A chemical tanker is a type of tanker ship designed to transport chemicals in bulk.Chemical tankers often have a system for tank heating in order to maintain the viscosity of certain cargoes, typically by passing pressurized steam through stainless steel ‘heating coils’ in the cargo tanks. These coils circulate fluid in the tank by convection, transferring heat to the cargo. All modern chemical tankers feature a double-hull construction. And most have one hydraulically driven and submerged cargo pump for each tank with independent piping, which means that each tank can load separate cargo without them being mixed. Consequently, many ocean going chemical tankers may carry numerous different grades of cargo on a single voyage, often loading and discharging these “parcels” at different ports or terminals. This means that the scheduling, stowage planning and operation of such ships requires a high level of coordination and specialist knowledge, both at sea and on shore.

Tank cleaning after discharging cargo is a very important aspect of chemical tanker operations, because cargo residue can adversely affect the purity of the next cargo being loaded. Before tanks are cleaned, they must be properly ventilated and checked to be free of potentially toxic or explosive gases. Chemical tankers usually have transverse stiffeners on deck rather than inside the cargo tanks, in order to make the tank walls smooth and thus easier to clean using permanently fitted tank cleaning machines. Cargo tanks, either empty or filled, are normally protected against explosion by inert gas blankets. Nitrogen is often used as inert gas, supplied either from portable gas bottles or a Nitrogen generator.