The International Marine Contractors Association (IMCA) has just published ‘Example Redundancy Concept and Annual DP Trials for a DP Class 3 Construction Vessel’ (IMCA M 225).
It’s a companion volume to ‘Guidance for developing and conducting annual DP trials programmes for DP vessels’ (IMCA M 190 – published in 2011), which described the method for creating an annual DP trials programme.
“The new IMCA M 225 has been developed to provide an example of how the guidance in IMCA M 190 could be used to create a trials programme that ensures that all the essential parts of the dynamic positioning (DP) equipment class 3 redundancy concepts are intact, and fully functional,” explainsJane Bugler, Technical Director of IMCA.
“Although this particular example uses a DP equipment class 3 vessel, the method described is applicable to any vessel, regardless of DP equipment class. Trials programmes developed using the guidance in this new document and that in IMCA M 190 should, if competently executed, provide benefits in terms of reduced trials time and improved verification of the redundancy concept when compared to traditional annual DP trials processes.”
The new document is divided into two parts. The first describes the DP redundancy concept for a fictitious project and construction (P&C) vessel, the ‘Norske Kommander’, with sections which are devoted to vessel overview; engines and auxiliary services; power generation; power distribution; power management system; vessel management system; thrusters; DP control system; safety systems; and an overview of tests created by analysis of redundancy concept.
The second part, the 67-page example of an Annual , aims to meet the requirements set out in IMCA M 190, and has been developed to demonstrate the range of tests and planned maintenance activities that are required to ensure the redundancy concept is intact and that the vessel remains fully fault tolerant in respect of the defined failure criteria for its DP class notation and equipment class.