The 2021 January edition of the DNV GL rules is now available.
The 2021 January edition of the DNV GL rules is now available on our Rules and Standards page.
1. General information
New and amended rules were formally approved on January 14th 2021 by Group CEO Remi Eriksen and are included in the January 2021 publication of the rules.
The main changes to the rules cover:
- Rules for Ships:
a) Revised class notation
b) General updates and corrections - Yachts - new class notations
The entry into force date for these rules is 1st of July 2021. The rules may, however, be applied to projects contracted before this date upon agreement between parties.
For more information on the changes, please contact your local DNV GL office.
Below is given a general overview of the main changes in the rules for classification of ships and the rules for classification of yachts.
2. Rules for Ships
Main class
| Topic | Rule reference
DNVGL-RU-SHIP | Type of change |
Materials and welding
| Pt.2 Ch.4 Sec.7 | Topic revison
NDT methods |
Class notations
| Class notation | Rule reference
DNVGL-RU-SHIP | Type of change |
Icebreaker | Pt.5 Ch.10 Sec.10 | Topic revision
Propeller loads |
| Tugs and escort vessels | Pt.5 Ch.10 Sec.11 | Topic revision
Towing winch emergency release systems |
| Double acting vessels | Pt.6 Ch.6 Sec.7 | Topic revision
Propeller loads |
Updates commented
a) Materials and welding
- IACS documents related to NDT have been updated, extended and put to a higher level. The new IACS requirements UR W33 and W34 complete a consistent overall picture of NDT requirements in the maritime industry.
- Rules update in relation to IACS UR W33
- added table for delay time requirements based on the strength levels of the materials
- revised minimum parent material thickness requirement
- aligned standards, abbreviations, quality levels and acceptance criteria.
- Rules update in relation to IACS UR W34
- Included definition of ANDT (advanced NDT) methods, standards, abbreviations, acceptance criteria
- added qualification procedure for ANDT methods.
b) Icebreaker
- The propeller loads for open propellers and ice pressure for structural loads have been reduced to meet actual operating conditions.
c) Tugs and escort vessels
- Implemented IACS resolution UR M79 (rev1 Feb 2020) regarding towing winch emergency release systems.
- Aligned with definitions for ‘black out condition’ and ‘safe location’.
- New documentation requirement for test procedure for quay and sea trials for emergency release systems for all types of tugs.
d) Double acting vessels
- Following changes to rules for Icebreakers, the backward blade force factor for DAV with icebreaker notation has been decreased from 1.2 to 1.1 accordingly.
3. Rules for Yachts
Class notation
| Class notation | Rule reference
DNVGL-RU-SHIP | Type of change |
MC | Pt.6 Ch.2 Sec.1 | New notation |
- Offering a new class notation (MC) differentiating on the requirements for certification of machinery systems and components based on yacht type/size.
4. Information on coming rule editions
DNV GL publishes main rule editions annually. The next main rule edition will be published in July 2021.
Additional amendments may be carried out, and all amendments will be specifically marked in the rules table of contents found here.
Oslo, Norway, 2021-01-21
Henning B. Karlsen
Service Responsible – Ship Class