[Show/Hide Left Column]

Ships’ Technical Requirements

By Morten Mejlænder-Larsen


Technical Requirements for Ships can be divided in to two categories; Rules, standards etc. and background papers documenting the background for or use of the rules.

The main technical requirements to ships are found in the Classification rules. All ships are required to have a valid Class Certificate, verifying that the ship has been designed and built according to a defined set of Class Rules. In addition IMO have mandatory requirements to Safety (SOLAS) and requirements to prevent pollution (MARPOL).  Normally the IMO requirements are included in the approval work carried out by the Classification Societies.

Generally the different Classification Societies are free to develop their own rules and standard, so there are minor differences in the rule requirements. During the last decade, the main Classification Societies who are member of IACS are working with the development of common set of rules. Ref IACS Common Structural Rules for Tankers and Bulk Carriers. In 2008 IACS also issued a common set of ice class rules, the Polar Classes (PC). The Polar Classes are divided into seven different steps (PC-1 to PC-7 depending on actual ice condition).

IMO is currently working with a mandatory Polar Code including a set of minimum requirements to ship, equipment and crew planning to operate in the Arctic and Antarctic.  

Strength Requirements

IMO: - Generally all IMO requirements for ships operating world-wide also apply in the Arctic. An overview can be found in: 

Classification Societies Strength rules:

  • All major Classification Societies have special requirements for vessels intended for operation in ice covered waters, ice classes. For the lighter ice conditions/first year ice, the ice class notations are based on the Finnish – Swedish Ice Class Rules
  • Since 2008, the International Association of Classification Societies, IACS, issued a common set of Polar Classes, ranging from PC-7, light first year ice condition, to PC-1 intended for year around operation in all ice conditions. Still, the old ice class rules issued by the different Classification Societies can be used in parallel with the new IACS Polar Classes.
  • Other references related to IACS Polar Code:


  • DNV Rules for Classification of Ships – Pt.5 Ch.1 Ships for Navigation in Ice
  • DNV CN 51.1 Ice strengthening of propulsion machinery

RS Rules:

  • RS Russian Maritime Register of Shipping, Rules for the Classification and Construction of Sea-Going Ships, Vol. 1 Part 3, Chapter 10,
  • Strengthening of ice ships and icebreakers, ISBN 978-5-89331-179-2, Russian Maritime Register of Shipping, St. Petersburg, Russia, 2012

ABS, LR, BV, NK etc. - separate ice classes in parallel with IACS Polar Classes.

Trafi: - Strength requirements for ships operating in Finnish-Swedish ice covered waters

  • Finnish Swedish Ice Class Rules
  • Guidelines for the application of Finnish – Swedish Ice Class Rules, TraFi; TRAFI/21816/, Helsinki, Finland, 20 December 2011.

ISO/national requirements etc.:  

  • ISO 19906
  • OCIMF, Oil Companies International Marine Forum


Relevant papers for the safety of ships and offshore structures in Arctic regions and ice infested waters can be found in the reference list in the paper presented at the 18th International Ship and Offshore Structures Congress, ISSC, 9th -13th  September 2012, report from the Arctic Technology committee, V6. This paper has included a comprehensive reference list relevant for ice loads and strength of ships and offshore units.

Search Guide [toggle]