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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Flat-Bottomed Boat, Keel, Standing Rigging, Chinese Junk, Daggerboard, Balanced Rudder, Compartment and Junk Rig

Posted by PITHOCRATES - May 16th, 2012

Technology 101

Typical River Transport has a Flat Bottom and a Shallow Draft with Little Freeboard

What do most of the oldest and greatest cities in the world have in common?  Madrid.  Lisbon.  Paris.  London.  Amsterdam.  Belgrade.  Vienna.  Rome.  Cairo.  Kiev.  Moscow.  Baghdad.  New Delhi.  Shanghai.  Ho Chi Minh City.  Bangkok.  Hong Kong.  São Paul.  Buenos Aires.  Santiago.  Quebec City.  Montreal.  Detroit.  Boston.  New York.  Philadelphia.  Pittsburgh.  What do these cities have in common?  Rivers.  Coastal water.  Or safe harbors on the oceans.

Why is this?  Is it because their founders liked a good view?  That’s why people today pay a premium to live on the water’s edge.  But back then it was more necessity than view.  These were times before railroads.  Even before roads connected these new cities.  Back then there was only one way to transport things.  On the water.  And rivers were the early highways that connected the cities.  Which is why we built our cities on these rivers.  To transport the food or raw materials a city produced.  And to transport to these cities the things they needed to survive and grow.  And some of the earliest river transports were flat-bottomed boats.  Like the scow.  Punt.  Sampan.  And the barge.

Rivers are calm compared to the oceans.  Which allows a different boat design.  River transport doesn’t have to be sturdy to withstand rolling waves and high winds.  Which allows the design to focus on the main purpose of a boat.  Hauling freight.  Typical river transport has a flat bottom.  A shallow draft with little freeboard (i.e., sitting very low in the water with the top deck very close to the surface of the water).  And a square bow.  This allows these boats to operate in shallow waters.  Allowing them to run up right onto a river landing or beach.  Where they can be easily loaded with their cargoes.  Or unloaded.  And their flat, rectangular shapes maximize the cargo they can carry.  Propulsion is simple.  A man can push a small boat along with a pole.  Animal power can pull larger barges.  Or, later, motors were able to power them.  Or a tugboat could pull or push them.

The Chinese Junk had a Flat Bottom with no Keel allowing them to Carry a Lot of Cargo

These flat-bottomed boats are great for hauling freight.  But they are not very seaworthy.  Because the ocean’s waves will toss around any boat with a shallow draft and little freeboard.  Breaking it up and sending it and its cargo to the bottom of the ocean.  Which has confined these to the calm of rivers, bays and coastal waterways.  Cargoes that have to travel further than these allow are loaded onto an ocean-going vessel with a deeper draft.  And a higher freeboard.  With a keel.  That can withstand the leeward force of the wind.  So instead of being pushed sideways (or simply rolling over) the keel allows those sideway winds to fill a sail and propel a ship forward.  By sticking deeper into the water.  So as the wind tries to push the boat sideways the large amount of water in contact with the keel pushes back against that leeward force.  Allowing it to sail across the wind.

But there is a tradeoff.  The curved sections of the hull that form the keel reduces the amount of cargo a ship can carry in its hull.  Also, these ocean-going vessels have a lot of sail.  And a lot of rigging to hold it in place.  Standing rigging.  While the sails required running rigging.  To raise and lower sails depending on the wind conditions.  Which takes up space that can’t be used for cargo.  And requires a lot of sailors.  In fact, much of the upper deck is full of rigging and sailors instead of cargo.  But this was the tradeoff to sail into the rougher waters of the ocean.  You had to sacrifice revenue-earning cargo.  But there was one ship design that brought together the benefits of the flat-bottomed river scow and the ocean-going fully rigged sailing ship.  The Chinese junk.

The Chinese junk dates as far back as the 3rd century BC.  And began crossing oceans as early as the second century AD.  Long before the Europeans ventured out in their Age of Discovery.  The junk has a flat bottom with no keel.  But a high freeboard.  Which lets it carry a lot of cargo.  And operate in shallower waters than a fully rigged sailing ship.  But it could also sail in the rougher seas of the ocean.  When it did it lowered a daggerboard.  A centerboard that can lower from a watertight trunk within the hull into the water to act like a keel.  To resist those leeward forces.  Often installed forward in the hull so as not to take up valuable cargo space in the center of the ship.  Because they mount this forward the leeward forces could cause the back end of the ship to torque around the daggerboard. To counteract this force they use an oversized rudder on the stern.  To balance the resistance to those leeward forces.  Because the rudder was so large and had to deflect a lot of water it was difficult to turn.  Taking a team of men to operate it.   To help turn such a large rudder they developed ‘powered’ steering.  With a balanced rudder.  The axis the rudder turned on was just behind the leading edge of the rudder.  So when they turned the rudder the water hitting the part in front of the turning axis helped turn the rudder in the direction the crew was trying to turn it.  So the large rudder area past the turning axis could deflect the large volume of water necessary to turn the ship.

The Chinese gave us Papermaking, Printing, the Compass and Gunpowder but the Europeans Conquered the World

So the junk could travel in the shallow waters of harbors and rivers.  And the deep water of the ocean.  It was the first ship to compartmentalize the hull.  Making it very seaworthy.  Especially if it struck bottom and punched a hole in the hull.  Because of the compartments the flooding was contained to the one compartment.  Allowing the ship to remain afloat.  A design all ships use today.  The junk also used a different sailing rig.  The junk rig.  It’s low tech.  Was inexpensive.  And required smaller crews.

A three-mast junk has three masts.  And three sails.  One sail per mast.  And the masts are free standing.  They don’t need any standing rigging to hold them in place.  Because they don’t carry heavy loads of running rigging and sailors.  The sail is stretched between a yard and a boom.  The yard is at the top.  The boom is along the bottom.  Between the yard and the boom battens give the sail strength and attach it to the mast.  Think of a batten as that stick in the bottom of a window shade.  Grabbing this batten allows you to apply an even force on that window shade when pulling it down.  If this stick wasn’t there and you pulled down on the window shade the uneven forces across the shade would tear it.  Same principle on a junk rig.  Which allows them to use less expensive sail material.  To raise this sail up the mast you pulled up the yard via a block and tackle at the top of the mast.  From the deck.  With fewer crew members.  The sail is attached to the mast near one edge.  It’s pivoted to catch and redirect wind to the stern.  Propelling the ship forward.  And the battens will bend in strong enough winds to curve the sail.  Creating lift on the other side of the sail to pull the ship forward.

The Chinese gave us papermaking, printing, the compass and gunpowder.  But it was the Europeans that used these inventions to conquer the world.  For the Chinese had no interest in civilizations outside of China.  For when you had the best, they thought, what was the point?  So the Europeans came to them.  Even took Hong Kong from them.  When it was the Chinese that could have had the technologically advanced civilization.  An army fielding muskets and cannon.  And a navy of junk warships that could have gone anywhere the Europeans could have gone.  And farther.  Into the shallow waters and up the rivers where the European warships could not go.  They could have sailed up the Thames to London.  Up the Seine to Paris.  Even into Amsterdam.  Home of the Dutch East India Company.  That took such a great interest in all those Asian goods in the first place.   That brought the British to China to compete against the Dutch.  Leading to the Opium Wars.  And the loss of Hong Kong.  Imagine how different the world would be had China embraced their technology.  Like they are today.  Perhaps we will soon see the answer to that great ‘what if’ question.

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

Posted by PITHOCRATES - January 11th, 2012

Technology 101

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.

www.PITHOCRATES.com

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