DNV GL rules for classification and offshore standards - January 2018 edition

The 2018 January edition of DNV GL rules for classification and offshore standards is now available.

1. General information

New and amended rules and offshore standards were formally approved on December 1st 2017 and are included in the 2018 January edition of the rules.  Entry into force date is generally 1st of July 2018. However please note the immediate entry into force for most hull related parts of the rules (to be found in Pt. 3); entry into force date being 1st of January 2018.

The changes to the rules for ship may be categorized into three:

  1. New class notations 
  2. Implementation of external requirements (IACS unified requirements and relevant IMO codes)
  3. General updates and corrections

Offshore classification makes an important step forward in further modernizing their rules, offshore standards and services by:

  • Establishing a new dedicated rule book for Fleet in Service, allowing use of sensor data and further development of survey arrangement to support continuous operations 
  • Introducing a barrier management approach as part of the completely revised DNVGL-OS-E101 Drilling facilities
  • Introducing software testing as an integral part of our class approval for drilling systems

In addition, general updates have been made to the offshore standards DNVGL-OS-D101 Marine and machinery systems and equipment, DNVGL-OS-B101 Metallic materials and DNVGL-OS-C401 Fabrication and testing of offshore structures.

Smaller updates to rules for High Speed and Light Crafts (HSLC), Naval Vessels, Underwater Technology and Yachts have also been published.

For more information, do see the linked presentations, the overview of changes in the new/ updated documents and/or contact your local DNV GL office for further information.

2. DNV GL rules for Ships

Below are highlights of the main changes in the DNV GL rules for classification: Ships (DNVGL-RU-SHIP).  

2.1 New class notations

Descriptive notation:

  • New notation type to accommodate for owners need to highlight vessel type and features not specifically covered by the rule requirements. (Pt. 1 Ch. 2 Sec. 6).

Ship type notations:

  • Tanker for potable water (Pt. 5 Ch. 10 Sec. 16).

Additional class notations:

  • Shaft align - Shaft alignment (Pt. 6 Ch. 2 Sec. 10).
  • ADW - Anchoring in deep and unsheltered waters (Pt. 6 Ch. 5 Sec. 17).
  • BCLIQ – Ships strengthened for liquefaction category cargoes (Pt. 6 Ch. 5 Sec. 18).
  • RO/RO (Pt. 6 Ch. 5 Sec. 19).
  • Gas power plant (Pt. 6 Ch. 5 Sec. 20).

2.2 Revised class notations

Additional notations:

  • Battery (Pt. 6 Ch. 2 Sec. 1).
  • FC – Fuel Cell (Pt. 6 Ch. 2 Sec. 3).
  • F – Additional fire safety (Pt. 6 Ch. 5 Sec. 4)
  • Gas fuelled (Pt. 6 Ch. 2 Sec. 5)
  • Silent (Pt. 6 Ch. 7 Sec. 6)

2.3 Changes to material related topics (Pt. .2)

Rule referenceDescription
Pt. 2 Ch. 2 
  • Introduces high manganese grades
  • Added pipe grades in accordance with EN 10305
  • Aligned with IACS UR W11 – Normal and higher strength hull structural steel
Pt. 2 Ch. 4 

Alignment with 

  • IACS UR W28 – Welding procedure qualification tests

2.4 Changes to hull related topics (Pt. 3 and Pt. 5)

For the January 2018 rules edition the following main topics are covered:

  • Anchoring and mooring
    • Alignment with IACS UR A1, A2 and new A3
    • General revision of rules for Anchor windlasses
  • Rules for smaller ships – length below 90 meters
    • Improvement of rules application for smaller ships
  • Combination of envelope accelerations
    • More efficient application of rules by introducing a combination of envelope accelerations for e.g. calculations of forces from heavy equipment/sea fastening
  • Fatigue
    • Adjusted fatigue loads to give consistent calculated fatigue in line with operational experience, legacy rules and customer feedback.
  • Streamline the application and refine scantling impact - following the new technical platform for hull structures introduced with the DNV GL rules in October 2015, further updates have been carried out.

2.5 Changes for system related topics

Rule referenceDescription
Pt. 4 Ch. 2
  • Shaft alignment requirements for single stern tube bearing installations
Pt. 4 Ch. 6
  • Accepting the use of R744 refrigeration systems in non-steel structures
Pt. 4 Ch. 7
  • Harmonization of hydraulic pressure test for valves/equipment of boilers
  • UT testing of plates
Pt. 4 Ch. 8
  • Electrical propulsion/redundancy
    • Accepting single propulsion motors with dual windings

3. Further information

3.1 New class notations

a)Tanker for potable water (Pt. 5 Ch. 10 Sec. 16)

  • Introducing a class notation for transport of potable water in bulk. 
  • The requirements cover material, tank arrangement and piping system to assure that the required quality as per European Union standard or equivalent is fulfilled when required by receiving port/country.

b) Shaft align - Shaft alignment (Pt. 6 Ch. 2 Sec. 10)

  • Ensure more robust stern tube designs by requiring larger range of applied hydrodynamic propeller loads + mandatory use of oil film criterion in alignment calculations.
  • Make application of multi slope bearings mandatory.
  • Set stricter requirements to bearing sighting (@ installation) – laser aided or equivalent. 
  • Present more extensive monitoring requirements.
  • Shaft align(2) includes use more advanced calculation methods (CFD & FEM) 

c)ADW - Anchoring in deep and unsheltered waters (Pt. 6 Ch. 5 Sec. 17)

  • Covers vessels capability for safe anchoring in deep and unsheltered waters with depth down to 120 meters.
  • The notation accounts for 3 meters wave height in combination with 14 m/s wind.
  • The windlass will be fit for lifting anchor from 120 meters, whilst normal standard is 85 meters.
  • Notation is based on IACS recommendation 10.

d)BCLIQ – Bulk cargo liquefaction (Pt. 6 Ch. 5 Sec. 18)

  • The notation documents compliance with requirements to specially constructed cargo ships, and supports in receiving approval from flag administrations. 
  • The capability of carriage of bulk cargoes with moisture content in excess of their transportable moisture limit will be documented to the market by the class notation BCLIQ.

e) RO/RO – transport of vehicles loaded as Ro/Ro cargo (Pt. 6 Ch. 5 Sec. 19)

  • In order to have the requirements associated with ships designed for the carriage of Ro/Ro cargo combined with other ship types, such as container vessels (ConRo) and Multi-purpose vessels.
  • Notation for is applicable to ConRo ships or multi-purpose dry cargo ships with RO/RO capabilities
f) Gas power plant (Pt. 6 Ch. 5 Sec. 20)
  • Power units on barges or ships, using gas as fuel like floating liquefied power stations are useful as an environmentally friendly and flexible power source for supply to cities and other power consumers around the world. 
  • The rules primarily provide a safety standard for gas power plants installed on barges/ships.

3.2 Revised class notations

a)Battery (Pt. 6 Ch. 2 Sec. 1)

  • Aligned rules with international standards and flag state requirements
  • Addressed safety issues related to lithium batteries that are venting (fire and explosions) with more specific requirements.

b) FC – Fuel Cell (Pt. 6 Ch. 2 Sec. 3)

  • Relevant rules meeting customer's needs for modular fuel cell installations. 
  • Increased transparency through clarifications on fuel cell specific safety concept. 
  • Increased safety of fuel cell installations, especially with respect to novel technologies.

c) F – Additional fire safety (Pt. 6 Ch. 5 Sec. 4)

  • Engine room fires still a concern / Low frequency – severe consequences
  • Fires in ro-ro spaces / Some fires not contained to ro/ro deck / Increasing trend with fatalities, total losses and abandonment of vessels
  • Updates to F(A) will provide enhanced total safety level without adding significant costs
  • Updates to F(M) will increase the safety level regarding protection of engine room casings on passenger vessels.
  • Updates to F(C) will increase safety for ro-ro decks onboard passenger and cargo vessels. 

d) Gas fuelled (Pt. 6 Ch. 2 Sec. 5)

  • Removed requirements for secondary enclosure for LNG pipes on open deck.  
  • Aligned with present IGF code

e) Silent (Pt. 6 Ch. 7 Sec. 6)

  • New simplified measurement method/on board verification measurements replaces open water measurements in support vessel.
  • Significantly reducing the verification costs.
  • Required dedicated vessel time is reduced by up to 80-90%.
  • Long transits to measurement position avoided.

4. Information on coming rule editions

DNV GL will as from July 2018 publish main rule editions annually. Enter into force date will be six (6) months from publication; i.e. January 1st the following year.