Shipyards Directory

Keihin Dock

shipyard Yokohama, Kanagawa, Japan

Keihin Dock Co., Ltd. is a Japanese shipyard, wholly owned by Nippon Yusen Kaisha (NYK), that repairs and builds small vessels — above all tugboats. Founded in 1968 as a small-craft repair business, it began newbuilding in 1971 and now handles around 200 small vessels a year for docking, maintenance and statutory ship surveys, while building tugboats under 500 tons at its Oppama yard. The company is known for a series of firsts, including Japan's first hybrid-propulsion tugboat "Tsubasa" (2013), Japan's first LNG-fuelled tugboat "Kai" (2015) and the 2024 conversion of "Kai" into what it describes as the world's first commercial ammonia-fuelled vessel. It also runs an environmental equipment division making water and air treatment systems, and operates two yards in Yokohama (Koyasu) and Yokosuka (Oppama).

Keihin Dock Co., Ltd.

Keihin Dock was established in July 1968 with investment from Nippon Yusen Kaisha (NYK), which holds 100% of its shares, to repair small vessels. It registered as a small steel shipbuilder in 1971 and has since built tugboats, general cargo ships, passenger ships, tankers and work boats. The company employs 82 people across its head office and two works, and works under the management philosophy "創・造・楽". ISO 9001 certification was obtained in 2004 (scope limited to the newbuilding division since 2009).

Services

  • Repair, maintenance and statutory survey support for small vessels, mainly tugboats — roughly 200 vessels a year
  • Periodic and intermediate ship inspections, typically handled by teams of under ten people over about two weeks
  • Propeller repair, hull bottom cleaning and antifouling painting, fender (used tyre) replacement, engine, electrical and piping inspection
  • Newbuilding of tugboats under 500 GT, from CAD design through steel cutting, block assembly, outfitting, painting, launching and sea trials (roughly 3–4 months)
  • Marine equipment parts manufacture and repair; machining, welding, piping, steel structure and machinery installation work
  • Environmental division: wastewater treatment systems for container/tank container washing, central ozone air deodorising systems, and pool and large bath water circulation purification systems

Facilities

  • Koyasu Works, Yokohama: three slipways and two repair quays
  • Oppama Works, Yokosuka: three slipways and three repair quays, plus finishing shops; newbuilding centre

Vessel Types

  • Tugboats (typically 30–40 m, 160–260 GT, twin 360° azimuth propellers, around 4,000 hp)
  • Work boats, including the battery-driven "e-Crea" (2025)
  • Tankers, passenger ships and fire-fighting boats for repair and survey work
  • Notable deliveries: hybrid tug "Tsubasa" (37.2 m, 256 GT, 2013), LNG-fuelled tug "Kai" (37.2 m, 272 GT, 2015), and tug "Kiyomi Maru" launched at Oppama in 2026

Location

  • Head office and Koyasu Works: 1-2-2 Moriyacho, Kanagawa-ku, Yokohama 221-0022 — about 7 minutes' walk from Keikyu Koyasu Station
  • Oppama Works: 1-65 Uragocho, Yokosuka 237-0062