Mooring
Mooring is the process of securing a vessel in position — alongside a quay or jetty, to a buoy, or to another ship — using mooring lines led from the ship to bollards, dolphins or a buoy. A typical alongside mooring uses a pattern of head lines, stern lines, breast lines and spring lines to control the ship in every direction.
The mooring must hold the ship against wind, current, tide, passing-ship effects and the surge from swell. Mooring operations are among the highest-risk tasks on deck because of the enormous tension in the lines and the snap-back danger if one parts.
A ship spends much of its life moored, and a mooring that fails — lines parting or the ship ranging along the berth — endangers people, damages the ship and the quay, and can shut a berth. Getting the pattern, line strength and tending right is fundamental port-safety work.
What is a spring line in mooring?
A mooring line led well forward or aft along the ship to stop it moving ahead or astern along the berth. Springs work with head, stern and breast lines to hold the ship in position.