In order to determine the ship’s attained EEDI required by MARPOL ANNEX VI, the ship speed in calm sea conditions is to be calculated based on the speed trial results. Since the ISO standard which is prescribed in IMO’s guidelines on survey and certification of EEDI as the methods for conduct/analysis of speed trial has been revised recently, ClassNK issued guidance on the effective date and relevant requirements of the new standard.
1. Background
In MEPC 62 held in July 2011, some issues to the existing ISO15016 (2002 edition) were pointed out by European shipowners and research institutes, and IMO urged ISO and ITTC to review the standard. In response to it, ISO and ITTC commenced their collaborative work at WG17 formed under the umbrella of ISO/TC8/SC6, and developed the draft international standard with the addition of new tidal correction method called “Iterative method”, while incorporating the basic concept of ITTC recommended procedure (2012 edition). Following the completion of prescribed procedure within ISO, new ISO standard has been published on 1 April 2015 as ISO15016:2015.
2. Application of ISO15016:2015
In MEPC 68 held in this May, it was agreed to revise the guidelines on survey and certification of EEDI to refer ISO15016:2015 as the conduct/analysis method to be used for speed trial of the ships. Further, as a result of the deliberations on the application of new ISO standard, it was agreed to recommend the use of ISO15016:2015 to ships for which the speed trial for EEDI verification is conducted on or after 1 September 2015. An early implementation of the new ISO standard prior to that date is encouraged as well, with no problem for EEDI verification.
3. Major change items of the conduct/analysis method of speed trial
For the major changes associated with the revision of ISO standard, please refer to Attachment 1.
In ISO15016:2015, the various kinds of constraint conditions, which is no provisions in 2002 edition, in relation to the preparation/conduct methods of speed trial are to be added as well as a changing of the analysis method of speed trial data. Therefore, the extra care is needed if the speed trial scheduled on or after 1 September 2015 and/or based on the new ISO standard for the first time is planned.