Dynamic positioning (DP) is a computer-controlled system to automatically maintain a vessel’s position and heading by using its own propellers and thrusters. Position reference sensors, combined with wind sensors, motion sensors and gyrocompasses, provide information to the computer pertaining to the vessel’s position and the magnitude and direction of environmental forces affecting its position. Examples of vessel types that employ DP include, but are not limited to, ships and semi-submersible mobile offshore drilling units (MODU), oceanographic research vessels, cable layer ships and cruise ships.
Important applications include:
This is due to the fact that, by the nature of the work performed, these vessels must hold a given position most of the time (for example, supply vessels, drilling vessels and mobile drilling platforms, vessels, ensure diving operations and others) or perform movements from position to position with high accuracy ( cable laying vessels, pipelaying vessels, seismic survey vessels, dredgers and others).
Less often, the DP system can be found on tankers, cruise passenger liners and others.
Elements of the system:
The power supply system includes all components and systems necessary for supplying the DP system with energy, namely:
The DP control system includes all components and systems, hardware, software and software, necessary for the task of the dynamic position of the vessel, and:
Classes of DP Systems
DP systems are divided into three classes (according to the degree of reliability):
Class 1 (DP 1). The “loss” of a given position by a ship can occur in the event of any single malfunction.
Class 2 (DP 2). “Loss” of position does not occur in the event of a single failure of any subsystem or component (propulsion, sensor, control console, etc.), including cables, pipes, etc.
Class 3 (DP 3). The term “single fault” includes, in addition to the faults specified for Class DP-2, the complete failure of all components within one waterproof or fireproof compartment due to fire or flooding.