7.3 - Consequence Analysis One of the requirements of the IMO Class 2 and 3 guidelines, is a system of Online Consequence Analysis to be incorporated in the DP system.

Alstom DP Control Systems - continued

7.3 - Consequence Analysis

One of the requirements of the IMO Class 2 and 3 guidelines, is a system of Online Consequence Analysis to be incorporated in the DP system. This function continually performs an analysis of the vessel's ability to maintain its position and heading after a predefined, worst case failure during operation. Possible consequences are based on the actual weather conditions, enabled thrusters and power plant status. Typical worst-case single failures are:
• failure in the most critical thruster • failure in one thruster group • failure in one power bus section
If the consequence of the predefined failure is a loss of position, it is reported to the operator via the DP alarm system. The consequence analysis can operate for different configurations and give Class 2 or Class 3 alarms and warnings. A typical alarm message is "Consequence Analysis Drift-Off Alarm". The associated description reads: "Single worst case failure will cause drift-off". The analysis function typically runs every minute and averages over the last minute.
7.4 - Watchkeeping
There are many different DP vessels and DP operations. Some tasks require the vessel to maintain a static or relatively static position for days or even months on end (drillships, flotels). Other vessels will be continually manoeuvring in order to execute their work. Irrespective of the work the Watchkeeping principles are similar and some general watchkeeping procedures are included here18.
Some Class 1 vessels operate with one DPO on watch, but the majority of DP operations are carried out with two operators manning the bridge. On some vessels, one DPO mans the DP desk exclusively, while the other watchkeeper carries out all other bridge functions. These two individuals then swap roles every hour. The watch relief arrangement should allow staggered watch change-over such that there are never two fresh DPOs taking over at the same time. When taking over the watch, DPOs must familiarise themselves with certain aspects of the management of the vessel at that time. The list of information that the bridge team must acquire at this time includes (but is not limited to) the following:
• Position and heading of the vessel • Status and recent performance of the DP system and its peripherals • Details of Position Reference Systems in use and their performance • Availability of further PRS on failure of the above • Level of redundancy • Status of the operation in hand. Planned changes/progress for the coming watch. • Details and status of any operational elements (e.g. if the vessel is a DSV and diving operations are underway, then the status, position, depth of the diving bell or basket, the number of divers in the water, their umbilical lengths and expected return times, also details of their operational task) • Weather conditions and forecasts • Communications, on-board and external • Traffic in the area. Any planned traffic movements that may affect the vessel and her operation or positioning • Any planned helicopter operations
7.5 - Checklists
Checklists are an essential and accepted feature of most DP operations. It is essential that checklists are treated as an aid to memory and not as a complete substitute for ‘thinking’. It is very easy for one person in a hurry to fill out a checklist without checking many of the items contained therein. Checklists need updating from time to time, as new important points are found and equipment is modified or updated. Checklists are usually controlled documents within the shipowner’s quality assurance system, where alterations may be seen as a ‘non-conformance’ and change takes too long.
Typical checklists to be maintained by the watchkeeping DPO include:
• Pre-DP checklist • Pre-operational checklist • Watch hand-over checklist • Periodic DP checklist • MCR checklist
8 - DPO Training
8.1 - The Training and Experience of Key DP Personnel
IMCA’s document "The Training and Experience of Key DP Personnel"17 has been referenced by IMO, which, in 1996, considered the issue of training of dynamic position system (DP) operators in relation to paragraph 4.12 of the 1989 MODU Code and noted that this IMCA document could be used as a guideline for the training of DP operators, encouraging member governments to bring them to the attention of bodies concerned and apply them to the training of key DP personnel
This document represents the recognised and agreed industry standard for the training, competence and experience required of all key DP personnel on dynamically positioned vessels.
Designed as an expansion of the International Maritime Organization (IMO) document on the same subject, it is designed for vessels engaged in operations where loss of position could cause one or more of the following: severe pollution, loss of life, major damage and economic loss.
The formal training courses to be attended by DP operators are defined in content, verification and approval. The practical experience required and the certification is also defined. Training for Electrical Technical Officers (ETOs), Electronic Radio Operators (EROs) and engineers is specified. The training can be performed either at an approved institution or onboard a vessel, provided the training is equivalent.
In addition, guidance is given on a structured familiarisation procedure for key DP personnel joining a DP vessel or commencing a new project.
The principles and practice for refresher training are provided as are the requirements for operators wishing to submit experience in lieu of formal training.
In general, formal training is to be assessed and all training is to be approved, so that a common standard can be achieved internationally.
8.2 - The Nautical Institute Training Scheme for DP Operators
Within the provisions of document IMCA M 117 referred to above, DP operator training and certification is internationally administered by the Nautical Institute, in London. The Nautical Institute is a recognised professional body with an international remit. Their main objective is the raising and maintenance of high standards of professionalism within commercial and other shipping. Part of this objective addresses the business of certification of DP Operators through a specified and regulated training programme.
This programme is intended to apply to bridge watchkeepers already qualified by means of a certificate of competency as a deck officer. The training programme is a five phase one, as follows:
1. Completion of a DP Induction Course. This is a shore-based course using DP simulation training equipment. Duration four to five days, with a course certificate issued on completion;
2. Seagoing familiarisation of a minimum of one month. The trainee DPO spends a month understudying a qualified DPO in a vessel engaged in DP operations;
3. Completion of a DP Simulator Course. Advanced shore-based training using a variety of scenarios built around the simulator. Again, four to five days with a course certificate issued on completion;
4. Completion of six months' supervised DP watchkeeping in Class 2 or 3 DP vessels, or longer on Class 1 vessels and at least two months on Class 2 or 3 vessels;
5. Assessment of the abilities of the candidate by the Master of the vessel, then documentation forwarded to the Nautical Institute in London for the issue of the DPO certificate.
A limited DP certificate is available under the Nautical Institute scheme wherein the fourth stage includes six months' DP experience on Class 1 DP vessels with a statement of suitability from the Master.
All of the five phases above are witnessed and recorded by entries in a DP Logbook, held by the trainee. All entries to be validated by the Master. The Nautical Institute logbook, scheme and certificate are internationally accepted. The Norwegians have a similar scheme, with similar logbooks and certification. Both schemes and certificates have equal standing in the international world of shipping.
The courses detailed above are approved by the Nautical Institute. In order to obtain such approval any training centre must apply to the Nautical Institute for validation of its scheme. The training centre will then be visited by the Nautical Institute's DP Validating Committee, which will inspect every aspect of the proposed training. Re- validation of the training centre will be required every three years.
The scheme outlined above is intended for bridge DP watchkeepers. These consist primarily of officers qualified in the traditional deck department, i.e. Mates and Masters.
8.3 - On-Board Training
The formal training scheme outlined above includes two periods of experience gained on board the vessel.
It is possible to devise and run formal DP induction and simulator courses aboard ship. This pattern of training falls within the Nautical Institute recommended scheme, provided that the shipboard training programme has been properly devised and written, is conducted in a suitable systematic manner, and that the person or persons conducting the training are sufficiently qualified and experienced for the task. All being well, the Nautical Institute will approve the scheme, allowing the operator to issue certification equivalent to a shore-based college relating to phases 1 and 3 of the Nautical Institute scheme.
8.4 - Technical Training
All the remarks made so far relate to the bridge watchkeepers. A vital function lies in the hands of the ETO or ERO (Electrical Technician, or Electronics and Radio Officer). If the DP system malfunctions or fails in any way, then the vessel is liable to immediate downtime penalties. The carriage on board of a technician skilled in the techniques of system diagnosis and repair may save the owners the considerable costs of downtime.
Technical training is also available from or supported by equipment manufacturers.
8.5 - IMCA Training Guidelines
As referred to above, IMCA has produced an in-depth study entitled "The Training and Experience of Key DP Personnel"17. Published in 1996, this document has been referenced as an industry standard by IMO. It addresses the training required for not only watchkeeping DPOs, but also Masters, Chief and Watchkeeping Engineers, Offshore Installation Managers (OIMs) and ETOs or EROs.
The primary and secondary objectives identified in this guideline include:
To improve the safety of DP operations by defining minimum standards for
• the formal training of key DP personnel • maintaining continuity of vessel experienced personnel on board a DP vessel • the familiarisation programme for key DP personnel new to a vessel
The primary objectives should assist in achieving the following secondary objectives:
• An internationally accepted standard for the training • Training resources are spent where they are most effective
On board training, familiarisation programmes and simulators are encouraged.
As may be seen from the above, this guideline reinforces and internationalises the objectives set by the Nautical Institute in 1983. Indeed, the Nautical Institute is referenced by IMCA as the validating body responsible for training and certification of DPOs. The IMCA document goes further, however, in detailing levels of competence and forms of training for key personnel other than the DPOs, i.e. ETO/EROs, Electricians and Engineers.
It is essential that skills acquired through DP training are maintained. This consideration introduces the need for refresher training. The maintenance of these skills may be assured by:
• continuous regular performance of DP operations; or • frequent regular training and practice of DP skills; or • formal refresher training.
8.6 - DP Logbooks
Personal logbooks for the maintenance of records of DP work carried out are issued by the Nautical Institute and IMCA.
The N.I. logbooks are specifically designed for the use of DPOs and bridge watchkeeping officers during the operator's training programme. Space is provided to record details of vessels served upon, tasks engaged upon and relevant DP experience. Entries are signed by the Master, and a record of sea-time is kept. Space is also provided to verify attendance at the shore-based courses comprising phases 1 and 3 of the training scheme. After the training scheme is complete, a testimonial or assessment is provided by the Master to verify the suitability of the officer concerned to carry out DP operations and keep a bridge DP watch. It is on the strength of evidence contained within this logbook that individual DPO certificates are issued by the Nautical Institute.
IMCA logbooks (and the earlier DPVOA logbooks) are intended to be used by all key DP personnel, not only bridge DP watchkeeping officers. IMCA logbooks are intended as a continuous record of DP service and would normally commence after DP training was complete. A page is provided to show details of training courses attended.
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