When severe snowstorms prevented life-sustaining fuel supplies from reaching the frozen Alaskan town of Nome, U.S. officials turned to a Russian company for help.

The relief mission through perilous, ice-choked seas was the first mid-winter fuel delivery to western Alaska, capping a year of pioneering shipping as oil and gas development and climate change increase traffic along northern trade routes sought by centuries of Arctic explorers.

Russia has staked future growth on mining the Arctic's vast energy resources, and reviving a Soviet-era shipping route along its Siberia coast is an integral part of that plan. It could also promise economic revival for Russia's ports and shipyards, struggling since their Soviet-era glory days.

But industry analysts and mariners say ice floes, narrow straits, shallow waters, poor infrastructure and stormy winters continue to loom as obstacles to safe and profitable shipping through the polar shortcut.

"We must develop the Arctic!" said Fazil Aliyev, a sea captain and owner of the tanker that voyaged to Alaska.

"It is profitable for everyone. Our clients win because their cargo is delivered faster, now we need to make it economically viable... try to make it a year-round route," he said, speaking by phone from Vladivostok, Russia's gateway port to Asian markets.

Aliyev's company, RIMSCO, tripled cargo along Russia's coastal waterway last year when a warm summer kept what Russia calls the Northern Sea Route open for a record 141 days, almost a month longer than usual.

Sometimes called the Northeast Passage, the circumpolar route is a network of sea lanes across the top of continental Eurasia which crosses Russian waters from the Kara Gate to the Bering Strait and trims some 4,000 nautical miles (7,400 km) off southern routes.

Danish shipping group Nordic Bulk Carriers said it saved a third of the cost and nearly half the time sending goods to China sailing north of Russia instead of via the Suez canal.

"It's a very promising region and an interesting shipping lane that almost halves the distance between Europe and the Far East," Aliyev said.

Tough Times at the Shipyard

In the White Sea port of Severodvinsk, once a closed city of 200,000 at the heart of the Soviet Union's Cold War nuclear submarine program, defence contracts won by the shipyard and tested at a nearby naval base still pay the bulk of wages.

Big black submarines lumbered out to sea from its docks in ice-free waters without the help of tugboats or icebreakers unusually late into the fall last year.

Built in the 1930s, the state-owned Sevmash shipyard 35 km (22 miles) north of the city of Arkhangelsk, is a jumble of buildings and factory floors big enough to be a town itself, with canteens, churches and a museum for its 27,000 employees.

The shipyard saw tough times in the 1990s as Moscow slashed defence spending, and Russia's share of the global shipbuilding market dwindled to just 0.2 percent. China and South Korea now dominate, with 37 and 35 percent of the market, respectively.

Yelena Makhovetskaya, 27, a graduate of Sevmash's shipbuilding university, said salaries were among the highest in the Soviet Union when her parents moved here in the 1970s. Wages have since fallen against the national average, many people have left and fewer are coming to work in the region, she said.

But new state contracts are fueling a revival. The sector was one of the few to see growth in crisis-hit 2009, with output up 62 percent and another 8 percent in 2010.

Sevmash's director, Andrei Dyachkov, said the shipyard hopes to profit from its know-how in the Arctic to win orders to build offshore drilling platforms, ice-capable support ships and even a floating airstrip to service oil fields in the Pechora Sea.

A race to exploit energy riches in the Arctic sea floor -- believed to hold as much as one quarter of the earth's untapped hydrocarbons -- has already brought new contracts.

Under an order from state energy firm Gazprom, Sevmash completed Russia's first ice-resist