Cargo Pump

Cargo pumps on tankers are large-capacity centrifugal or positive-displacement pumps used to discharge liquid cargo from individual or grouped cargo tanks at high flow rates — often several thousand cubic metres per hour on a VLCC — through the vessel's cargo piping to shore tanks or shuttle tankers. Most modern tankers use submerged electric deepwell pumps installed in each tank, eliminating the need for a central pump room and reducing the risk of pump room fires and flooding. Older vessels use steam-driven centrifugal pumps in a dedicated pump room, requiring careful vapour detection and gas-freeing procedures before entry. The performance of cargo pumps directly affects the vessel's commercial turn-around time: a reduction in discharge rate caused by pump cavitation, worn impellers, or stripping line blockages can add significant cost by delaying the ship in port beyond the agreed laytime. Engineers monitor pump suction pressure, discharge pressure, and motor current during cargo operations and switch to stripping pumps as tanks approach empty. All pump operations must be recorded in the Cargo Record Book in accordance with MARPOL. Pump room entry is one of the most dangerous confined space operations on a tanker and requires a valid enclosed space entry permit under SOLAS II-2 and IMO guidelines.