Tōya Maru

1954

Typhoon 15, the Hokkaido ferry Location: Tsugaru Strait, between Honshu and Hokkaido, Japan · Coordinates: 41.77°N 140.70°E · Casualties: ~1,155 · Survivors: ~159 · Depth: 60 m · Cause: typhoon — Capsized in Typhoon Marie (Typhoon 15) in the Tsugaru Strait on the evening of 26 September 1954 while attempting to return to harbour after departure. The typhoon's eye appeared to pass, prompting her captain to sail; the second half of the storm capsized her in under an hour. Cargo deck flooding through vehicle ramps hastened the roll. · Fate: salvaged · scrapped · Type: rail ferry · Japanese National Railways · Tonnage: 4,337 tons · Crew: 120 · Flag: Japan · Launched: 1947 Japanese National Railways ferry between Honshū and Hokkaidō, the main link across the Tsugaru Strait. Capsized in Typhoon Marie on the evening of 26 September 1954 after her captain mistook the eye of the storm for its end and sailed from harbour. 1,155 dead, the deadliest civilian maritime disaster in Japanese history. The catastrophe was the direct spur to the 54-kilometre Seikan Tunnel, the world's longest undersea rail tunnel, completed in 1988. The Vessel The Tōya Maru was a Japanese train ferry of the Japanese National Railways, built at the Mitsubishi Heavy Industries yard at Nagasaki between 1947 and 1948 and commissioned on 27 November 1947. She was 118 metres long, 3,898 gross tons, and powered by twin steam turbines producing approximately 5,400 horsepower. Her specific design was a combined passenger-and-railway-car ferry intended for the Seikan Strait route between Aomori (on the northern tip of Honshu island) and Hakodate (on the southern tip of Hokkaido island). The Seikan Strait ferry service was a critical piece of Japanese national transport infrastructure. The strait, approximately 20 kilometres wide, had no bridge or tunnel connection until the Seikan Tunnel opened in 1988, meaning that all passenger and rail traffic between Hokkaido and Honshu had to transit by ferry. The Japanese National Railways operated a fleet of approximately 8 train ferries (Tōya Maru and her sister-ships) on the Seikan route, providing approximately 12 scheduled daily crossings between the two ports. Tōya Maru was, at her commissioning in 1947, the largest and most modern of the Seikan ferries. Her design combined passenger accommodation (approximately 1,200 passengers) with railway-car accommodation (approximately 18 passenger cars plus 15 freight cars on a single rail deck) and a crew of approximately 120. The specific configuration made her substantially top-heavy compared to conventional ferry designs, but the operational demands of The Disaster By approximately 21:00 on 26 September 1954, Tōya Maru was approximately 8 kilometres south of Hakodate, in the central Seikan Strait. The typhoon's full intensity had reached her: wind velocity was measured at force 12 (hurricane force, approximately 120 kilometres per hour); wave heights in the Strait were approximately 8-10 metres; rainfall was intense. Captain Kondo's operational response was to attempt a return to Hakodate. The specific direction was retrograde (east-northeast) into the prevailing wind and seas. The ship's engines were substantially compromised by the conditions: at approximately 21:30 on 26 September 1954, her main engines shut down due to water ingress through her ventilation systems. With her engines inoperative, Tōya Maru was unable to maintain steerage; she drifted broadside to the wind and seas. Her specific design vulnerability - the top-heavy combined passenger-and-railway-car configuration - became fatal in these conditions. The critical failure mechanism was the movement of the railway cars on her open rail deck. As she rolled in the heavy seas, the rail cars (approximately 720 tonnes combined weight) began shifting on their rail mountings; some rail cars broke free of their mountings and rolled to the leeward side of the deck; the cumulative lee-side weight shift substantially compromised Tōya Maru's stability. At approximately 22:45 on 26 September 1954, Tōya Maru grounded on a shoal approximately 200 metres off the eastern coast of Mt. Nanae