The reduction in the ice covering the Arctic Sea creates both new opportunities and challenges for shipping in these areas.
Arctic ice is retreating at an alarming rate. One of the few benefits of this is that year-round commercial routing of ships via the Northwest Passage and Northern Sea Route (or Northeast Passage) is a distinct future possibility. The Northern Sea Route dramatically reduces the travelling distance between Europe and the Far East or the west coast of North America. Via the Northern Sea Route, the navigational distance between Hamburg and Yokohama, for instance, is only 6,900 miles, compared with 11,430 miles via the Suez Canal.
In the summer, some people predict that major parts of the polar sea will be ice-free in a few years’ time, making it possible to go almost straight over the North Pole with a minimum of ice strengthening. The reduction is mainly in the summer ice, as the coverage during the winter will be more or less the same as it is now. However, the main difference is that a larger part of the winter ice will be first-year ice, reducing the amount of multi-year ice.
Today
The container traffic in the Arctic ice is today limited to the transport of supplies to remote settlements and export of some mineral resources. The main traffic is in Canadian waters and using the Northern Sea Route along the Siberian coastline. In Russia, this transport is often carried out using SA-15 vessels assisted by nuclear-powered icebreakers.
Challenges
“There are several challenges involved when moving container transport from world wide to Arctic areas. The main difference is, of course, the impact of ice and low temperatures, but 24-hour darkness during the winter season, problems with icing and the lack of crew with experience and training are also issues to be considered before entering these areas,” says Morten Mejlænder-Larsen, who is responsible for ice activities in DNV Maritime.
Most of the vessels operating today are designed for ice-breaker assistance, and those expected to be designed in the near future will be the same. However, some vessels will also be designed for independent operation, either from port to port or in a kind of shuttle, loading the containers onto regular container ships in a port outside the ice.
Transit operations at cruising speed in open waters, which may include some pieces of multi-year ice whose size is difficult to observe, represent a collision risk.
Another challenge is to operate the ship within the design limitations stipulated by the selected ice class when operating in changing ice conditions. Even experienced officers often find it difficult to evaluate the actual strength properties and thickness of the ice in which the ship is operating. In order to support the bridge with information about the actual loading on the hull, DNV is heading a project called Ice Load Monitoring, where sensors along the ice belt measure the ice load and present the load as a utilisation factor of the structure. The aim is to operate in the elastic range of the material and not in the plastic range which results in permanent deformations.
Class Notations
DNV has rules for ships intended for ice operation and these are aligned with the other major classification societies’ rules (IACS PC rules). The rules, including requirements regarding hulls and propulsion, are divided into seven different levels depending on the type of ice and operation.
In order to ensure that the ship can operate properly, DNV has the additional WINTERIZED notation, with requirements related to the safety and operation of the ship and equipment. The notation is divided into three different levels, depending on the conditions in the area of operation. The WINTERIZED notation also includes requirements as to low temperature steel grades in order to avoid brittle fracture. Other notations like the CLEAN notation should also be considered, as there is a special focus on the environment in the Arctic.
Operations in cold climates – managing the risk
DNV’s focus is on evaluating the additional risk when moving shipping from world wide operations to Arctic areas. What is the increase in the risk elements known from world wide shipping and what are the additional risk elements caused by ice and low temperatures. The additional risks are estimated, and possible risk-mitigating measures are assessed in order to find the best design for a given operation. DNV is involved in several R&D projects related to Arctic operations.
In addition to the common challenges facing all vessels operating in Arctic areas, icing caused by freezing sea spray can create problems from a stability point of view and when loading/unloading the containers. The WINTERIZED notation includes requirements as to equipment and areas to be kept ice free from a safety and operational point of view.