North Star Port

12 | NORTH STAR PORT | FALL 2024 PHOTOS / Jayson Hron; Stephanie Judd Irwin ILLUSTRATION / Michael Iver Jacobsen TOOLS TRADE OF THE When the chain is paid out so that it lays on the seabed, the shank will lay flat, and the flukes will be forced into the lakebed by the pull of the vessel against the chain. The stronger the wind or current, the more chain will need to be paid out so that the pull is parallel to the seabed. A ship must carry sufficient length of chain to allow it to anchor with the chain laying on the bottom. The required length of chain for each anchor will vary with ship size, but a common length for a large vessel is 8 to 10 shots of chain. On U.S. vessels, a shot is made of continuous links that total 90 feet. Each shot has a connecting link so it can be separated and replaced if needed. There are markings on each connecting link so the mate on the bow can tell how much chain is out of the locker. Anchoring in Duluth-Superior Ships at anchor off the entrances to Duluth-Superior have put a great deal of thought into how and where they will anchor. The number of shots paid out when anchoring is determined by the depth of the water, weather, bottom type and the location of vessels, land, buoys or other objects around the intended anchoring location. Nautical charts will show approved anchorage areas, the depth, type of seabed and any known obstructions, such as pipelines. The water's depth and the anticipated time in the anchorage will determine the amount of chain needed. A vessel may anchor for hours in what is called a short stay, while another vessel may anchor for days. The ratio between the depth of the water and amount of chain out is called the scope. A vessel on a short stay in good weather may only put out chain equaling three times the depth of the water, or a scope of three-to-one. A vessel anchored for a longer duration may have a scope of five-to-one. The anchor on the bottom is the point about which the vessel revolves as wind and currents move the ship. The length of chain paid out and the length of the vessel will determine the diameter of the anchoring circle. A thousand-foot lake freighter with five shots out can have an anchoring circle with a diame - ter of almost a quarter-mile. There must be nothing within that diameter that the vessel could hit as it revolves around the anchor. The officer of the watch will take frequent bearings and radar observations to ensure that the vessel is not dragging the anchor along the bottom. The office will also warn other ships that may try to anchor too close. Should the wind or current increase so that the anchor is no longer fixed, but is dragging along the bottom instead, then more chain will be paid out to increase the scope, driving the flukes into the bottom and increasing the holding power. Weather, Deep Water, and Rock Bottom The location of anchorages also depends on the depth, type of bottom and shelter from storms. Sometimes a vessel that is due to call at Two Harbors, Minnesota, will anchor off Duluth-Superior because the deep water close offshore of Two Harbors does not allow a vessel to safely DESIGNED TO DIG // The stockless anchor is designed to bite into the lakebed and dig deeper as the vessel pulls against the chain. "The Duluth-Superior outer anchorage has a good mud and sand bottom and for several miles offshore is less than 100 foot deep, allowing a scope of up to six- or eight-to-one. However, it is not well sheltered from northeast gales." Vlieborg of the Royal Wagenborg fleet waits at anchor outside the Port of Duluth-Superior on Sept. 21, 2024.

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