Poling, Paddling, Oarlock, Oar, the Galley, Sail, Square-Rig, Lateen-Rig and the Carrack

Posted by PITHOCRATES - August 14th, 2013

Technology 101

(Originally published January 11th, 2012)

The Modern Container Ship is Powered by Diesel Engines making Ocean Crossings Safe, Reliable and Efficient

Trade required a way to move heavy things in large quantities.  Railroads do a pretty good job of this.  Ever get stopped by a mile long train with double-stack containers?  These are the hot-shot freights.  They get the right-of-way.  Other trains pull aside for them.  And they get the best go-power.  They lash up the newest locomotives to these long freights.  Carrying containers full of expensive treasures like plasma televisions, smartphones, computers, clothing, perfume, cameras, etc.  Unloaded from great container ships days earlier.  And hustled out of these great container seaports to cities across the U.S.

These goods came into the country the way goods have for millennium.  On a ship.  Because when it comes to transporting large cargoes there is no more cost efficient way than by ship.  It’s slow.  Unlike a train.  But it can carry a lot.  Which really reduces the cost of shipping per unit shipped.  Keeping sale prices low.  And profits high.

Diesel engines power the modern container ship.  That either turn a propeller directly.  Or by turning an electric generator.  Which in turn powers an electric motor that turns a propeller.  Makes crossing the oceans pretty much a sure thing these days.  And timely.  Day or night.  Wind or no wind.  With the current.  Or against the current.  But travel on water was not always this safe.  Reliable.  Or efficient.

Galleys were Fast and Maneuverable but Decks full of Rowers left Little Room for Cargo

Earliest means of marine propulsion was a man using a pole.  Standing in a boat with his cargo, he would stick the pole through the water and into the riverbed.  And push.  The riverbed wouldn’t move.  So he would.  And the boat he was standing in.  A man kneeling in a canoe could propel the canoe forward with a paddle.  By reaching forward, dipping the paddle into the water and pulling.  By these strokes he would propel himself forward.  And the canoe he was kneeling in.  We transfer the force of both poling and paddling to the vessel via the man-vessel connection.  The feet.  The knees.  Or, if sitting, the butt.  A useful means of propulsion.  But limited by the strength of the man poling/paddling.

The oarlock changed that.  By adding leverage.  Which was a way to amplify a man’s strength.  An oar differs from a paddle because we attach it to the boat.  In an oarlock.  A pivot point.  An oar is similar to a paddle but longer.  It attaches to the oarlock so that a short length of it extends into the boat while a longer length extends outside of the boat.  The rower then rows.  Facing backwards to the boat’s direction.  His short stroke inside the boat transfers into a longer stroke outside of the boat (the leverage).  And the attachment point allows the rower to use both hands, arms and legs.  He pulls with his arms and pushes with his legs.  The force is transferred through the oarlock and pushes the boat forward.  So a single stroke from an oar pulled a boat much harder than a single stroke of a paddle.  And allowed more rowers to be added.  We call these multiple-oared boats galleys.  Such as the Viking longship.  With up to 10 oars on a side.  Or the Phoenician bireme which had two decks of rowers.  Or the Greek trireme which had three decks of rowers.  Or the Carthaginian/Roman quinquereme which had five decks of rowers.

Of course, decks full of rowers left little room for cargo.  Which is why these ships tended to be warships.  Because they could maneuver fast.  Another means of propulsion was available, though.  Wind.  It had drawbacks.  It didn’t have the quick maneuverability as a galley.  And you couldn’t just go where you want.  The prevailing winds had a large say in where you were sailing to.  But without rowers you had a lot more room for cargo.  And that was the name of the game when it came to international trade.

The Carrack opened the Spice Trade to the European Powers and Kicked Off the Age of Discovery

Our first civilizations used sailing ships.  The Sumerians.  And the Egyptians.  The Egyptians used a combination of sail and oars on the Nile.  Where the winds and current were pretty much constant.  They used wind-power to sail upstream.  And oared downstream.  Both the Egyptians and Sumerians used sail to reach India.  The Phoenicians, Greeks and Romans used sail to ply the Mediterranean.  Typically a single square sail on a single mast perpendicular to the keel.  Then later the triangular lateen parallel to the keel.  A square-rig square sail worked well when the wind was behind you.  While the lateen-rig could sail across the wind. And closer into the wind.

The wind blew a square-rig forward.  Whereas the wind pushed and pulled a lateen-rig forward by redirecting the wind.  The lateen sail split the airstream.  The sail redirects the wind towards the stern, pushing the boat forward.  The wind going over the outside of the sail curved around the surface of the sail.  Creating lift.  Like an airplane wing.  Pulling the boat forward.

It was about this time that Europeans were venturing farther out into the oceans.  And they did this by building ships that combined these sails.  The square rigging allowed them to catch the prevailing winds of the oceans.  And lateen rigging allowed them to sail across the wind.  One of the first ships to combine these types of sails was the carrack.  The Portuguese first put the carrack to sea.  The Spanish soon followed.  Christopher Columbus discovered The Bahamas in a carrack.  Vasco da Gama sailed around Africa and on to India in a carrack.  And Ferdinand Magellan first sailed around the world in a carrack (though Magellan and his other four ships didn’t survive the journey).  It was the carrack that opened the spice trade to the European powers.  Beginning the age of discovery.  And European colonialism.

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