Guest Author – Sean Hogue
Having concentrated on DP for my entire career, many of the concepts & knowledge have become second nature. Others may be unfamiliar with the industry & its technology so I thank the Marine for allowing me to present a brief introduction here.
How Did DP Develop?
DP technology was created to address the needs of the Oil companies to move farther offshore in the quest for oil.
The first true DP vessel was the Eureka, launched in 1961 by Shell. Equipped with 2 thrusters capable of rotating through 360 degrees & utilizing an analogue controller she was the first to be able to hold position (within a 180m radius!) without operator intervention.
Increasing refinement of control & reference systems, particularly GPS through the 80′s, has paved the way for the highly accurate systems we use today.
What Does it Do?
In its most basic form the DP system is a control system that measures environmental inputs then sends commands to the thrusters to counter these forces to keep the vessel stationary, or to move it along a specified track. The type of task the vessel performs will determine which Class of system is used.
Class 1 systems are installed on supply vessels & other ships where a loss of position will not immediately threaten life or major environmental damage.
Class 2 systems will have 2 computer stations & enough redundancy built into the installed equipment so that the vessel will not lose position in a worse case failure scenario. Diving vessels must be class 2.
Class 3 vessels have the same requirements as class 2, with the additional requirement of having a 3rd control station installed in a separate location. This type of vessel will be able to withstand total loss of a single compartment due to fire or water egress & still have another station from which to control the vessel. Drill ships or other vessels where there is a chance of major loss of life or environmental damage are built with class 3 systems.
DP Technology is the Future
Besides the traditional uses offshore we are seeing it installed more on vessels of all types, including cruise & cargo ships. This eliminates the need for anchoring in many situations & aids the docking process.
With careers at sea growing shorter before officers move to positions ashore, ship handling experience time is reduced. By utilizing DP while turning a large vessel in a basin or coming alongside, these operations become intrinsically safer.
Getting the License
DP licensing is regulated by the Nautical Institute. Training begins with an Induction course, followed by 30 days of shipboard experience & an Advanced Simulator. Once this is complete the candidate requires 6 months of DP time to receive the full ticket.
A PDF file of NI accredited training providers can be found HERE
For more information on DP, the IMCA website has a detailed explanation.