Bitts are a pair of sturdy vertical steel posts, mounted on the deck, used to secure mooring lines or heavy chain under significant load.
How They’re Used
A mooring line is wrapped in a figure-eight pattern around the two posts of a bitts, creating friction that holds the line securely without needing knots — allowing controlled, adjustable tension rather than a fixed, hard-to-release attachment.
Where Bitts Are Found
Bitts are positioned at multiple points around a vessel wherever mooring lines need to be made fast — forward, aft, and often at intervals along the length of the ship, depending on the vessel’s mooring arrangement and line-handling needs.
Construction
Bitts are built to withstand very high loads, given that mooring lines under tension — especially during berthing in wind or current, or when handling a heavy tow — can exert significant force. They’re welded or bolted to reinforced deck structure specifically designed to distribute that load safely into the hull.
Bitts vs Bollard
These terms are sometimes used loosely, but bitts specifically refers to the paired-post deck fitting used aboard the ship itself, while “bollard” more commonly refers to the single or paired posts fixed on a quay or pier that a ship’s lines are made fast to ashore.
Maintenance
Bitts require routine inspection for corrosion and structural integrity, given the repeated heavy loading they experience during every mooring operation — a genuine safety-relevant maintenance item, not just cosmetic upkeep.
Exam Relevance
Bitts and their role in mooring operations are covered within Ship Knowledge and deck equipment topics in deck officer competency exams.