Dynamic positioning

One may also position the ship at a favorable angle towards wind, waves and current, called weathervaning.

It was possible to keep the ship in position above a well off La Jolla, California, at a depth of 948 meters.

The costs are falling due to newer and cheaper technologies, and the advantages are becoming more compelling as offshore work enters ever deeper water and the environment (coral) is given more respect.

With container operations, crowded ports can be made more efficient by quicker and more accurate berthing techniques.

Cruise ship operations benefit from faster berthing and non-anchored "moorings" off beaches or inaccessible ports.

Important applications include: A ship can be considered to have six degrees of freedom in its motion, i.e., it can translate and rotate on three perpendicular axes.

In particular, for good control of position in adverse weather, the thrust capability of the ship in three axes must be adequate.

Maintaining a fixed position is particularly difficult in polar conditions because ice forces can change rapidly.

Ship-borne ice detection and mitigation is not sufficiently developed to predict these forces, but may be preferable to sensors placed by helicopter.

Producers of DP systems are: Marine Technologies LLC, Kongsberg Maritime, Navis Engineering Oy, GE, SIREHNA, Wärtsilä (ex L-3), MT-div.

The ship's position and heading are fed into the system and compared with the prediction made by the model.

An LNG-powered platform supply vessel started operation in 2016 with a 653 kWh/1600 kW battery acting as spinning reserve during DP2, saving 15-30% fuel.

[19] Redundancy is the ability to withstand, while on DP mode, the loss of equipment which is online, without losing position or heading.

For this reason, there are also three DP control computers, three gyrocompasses, three MRU's and three wind sensors on Class 3 ships.

If a single fault occurs that jeopardizes the redundancy, i.e., failing of a thruster, generator or a PRS, and this cannot be resolved immediately, the operation should be abandoned as quickly as possible.

To have sufficient redundancy, enough generators and thrusters should be on-line so the failure of one does not result in a loss of position.

IMO issued MSC/Circ.738 (Guidelines for dynamic positioning system (DP) operator training) on 24-06-1996.

The NI issue logbooks to trainees, they accredit training centres and control the issuance of certification.

This shifting landscape led to the creation of The International Dynamic Positioning Operators Association (IDPOA) in 2009. www.dpoperators.org IDPOA membership is made up of certified DPO's who qualify for fellowship (fDPO), while Members (mDPO) are those with DP experience or who may already be working within the DP certification scheme.

In addition, a growing set of unique documents called TECHOP's address specific topics of significant interest and impact.