PSV Operations: Cargo Types & DP Impact
Role of a PSV
A Platform Supply Vessel (PSV) supports offshore installations by delivering deck cargo,
dry bulk, liquid bulk, and backload. PSV DP operations are short, frequent, and highly dynamic,
with cargo transfer actively changing the vessel’s condition.
Deck cargo
Containers, baskets, pipes, skids, and equipment are carried on the open deck.
Sea fastening is mandatory for transit and cargo layout directly affects windage,
centre of gravity, and DP thrust demand.
Common mistake: treating deck cargo as static during DP.
Dry bulk cargo (cement, barite, bentonite)
Dry bulk is stored in pressure tanks and transferred using compressed air.
Tanks must remain dry to prevent cement from setting.
During long discharges, DP stability is prioritised over fast response.
Liquid bulk cargo (mud, fuel, water, brine)
Liquid cargo is transferred by pumps and causes continuous changes in trim and list.
DP operators must monitor thrust utilisation and power trends throughout the operation.
Backload cargo
Backload includes waste, empty containers, contaminated mud, and scrap.
Unknown weights and residues make backload a frequent source of incidents.
Why PSV DP operations are different
Cargo operations are performed while on DP, with continuous changes in weight and windage.
Thruster responsiveness is prioritised, and Power Mode is often not used during active cargo work.
Operational takeaway: A PSV is a dynamic cargo platform.
Safe DP operations depend on understanding how cargo behaviour affects vessel response in real time.