Bulk carriers have two bow anchors and one spare. Anchors raised and lowered by a special winch known as the windlass, or perhaps by a capstan on very large ships. The cable drops down off the windlass into the chain locker. A few ships have stern anchors. When considering an anchorage for a ship, the depth of water, the nature of the bottom and prevailing winds should be known. On long salvage tows the anchor cable is often used as part of the towing line.