DP1/DP2/DP3 (IMO MSC/Circ.645 + IMO MSC.1/Circ.1580)

The DP equipment classes set the redundancy a dynamically positioned vessel must have, defined in IMO MSC/Circ.645 and updated by MSC.1/Circ.1580. In DP1 a single fault can cause loss of position. In DP2 no single fault in an active component (a thruster, generator, or control element) causes loss of position. In DP3 no single fault, including fire or flood in any one watertight compartment or fire zone, causes loss of position. The required class follows from the consequence of a position loss in the operation.