If you have ever watched a movie in which the captain of a Navy ship yells down from the bridge wing, telling his deck crew to “Cast off all lines,” the film was not made by a sailor. Navy ships do not leave their lines on the pier as they head out to sea.
Like many things in the nautical world, mooring a ship to a pier, a wharf, or another ship is a somewhat complicated process marked by specific practices and its own language. Standard commands, specialized deck fittings, and the lines themselves all are referred to in precise nautical terms.
A mooring line will do no good without the necessary fittings on board the ship and on the pier. A cleat consists of a pair of projecting horns for belaying (securing) a line. Bitts are cylindrical metal shapes (usually cast iron or steel) arranged in pairs on a ship’s deck and/or on a pier. A bollard is a heavy cylindrical object with a bulbous top and often a horn that is found on piers but not on board ships. A chock is different from the other fittings so far mentioned because lines are passed through it, not secured to it. Chocks come in three varieties—open, closed, and roller—and are used to feed lines in the direction you want. A typical mooring configuration would have lines running from bitts on board a ship, through chocks, to a bollard (or a cleat or another set of bitts) on the pier. Fenders, or bumpers, prevent the ship from rubbing against the pier.
Mooring lines are referred to by both numbers and names. They are numbered starting with the forward-most line (number 1) and continuing aft in sequence, and are named by a combination of their location, their use, and the direction in which they tend as they leave the ship.
Mooring lines that prevent ships from drifting away from the pier are rigged perpendicular, or nearly so, to the pier and are called breast lines. Lines that minimize forward and aft movement are rigged nearly parallel to the pier and are called spring lines.
The mooring configuration will differ depending on the size of the vessel being moored and the surrounding conditions, such as tides, currents, and weather, but a standard six-line moor will illustrate most of what one needs to know about securing a ship to a pier. The bow line runs through the bull nose (a chock on the very front of the ship) and then to the pier. The after bow spring, so-named because this line tends (goes) aft, prevents forward motion of the ship. The number 3 line, called the forward bow spring, keeps the ship from moving backward along the pier. The after quarter spring and the forward quarter spring function the same as their counterparts on the bow. Because they are located on the after half of the ship, they are identified by the word “quarter” instead of “bow.” The stern line, like the bow line, usually is rigged as a breast line.
Larger ships require more lines, and the ones rigged in the middle part of the ship (amidships) are called waist lines. So, an extra line rigged amidships to keep a ship snug to the pier is called a waist breast line. If more lines are rigged, they still follow the rule of numbering from forward, so that the last line aft on a ship moored with 11 lines would be called number 11.
In the modern world, where new naval technologies seem to emerge every day, it is somewhat amazing that sailors still moor ships to piers the same way they have since the earliest of seafaring times. The lines themselves have improved, growing larger and stronger as ships have evolved, but before a captain can get under way to take all that technology to sea, he or she still must give the (proper) command: “Take in all lines.”