A rule set open to the future

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DNV GL Rules
Supporting the implementation of new technologies, the new DNV GL rule set embraces the next generation of shipbuilding.
Years of hard work, an unprecedented effort to gather input from customers and partners across the maritime industry, and the experience of two highly respected classification societies are bearing fruit.
DNV GL load line mark
The new load line mark is composed of the letters V for "Veritas" and L for "Lloyd".

Two classification societies. 301 years of combined expertise. More than 20,000 pages. 2,000 detailed comments from 800 stakeholders. 27 joint development projects involving contributions from many leading shipyards in the world: these numbers tell a unique story of how two classification societies managed to merge their “DNA” into one for the first time in history. This was a huge undertaking and an important milestone for the organization.

The rules are now in force and are actively applied by the industry (see last paragraph). “Building upon our history of competence and a fleet of almost 13,000 vessels, we have consistently applied our experience in the development of our rules in order to make them future-proof and enhance the performance of our customers,” says Geir Dugstad, Technical Director Maritime at DNV GL. “Our clear ambition has been to develop the preferred industry standard, which also means offering the widest range of class notations in the industry,” he adds.

Future-readiness involves flexibility

Alongside 38 ship type-specific notations, the new rule set features 72 additional notations, and the number is growing. These notations ensure that vessels are designed and equipped for their intended operation while supporting the use of latest technology and enabling shipowners and managers to stay compliant.  As the regulatory and technology outlook can be quite complex and sometimes unclear, “Ready” notations for gas or scrubber technology, for example, can help prepare vessels in the newbuilding stage for potential future installation of the respective technology.

Sustainable approach on regulations

While DNV GL has recently updated its Gas Ready notation for the use of gas as ship fuel, a wholly new class notation, Scrubber Ready, was launched in spring 2016. “There is no doubt that stricter emission regulations for sulphur oxides are here to stay,” says Knut Ørbeck-Nilssen, CEO at DNV GL – Maritime. “Our new Scrubber Ready class notation gives shipowners the flexibility to minimize their initial investment when ordering a newbuild, and the confidence that their vessels are on track for compliance with upcoming emission regulations.” The new notation not only identifies the general type and category of scrubber system that can be installed on the given vessel. It also details the level of scrubber readiness, with the minimum scope attesting that the space is available and the future installation arrangement meets class and statutory requirements. This can be expanded to more extensive preparations, through to a complete review of the scrubber documentation according to the main class rules, including certification and installation of piping and subsystems. Another good example of how the new rule set offers greater flexibility to shipowners are the revised class notations for water-lubricated tail shafts, TMON (closed-loop water) and TMON (open-loop water). DNV GL is the first classification society to use a condition monitoring-based survey process which eliminates the requirement for tail shaft withdrawal surveys at predetermined intervals.

A monitoring system, which is primarily based on a remote sensor that measures stern tube bearing wear each time the propeller shaft stops turning, allows the crew to keep track of the condition of the bearings. This means they can optimally plan maintenance, avoiding unnecessary tail shaft withdrawals while having a system in place to identify any indication of beginning deterioration. The TMON notations can be assigned to both newbuilds and ships in service.

Fit for new technology and designs

An important aspect of the new DNV GL rules is also to ensure that they cater for the application of modern technology. Battery and hybrid technology, for example, enable the vessel’s engine to run at more favourable loads and thus reduce fuel consumption and therefore emissions to air. Further benefits include an improved response time in safety-critical operations, an extended engine lifetime, less maintenance and less noise and vibrations. The DNV GL rules cover the use of batteries as part of a vessel’s propulsion energy in either hybrid battery solutions or “pure” battery-driven vessels. The rules also stipulate requirements for the use of batteries as a power source for dynamic positioning systems. Another example of the future-readiness of the rule set is the new Class Guidance for Wave Load Analysis. It describes a procedure for establishing wave loads for ships with unusual and innovative hull forms. It also includes procedures for consideration of particular wave environments or marine operations at a given sea state. This makes the rules adaptable for possible future changes to the wave environment which could be induced by climate change.

New DNV GL rules now actively applied in the industry 

Following an extensive hearing process, the DNV GL rules were published in October 2015 and came into force in January 2016. Around 800 stakeholders provided more than 2,000 comments which resulted in over 700 rule modifications. 

These new rules are thus the first that can truly claim to have been developed in close cooperation with the industry. And this collaboration continues: 27 joint development projects focusing on the new DNV GL are already under way. 

The first contract signed for newbuilds according to the combined DNV GL rules were Finnish ESL Shipping’s two dual-fuelled bulk carriers, which will also be the first large LNG-fuelled bulkers globally. Designed by Deltamarin and constructed by Sinotrans & CSC Qingshan Shipyard in China, they are due for delivery in early 2018. The vessels will be built to the new DNV GL rules for general dry cargo ships with DNV GL Ice Class and will have type C LNG tanks of approximately 400 m3. They can bunker at several terminals within the Baltic region. 

Additional ships built to the new rule set will be commissioned in the near future. They will receive a class notation starting with the main character 1A, which was previously 1A1 for DNV and 100A5 for GL. DNV GL has also introduced a new load line mark, sometimes termed the Plimsoll mark due to its origin, with the letters “VL”. Linking back to the history of the merged company, “VL” stands for “Veritas” and “Lloyd”. A new seal has also been introduced.

Building upon our history of competence and a fleet of almost 13,000 vessels, we have consistently applied our experience in the development of our rules in order to make them future-proof and enhance the performance of our customers.
Geir Dugstad,,
  • Technical Director Maritime
  • DNV GL

Selected DNV GL class notations

Class notations
Class notations
New Scrubber Ready notation:
This class notation includes a set of rules to prepare the vessel for future scrubber installation. It accounts for parameters such as space, weight and overboard connections while helping to reduce off-hire time and retrofitting costs.
Class notations
New Chem notation:
This notation reflects the upcoming IOSVC (International Offshore Support Vessel Chemical) code as anticipated by DNV GL, offering a new standard for the design of OSVs carrying bulk chemicals. It also creates the possibility of designing OSVs to function as chemical tankers with the ability to carry a range of cargoes.
Class notations
Revised HOT notation:
This notation defines requirements for strengthening cargo tanks and hull structures of ships intended to carry liquid cargo at high temperatures.
Class notations
Revised TMON notation:
This notation spells out rules for water-lubricated stern tube systems under condition monitoring. They account for the increased focus on environmental protection, enabling unlimited survey intervals.
Class notations
Revised Gas Ready notation:
This notation now defines requirements for a maintenance plan on installed systems/equipment to meet the gasready intention and as such helps in ensuring these are kept in good order until time for use.
Class notations
Battery (Power) notation:
This notation ensures that vessels using battery power are properly equipped for battery operations. It applies to battery installations in battery-powered vessels, ships with redundant propulsion, or DP vessels where the batteries are included in the redundancy for dynamic positioning.
Class notations
Ship-to-Ship Gas Bunkering notation:
This notation addresses safety concerns in this field, covers gas bunkering vessel design and additional requirements to support the development of gas-fuelled shipping and bunker operations in ports. The rules are flexible and include a variety of gas fuels as well as the configuration of bunker transfer systems.

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Stian Sollied, Business Development Manager and Rules Expert

This topic was taken from our latest Maritime Impact

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