Mooring line handling and operations are some of the most common practices
aboard any ship. Whenever a ship comes along a dock, it tosses out lines. If the lines are put out wrong, it could kill someone.
The lines are heavy and strong, but under the right conditions act just like rubber bands and snap back with enough force
to cut someone in half. Knowing that, studying the proper procedures for tying up and letting go take on all that much more
importance. Here are some basic things to know with mooring operations.
When a ship comes into port, the type of arrangement and number of lines that it will put out depends on the dock
type and load condition of the ship. Most large cargo ships will often double up on all of their lines, putting out 2 each
of the bow, bow and quarter spring, fore and after breast, and stern lines.
-Bow lines: typically run through the bull nose on the bow and run forward down the dock, leading ahead
of the ship. When backed against, these lines will help to bring the ship in toward the dock.
-After bow spring: From the bow leading aft, these lines prevent the ship from surging forward should
a ship's wake or wind force the ship ahead. Also, when run forward against, they will help to kick the stern out away from
-Forward bow spring: From the after section of the bow leading forward, these help to prevent the ship
from surging backward should a wake or wind force the ship astern. When backed against, they will help to pull the ship in
to the dock.
-Breast lines: usually put out from the bow or stern, and occasionally amidships, these lines hold the
ship alongside the dock. They do not prevent surging in any direction other than away from the dock, and are usually the last
lines sent out and the first brought in.
-After quarter Spring: the lines run from the quarter aft and prevent the ship from surging forward.
When pulled forward against, these lines help to pull the ship in toward the dock.
-Forward Quarter Spring: These lines run from the stern forward, and prevent the ship from surging aft.
When pulled astern against, these lines help to push the bow out away from the dock.
-Stern lines: These lines run from the stern, usually run through the centerline chock, and run
aft of the ship. When pulled forward against, these lines help to bring the ship alongside the dock.