How might we empower vessels with DPS to make better weather-based decisions to improve performance efficiency and crew safety?
Key Focus Area:
A vessel is subjected to three environmental forces – wind, currents and waves. The onboard Dynamic Positioning System (DPS) tries to counteract these forces to maintain the vessel’s position and heading, by using its propellers and thrusters. However, wind is currently the only known force via the wind sensors onboard, and the remaining two are unknown for the DPS.
As the only known environmental force is wind, the DPS has a station keeping error, which is known as the ‘Watchkeeping Circle’. The currents and waves pushes the vessel away from its pre-defined location, and causes it to “float” around the desired position. This circumference within which the vessel “floats” is the watchkeeping circle, which can be greatly reduced if wave is added as a known environmental force to the DPS.
The unknown forces for the DPS bring about several adverse implications in terms of fuel consumption and safety:
Returning the vessel to its desired position burns more fuel
Keeping the vessel’s position is crucial especially when transporting people via the gangway, which is unsafe or may even disconnect if the vessel moves away too much
Vessels have the tendency to stay in dynamic positioning mode with a higher engine energy output than needed, to be on the safe side
Furthermore, measuring waves is complex as they come in many patterns from various directions, making it difficult to be certain which wave will hit the ship and which side of the ship it will hit. The anticipated wave force might also vary when it finally reaches the ship since it might be reduced or amplified by another oncoming wave. In all, waves are continuously changing.
Bernhard Schulte Offshore (BSO) and INNOPORT are looking for a solution that will provide the vessel’s DPS with more accurate intelligence and empower it to make better predictions and decisions to reduce fuel consumption, improve operational efficiency as well as crew safety.