Twohatch

Twohatch, or two-hatch, is a term used in maritime design to describe a configuration of two hatchways or hatch covers that provide access to adjacent compartments or a shared hold. The term is used primarily in the description of deck layouts on cargo vessels and barges. A twohatch arrangement typically consists of two coamings aligned along the same deck line, with independent or linked hatch covers, allowing simultaneous loading and discharge of two separate holds or a common space divided by a bulkhead.

In design, twohatches aim to balance accessibility, weather protection, and structural integrity. Each hatch opening is fitted with a cover, typically steel or aluminum, supported by handling gear such as hatch wheels, chain blocks, or hydraulic systems. Sealing gaskets and weather-tight variants are common to prevent water ingress.

Variants include straight twin hatch (two adjacent, parallel openings) and offset or staggered twin hatch (two openings with offset positions to suit hold geometry). The selection depends on cargo type, vessel size, and crane reach. In some ships, twohatch layouts enable independent loading of each space, while in others, a single cargo space is accessed through both hatches.

See also: hatch, hatch cover, coaming, deck arrangement.

Etymology: from hatch, the opening in a deck, with the prefix two- indicating pair.

Notes: Twohatch is not a formal standard term in all fleets; terminology varies by shipyard and region.