Sounding the Depth, Sea Marks and Bridge Lights

Posted by PITHOCRATES - December 11th, 2013

Technology 101

It’s Important to know both the Depth of the Water beneath you and the Hidden Dangers below the Surface

On November 10, 1975, the Great Lakes bulk ore carrier S.S. Edmund Fitzgerald sank in a powerful Lake Superior storm.  Waves of 35 feet crashed green water across her deck.  But time and again she bobbed back up from under the waves.  Until she began to lose her buoyancy.  No one knows for sure what happened but the Fitzgerald was taking on water prior to her sinking.  One theory said that she bottomed out on Six Fathom Shoal off of Caribou Island.  As she fell into the trough between two huge waves.

A fathom is 6 feet.  So six fathoms would be 36 feet.  Though the water over Six Fathom Shoal could be as shallow as 26 feet.  Which is pretty deep.  But is dangerously shallow for a ship like the Fitzgerald.  For she had a draft of 25 feet.  At best she had 11 feet (36-25) of clearance between the shoal and her hull.  Or in the worst case, 1 foot (26-25).  With the gale force winds pushing the waves as high as 35 feet that would put the trough approximately 17.5 feet (35/2) below the ‘calm’ surface level of the lake.  Which would bring the top of the shoal above the hull of the Fitzgerald.  Thus making a strong case that she bottomed out and fractured her hull and began to take on water.

The theory continues that as she took on water she settled deeper and deeper into the water.  Growing heavier.  And less buoyant.  Until a wall of water swept across her that was too great for her to shake off.  Sending her to the bottom of Lake Superior so quickly that the propeller was still spinning when the bow hit bottom.  Causing the hull to break.  With the torque of the spinning shaft rotating the stern over until she rested hull-up on the bottom.  This is only one theory of many.  People still debate the ultimate cause of her sinking.  But this theory shows the importance of knowing the depth of the water beneath you.  And the great danger of unseen objects below the surface of the water.

Ships use Sea Marks to guide them Safely through Navigable Channels

Those mariners who first crossed the oceans were some of the bravest ever to live.  For if a ship sank in the middle of the ocean chances are people never saw those sailors again.  For there’s nothing to sustain life in the middle of the ocean.  Everything you ate or drank you brought with you.  And crossed at the greatest speed possible to get to your destination before your supplies ran out.  Which was easy to do in the deep waters of the middle of the ocean.  But very dangerous when the water grew shallower.  As you approached land.  Especially for the first time.

If a ship struck a submerged object it could break up the hull and sink the ship.  Especially if you hit it at speed.  This is why they had lookouts high up in the crow’s nest looking for land.  Or indications that the water was growing more shallow.  And they would ‘heave the lead’.  Big burly men (leadsmen) would throw a lead weight on a rope as far out in front of the ship as possible.  Once the lead hit bottom they’d pull it up.  Counting the knots in the rope spaced at 6-foot intervals.  Or fathoms.  Sounding the depth of the water beneath them.  As the sea bottom raced up to the water’s surface they furled their sails to catch less wind.  And slow down.  As they approached land they would approach only so far.  And safely anchor in a safe depth of water near a promising location for a harbor.  Some sailors would then board a dinghy and row into the shallow waters.  Sounding the depth.  And making a chart.  Looking for a safe channel to navigate.  And a place suitable to build a deep-water dock.  Deep enough to sail in to and moor the large sailing vessels that would sail to and from these new lands.

Of course, we could do none of this during the night.  It may be safe to sail in the middle of the ocean at night but it is very dangerous in the shallow waters around land.  At least, for the first time.  After they built a harbor they may build a lighthouse.  A tall building with a beacon.  To guide ships to the new harbor in the dark.  And even add a fog horn to guide ships in when fog obscures the light.  This would bring ships towards the harbor.  But they needed other navigational aids to guide them through a safe channel to the dock.  As time passed we made our navigational aids more advanced.  As well as our ships.  Today a ship can enter a harbor or river in the black of night safely.  Thanks to sea marks.

If Ships wander just Inches off their Course the Results can be Catastrophic

Landmarks are navigational aids on land.  Such as a lighthouse.  While a sea mark is a navigational aid in the water.  Typically a buoy.  A buoyant vessel that floats in the water.  But held in place.  Typically with a chain running from the bottom of the buoy to an anchorage driven into the bottom of the water channel.  Holding it in place to mark the edge of the navigable channel.  In North America we use the colors green and red to mark the channel.  With the “3R” rule “Red Right Returning.”  Meaning a ship returning from a larger body of water to a smaller body of water (and ultimately to a dock) would see red on their right (starboard).  And green on their left (port).  If you’re leaving dock and heading to open water the colors would be the reverse.

As ships move up river the safe channel narrows.  And there are bridges to contend with.  Which compounds the problem of shallow waters.  Fixed bridges will have red lights on piers rising out of the water.  And a green light over the center of the safe channel.  A vertical lift span bridge or a double leaf (lift) bascule bridge will have red lights at either end.  And red lights over the center of the channel when these bridges are closed.  When the center span on a lift bridge is open there will be a green light marking the center of the channel on the lifted center span.  Showing the center of the channel and the safe height of passage.  When the bascule bridge is open there will be a green light on the tip of each open leaf.  Showing the outer edges of the safe channel.

Ships are massive.  And massive things moving have great momentum (mass multiplied by velocity).  The bigger they are and the faster they go the harder it is to stop them.  Or to turn them.  Which means if they wander out of that safe channel they will probably hit something.  And cause great damage.  Either to the ship.  Or to the fixed structures along the waterway.  Like on an Alabaman night.  When a river barge made a wrong turn in poor visibility and entered an un-navigable channel.  Striking a rail bridge.  Pushing the bridge out of alignment.  But not enough to break the welded rail.  Which left the railroad block signal green.  Indicating the track was clear ahead.  The river pilot thought that one of the barges had only run aground.  And was oblivious to what he did.  And when Amtrak’s Sunset Limited sped through and hit that kink in the track it derailed.  Killing 47 people.  About twice the loss of life when the Fitzgerald sank.  Showing the importance of navigation charts, sea marks and bridge lights.  For if ships wander just inches off their course the results can be catastrophic.

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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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Celestial Navigation, Insurance and the Joint Stock Company

Posted by PITHOCRATES - July 10th, 2013

Technology 101

(Originally published November 30th, 2011)

Despite Precise Celestial Navigation a lot of Ships and Valuable Cargoes still got Lost at Sea

Open sea navigation was once very perilous.  It took a long time before ships ventured from sight of the shoreline.  And a lot of technology.  Boats used to go the long way across the Mediterranean Sea.  Because being in open water at night without any visible landmarks was very dangerous.  So they hugged the coastline.  Adding days to every voyage.  And more danger.  Because the longer at sea the greater the risk there was of sinking.  Especially when you were skirting the rock-infested shallows of the shoreline.

The Sumerians charted the stars.  The Greeks continued this work, producing charts that could tell you what latitude (north/south position) you were at by looking at the stars and planets.  By measuring the angle of the stars and planets above the horizon.  The Arabs created one of the first tools to measure these angles.  The kamal.  Knowing this angle you could do a little math and look at a pre-calculated table of values.  And get your latitude.  Better instruments followed.  The cross-staff.  The astrolabe.   And then the sextant.  The gold standard of angle measuring until the advent of Global Positioning Satellites (GPS).  Calculating longitude (east/west position) was a bit more complicated.  Because the earth rotated.  Which required some more skillful measuring and more calculations.  And/or a reliable and accurate clock.  To adjust your results by the time of day.  As the time as well as the stars moved from east to west as the planet rotated.

The Chinese developed the magnetic compass.  A helmsman steered his ship by the compass.  The navigator checked the angles of celestial bodies (sun, moon, stars and planets), checked time and the ship’s speed to fix the ship’s position.  By determining latitude and longitude.  The navigator fed course headings and course corrections to the helmsman.  Armed with these skills, tools, celestial charts and tables, the navigator could do a little math and navigate a ship across a vast ocean day or night to any port in the world.  Transporting valuable cargoes safely and timely across the globe.  Pretty impressive for the time.  But despite this precise celestial navigation, a lot of ships still got lost at sea.  As well as their valuable cargoes.

The Joint-Stock Company and Insurance Reduced the High Risks of Transoceanic Shipping

No matter how well a navigator could fix a ship’s position there were some things he just couldn’t do.  Such as avoid an uncharted reef.  Prevent a mutiny.  Fend off pirates.  Fend off enemy warships.  Make storms go away.  Or even see through dense fog.  Simply put being on a small wooden ship in the middle of an ocean was very dangerous.  Which poised quite the problem for early global trade.

It was a huge investment to put a ship to sea.  It took another huge investment to fill a ship with valuable cargo.  And if that ship didn’t make it back to sell that cargo it was very bad news for the investor.  A lost ship could financially ruin them.  So not only could you get rich in this new global trade you could become impoverished.  Which made rich people reluctant to finance this early trade.  Because it was so risky.  Two things helped to reduce this risk to manageable levels.  Insurance.  And the joint-stock company.

A group of investors could buy stock into a company that was going to make numerous voyages on various ships.  In exchange for a share of the profits from this trade each investor paid a share of its cost.  Thus the joint-stock company spread the risk to multiple investors, reducing the risk to any one person.  So one lost ship would not cause financial ruin to any one investor.  Thus encouraging investment into this lucrative new trade of transoceanic shipping.  And with the advent of insurance, shippers could insure each voyage for a small affordable fee.  By collecting this small fee on every voyage the insurer could pay for the few ships and cargoes lost at sea.  Not the investors.  Thus further encouraging investment into this very risky endeavor.

Celestial Navigation, Insurance and the Joint-Stock Company made Transoceanic Shipping Possible

The smartphone you can’t live without today most likely came to you via a large container ship from a port across some ocean.  It made a long and perilous voyage to get to you.  Which wouldn’t have been possible without celestial navigation, insurance and the joint-stock company.  The things that made transoceanic shipping possible.  Most of which are still in use today.  As they were when brave mariners took to the open seas in those small wooden ships of yesteryear.

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Flood Insurance Premiums rise following Katrina and Sandy beyond what Some can Afford

Posted by PITHOCRATES - June 9th, 2013

Week in Review

Few things are as enjoyable as a beachfront view.  What a way to live.  Seeing the sunrise over the ocean.  Breathing that sea air.  Walking out your door to the water’s edge.  How lucky those lucky few are who live on the ocean’s edge.  Of course, there are some drawbacks to living on the ocean’s edge (see After Sandy, a new threat: Soaring flood insurance by Katie Zezima and Meghan Barr, Associated Press, posted 6/10/2013 on Yahoo! News).

George Kasimos has almost finished repairing flood damage to his waterfront home, but his Superstorm Sandy nightmare is far from over.

Like thousands of others in the hardest-hit coastal stretches of New Jersey and New York, his life is in limbo as he waits to see if tough new coastal rebuilding rules make it just too expensive for him to stay.

That’s because the federal government’s newly released advisory flood maps have put his Toms River home in the most vulnerable area — the “velocity zone.” If that sticks, he’d have to jack his house up 14 feet on stilts at a cost of $150,000 or face up to $30,000 a year in flood insurance premiums…

Officials are urging people to elevate their houses now because they are eligible for federal financial aid. About $350 million of New York City’s and $600 million of New Jersey’s Sandy relief funding has been allocated for the repair of single- and two-family homes, which could help defray the cost…

Several months before Sandy hit, Congress quietly passed the Biggert-Waters Flood Insurance Reform Act, a bill that authorized skyrocketing premium increases for people in flood-prone communities.

It was a desperate attempt to keep the program financially solvent after it was nearly bankrupted by an onslaught of claims from Hurricane Katrina, which forced the federal government to borrow about $17 billion from the Treasury.

Borrowing $17 billion from the Treasury?  That means borrowing $17 billion from the taxpayers.  And that’s the sad truth.  The people who don’t enjoy living on the ocean’s edge are the ones who end up paying for storm damage suffered by those living on the ocean’s edge.  People who shouldn’t be subsidizing someone’s dangerous home location.  Unless these people throw open their doors for all of us to come over and spend a few weeks on the beach with them.

Living on the ocean’s edge is both beautiful and dangerous.  Those who enjoy the beauty should pay for the privilege of enjoying that beauty.  Yes, it’s sad these people lost so much from Sandy.  But it was their choice to live there.  And they should pay all the costs required to live there.  Including all their insurance costs.  Like every other home owner must do that doesn’t have that gorgeous ocean view.

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Prevailing Winds, Channel Markers, Buoys, Portage, Canals, Locks, Niagara Falls and the Welland Canal

Posted by PITHOCRATES - January 30th, 2013

Technology 101

The Lateen-Rigged Sail allows Ships to Maneuver onto the Prevailing Winds Superhighways

Oceans are deep.  Allowing ships to cross them without fear of striking bottom.  Which helped the age of sail.  As sailors could use the prevailing winds to fill large masts of square-rigged sails to blow them across oceans.  Sailing to the New World with the trade winds (near the equator) and polar easterlies (near the poles) filling their sails.  And sailing from the New World with the westerlies (in the middle latitudes in both hemispheres) filling their sails.  The deep oceans let these sailing vessels move unrestricted to find the best wind.

That is, once these sailing vessels got to the proper latitude.  Getting there they had to use another kind of sail.  A lateen-rigged sail.  A triangular sail with a leading edge that cut into the wind.  Splitting the wind so part of it filled the sail.  The sail blew out and redirected the wind to the stern of the ship.  While the wind passing over the top of the curved sail created lift.  Like on an aircraft wing.  Pulling the ship forward.  This allows a wind blowing in from the side of a ship to propel it forward.  Which allows a sailing vessel to sail into the wind.  By sailing in a zigzag path.  Or beating.  After sailing in one direction they come about.  Or tack.  Turning the bow through the wind so it blows in from the other side of the ship.

The wide open and deep oceans let these sailing vessels maneuver at will to catch the wind.  Propelling them forward at speed.  Without fear of grounding out on the bottom.  Taking them to the great superhighways across the oceans.  To the trade winds and polar easterlies to sail west.  And to the westerlies to sail east.  Where these winds could fill multiple squared-rigged sails on a single mast.  On ships with multiple masts.  Allowing them to catch a lot of wind.  And to drive them forward to their destination.

Channel Markers and Buoys are Color-Coded telling Ship Captains ‘Red Right Returning’

Of course it’s these destinations that really matter.  For sailing around in the middle of the ocean is worthless unless you can load and unload cargo somewhere.  Getting to these ports was a little trickier.  Because it required sailing closer to land.  Where the ocean floor rises up quickly from great depths.  Making sailing near shores hazardous.  As hidden shoals and reefs hide just below the surface.  Threatening to cut a deep gash in a ship’s hull.  Or a ship could run aground in the shallows.  Where they may have to wait for a rising tide to free them.  All the while risking being damaged by any storm that blew in.

The first sailors who arrived in the New World had no navigational aids like we do today.  Often having to rely on the experience of a grizzled captain who could see and smell dangers in the water.  Or they dropped anchor away from the shore and explored the coast in smaller boats to sound out sea approaches to a deep-water harbor.  As time passed lighthouses dotted the shoreline.  And other navigational aids guided ship captains.  To warn them of dangerous waters.  And show safe channels to navigate.    Channel markers and buoys are color-coded.  With paint for day navigation.  And lights for night navigation.  In the New World (and Japan, South Korea and the Philippines) the colors are red and green.  When entering a harbor or river from the sea the red is kept on the right of a ship.  Mariners learn this with the memory device ‘red right returning’.

When the French sailed up the Saint Lawrence River they founded the oldest walled-city in North America.  Quebec City.  They then sailed as far upstream as they could.  Founding the city of Montreal.  Going beyond Montreal required portaging around the rapids at Montreal.  And a few others until they got to Lake Ontario.  Where they could re-embark ships and sail across Lake Ontario and into the Niagara River.  Where they had to portage around the rapids.  And Niagara Falls.  Where they once again could re-embark ships and enter Lake Erie.  Then sail up the Detroit River.  Across Lake St. Clair.  Up the St. Clair River.  And into Lake Huron.  Where they could sail through the Straits of Mackinac and into Lake Michigan.  Or up the St. Marys River.  Where they could portage around the rapids in the St. Marys River.  Reentering the river upstream of the rapids to let them sail into Lake Superior.  Where they could sail all the way to Minnesota.  And take on iron ore.  Mined from the great iron ore deposits beyond Lake Superior.  To feed the blast furnaces of America’s steel industry.

A Lock consists of a Chamber with Watertight Gates at each end and some Valves

Of course, iron ore is heavy.  As is a lot of the bulk freight shipping on the Great Lakes.  Making those portages around rapids and falls difficult and costly.  They needed to find a better way.  And they have.  Which is why Great Lakes freighters can travel from the western end of Lake Superior to the Saint Lawrence River.  And ocean-going freighters can enter the Saint Lawrence River and travel to the western end of Lake Superior.  Without a single portage.  Thanks to canals.  And locks.

A canal provides a passage around rapids or falls.  And locks in the canal can raise or lower a ship to the water level at either side of the rapids or falls.  Getting around the rapids between Montreal and Lake Ontario and in the St. Marys River didn’t require long canals.  Just enough to provide a passage around the rapids.  The Niagara River posed a bigger problem.  For there were both rapids.  And Niagara Falls.  As well as a great change in water levels.  The level in Lake Erie is 326.5 feet above the level in Lake Ontario.  As the typical lock doesn’t raise and lower water 326.5 feet one lock just wasn’t a solution.  So they used 8 (7 for raising and lowering ships and the 8th as a control lock).   And dug a canal across the Niagara peninsula.   The Welland Canal.  From Port Weller on Lake Ontario to Port Colborne on Lake Erie.  Interconnected by 26 miles of canal.  Allowing fully loaded bulk freighters to travel between Lakes Erie and Ontario.  And ocean-going freighters to travel from the Atlantic ocean (and the world beyond) to the western end of Lake Superior.

So how does a lock work?  Are there massive pumps to pump in water to raise a ship?  No.  There are no pumps.  Just a couple of valves.  A lock consists of a chamber with watertight gates at each end.  The gates swing open towards the upstream side.  When they close they form an 18-degree angle that points upstream.  So when the water level is higher on the upstream side the force of the water presses the gates closed and makes a watertight seal.  When the water level is equal on both sides of the gate they can easily open the gates.  When a ship enters a lock both gates seal.  If they are lowering a ship they open valves between the chamber and the canal on the downstream side.  The high water level inside the chamber drains until the water levels equalize.  If they are raising a ship they open valves between the chamber and the canal on the upstream side.  Water from the canal enters the chamber until the water levels equalize.  Then the appropriate gate opens and the ship goes on its way.  A very simple and low-tech process.  Allowing ships with deep drafts to travel the oceans.  Rivers.  And inland lakes.  Thanks to navigational aids.  Canals.  And locks.

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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.

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Celestial Navigation, Insurance and the Joint Stock Company

Posted by PITHOCRATES - November 30th, 2011

Technology 101

Despite Precise Celestial Navigation a lot of Ships and Valuable Cargoes still got Lost at Sea

Open sea navigation was once very perilous.  It took a long time before ships ventured from sight of the shoreline.  And a lot of technology.  Boats used to go the long way across the Mediterranean Sea.  Because being in open water at night without any visible landmarks was very dangerous.  So they hugged the coastline.  Adding days to every voyage.  And more danger.  Because the longer at sea the greater the risk there was of sinking.  Especially when you were skirting the rock-infested shallows of the shoreline.

The Sumerians charted the stars.  The Greeks continued this work, producing charts that could tell you what latitude (north/south position) you were at by looking at the stars and planets.  By measuring the angle of the stars and planets above the horizon.  The Arabs created one of the first tools to measure these angles.  The kamal.  Knowing this angle you could do a little math and look at a pre-calculated table of values.  And get your latitude.  Better instruments followed.  The cross-staff.  The astrolabe.   And then the sextant.  The gold standard of angle measuring until the advent of Global Positioning Satellites (GPS).  Calculating longitude (east/west position) was a bit more complicated.  Because the earth rotated.  Which required some more skillful measuring and more calculations.  And/or a reliable and accurate clock.  To adjust your results by the time of day.  As the time as well as the stars moved from east to west as the planet rotated.

The Chinese developed the magnetic compass.  A helmsman steered his ship by the compass.  The navigator checked the angles of celestial bodies (sun, moon, stars and planets), checked time and the ship’s speed to fix the ship’s position.  By determining latitude and longitude.  The navigator fed course headings and course corrections to the helmsman.  Armed with these skills, tools, celestial charts and tables, the navigator could do a little math and navigate a ship across a vast ocean day or night to any port in the world.  Transporting valuable cargoes safely and timely across the globe.  Pretty impressive for the time.  But despite this precise celestial navigation, a lot of ships still got lost at sea.  As well as their valuable cargoes.

The Joint-Stock Company and Insurance Reduced the High Risks of Transoceanic Shipping

No matter how well a navigator could fix a ship’s position there were some things he just couldn’t do.  Such as avoid an uncharted reef.  Prevent a mutiny.  Fend off pirates.  Fend off enemy warships.  Make storms go away.  Or even see through dense fog.  Simply put being on a small wooden ship in the middle of an ocean was very dangerous.  Which poised quite the problem for early global trade.

It was a huge investment to put a ship to sea.  It took another huge investment to fill a ship with valuable cargo.  And if that ship didn’t make it back to sell that cargo it was very bad news for the investor.  A lost ship could financially ruin them.  So not only could you get rich in this new global trade you could become impoverished.  Which made rich people reluctant to finance this early trade.  Because it was so risky.  Two things helped to reduce this risk to manageable levels.  Insurance.  And the joint-stock company.

A group of investors could buy stock into a company that was going to make numerous voyages on various ships.  In exchange for a share of the profits from this trade each investor paid a share of its cost.  Thus the joint-stock company spread the risk to multiple investors, reducing the risk to any one person.  So one lost ship would not cause financial ruin to any one investor.  Thus encouraging investment into this lucrative new trade of transoceanic shipping.  And with the advent of insurance, shippers could insure each voyage for a small affordable fee.  By collecting this small fee on every voyage the insurer could pay for the few ships and cargoes lost at sea.  Not the investors.  Thus further encouraging investment into this very risky endeavor.

Celestial Navigation, Insurance and the Joint-Stock Company made Transoceanic Shipping Possible

The smartphone you can’t live without today most likely came to you via a large container ship from a port across some ocean.  It made a long and perilous voyage to get to you.  Which wouldn’t have been possible without celestial navigation, insurance and the joint-stock company.  The things that made transoceanic shipping possible.  Most of which are still in use today.  As they were when brave mariners took to the open seas in those small wooden ships of yesteryear.

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