Triangular tank in upper corner of a bulk carrier hold; carries ballast and reduces free surface of grain cargo.
Regulatory detail & full definition
Triangular ballast tank in the upper inboard corner of a bulker hold, formed between the deck, side shell, and a sloped longitudinal bulkhead. The slope reduces the free surface of grain or other shifting cargoes by limiting the volumetric heel — a key requirement of the International Grain Code (IMO Resolution MSC.23(59)) for grain stability assessment. Topside tanks also serve as ballast capacity in light condition and provide structural continuity for the deck girder. Surface preparation under IMO Resolution MSC.215(82) (PSPC) is required at newbuilding for a 15-year coating life.