Maritime

DNV has published the July 2023 edition of the rules for classification of ships

The July 2023 edition of the rules for classification of ships was formally approved on June 14th, 2023 by DNV Group CEO Remi Eriksen and will enter into force on the 1st of January 2024.

DNV rules update - July 2021

General information

The main changes to the rules cover new and revised class notations, implementation of external requirements from organisations such as IACS and IMO, as well as general updates based on market and technology development.

“The new and updated rules are aligned with international regulations and are expected to improve the safety and reliability of ships,” said Geir Dugstad, Technical Director for DNV Maritime.

In addition to the changes in the rules for ships, smaller changes have also been made to the rules for classification of underwater technology and high speed and light crafts.

The rules for classification of offshore units will be presented separately.

Customers can contact their local DNV office for more information on the changes.

The rules may be applied to projects contracted before the entry into force date, upon agreement between parties. 

DNV publishes one main rule edition every year. The next main rule edition is scheduled to be published in July 2024. From time to time, additional amendments may be made to the rules. These amendments will be announced in the Rules and Standards Explorer

Summary of the main changes in this edition

Main class

Topic
DNV-RU-SHIP
Main updates
Topic
Scantlings – minimum requirements    
DNV-RU-SHIP
Pt.3 Ch.1 Sec.2
Main updates
Opened for scantlings below specified minimum requirements on certain conditions being fulfilled
Topic
Fuel tanks type C
DNV-RU-SHIP
Pt.3 Ch.11 Sec.2
Main updates
Introduced requirements for foundation/supporting structure
Topic
Special hull structures
DNV-RU-SHIP
Pt.3 Ch.10 Sec.6
Main updates

The requirements for berthing and tug impact are aligned with IACS CSR (Common Structural Rules for Bulk Carriers and Oil tankers) 

Berthing requirements to stiffeners and primary supporting members are taken out 

Particular requirements to Tug Impact areas are taken out of the main class scope and are planned to be offered as a separate class notation

Topic
Welding
DNV-RU-SHIP
Pt.3 Ch.13
Main updates

Updated rules for tee and cross joints with a more specific list of details for partial or full penetration welding 

Simplified requirements for welding of primary support members introducing weld factors dependent on actual stress factors

Topic
Rotating machines – drivers
DNV-RU-SHIP
Pt.4 Ch.3
Main updates
Introduced engine-related requirements for fuels methanol, ethanol, LPG and ammonia
Topic
Electrical installations
DNV-RU-SHIP
Pt.4 Ch.8
Main updates
Introduced requirements for lithium-ion battery systems less than 20kWh

Ship type notations

Topic
DNV-RU-SHIP
Main updates
Topic
Bulk carriers and dry cargo ships
DNV-RU-SHIP
Pt.5 Ch.1
Main updates
Clarified that the requirement for water ingress alarm is valid for ships below 80 m of length only
Topic
Oil tankers
DNV-RU-SHIP
Pt.5 Ch.5
Main updates
Opened for class notation Shore power
Topic
Chemical tankers
DNV-RU-SHIP
Pt.5 Ch.6
Main updates
Opened for class notation Shore power
Topic
Liquefied gas tankers
DNV-RU-SHIP
Pt.5 Ch.7
Main updates
Introduced alternatives to ventilations systems for CO2 transportation

Additional class notations

Topic
DNV-RU-SHIP
Main updates
Topic
Electrical energy storage   
DNV-RU-SHIP
Pt.6 Ch.2 Sec.1  
Main updates
Updated rules to increase safety level
Topic
Gas fuelled - LNG
DNV-RU-SHIP
Pt.6 Ch.2 Sec.5
Main updates
Aligned with IGF code entering into force January 2024, however requirement for double wall piping on deck is not included.
Topic
Low flashpoint liquid fuels
DNV-RU-SHIP
Pt.6 Ch.2 Sec.6
Main updates

Aligned rules with IMO requirements 

Addressed the toxic aspects of methanol 

Introduced requirements for boiler arrangements fuelled by methanol

Topic
Gas fuelled - LPG
DNV-RU-SHIP
Pt.6 Ch.2 Sec.13
Main updates

Aligned with IMO draft interim guideline for the use of LPG as fuel 

Aligned with IGF code entering into force January 2024, however requirement for double wall piping on deck is not included.

Topic
Gas fuelled - ammonia
DNV-RU-SHIP
Pt.6 Ch.2 Sec.14
Main updates
Project experienced based update – introducing both decrease and increase in rule requirements
Topic
Navigation, manoeuvring and position keeping
DNV-RU-SHIP
Pt.6 Ch.3
Main updates

Introduced specific requirements for field of vision for vessels of unconventional design like WAPS and WTIV. 

Opened for replacing line of sight requirements with the use of CCTV systems

Topic
Transportation of containers
DNV-RU-SHIP
Pt.6 Ch.5 Sec.1
Main updates
Changed the requirement for wave breaker to a voluntary option
Topic
Cyber security
DNV-RU-SHIP
Pt.6 Ch.5 Sec.21
Main updates
Aligned technical content of rules with IACS UR E26 and E27
Topic
Additional safety for container vessels
DNV-RU-SHIP
Pt.6 Ch.5 Sec.23
Main updates
Reduced the discharge rate for fixed monitors
Topic
Electrical shore connections
DNV-RU-SHIP
Pt.6 Ch.7 Sec.5
Main updates
Opened for high voltage shore connection within the cargo deck area for oil and chemical tankers
Topic
Data collection infrastructure
DNV-RU-SHIP
Pt.6 Ch.11 Sec.1
Main updates
Introduced simplified D-INF notation

A few comments regarding a selected part of the updates

Additional class notations (Pt.6)

Propulsion, power generation and auxiliary systems (Ch.2)

Electrical energy storage - Battery (Sec.1)

Introducing further developed rules on: 

  • prevention of water ingress into the EES space considering collision and grounding 
  • prevention of gas spreading to other spaces and outside escape and evacuation areas
  • prevention of humid/salty air and leakages from cooling systems and ventilation ducts that may cause fault currents 
  • alternative designs, new class guideline planned for publication late 2023.

Gas fuelled LPG (Sec.13)

Aligning with IMO and IGF code on the following: 

  • machinery space shall be arranged as gas safe machinery space
  • accepting self monitoring gas detectors in place of voting principle
  • hazardous zone 2 for spaces containing fans serving hazardous area.
Gas fuelled ammonia (Sec.14)

The rule update focuses on: 

  • increase in allowable limits for normal operation emissions of ammonia to the atmosphere
  • requirements for dispersion analysis to be carried out for emergency scenarios
  • increased use of water-based safety systems in relation to ammonia leaks
  • reference to alternative design process for matters related to fire safety and life saving
  • prescriptive requirements included for enclosed bunkering stations

Equipment and design features (Ch.5)

Cyber security (Sec.21)

  • general alignment with IACS UR E26 and E27
  • class notation Cyber secure(Essential) is kept as voluntary for new vessels contracted on or after 2024-01-01
  • cyber security capabilities are subject to product certification before delivery of systems to shipyard
  • clarification of benefits gained by type approved cyber security capabilities
  • added systems to default system under consideration (SuC), serving vessel functions anchoring, lighting and pollution prevention
  • added secure product development lifecycle requirements to manufacturer.

 

 

Oslo, Norway, 2023-06-25
Henning B. Karlsen
Service Responsible – Ship Class

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