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The art of navigation in ice

Despite alarming reports of global warming it has happened again. Large areas in the Gulf of Bothnia and Gulf of Finland are covered by ice. In the end of February most of the icebreakers in the northern Baltic Sea area were in service. Without taking up a stand in the emotional debate about the consequences of the greenhouse effect, we have to live with the fact that there will be cold winters up here in the north, also in the future for many years to come.

From the shipping industry’s point of view cold winters mean nothing else than trouble. When the ice cover grows, schedules lose their significance. Shipping is left in the hands of the natural forces – and the icebreakers. The costs increase dramatically as the bunker consumption may be several times higher than in open water.

Navigation in ice is not easy. During the first half of the last century, vessels were even lost as their hull structures crushed under the pressure of ice. Today the rules of the highest Finnish/Swedish ice classes demand such strong hulls that total losses due to ice pressure most likely have been eliminated in Baltic Sea conditions. Still, it is common that the hull, or even more often the rudder and the propeller, are damaged by ice. During an icy winter the local repair yards are kept busy.

Despite stronger vessels, many of the dangers of ice navigation remain. If a vessel gets stuck in a drifting ice field, there may be a risk that it enters shallow water and runs aground. The collisions between vessels in a convoy form a chapter themselves. As the ships run with maximum power and the distances in the convoy must be kept at a minimum, a following vessel occasionally runs into the stern of a leading vessel, that loses its speed in heavy ice pressure. It is also quite common that an icebreaker leading a convoy suddenly stops in a ridge and if the officer on watch in the following vessel is not extremely alert, it may run into the icebreaker’s stern.

When a severe ice winter occurs next time – that is for sure going to happen, it is just a matter of time – the whole Baltic Sea freezes. In that stage the current icebreaker fleet is by no means sufficient. Already during a normal ice winter, when the Gulf of Botnia, Åland Sea and the whole Gulf of Finland is covered by ice, the large number of vessels in the area will provide more than a match for the icebreakers. Especially the large aframax-tankers may present a problem as they, despite their ice class, are no icebreakers. So far there are only two icebreaking aframax-tankers, which are equipped with podded propulsion and capable of sailing independently in most ice conditions.

Sharing resources is a solution. There is a long tradition in co-operation between Sweden and Finland when it comes to icebreaking. The key to the successful co-operation is of course that the two countries have a similar attitude towards winter navigation and that the cultural differences are minimal.

It is also essential that the crews of all vessels regularly sailing in the northern Baltic Sea have adequate knowledge about navigation in ice. The officer on watch must understand the signs of nature and the behaviour of an ice field to find the easiest way to get through. Following the directives from the icebreakers is a good start, but this does not eliminate the need of ice knowledge onboard the vessel too.

During normal ice conditions a modern vessel built to the highest ice class should be able to manage quite independently from icebreaker assistance. And, in theory, when all vessels are strong and manned with competent crews, many problems could be eliminated. The icebreakers could concentrate their resources to areas where it is really impossible to force through.

But how is it possible to reach such an ideal situation? For officers regularly sailing in icy waters, training is very important. But for those visiting the area once or maybe only now and then, ice advisors is a working solution. A pilot or a deck officer boards the vessel at the ice edge and provides the master with ice-knowledge and information about how to proceed.

Such a service exists for example in Finland, but so far the interest for it has been quite low. As long as these are not mandatory services, most of the owners and charterers will probably see them only as another extra cost.
Even though the problems of winter navigation are discussed in several forums, consensus about compulsory measures still seems to be far away in the future. To have the slightest chance to advance further from the discussion stage, all the Baltic Sea countries concerned must stand united.
Today the authorities’ traffic restrictions provide an efficient way to regulate the traffic and eliminate unsuitable vessels. In Sweden and Finland these are connected to ice class and deadweight. Both the restrictions and the ice classes are harmonized in these two countries. The Finnish/Swedish model would certainly work in the whole Baltic Sea area. Today there is a jungle of different ice classes, issued by authorities or classification societies.

Just a thought: Perhaps we one day may have an “ice class” also for the crew, certifying that the navigators have been trained in ice navigation? Why not let this lead to discounts in the fairway dues?

It is all positive that winter navigation is discussed in the Baltic Sea countries. The problem is that this discussion usually disappears with the ice in the spring.

//Pär-Henrik Sjöström