North Star Port

DULUTHPORT.COM | 13 anchor. Anchoring in deep water limits the ability to have sufficient scope to provide good holding power. Similarly, a rock bottom will not allow the flukes to dig in and hold the vessel in place, which also diminishes holding power. The Duluth-Superior outer anchorage has a good mud and sand bottom and for several miles offshore is less than 100 feet deep, allowing a scope of up to six- or eight-to-one. However, it is not well sheltered from northeast gales. Should a vessel start to drag anchor in a gale, the ship master may start the engines and steam into the force of the wind and current to stop the drag- ging and keep the vessel in place. If this maneuver does not stop the vessel from dragging, the anchor may be heaved in and the vessel will steam away from shore to ride out the storm. The Duluth anchorage area (located northeast of the Duluth Harbor Basin shipping channel) provides shelter from the waves, but does not have room for large ships to pay out a lot of chain. Consequently, it is normally used by smaller vessels for short stays in rela- tively calm weather. A Fine Art Normally only one anchor is used when anchoring a vessel. Two anchors can give more holding power, but as the vessel spins while moved by wind and current, the two anchor chains may wrap around each other. Care must be taken to track the vessel's movements so the master knows what direction to move the vessel to untangle the anchor chains. Even then, assistance from a tugboat may be required to spin the vessel in the correct direction. Anchors may also be used as an emer- gency brake, however, as the anchor digs into the bottom, the vessel will sharply pivot to the opposite side that the anchor is dropped. Many ocean vessels have only a single propeller and no bow or stern thrusters. An experienced master may deliberately drop an anchor and pivot around it. This controlled maneuver is called "using a poor man's tugboat." Both anchors may also be used in what is called a "Mediterranean Moor." One anchor is dropped some distance from a dock and then the vessel is moved in the opposite direction and the second anchor is dropped. The vessel, using the wildcat to pay out chains, goes astern on the engine until the stern is just off the dock. The two anchors and vessel then form a Y. The anchors hold the bow steady and only stern lines go to the dock. Hold Steady S o m e v e s s e l s m a y elect to carry a stern (stream) anchor. This optional anchor must also be classed, tested and maintained. Using a bow anchor and the stern anchor allows a vessel to anchor in a river and maintain position in the cur - rent. Using the stream anchor requires care- ful ship handling and knowledge of what is on the bottom of the river. It's common for elec- tric cables, pipelines or other underwater obstructions to cross rivers and anchors can foul on or wreck these relatively frag- ile obstacles, not all of which are clearly or accurately marked on charts. Ocean vessels may also use their anchor chains to attach the vessel to a single point mooring buoy. These buoys are fixed to the bottom so that the vessel can safely remain in one location pivoting around the buoy for cargo operations or long-term mooring. Attaching the anchor chain requires that the anchor be secured to the ship and then uncoupled from the anchor ring using the detachable link. The chain is then low- ered to the buoy where it is attached. Anchors are an essen- tial part of a vessel's operating equipment. Using them requires a s o u n d k n o w l e d g e of seamanship, ship handling, and safety procedures. Most of the actions described in this article are per - formed by only an offi- cer and two or three mariners working on the bow of the ship in concert with the master controlling the vessel from the bridge. Dual bow anchors ride prominently on the Marshall Islands-flagged Federal Oshima. Built in Japan, the Handysize bulk carrier has been a regular visitor to the Great Lakes since its launch in 1999. Richard Stewart, Ph.D. Professor Emeritus, University of Wisconsin-Superior Dr. Stewart sailed as a mariner for decades and held an Oceans and Domestic Unlimited Tonnage Master's License. He commanded large oceangoing vessels, managed a fleet of vessels and taught at the U.S. Merchant Marine Academy as well as UW-Superior. He was also a captain in the U.S. Naval Reserve.

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