Evaluation of the Northern Sea Route Using the Ice Regime Shipping Control System

(By Douglas L, Stephen J. Jones ; INSROP Working Paper No. 32 – 1996, I.2.2)


The object of this research was to assess the feasibility of using the Northern Sea Route as a regular commercial trade route between Japan and Europe, using the Canadian Ice Regime Shipping Control System (IRSCS).

Under the IRSCS each ice type is given a weighting relative to each type and class of ice strengthened vessel. When an ice type is deemed too severe for the construction standard specified for that type or class of vessel, that ice type is considered hazardous, and is given a negative weighting. One then takes the sum of the products of each ice type weighting, times the amount of ice that is present in tenths, to arrive at a decision numeral. If the decision numeral is zero or positive the vessel can proceed, but if the decision numeral is negative the vessel must stop. In this way it is possible to determine the minimum ice class of vessel that is required to transit the entire route in zero or positive decision numerals. The decision numeral is modified for ridged ice or for brash, or decayed, ice.

Our objective was reached, therefore, by assessing several different data sets and published reports describing ice conditions along the NSR, comparing them to the various classes and types of ice strengthened vessels, and hence determining the minimum ice class a vessel would need to possess in order to make the transit safely.

The four conclusions of this work are summarized as:

  • CAC 2/1 - required 8 times
  • CAC 3 - 5 times
  • CAC 4 - 1 time
  • Type A - 1 time and
  • Type E - 1 time

1. The minimum ship class that would be allowed passage through the Northern Sea Route under the IRSCS has been determined. The resulting minimum ice class of vessel that would be required by the proposed Canadian Arctic Shipping Pollution Prevention Regulations’ Ice Regime Shipping Control System to transit the Northern Sea Route during the sixteen time slots investigated are shown in the box above.

2. Analysis of the various data sources available for this project clearly identified the eastern portion of the Northern Sea Route, particularly just west of Wrangel Island, as the potentially most difficult area. In this area in 1987 and 1988 a CAC 2/1 vessel would have been required all year.

3. The need for icebreaker escort to conduct regular transits of the Northern Sea Route by a low ice class cargo ship is clearly apparent in the data analysed in this project.

4. The Ice Regime Shipping Control System appears to be a reasonable method of controlling shipping in the Russian Arctic.


    Douglas L, Stephen J. Jones, 1996, Evaluation of the Northern Sea Route Using the Ice Regime Shipping Control System, INSROP.©