A vessel specific DP Operations Manual should be prepared for each DP vessel. The vessel specific DP Operations Manual is the most important operational document in the list of required documents. The requirement for a manual has its origins in IMO MSC/Circ 645 (1994) "Guidelines for Vessels with Dynamic Positioning Systems". The IMO Guidelines require a series of checklists, test procedures and DP operating instructions to be incorporated into one manual. Each Classification Society has its own specific requirements for a DP Operations Manual, each with different requirements for content. The recommendations set out below address areas that are not necessarily required by class. They are based on current industry practices.
The manual should contain sufficiently detailed instruction and guidance to enable the vessel to be operated safely in DP and safely execute its intended activities. This will include a clear statement on the DP philosophy for the vessel, the organisation, responsibilities and roles of key DP personnel, training and competency, watchkeeping and manning, vessel technical data and layout, vessel DP capabilities, operating limits, operating modes, the planning and preparation of DP operations, DP operating procedures, emergency procedures, DP incident handling and alert systems and vessel specific trials and checklists that apply uniquely to the vessel.
The manual should specifically address operational interfaces between different vendor systems and equipment to ensure that they are configured and operated properly. This should include interfaces between systems and equipment that are not part of the DP system but which may affect the DP system. The vessel specific manual may also contain generic content, such as company policies, procedures and standing orders.
The manual should represent the way the vessel is operated in DP. For complicated power systems and/ or thruster configurations, it may be useful provide the operator with a thruster and generator operating strategy (TAGOS) to assist in the decision on what generators and thrusters to use for different circumstances and different equipment availabilities. Guidance on the contents of vessel specific DP Operations Manuals is provided in the following IMCA guidelines, M103, M109, M117 (contingency training) and in class society DP rules.
In recognizing that exposure to risks manifests itself during vessel operations it is recommended that activities performed by DP vessels should be subject to planning and preparation. In planning and preparing for the activities the following should be considered and, where appropriate, documented:
- Configuration for the Safest Mode of Operation (SMO) or, where appropriate, the Task Appropriate Mode (TAM).
- Preparation of the Activity Specific Operating Guidelines (ASOG), including onboard discussion with all relevant stakeholders as part of the pre-project execution/ activity.
- Discussion to be included in pre-project execution readiness checklist.
- Capabilities of the vessel, both intact and residual capability, following Worst Case Failure (WCF).
- Limitations imposed by water depth.
- Consequences of a loss of position and/ or heading.
- Limitations imposed upon operations by residual capability.
- SIMOPS and marine vessel interaction and consequences arising from change of status (Green to Blue, Yellow or Red).
Post DP Incident Trials: Tests performed to ensure that the corrective/ repair measures taken following a DP incident have properly addressed the causes of the incident
and that the vessel’s DP system is in a safe and operable condition.
Post DP Modification Trials: A series of checks and tests that are used to determine the effects of modifications and/ or additions on the DP system and the vessel’s subsequent station keeping performance. Hardware in the Loop (HIL) tests: Extensive testing of functionality, failures and performance by using advanced simulation techniques and embedded systems. It can be used in factory acceptance tests, sea trials, annual tests, periodical tests and testing after upgrades.
Note: The nomenclature used for the trials and checklists listed above is based on the guideline document, IMCA M112: "Guidelines for Auditing Vessels with DP Systems". It is
recognized that these trials and checklists could be given other titles.
The activity being performed and the necessary time to terminate to bring vessel to a safe position upon the onset of failure.
Activities should include day to day operations, any specific operation relevant to the design of the vessel, as well as any unique operations the vessel is called upon to perform.
Appropriate measures should be in place to clearly identify critical tasks/ operational phases of the activity and to ensure that the vessel is set up in Safest Mode of Operation and operating within post WCF capability. Where a decision has been made to operate in a TAM a separate ASOG covering TAM should be produced.
Note: The ASOG should be developed by extracting all the relevant information from detailed technical review of the vessel’s DP FMEA, operational manuals and project specific procedures. The ASOG should be validated on board.
