Dynamic positioning
The dynamic positioning (DP short; also dynamic-positioning system (DPS)) is a computer controlled system for automatic positioning of a ship . Ships with DPS can hold a position without anchoring or mooring. This is important for B. for ships that install offshore wind turbines or supply drilling platforms with personnel, fresh water and drilling material.
Function and structure
The compensation of the side forces acting on a ship (wind and current) is done with the help of its own propeller pods and propellers . Position reference sensors in combination with wind sensors, motion detectors and gyro compasses provide a computer program with information about the position of the ship and the strength and direction of lateral forces that influence its position. The DPS is normally operated with the support of a Differential Global Positioning System (DGPS).
The DPS is not limited to ships, submarines or semi-submersible , but is also used on Mobile Offshore Drilling Units (MODU).
The computer program contains a mathematical model of the ship that contains information about the current wind , waves and the position of the ship's engines. From this data and the sensor information, the program calculates the steering angle of the thrusters and their thrust to compensate for the movement.
Dynamic positioning can either be absolute - that is, the ship is held at a fixed point above the ground - or relative to a moving object such as a ship or an underwater vehicle. You can also keep the ship at a favorable angle to the wind direction, waves and currents ( weathervaning ). It can also be used together with an anchor system.
application
Today there are more than 1000 ships equipped with such a system. The Eureka, built in 1961, is considered the first ship with DPS .
Web links
- DP using the example of a catamaran (pdf, 9 MB, Deutsche Seeschifffahrt 9/2014)
- Description of the catamaran ( Voith Turbo )