Vote for a revised, generally acceptable, lasting edition of ISO 15016, concerning not only trials, but monitoring of ship powering performance, meeting theoretical, contractual and legal standards and requirements. A comment by Michael Schmiechen
Evaluation of ship powering trials is traditionally treated as hydro-mechanical problem, though it is of conventional nature, part of[ds_preview] a whole range of legal and contractual conventions, fundamental pre-requisites of which are shared convictions, fashionably called ›principles‹, being prejudices as Mark Twain aptly noted. As their name says, conventions are not ›one man or one institute shows‹ as currently being performed by MARIN (Maritime Research Institute Netherlands).
That the present version ISO 15016:2002-06 of the pertinent international standard, based on the conceptions of our great-grandfathers, is error prone has already been demonstrated 1998, long before it nevertheless has been standardised. »Reliable ship-speed assessment more relevant than ever« was thus the perfectly correct title of a note in this journal (HANSA 4/13, p. 58).
»In view of the deficiencies of the ISO and STA methods, the only reasonable decision is promptly to agree on a revised, generally acceptable, lasting edition of ISO 15016«
But the note itself is quite ›incredible‹, hardly any of the claims in the detailed exposition of the STA method developed at MARIN being substantiated, but reminding of the time when railway gauges were purposely selected differently in different countries for ›protective‹ reasons. A detailed review of the STA (Sea Trial Analysis) method promoted by MARIN even at ITTC (International Towing Tank Conference) and IMO, has been published in section 4.3.4 »The Emperor‘s New Clothes« in my paper on »Future Ship Powering Trials and Monitoring Now!«
At the end of Andersen‘s archetypal tale, »a child in the crowd, too young to understand the desirability of keeping up the pretence, blurts out that the Emperor is wearing nothing at all and the cry is taken up by others. The Emperor cringed, suspecting the assertion is true, but continued the procession«. To continue the procession will further delay progress for decades as did ISO 15016:2002-06.
In view of the deficiencies of the ISO and STA methods, both ›adopted‹ by the IMO MEPC in its Final Report (65/22), the only reasonable decision is promptly to agree on a revised, generally acceptable, lasting edition of ISO 15016, concerning not only trials, but monitoring of ship powering performance as well, meeting theoretical, contractual and legal standards and requirements.
The purpose of the standard, to permit the objective resolution of ›conflicts‹, is to be met by simple conventions with few parameters jointly identified from the data acquired, without any reference to results of model tests or other prior data.
A detailed note on trials and monitoring is provided online:
www.hansa-online.de/fileadmin/pdf/fachartikel/Schmiechen.pdf
Author:
Michael Schmiechen is apl. Prof., released from duties,
for Hydro-Mechanical Systems at ISM of TUB and retired Deputy Director and Head of R&D of VWS, the Berlin Model Basin,
m.schm@t-online.de, www.m-schmiechen.de
Michael Schmiechen
