Dynamic Positioning or DP as it is commonly known is a method of positioning specially designed marine vessels within predefined limits at sea using a combination of computers, thrusters, and position reference systems/units.
Dynamic Positioning System works on the principle of using propulsion to work against the effects of displacing forces such as wind, current and wave action. There are different types of vessels that make use of this system, which relates to either maintaining a position or following a pre-determined track for various jobs related to the offshore and the sub-sea culture.
The DP capable vessels, or DP ships as they are commonly known, are highly manoeuvrable, fully functional, and reliably self- propelled vessels, which do not require any tugs at any phase of their operations at sea. Vessels fitted with DP systems are capable of working in any depth or ocean environment.
Dynamic positioning systems are more commonly used in vessels that perform – Diving, Drilling, ROV, Pipe-laying, Cable-laying, FPSO’s, and Supply or Multi-purpose support operations. Although these operations are not limited to only the above mentioned ones, if need be, DP systems could be fitted to any type or shape of a sea-going vessel.
With the rise of increased research and developments in the offshore and sub-sea sectors, DP systems have evolved for various reasons such as, but are not limited to -
- Job effectiveness with the means of safe station keeping and manoeuvring. This is turn allows the system to be in command of very intricate operations in a safe and efficient manner.
- Financial flexibility and time saving in order to develop and maintain these systems.
- Operations wherein conventional systems such as sub-sea and platform moorings are not practicable in the offshore operations and for various other safety reasons.
- Where oil explorations require complex operations which cannot be undertaken solely by conventional vessels.
DP capable vessels can conclude short tasks rapidly, thus their operations evade the hazard of damaging the infrastructure in the seabed from their mooring lines and anchors. However, they require a higher capital investment and functioning expenditure. This is due to more consumption of fuel, costly equipment / systems and requirement of trained manpower to handle the systems.
A typical scenario wherein dynamic positioning system is used would be a Diving Support Vessel, which has to work on all four sides of a platform involved with sub-sea operations, moving around the platform quickly and safely with the help of the DP system. If DP system and technically sound systems are not used then the same operation would become extremely time consuming and practically unsafe. A DP vessel is therefore designed to handle more than what a conventional moored vessel can.