Hopper Tank

Sloped lower wing tank along the bilge of a bulker hold, with the slope set at roughly 30–50° to encourage cargo to flow toward the central hold during gravity-fed discharge. The tank is normally a ballast space and forms the lower web of the side structure, working with the topside tank above to constitute the IACS CSR-BC double-side system. Hopper tanks are also a primary corrosion-monitoring zone under IACS UR Z10.2 — internal coating breakdown there often signals broader hold-frame degradation.