For all the talk of using the Arctic as a northern shipping route, year-round trade in the region is probably still far off. The main problem is the availability of nuclear icebreakers to make way for the cargo vessels.

A recent report in the High North News, indicated that two convoys transited the the Northern Sea Route in the months of December and January. These were the first winter voyages in almost 30 years. The last occurred before the collapse of the Soviet Union.

A westbound convoy reached its destination in the Kara Sea without incident, but four eastbound vessels were stuck in the ice of the East Siberian Sea for a week. The eastbound vessels departed the port of Arkhangelsk on the White Sea December 14 and arrived in Pevek in the East Siberian Sea on January 7, according to The Siberian Times. The ships got stuck in the ice after leaving Pevek, and, once extricating themselves, returned to Pevek for the rest of the winter. Officials say the ships will begin their return journey at the end of May or June.

The convoy, consisting of bulk carriers and their icebreaker escort, delivered building supplies for a quay wall part of the world’s first floating nuclear power plant, which will transported to Chukotka for assembly on site in 2018.

Researchers say the voyage was intended to demonstrate the feasibility of voyages under these harsh conditions. This experience also demonstrated the limitations of the vessels involved. The ice which compromised the journey was unexpected. Moreover, the icebreaker accompanying the the bulk carriers were not up to the job.

Nuclear icebreakers may have been more successful but those are more costly tate and are not necessarily available for every voyage. The successful westbound convoy also encountered ice conditions in the East Siberian Sea, but was escorted by a nuclear-powered icebreaker.

That voyage consisted of the a tanker Shturman Ovtsyn, a heavy load carrier, and a general cargo ship Arktika-1, along with the icebreaker. The transit began in the Bering Strait on December 21 and concluded after 2,400 miles in the Gulf of Ob on January 3.

The tanker was used to transport crude oil from the Arctic Gate terminal to the port of Murmansk under a contract with Gazprom Neft. Between August 2016 and the end of January 2017 33 voyages delivering one million tons of crude oil along that route.

Researchers say that winter transits along the Northern Sea Route are still not realistic on a regular basis. The primary challenge is a commercial one: the cost of providing a nuclear icebreaker.