IMCA publishes industry’s first dedicated guidance for DP1 vessel operators

IMCA has published the marine contracting industry’s first comprehensive guidelines for the safe and efficient operation of DP1 Vessels.

The newly published IMCA M268 – Recommended Practice for the Operation of Class 1 DP Vessels, sets out best practice in the operation of DP1 ships, which do not have the redundant capabilities of Dynamic Positioning (DP) class 2 & 3 systems.

The guidance, now available for IMCA Members to download, emphasises the importance of understanding the limitations of DP1 vessels, and contains recommended guidance on achieving operational preparedness and ensuring that crew members have the required training and experience.

Power system redundancy is a critical mechanism within DP systems that ensures a vessel can maintain its position in the event of the failure of power components.

Given these limitations, IMCA now recommends that:

·         DP1 vessels should not undertake any operation where a loss of position or heading would be deemed unacceptable,

·         Using only two differential GNSS systems for position reference is not acceptable for DP1 operations,

·         The lower level of redundancy on DP1 vessels requires a significantly higher level of experience and understanding. There is no guarantee that a DP operator from a DP2 vessel has the transferable skills to operate a DP1 vessel safely and efficiently.

IMCA’s DP Committee produced the guidance in response to the growth in the number of DP1 vessels entering service in recent years.

Of the offshore vessels, dredgers, and other non-cargo vessels built since 1975, more than 1,000, some 8%, have a DP1 system according to Clarksons data, representing 25% of all DP vessels.

However, these vessels are not required to have redundant systems or equipment, and are not required to maintain their position and/or heading after single point failure.

This means that, without a clear understanding of the characteristics and limitations of DP1 vessels, charterers may have unrealistic expectations of these vessels’ performance and their ability to meet the assurance standards normally expected of DP equipment class 2 or 3 vessels.

There are multiple IMCA documents that contain guidance and best practices for DP operations. This year, IMCA published revised versions of IMCA M140 – Recommended Practice for Specification and Use of DP Capability Plots, and to IMCA M220 – Recommended Practice on Operational Activity Planning, both of which are available now for IMCA Members to access.