rode

A rode is the complete assembly connecting a vessel to its anchor, consisting of chain, rope, or a combination of both. It absorbs shock loads from wind and tide, keeps the ship from dragging, and must be strong enough to hold the vessel safely even in heavy weather. The rode is paid out (released) from a winch or capstan when anchoring and recovered when the ship must move.

Most modern commercial vessels use all-chain rodes because chain is stronger, resists chafing, and withstands the abrasion of rocky or rough seabed. Smaller vessels and some sailing ships use nylon rope rodes, which are lighter and provide better shock absorption but require more scope (length deployed) to achieve holding power. A combination rode pairs rope at the surface with chain near the anchor, balancing weight and elasticity. The rode diameter depends on vessel size and the holding ground expected; a 50-metre cargo ship might carry 12 mm chain, while a 200-metre bulk carrier needs 28 mm or larger.

The length of rode deployed is called scope, expressed as a ratio of water depth. In sheltered anchorages, a 3:1 scope (three metres of rode for each metre of water depth) is typical; in open anchorages or heavy weather, crews pay out 5:1 or more to increase the angle of pull on the anchor and reduce breakage risk. Too little scope means the rode pulls at a steep angle, reducing holding power and risking anchor slip or chain breakage.

Wear and failure modes

Chain rodes corrode from salt water and electrolytic action, requiring periodic inspection and replacement of worn links. Shackles connecting chain sections can seize or fail if not properly maintained. Rope rodes chafe where they pass through the hawse pipe (the deck opening) and degrade in ultraviolet light; they must be inspected for mildew, broken strands, and loss of lay. Anchors can break free of the rode if it catches on underwater obstacles or if the vessel swings suddenly in changing tidal flows.

The term "rode" comes from Old English and Old Norse roots meaning "to stretch" or "to reach." It appears in maritime records from at least the 17th century. Today, the rode remains one of the most critical pieces of vessel equipment, and its failure in heavy weather has caused groundings and collisions. Insurance surveys and flag state regulations specify minimum breaking strengths and maintenance intervals for rodes based on vessel tonnage and trading area.