Arctic hazards include shallow water, fickle weather and herds of caribou

Top, Chief Mate David Hammitt prepares barge 120-2 for docking at the Crowley terminal in Kotzebue. Above, the 860-hp tugboat Aku on a test run in Kotzebue Sound after repair of one of its rudders.

While some commercial vessel operators are only now discovering their ability to navigate in the Arctic, Capt. Sean Anderson and the pushboat Aku have been fixtures on the northwestern Alaska waters for decades.

Each summer, the 860-hp towing vessel and a 120-foot fuel barge are busy delivering gasoline and other products to villages along Alaska’s Kobuk, Selawik and Buckland rivers. Operated by Crowley Maritime Corp., the vessels are based at a fuel terminal at Kotzebue, the state’s largest native village.

The quad-screw towboat and barge not only transit the rivers, but sail out to sea to lighter larger oceangoing fuel barges that deliver inbound to Norton Sound from the Chukchi Sea. Aku’s crew faces the usual maritime headaches including sandbars, shifting gravel and unforecasted swells. The Arctic river environment also confronts the men with unique hazards, ranging from insufficient snowmelt runoff to herds of migrating wildlife that refuse to yield to vessels in the waterways.

Crowley needs the melting springtime snow to deepen the otherwise unnavigable rivers. Aku’s crews, therefore, probably operate within the narrowest navigation season in the nation. Some villages can be reached for only a few weeks each June. The mariners must time their deliveries just right, or those communities won’t receive the gasoline, heating oil and jet fuel they need to nourish their remote economies.

And because they are the only commercial mariners who regularly use the rivers, Aku’s crews sail on mostly uncharted waters.

“A lot of it is local knowledge. There are no charts for these rivers. We drew our own homemade charts,†said Anderson, who has been based at Kotzebue each summer since 1995.

“Some of the places are pretty tight,†he said at the wheelhouse’s chart table. “Sometimes there’s only a few feet underneath us.â€

Aku was built in 1984 by Nichols Brothers Boat Builders Inc. in Freeland, Wash. The 58-foot-long pushboat was specially constructed for the Kotzebue region’s rivers and coastline. Its draft is only 3 feet 9 inches at its stern and 3 feet 6 inches at the bow.

In preparation for repair of the tug’s rudder, a crane begins lifting the vessel out of the water and onto blocks on the beach at Crowley Maritime Corp.’s fuel terminal in Kotzebue, which is located above the Arctic Circle.

On a voyage in August 2009, Aku pushed the single-hull Crowley barge 120-1 on Norton Sound out to the sea buoy, where it rendezvoused with the anchored tugboat Sea Prince and barge 360. Although 120-1’s capacity is 185,000 gallons, on this day Anderson’s crew loaded only 58,000 gallons of unleaded gasoline, because their next voyage would be up the shallow Kobuk River to the village of Kiana.

120-1 and sister barge 120-2 draw 6 feet 6 inches when fully loaded. For upriver deliveries, Crowley limits their draft to no deeper than 4 feet 6 inches or even sometimes 3 feet 9 inches. Aku, with four 30-inch screws and four rudders, is powered by four Caterpillar 3306 engines. “Aku†means “beaver†in the Inupiaq language spoken in the area.

Standing between the Kotzebue terminal and Sea Prince’s anchorage on the 12-mile voyage is a massive sandbar that is a constant barrier to navigation in Norton Sound. The sandbar allows a maximum draft of only 7 feet. The barge 360 draws as much as 17 feet.

When transiting the sandbar and the rivers, Anderson, or Chief Mate David Hammitt, is constantly checking Aku’s Furuno depth finder and radar and Garmin global positioning system. The boat also is equipped with a ComNav autopilot system.

The crewmen go to great lengths to ensure that their vessels will not run aground on the ever-changing river bottom. Anderson sometimes sends Hammitt upriver in a skiff to check the depth by hand with a pole.

“A lot of times you just learn how to read the water,†Anderson said. “You look for ripples and current streams. Sometimes the gravel bar moves downriver 20 or 30 feet.â€

The navigation hazards and slim margin for error in Alaska were underscored in September 2009, when Crowley’s 160-foot barge 160-1 ran aground on a sandbar in the Kanektok River near the Bering Sea. That barge, which was being towed by the 73-foot tugboat Sesok, contained 71,000 gallons of gasoline and 71,000 gallons of jet fuel. Rising tides failed to refloat the vessel, and responders were forced to lighter 64,000 gallons of cargo, the U.S. Coast Guard said.

Top, welder Danny Shield works under the tug. Above, Capt. Sean Anderson brings Aku from the sea buoy into Kotzebue Sound.

Aku regularly serves 10 villages. The fuel deliveries are the lifeblood of Alaska’s remote inland villages. The inhabitants are grateful, and often greet the mariners with gifts of seal meat, dried fish and scrimshaw.

A lack of snowmelt is terrible news for these villagers. In 2008, Aku was able to manage only two voyages upriver to the village of Kobuk, population of 109. Crowley usually tries to make at least three trips to Kobuk — a 44-hour, 227-mile one-way run from Kotzebue. With insufficient deliveries in 2008, the community was forced to fly in the rest of the fuel it needed for the year. Until recently, Crowley transported fuel up the Noatak River for delivery to the village of Noatak, but the river bottom changed and it’s now too shallow.

Tugboats and barges have moved fuel and cargo from the Kotzebue terminal since the early 1950s. The initial vessels, operated by B&R Tug and Barge, were World War II surplus wooden tugs. Later, surplus landing craft were used. The operation was eventually sold to PAC Cos. Crowley acquired the assets in 1975. The Kotzebue fuel terminal’s capacity is 6 million gallons.

Aku’s August voyage to meet Sea Prince included Anderson, Hammitt, Second Mate Steve Burg, Engineer Ron Lively and Able Tankermen Syed Qasmi and Carlito Abriol. Hammitt had the helm during Aku’s foggy outbound voyage to the sea buoy. While the tug sailed at 6 to 7 knots, Hammitt’s head was on a swivel as he eyed the behavior of Norton Sound out the wheelhouse’s port and starboard windows.

“Sometimes we come out here and the sandbar is really showing, on both sides. You see those birds sitting out there?†Hammitt said. “Most of the tides are wind-driven tides. That can make a difference of a foot or two. … Sometimes you even see a trail of mud behind us, because we’re pushing up the mud.â€

The two-hour voyage can get interrupted by surprise weather. Climate change has caused the northwestern Alaska coast to endure more storms. An absence of sea ice for a longer spell in the summer allows warmer, turbulent waters to push into the region. The resulting erosion has damaged Shishmaref and Kivalina, two coastal villages that rely on the Crowley vessels for fuel deliveries. Sea walls are being constructed to protect those communities from the encroaching Chukchi Sea. In 2009, Kotzebue experienced its first thunderstorm in anyone’s memory.

“Five-foot seas are too much†for Aku and the 120s in Norton Sound, Hammitt said. “Sometimes we have to turn right around and come back.â€

The seasonality of the work at Kotzebue can make operations extremely tricky. Vessel maintenance work at Kotzebue begins in May. Ice clears on the river before it thaws in the sound. Therefore, deliveries from the terminal to the villages are completed first — in June. At that time, Aku sails into Hotham Inlet, which the Crowley crews often call “Kobuk Lake,†and up the Kobuk river in 24-hour daylight. The process needs a little bit of luck too.

“Sometimes up at Kobuk (village) the river is high enough, but there’s still too much ice downriver and in the lake,†said Crowley’s Kotzebue terminal manager, Herman Reich. “When that ice is clear, sometimes the water has already dropped too much in the river. If we don’t have much snow, it takes a little longer to push that ice out.â€

Fuel deliveries to the terminal from the oceangoing barges run from July to September. Aku and the 120s also transport fuel to seaside villages in summer. The vessels make return visits for “fall top-offs†wherever they can, Reich said. By the end of September, the vessels are pulled out of the water and the navigation season is over.

Crowley’s mariner and shore-based teams need to pay keen attention to the weather conditions and water depths. Tides impact each vessels’ ability to transit shallow waters, while wind direction is a major factor along the seacoast.

“For upriver, we usually send a local guide to help with operations who knows the river really well,†Reich said. “When we go up the Buckland River, we have to use the tide. They go in there on the high tide, and they usually have to stay for 12 hours to wait for the next high tide to get out.â€

On the Kobuk River, “between Kiana and Ambler, there’s kind of a shallow area that we have to get past,†Reich said. “For Kivalina we need northeast winds — offshore winds. If there is a big swell, we can’t get to the beach and pump off.â€

Vessel upkeep also poses an expensive challenge. Kotzebue isn’t exactly a maritime cluster, and it’s perhaps 1,000 nm away from the nearest shipyard. Operating on such a tight seasonal schedule, Crowley must perform emergency repairs and regularly scheduled maintenance in the company’s own Kotzebue terminal yard.

During the August work, for example, one of Aku’s rudders broke off. Kotzebue has Coast Guard-certified welders, but a marine chemist needed to be flown in from Washington state to approve the hot work. Forget about sending Aku to a dry dock. A Crowley crane lifted the towboat’s stern onto blocks on the beach.

Hammitt spends part of his summer on Crowley vessels that transport fuel and cargo along Alaska’s North Slope to Barrow. That navigation season lasts from the middle of July to the end of August. Cargo loads have included modular houses, propane tanks, skiffs and even an ambulance. The locals and the professional mariners say that area of the Arctic Ocean has had less ice in recent years.

“I notice a big difference on that North Slope,†Hammitt said. “It used to be you’d have to dodge the icebergs. It’s much more open now. It’s dramatic. It’s actually better for us, because we can do our jobs easier.â€

As they navigate the Kobuk River’s remote stretches at 5.5 knots, the Crowley crews observe Alaska landscapes and wildlife that most people will never see. Hammitt has spotted grizzly bears and musk oxen along the riverbanks. While maps indicate that the region is officially above the tree line, the Aku crew can confirm that there are plenty of trees in the river valleys they navigate. The Alaska mariners witness the effects of climate change on the flora.

“The tundra is getting soft, and you see trees slumped over like they’re drunk,†Hammitt said.

Occasionally the wildlife interfere with Aku’s operations, requiring quick thinking by the pilot.

“Sometimes you’ll come around a corner and you see a thousand caribou crossing the river,†Hammitt said with a deep exhale. “You have to pull back on the throttles and slow down — or you have to stop entirely. You lose momentum.†•

By Professional Mariner Staff