It’s shortly after midnight and I’m standing at the portside rail with a couple of other gawkers squinting into bright sunlight as Healy heaves up chunks of ice over two meters thick, some larger in area than the average one-bedroom New York apartment. The ship backs and rams, and when she backs, the prop wash propels broken ice forward of the bow where it stacks and congeals, further impeding her way. A one-time visitor might think she’s in death throes the way she shudders, lurches, slews, and vibrates. She’s been doing that a lot during the last week, but never like this, never such strain, never so loud as to preclude normal conversation. And we’re going nowhere. (At lunch today Chief Engineer Tom Lowry told me that during the night they’d cranked on all four engines—and in one hour she’d made good three ship lengths.) No one aboard has ever had her in ice this dense. Earlier, I wrote that the Chukchi spawns no multi-year ice, yet last night and still today, the upturned blocks of ice reveal their cross sections where we see the deep blue hue that distinguishes multi-year ice from first-year ice. I ask one of our ice scientists if that statement was too categorical? No, he says, the Chukchi melts out entirely every summer, so if that was multi-year ice, then wind and currents probably delivered it here from the chaotic, broken-glass geography in the Canadian Archipelago. It’s hard not to perceive the solid ice field as landscape, inert and constant. But of course this ice is floating (because it’s less dense than seawater), and therefore governed by ocean and atmospheric dynamics. Floes grind and crash against one another, heaving up high hummocks and rumpled pressure ridges as the currents and the wind quarrel over dominance. Floes grind and crash against one another, heaving up high hummocks and rumpled pressure ridges as the currents and the wind quarrel over dominance. In the Greenland Sea several years ago, I took informal ice-piloting lessons from the captain of the British Antarctic Survey ship James Clark Ross, who has decades of experience in both polar regions. He said that ice pilots used to operating in Antarctica are unpleasantly surprised when they come up against Arctic ice, far harder than its Southern Hemisphere counterpart. This is due to the close continental quarters in the Arctic, where gyring currents further congeal and harden the ice as they spin it around the ocean basin, grinding it against shore-fast ice. The Ross, an ice-strengthened ship, not an icebreaker, would have no business in these “waters,” where even Healy, a full-on icebreaker is forestalled. However, today not withstanding, there are some subtleties to piloting her in the ice, as Captain Reeves generously explained in his expansive stateroom. (“The biggest in the Coast Guard,” he said.) First, he listed three basic principles: speed management, momentum/swing management, and predictive versus reactive thinking. Healy has a pronounced knuckle in her bow just above the waterline. She breaks ice not by crashing through it, but by bending it under the weight of the ship as the knuckled bow allows her to ride up on the floes. To optimize this effect, you want to enter the ice at seven knots, but naturally the impediment will slow the ship, so you add power to maintain momentum; don’t let the ice take over. Ideally, you enter a ridge of ice at 90° and keep the power on until the stern, not just the bow, reaches clear water. Healy is good at going straight ahead, but, slab-sided, she doesn’t turn very nimbly. So the prudent pilot will set up for the ice by completing the turn to a perpendicular course several ship lengths prior to the encounter. Sometimes, of course, conditions will force you to hit the ice at an angle, say, on the port bow. In that case, the impact will kick her bow to starboard. To counter this predictable event, you want to enter the ice with some degrees of port rudder—again, don’t let the ice take over by directing your bow away from your intended course. And speaking of awareness, always mind the fundamental nautical elements. The current’s set and drift and the wind’s angle and velocity will affect your heading and the behavior of the ice ahead. And then there’s this matter of backing and ramming that we saw so much of today. The bow is her strong point; nothing nautical is indestructible, but the bow is as close as anything gets. Her weak point lies astern, with the propellers and rudder. Healy’s props, 16 feet in diameter, have fixed blades, which are less vulnerable than variable-pitch props. However, all propellers and the still more vulnerable rudder always need to be protected. When backing, the rudder should to be kept amidships, that is, in a fore-and-aft position. Any rudder angle when backing will put untoward strain on this vital control surface. Unlike cars, all vessels from sailing dinghies to super tankers turn by the stern. Therefore, trying to turn in ice also jeopardizes the propellers. Before actually backing, you want to use the props to chop and expel as much ice rubble as possible; it’s called flushing. And repeatedly ramming the same area of ice increases the risk of getting beset. Instead, widen the track by striking the ice in a herringbone pattern. Finally, Captain Reeves warned against entering any lead (a channel of open water between floes) narrower than the ship’s beam. “We’re not only breaking ice, we’re also displacing it.” So you’ve got to think about where the displaced ice will go before you enter it. Tempting though the lead may be, you can easily get stuck in it. So you want to attack the floe adjacent to the lead, thereby using the lead as a soft place for the shunted ice to go. “There’s more to it, but those are the basics. Oh, wait, one other thing. Observe your track astern. If your track closes rapidly, this indicates the ice is under heavy pressure, and you have reason for concern about getting beset.” “Many thanks, Captain.” The ice relaxes a bit after dinner. A few leads appear, even a polynya or two in which kittiwakes dive on edible things. We reach cruising speed for a while. But now, at 2030, we’ve reverted to backing and ramming. Leave a Reply Cancel Reply Your email address will not be published. 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