Harima Shipyard (Aioi Works)

Harima Shipyard (株式会社播磨造船所) in Aioi, Hyogo Prefecture was one of Japan's most important wartime shipbuilding facilities. Originally established in the late Meiji era as a small dockyard on the shores of Aioi Bay, the shipyard was acquired by the major trading house Suzuki Shoten (Suzuki & Co.) in 1916. Under Suzuki's ownership, the workforce rapidly expanded from 250 to 5,000 workers, and the facility was transformed into a modern shipbuilding operation capable of constructing large vessels.

During World War II, the shipyard's workforce grew to over 20,000 as it became a critical component of Japan's wartime merchant fleet replacement program. In 1943, the Navy Technical Department (海軍艦政本部) directed Harima to construct a new simplified shipyard at Matsunoura on reclaimed municipal land in Aioi. Construction began in January 1943, and the Matsunoura Plant was completed in March 1944. The facility was built as a government-owned, privately-operated (官設民営) yard, with the Navy providing most of the machinery and equipment while Harima managed construction and operations.

The Matsunoura Plant pioneered innovative mass-production techniques for wartime standard ships (戦時標準船). It employed a longitudinal-movement construction system (縦移動建造方式), essentially an assembly-line approach to shipbuilding, combined with a block-line system that broke ship construction into standardized segments. These methods radically simplified the work, enabling large numbers of unskilled laborers — including mobilized students and conscripted workers — to participate in production. To address severe congestion between residential areas and the factory, a 208-meter pontoon bridge consisting of ten floating boxes (each 7.5m wide and 15m long) was completed on June 18, 1943.

By the time a construction halt order was issued in February 1945, the Matsunoura Plant had completed an extraordinary output: 15 modified E-type cargo ships (12,989 GRT), 32 modified E-type tankers (26,699 GRT), 105 Type 2ET tankers (87,622 GRT), and 11 Type 3ET tankers (9,180 GRT) — a total of 163 vessels aggregating 136,490 gross tons. At peak production, the yard launched 14 ships per month. Among all yards building modified E-type vessels, Harima ranked first nationally and sixth overall among all wartime shipyards.

On July 28, 1945, at approximately 7:10 AM, a force of about 30 US Navy carrier aircraft attacked the shipyard, strafing and dropping 250 kg bombs and numerous 10 kg bombs. The raid killed 39 people — 10 staff, 21 workers, one mobilized student and seven others — and wounded many more; tower cranes were toppled and a dock wall damaged, and a second raid around 12:30 PM burned out the mold loft and woodworking shop.

After the war, the shipyard faced severe hardship due to Allied restrictions on large ship construction. It rebounded dramatically in 1951 with the technically celebrated salvage and reconstruction of the whaling factory ship Tonan Maru, which had been sunk in the South Pacific. In 1960, Harima Shipbuilding merged with Ishikawajima Heavy Industries to form Ishikawajima-Harima Heavy Industries (IHI). By 1962, the Aioi First Factory achieved the world's highest annual launch tonnage at 287,713 gross tons. The shipyard eventually ceased new construction in October 1987 due to the shipping recession. Today the site operates as JMU AMTEC Co., Ltd., continuing ship repair and steel fabrication work.