and King George V was assigned targets similar to those engaged by the US battleships. By the time the bombardment came to an end at about 01.10, the US battleships had fired 1,238 16-in (406.4-mm) shells, and the British battleship 267 14-in (355.6-mm) shells. The two light cruisers also fired 292 6-in (152.4-mm) shells at radar and electronics installations to the south of Hitachi. All firing was conducted at ranges between 23,000 and 35,000 yards (21030 and 29260 m).

The attack on Hitachi had mixed results. Only three of the bombardment’s nine targets were hit, and the overall damage to the city’s industrial area was assessed as slight. However, the attack inflicted considerable damage on the city’s urban area and essential services. This damage was greatly increased by a B-29 raid on Hitachi on the night of 18/19 July, which destroyed or damaged 79% of the city’s urban area. The official history of the US Navy in World War II states that 'individual Japanese' deemed the naval gunfire bombardment to have been more terrifying than the air attack.

On 18 July, Task Force 37 and Task Force 38 undertook more air attacks in the Tokyo area, the US force’s main effort being an attempt to sink the Japanese battleship Nagato at Yokosuka naval arsenal. On that same night, Rear Admiral J. Cary Jones’s Cruiser Division 17, which comprised the light cruisers Astoria, Pasadena, Springfield and Wilkes-Barre, together with six destroyers, fired 240 6-in (152.4-mm) shells at a radar station on Cape Nojima over a five-minute period but did not hit it.

After completing its attacks in the Tokyo region, the Allied fleet conducted an under-way replenishment from 21 to 23 July before attacking Kure and the Inland Sea between 24 and 28 July. On the night of 24/25 July, Cruiser Division 17 patrolled the Kii Channel and bombarded the naval seaplane base at Kushimoto, a landing field near Cape Shionomisaki, and a radio station. This attack lasted for only four minutes and caused little damage.

On 29 July, a group of warships was detached from the main body of the Allied fleet to bombard the city of Hamamatsu, which lies on the southern coast of Honshu island between Nagoya and Tokyo. This force comprised the same ships which had attacked Kamaishi on 14 July, supplemented by King George V and the British destroyers Ulysses, Undine and Urania: the four British ships were designated TU 37.1.2). The overall task in unit was again Shafroth. The city had previously suffered extensive damage from air attacks. The British and US warships engaged their targets independently. King George V opened fire at the Japan Musical Instrument Company’s Plant No. 2, which was manufacturing aircraft propellers, from 21.19 at a range of 20,075 yards (18355 m): the battleship fired 265 14-in (3355.6-mm) rounds at the plant in 27 minutes and was able to make use of spotter aircraft as the visibility being good. Even so, little damage was inflicted on the facility. Massachusetts fired at Plant No. 1 but scored only a few hits. Despite the limited physical damage, the shelling caused increased labour absenteeism and disruption to vital services that caused the factory to cease production. The US ships also shelled the Imperial Government Railway locomotive works and three other industrial facilities. Of these targets, the locomotive works ceased operations for about three months, but two of the other facilities had almost ceased production before the attack and the third was not damaged. Two bridges on the important Tokaido main line railway were targeted but not hit, though damage to rail infrastructure in Hamamatsu closed the line for 66 hours. During the bombardment Undine twice opened fire on small groups of ships that were probably fishing boats. No Japanese aircraft or shore batteries responded to the Allied attack. The bombardment of Hamamatsu was the last time a British battleship fired its guns in anger during World War II.

The next bombardment of Japan took place during the night of 30/31 July. On that night Destroyer Squadron 25, under the command of Captain J.W. Ludewig on board John Rodgers, searched the Suruga Gulf for Japanese shipping to attack. No ships were located, and in the early hours of 31 July the squadron sailed deep into the gulf and fired 1,100 5-in (127-mm) shells during seven minutes at a railway yard and aluminium plant in Shimizu. The aluminium plant was hit, but this was of little importance as it had almost ceased for lack of raw materials. No damage was caused to the railway marshalling yard.

During the last days of July and first days of August, the Allied fleet sailed away from the Japanese coast to avoid a typhoon and allow the ships to replenish their stocks of fuel and ammunition. The fleet then sailed to the north and, on both 9 and 10 August, its carrierborne aircraft attacked a large concentration of Japanese aircraft on airfields in the northern part of Honshu. The carrier pilots claimed the destruction of 720 Japanese aircraft in this operation.

As part of these operations off northern Japan, Kamaishi was bombarded again on 9 August in the mistaken belief that the iron works had not been badly damaged. For this attack, TU 34.8.1 comprised the ships which had bombarded the city in July with the addition of the US heavy cruisers Boston and Saint Paul, the British light cruiser Newfoundland, the New Zealand light cruiser Gambia, and the British destroyers Terpsichore, Termagant and Tenacious.King George V did not participate in this action as mechanical problems affecting two of her propeller shafts meant that she was unable to sail at the speed specified for the bombardment force.

The Allied ships opened fire on the iron works and docks in Kamaishi at 12.54. The bombardment was conducted from an average range of 14,000 yards (12800 m) and lasted for almost two hours. During this time, the ships made four passes across Kamaishi harbour and fired 803 16-in (406.4-mm mm), 1,383 8-in (203.2-in), and 733 6-in (152.4-mm) shells. Gambia fired the final shots of the attack, during which several Japanese aircraft approached the Allied ships and two were shot down by Allied naval fighters. This bombardment caused more damage than the attack conducted in July, and large quantities of pig iron were destroyed. The attack was also directed against areas of housing near the iron works, destroying 1,471 houses and killing 281 civilians. The sounds of this bombardment were broadcast live on radio in the USA via a radio relay on board Iowa. One of the prisoner of war camps in Kamaishi was destroyed by this second Allied attack, resulting in the deaths of 27 Allied prisoners.

A further bombardment by King George V, three light cruisers and escorting destroyers was planned against an unspecified Japanese target on 13 August, but the attack was cancelled for both the battleship’s mechanical problems and the atomic bombings of Hiroshima and Nagasaki. The Allied fleet did not conduct any other bombardments, as Japan surrendered on 15 August.

Two US submarines attacked locations in the Japanese home islands during June and July 1945. On 20 June Barb arrived off Japan’s northern islands under the command of Commander Gene Fluckey. For this patrol the submarine had been fitted with an experimental 5-in (127-mm) rocket launcher intended for shore bombardments. Shortly after 00.00 on 22 June the submarine fired 12 rockets at Shari in the north-eastern part of Hokkaido, and then proceeded to the north. On 2 July the submarine bombarded Kaiyo in the south-eastern part of Sakhalin island with its deck gun, destroying three sampans docked in the town, damaging a seal rookery and causing several fires. On the following day, the submarine fired more rockets at Shisuka. A party of eight men landed from Barb on the eastern coast of Sakhalin island during 23 July and planted demolition charges on a railway track. Shortly after the men began rowing back to the submarine the charges were triggered by a passing train and 150 people, including civilians, were killed. On 24 July, Barb fired 32 rockets at Shirutoru and 12 rockets at Kashiho on the island of Motodomari. As the submarine returned to base it shelled Chiri on 25 July and Shibetoro on the next day. The attack on Shibetoro targeted a shipyard building sampans, and destroyed 35 newly built vessels.

The other submarine bombardment took place during the morning of 24 June, when Trutta fired some shells at the island of Hirado-shima in the Tsushima Strait between Japan and Korea. This attack was intended to persuade the Japanese that a force of US submarines which had been operating in the Sea of Japan were attempting to depart via the Tsushima Strait, instead of their actual route far to the north through the La Pérouse Strait between Hokkaido and Sakhalin islands.

Although the naval bombardments did not trigger the reaction the Allies wanted from the Japanese military, they disrupted the country’s steel industry. While several of the factories attacked were operating at reduced capacity, the important Kamaishi and Wanishi iron works suffered heavy damage when they were bombarded in July and August. During both these attacks, the Allied gunnery was accurate and focused on the factories' coking facilities, which were critical to continued production. Post-war assessments found that the damage caused to industrial buildings by even the 1,900-lb (862-kg) high-capacity shell fired by the 16-in (406.4-mm) gun was less than that which could be inflicted by the 2,000- and 1,000-lb (907- and 454-kg) general-purpose bombs delivered by Allied carrierborne aircraft. While this supported a view put forward by McCain that the aircraft assigned to protect the bombardment forces could have caused more damage than the ships themselves, the post-war US Strategic Bombing Survey judged that the naval bombardments were justified as there had been little risk to the ships involved.

The bombardments also affected Japanese morale. Japanese civilians who experienced both air and naval bombardment found the naval attacks to be more terrifying as a result of the latter’s unpredictability and longer duration. Several of the industrial facilities which suffered little damage in bombardments then incurred a significant loss in production due to absenteeism and reduced productivity. This was not the case for all facilities that were attacked, however, and the morale among workers in two of the bombarded factories was reported to have increased. The appearance of Allied warships just off the coast also convinced many Japanese that the war had been lost. However, such attitudes did not contribute to bringing the war to an end as the views of civilians had little influence on the Japanese government.

In 1949, the Japanese Economic Stabilisation Agency calculated that the Allied naval bombardments and other forms of attack other than bombing had caused 3,282 casualties, representing 0.5% of all casualties inflicted by the Allies in the Japanese home islands. The casualties attributed to naval bombardments and other causes included 1,739 fatalities, 46 persons categorised as missing, and 1,497 people wounded.