Ice class
The ice class is the classification of the ice strength of ships ( icebreakers ) that are designed for ice-covered waters and therefore have ice reinforcement .
The number and classification of the ice classes differ depending on the state. The ice classes of the classification societies are equated with the corresponding national ice classes.
In various countries that rely on year-round supply by ships, port and pilot fees are graded according to the national ice class. This is intended to compensate the owners of ice-reinforced ships for the higher construction costs and reduced load-bearing capacity in summer.
National ice classes

Norway , Sweden , Finland
- 1A super extreme ice conditions (ice thickness up to 1 m)
- 1A Difficult ice conditions (ice thickness up to 0.8 m)
- 1B Average ice conditions (ice thickness up to 0.6 m)
- 1C Light ice conditions (ice thickness up to 0.4 m)
- II Very light ice conditions (ice thickness up to 0.15 m)
- III Normal ship
Russia
- Eisbrecher9 Ice thickness up to 4.0 m (winter / spring) or unlimited in summer / autumn (wave power at least 48,000 kW)
- Eisbrecher8 Ice thickness up to 3.0 m (winter / spring) or unlimited in summer / autumn (wave power at least 22,000 kW)
- Eisbrecher7 Ice thickness up to 2.0 m (winter / spring) or up to 2.5 m (summer / autumn) (wave power at least 11,000 kW)
- Icebreaker6 Ice thickness up to 1.5 m (limited) or up to 1.0 m (continuous ice breaking)
- Arc9 ice thickness up to 3.5 m (winter / spring) or up to 4.0 m (summer / autumn)
- Arc8 ice thickness up to 2.1 m (winter / spring) or up to 3.1 m (summer / autumn)
- Arc7 (formerly ULA) Ice thickness up to 1.4 m (winter / spring) or up to 1.7 m (summer / autumn)
- Arc6 ice thickness up to 1.1 m (winter / spring) or up to 1.3 m (summer / winter)
- Arc5 (formerly UL) Ice thickness up to 0.8 m (winter / spring) or up to 1.0 m (summer / autumn)
- Arc4 (formerly L1) Ice thickness up to 0.6 m (winter / spring) or up to 0.8 m (summer / autumn)
- Ice3 (formerly L2) Ice thickness up to 0.7 m
- Ice2 (formerly L3) Ice thickness up to 0.55 m
- Ice1 (formerly L4) Ice thickness up to 0.4 m
- LL1 ice thickness over 2.0 m (shaft power over 47,807 kW)
- LL2 ice thickness over 2.0 m (shaft power between 22,065 and 47,807 kW)
- LL3 ice thickness over 1.5 m (shaft power between 11,032 and 22,065 kW)
- LL4 ice thickness over 1.0 m (shaft power below 11,032 kW)
United States
- A3 Ice thickness over 1 m
- A2 Ice thickness up to 1 m
- A1 Ice thickness up to 0.6 m
- A0 Ice thickness up to 0.3 m
Germany ( Germanischer Lloyd )
Baltic ice classes:
- E4 (ice thickness up to 1.0 m, corresponding Finnish-Swedish ice class: 1A Super)
- E3 (ice thickness up to 0.8 m, corresponding Finnish-Swedish ice class: 1A)
- E2 (ice thickness up to 0.6 m, corresponding Finnish-Swedish ice class: 1B)
- E1 (ice thickness up to 0.4 m, corresponding Finnish-Swedish ice class: 1C)
- E (ice thickness up to 0.15 m, corresponding Finnish-Swedish ice class: II or III)
Arctic ice classes:
- ARC 7
- ARC 6
- ARC 5
- ARC 4
- ARC 3
- ARC 2
- ARC 1 (corresponds roughly to the Baltic ice class E4)
Polar classes
In 2006, the International Association of Classification Societies (IACS), as the umbrella organization, published a draft for global classes PC 1 to PC 7. These are intended for ships or icebreakers operating permanently in arctic waters. Therefore, their claims go far beyond the ice classes. The highest German class E4 corresponds to about PC 6. The higher classes can therefore be compared more with the Russian icebreaker classes.
IACS polar classes
- PC 1 Year-round voyage in all polar waters
- PC 2 Year-round trip in medium multi-year ice
- PC 3 Year-round trip in two-year ice with inclusions over several years
- PC 4 Year-round trip in thick annual ice with older inclusions
- PC 5 Year-round ride in medium one-year ice with older inclusions
- PC 6 Summer trip in average annual ice with older inclusions (equivalent to E4)
- PC 7 Summer trip in thin one-year ice with older inclusions (equivalent to E3)
swell
- ↑ IACS Unified Requirements: UR I Polar Class (PDF; 4.7 MB).
- ↑ Guidelines for Ships Operating in Arctic Ice-covered Waters ( Memento of February 21, 2007 in the Internet Archive ). Ref. T1 / 3.02, December 23, 2002. International Maritime Organization , London (PDF, English).