We’re going to talk
about a for-and-aft rigged ship, the most common sort of pirate ship. Imagine a
ship with a single triangular sail, just like the sailboats you drew as a
child. The wind blows from behind, the sail stretches out, and the boat moves.
You imagine that
the sail is being pushed by the wind. It is not. It is being pulled by a vacuum formed
in front of the sail by the moving
wind. Much the way an airplane is being pulled into the sky by suction on top
of the wing.
The sailors did not
understand why this worked, but they knew how to use the way it worked. By
changing the angle of the sail to the ship – rotating sail around the mast - they could harness the power of the suction to
move the ship at right angles to the wind. If the wind is blowing from the
north, a ship can sail due east or due west with no trouble.
But how do you go
north? No matter how much you adjust the angle of the sail, you cannot sail
directly toward the direction of the wind. But by fine adjustments the ship can
sail at less than a 90 degree angle to the wind. Into a north wind, a ship can
sail northeast of northwest. This is called sailing “close to the wind.” The “closer” you were sailing to the wind,
the more near you were to sailing directly in the direction the wind was coming
from.
Still - how do you
sail right into the wind?
Well, if the ship
is traveling northeast, and suddenly turns into the wind, it will, if properly
handled, face due north for a second, then keep turning to the west until it is
sailing northwest. Keep doing this, and the ship follows a zigzag track, which
averages out to due north. This is called “tacking.” The only problem is that
because of the zigzag motion, the ship has to sail roughly three times the
distance.
A ship that can
sail closer to the wind, more nearly right into the direction the wind is
coming from, can travel “faster” by traveling in a shallower sort of zigzag. A
ship with the moveable, triangular sail can always travel closer to the wind
than a ship with square sails, which are not as adjustable.
This is why, in
spite of what movies tell us, that pirates preferred the triangular-sailed
(for-and-aft rigged) ship over the bigger square-rigged ships. By sailing close
to the wind, they could travel “faster” while moving at the same speed.
They could (so to
speak) make the kessel run in 12 parsecs. What Makes a Pirate Ship Sail?
White clouds skated
across the clear blue sky, a fresh breeze blew from the north, and the pirate
ship Donnybrook was under full sail.
“Course north, northeast!” called Captain Scarlet, and the helmsman spun the
wheel, turning into the wind…
Hold it, how did
they do that?
Sailing ships are
powered by the wind. It’s easy to understand how a ship sails away from the
direction the wind is blowing.