Conclusions

The first classification societies, such as Lloyd’s Register, Bureau Veri-tas and Det Norske Veritas were established mid-19th century to fill the need of uniform rules and procedures for assessing the risk of underwriting individual vessels. On other words, insurance companies and their need to ensure the safety of insured vessels and cargoes, are the main reason why classification societies exist today. The first rule sets were mainly based on experience and what was considered to be a good construction standard. The regulations were very similar between the classification societies as the rules for new technologies, such as iron and steel hulls, and engines with boilers, were more less just adopted between the classification societies in lack of own experience.
IACS, International Association of Classification Societies, has established minimum technical standards and requirements that address maritime safety and environmental protection and ensures their consistent application. That is sort of a base line, which all the member classification societies are following adding their own rules on top of that. Over the years the differences between the rules have anyhow grown bigger due the different approaches and experiences the classi-fication societies are having.
It is a well-known fact is that the major changes in maritime regulations are often “disaster-driven” caused by a major accident such as Titanic, Herald of Free Enterprise, Exxon Valdez, Scandinavian Star or Estonia. DNV rules are updated twice a year to accommodate new knowledge, rules for new types of technology and clarifications of the older rule versions. The rules are aimed to be more accident preventive and risk-based using formal safety assessment, where the risk of potential failure and severity of the failure consequences are taken into consideration.
After the accidents of Erika and Prestige in 1999 and 2002, a common set of IACS structural rules was developed to cover the rules for tanker ships and bulkers’ hull structures. Attempts for further harmonization of the classification rules have been made, but those have never covered the machinery part of rules. EU directive from 2009 anyhow imposes mutual recognizing of certification of materials and components carried out by any EU recognized organization, so for example a ship built in DNV class can have components certified by Bureau Veritas.
Due the IACS base line, as can be seen in the previous chapters, M/S MERSol would most of the time be in compliance with the general DNV rules from 2021 as well. There are some differences regarding for example the required control and safety functions for engines and number of non-return valves in ballast lines.

It’s always important to remember which rule set applies to your ship, as most of the rules are not retroactive, i.e., the ship doesn’t need to fulfill rules 2021 if built 2012. That applies also for statutory requirements such as load line, SOLAS, MARPOL and COLREG. Classification surveyors are normally operating with vessel specific checklist applying the rules the ship should be in compliance with, but you might face situations where especially port state control wants to inspect the ship using requirements from a newer set of rules.