Heavy-Lift Vessel (HLV)

A heavy-lift vessel (HLV) is a project-cargo ship built to load, carry, and discharge oversized indivisible units (transformers, modules, port cranes, yachts) using high-capacity onboard cranes, often two working in tandem. Crane SWLs commonly run 250 to 900 tonnes, with combined tandem lifts higher. HLVs feature strengthened tween decks, low-air-draft profiles, and ballast systems for heel and trim control during the lift. The term overlaps with semi-submersible (float-on/float-off) heavy-lift ships, which submerge to load by flotation rather than by crane. Operations follow the IMSBC and the cargo securing manual.