Semi-submersible heavy-lift
- Category
- heavy-lift
- Size envelope
- 70,000-115,000 DWT
- LOA typical
- 210-275 m
- Cargo
- Oil rigs, warships, other vessels
- Route archetype
- Global — heavy-transport contract
- Crew size
- 14-20
Overview
Semi-submersible heavy-lift vessel: ballasts down until the cargo deck submerges below cargo waterline, receives the floating cargo (typically a jack-up drilling rig, semi-submersible rig, warship, or other vessel), then de-ballasts to lift + transport. Owners: Dockwise (now BOKA / Boskalis Heavy Transport), COSCO Heavy Transport. Small fleet of ~15 vessels globally. Recent transports include BOKA Vanguard (2018 delivery, 275m LOA, 117,000 DWT). Rare specialised trade.