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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Archimedes’ Principle, Buoyancy, Spar Deck, Freeboard, Green Water, Bulkheads, Watertight Compartments, RMS Titanic and Edmund Fitzgerald

Posted by PITHOCRATES - January 2nd, 2013

Technology 101

(Originally published April 4th, 2012)

The Spar Deck or Weather Deck is Where you Make a Ship Watertight

Let’s do a little experiment.  Fill up your kitchen sink with some water.  (Or simply do this the next time you wash dishes).  Then get a plastic cup.  Force the cup down into the water with the open side up until it rests on the bottom of the sink.  Make sure you have a cup tall enough so the top of it is out of the water when resting on the bottom.  Now let go of the cup.  What happens?  It bobs up out of the water.  And tips over on its side.  Where water can enter the cup.  As it does it weighs down the bottom of the cup and lifts the open end out of the water.  And it floats.  Now repeat this experiment.  Only fill the plastic cup full of water.  What happens when you let go of it when it’s sitting on the bottom of the sink?  It remains sitting on the bottom of the sink.

What you’ve just demonstrated is Archimedes’ principle.  The law of buoyancy.  Which explains why things like ships float in water.  Even ships made out of steel.  And concrete.  The weight of a ship pressing down on the water creates a force pushing up on the ship.  And if the density of the ship is less than the density of the water it will float.  Where the density of the ship includes all the air within the hull.  Ships are buoyant because air is less dense than water.  If water enters the hull it will increase the density of the ship.  Making it heavier.  And less buoyant.  As water enters the hull the ship will settle lower in the water.

The spar deck or weather deck is where you make a ship watertight.  This is where the hatches are on cargo ships.  We call the distance between the surface of the water and the spar deck freeboard.  A light ship doesn’t displace much water and rides higher in the water.  That is, it has greater freeboard.  With less ship in the water there is less resistance to forward propulsion.  Allowing it to travel faster.  However, a ship riding high in the water is much more sensitive to wave action.  And more susceptible to rolling from side to side.  Increasing the chance of rolling all the way over in heavy seas.  (Interestingly, if the ship stays watertight it can still float capsized.)  So ship captains have to watch their freeboard carefully.  If the ship rides too high (like an empty cargo ship) the captain will fill ballast tanks with water to lower the ship in the water.  By decreasing freeboard the ship is less prone to wave action.  But by lowering the spar deck closer to the surface of the water bigger waves can crash over the spar deck.  Flooding the spar deck with ‘green water’.  Common in a storm with high winds creating tall waves.  As long as the spar deck is watertight the ship will stay afloat.  And the solid water that washes over the spar deck will run off the ship and back into the sea.

The Titanic and the Fitzgerald were Near Unsinkable Designs but both lost Buoyancy and Sank

Improvements in ship design have made ships safer.  Steel ships can take a lot of damage and still float.  Ships struck by torpedoes in World War II could still float even with a hole below their waterline thanks to watertight compartments.  Where bulkheads divide a ship’s hull.  Watertight walls that typically run up to the weather deck.  Access though these bulkheads is via watertight doors.  These are the doors that close when a ship begins to take on water and the captain orders, “Close watertight doors.”  This contains the water ingress to one compartment allowing the ship to remain buoyant.  If it pitches down at the bow or lists to either side they can offset this imbalance with their ballast tanks.  Emptying the tanks where the ship is taking on water.  And filling the tanks where it is not.  To level the ship and keep it seaworthy until it reaches a safe harbor to make repairs.

They considered RMS Titanic unsinkable because of these features.  But they didn’t stop her from sinking on a calm night in 1912.  Why?  Two reasons.  The first was the way she struck the iceberg.  She sideswiped the iceberg.  Which cut a gash below the waterline in five of her ‘watertight’ compartments.  Which basically removed the benefit of compartmentalization.  They could not isolate the water ingress to a single compartment.  Or two.  Or three.  Even four.  Which she might have survived and remained afloat.  But water rushing into five compartments was too much.  It pitched the bow down.  And as the bow sank water spilled over the ‘watertight’ bulkheads and began flooding the next compartment.  Even ones the iceberg didn’t slash open.  As water poured over these bulkheads and flooded compartment after compartment the bow sank deeper and deeper into the water.  Until the unsinkable sank.  The Titanic sank slowly enough to rescue everyone on the ship.  She just didn’t carry enough lifeboats.  For they thought she was unsinkable.  Because of this lack of lifeboats 1,517 died.  Of course, having enough lifeboats doesn’t guarantee everyone will survive a sinking ship.

The Edmund Fitzgerald was the biggest ore carrier on the Great Lakes during her heyday.  These ships could take an enormous amount of abuse as the storms on the Great Lakes could be treacherous.  Like the one that fell on the Fitzgerald one November night in 1975.  When 30-foot waves hammered her and her sister ship the Arthur Andersen.  No one knows for sure what happened that night but some of the clues indicate she may have bottomed out on an uncharted shoal.  For she lost her handrails indicating that the ship may have hogged (where the bow and stern bends down from the center of the ship held up by that uncharted shoal).  The handrails were steel cables under tension running around the spar deck.  If the ship hogged this would have stretched the cable until it snapped.  She had green water washing across her deck.  Lost both of her radars.  A vent.  Maybe even a hatch cover.  Whatever happened she was taking on water.  A lot of it.  More than her pumps could keep up with.  Causing a list.  And the bow to settle deeper in the water.  Waves crashed over her bow as well as the Andersen’s.  The ships disappeared under the water.  Then reemerged.  As they design ships to do.  Then two massive waves rocked the Andersen.  She was following the Fitzgerald to help her navigate by the Andersen’s radar.  So these two waves had hit the Fitzgerald first.  The Fitzgerald had by this time taken on so much water that she lost too much freeboard.  When she disappeared under these two waves she never came back up.  It happened so fast there was no distress call.  The ship was longer than the lake was deep.  So her screw was still propelling the ship forward when the bow stuck the bottom.  She had lifeboat capacity for all 29 aboard.  But the ship sank too fast to use them.  Or even for the Andersen to see her as she sailed over her as she came to a rest on the bottom.

Our Ships have never been Safer but Ship Owners and Merchants still need to Protect their Wealth with Marine Insurance

We build bigger and bigger ships.  And it’s amazing what can float considering how heavy these ships can be.  But thanks to Archimedes’ principle all we have to do to make the biggest and heaviest ships float is too keep them watertight.  Keeping them less dense than the water that makes them float.  Even if we fail here due to events beyond our control we can isolate the water rushing in by sealing watertight compartments.  And keep them afloat.  So our ships have never been safer.  In addition we have far more detailed charts.  And satellite navigation to carefully guide us to our destination.  Despite all of this ships still sink.  Proving the need for something that has changed little since 14th century Genoa.  Marine insurance.  Because accidents still happen.  And ship owners and merchants still need to protect their wealth.

www.PITHOCRATES.com

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Archimedes’ Principle, Buoyancy, Spar Deck, Freeboard, Green Water, Bulkheads, Watertight Compartments, RMS Titanic and Edmund Fitzgerald

Posted by PITHOCRATES - April 4th, 2012

Technology 101

The Spar Deck or Weather Deck is Where you Make a Ship Watertight

Let’s do a little experiment.  Fill up your kitchen sink with some water.  (Or simply do this the next time you wash dishes).  Then get a plastic cup.  Force the cup down into the water with the open side up until it rests on the bottom of the sink.  Make sure you have a cup tall enough so the top of it is out of the water when resting on the bottom.  Now let go of the cup.  What happens?  It bobs up out of the water.  And tips over on its side.  Where water can enter the cup.  As it does it weighs down the bottom of the cup and lifts the open end out of the water.  And it floats.  Now repeat this experiment.  Only fill the plastic cup full of water.  What happens when you let go of it when it’s sitting on the bottom of the sink?  It remains sitting on the bottom of the sink.

What you’ve just demonstrated is Archimedes’ principle.  The law of buoyancy.  Which explains why things like ships float in water.  Even ships made out of steel.  And concrete.  The weight of a ship pressing down on the water creates a force pushing up on the ship.  And if the density of the ship is less than the density of the water it will float.  Where the density of the ship includes all the air within the hull.  Ships are buoyant because air is less dense than water.  If water enters the hull it will increase the density of the ship.  Making it heavier.  And less buoyant.  As water enters the hull the ship will settle lower in the water.

The spar deck or weather deck is where you make a ship watertight.  This is where the hatches are on cargo ships.  We call the distance between the surface of the water and the spar deck freeboard.  A light ship doesn’t displace much water and rides higher in the water.  That is, it has greater freeboard.  With less ship in the water there is less resistance to forward propulsion.  Allowing it to travel faster.  However, a ship riding high in the water is much more sensitive to wave action.  And more susceptible to rolling from side to side.  Increasing the chance of rolling all the way over in heavy seas.  (Interestingly, if the ship stays watertight it can still float capsized.)  So ship captains have to watch their freeboard carefully.  If the ship rides too high (like an empty cargo ship) the captain will fill ballast tanks with water to lower the ship in the water.  By decreasing freeboard the ship is less prone to wave action.  But by lowering the spar deck closer to the surface of the water bigger waves can crash over the spar deck.  Flooding the spar deck with ‘green water’.  Common in a storm with high winds creating tall waves.  As long as the spar deck is watertight the ship will stay afloat.  And the solid water that washes over the spar deck will run off the ship and back into the sea.

The Titanic and the Fitzgerald were Near Unsinkable Designs but both lost Buoyancy and Sank

Improvements in ship design have made ships safer.  Steel ships can take a lot of damage and still float.  Ships struck by torpedoes in World War II could still float even with a hole below their waterline thanks to watertight compartments.  Where bulkheads divide a ship’s hull.  Watertight walls that typically run up to the weather deck.  Access though these bulkheads is via watertight doors.  These are the doors that close when a ship begins to take on water and the captain orders, “Close watertight doors.”  This contains the water ingress to one compartment allowing the ship to remain buoyant.  If it pitches down at the bow or lists to either side they can offset this imbalance with their ballast tanks.  Emptying the tanks where the ship is taking on water.  And filling the tanks where it is not.  To level the ship and keep it seaworthy until it reaches a safe harbor to make repairs.

They considered RMS Titanic unsinkable because of these features.  But they didn’t stop her from sinking on a calm night in 1912.  Why?  Two reasons.  The first was the way she struck the iceberg.  She sideswiped the iceberg.  Which cut a gash below the waterline in five of her ‘watertight’ compartments.  Which basically removed the benefit of compartmentalization.  They could not isolate the water ingress to a single compartment.  Or two.  Or three.  Even four.  Which she might have survived and remained afloat.  But water rushing into five compartments was too much.  It pitched the bow down.  And as the bow sank water spilled over the ‘watertight’ bulkheads and began flooding the next compartment.  Even ones the iceberg didn’t slash open.  As water poured over these bulkheads and flooded compartment after compartment the bow sank deeper and deeper into the water.  Until the unsinkable sank.  The Titanic sank slowly enough to rescue everyone on the ship.  She just didn’t carry enough lifeboats.  For they thought she was unsinkable.  Because of this lack of lifeboats 1,517 died.  Of course, having enough lifeboats doesn’t guarantee everyone will survive a sinking ship.

The Edmund Fitzgerald was the biggest ore carrier on the Great Lakes during her heyday.  These ships could take an enormous amount of abuse as the storms on the Great Lakes could be treacherous.  Like the one that fell on the Fitzgerald one November night in 1975.  When 30-foot waves hammered her and her sister ship the Arthur Andersen.  No one knows for sure what happened that night but some of the clues indicate she may have bottomed out on an uncharted shoal.  For she lost her handrails indicating that the ship may have hogged (where the bow and stern bends down from the center of the ship held up by that uncharted shoal).  The handrails were steel cables under tension running around the spar deck.  If the ship hogged this would have stretched the cable until it snapped.  She had green water washing across her deck.  Lost both of her radars.  A vent.  Maybe even a hatch cover.  Whatever happened she was taking on water.  A lot of it.  More than her pumps could keep up with.  Causing a list.  And the bow to settle deeper in the water.  Waves crashed over her bow as well as the Andersen’s.  The ships disappeared under the water.  Then reemerged.  As they design ships to do.  Then two massive waves rocked the Andersen.  She was following the Fitzgerald to help her navigate by the Andersen’s radar.  So these two waves had hit the Fitzgerald first.  The Fitzgerald had by this time taken on so much water that she lost too much freeboard.  When she disappeared under these two waves she never came back up.  It happened so fast there was no distress call.  The ship was longer than the lake was deep.  So her screw was still propelling the ship forward when the bow stuck the bottom.  She had lifeboat capacity for all 29 aboard.  But the ship sank too fast to use them.  Or even for the Andersen to see her as she sailed over her as she came to a rest on the bottom.

Our Ships have never been Safer but Ship Owners and Merchants still need to Protect their Wealth with Marine Insurance

We build bigger and bigger ships.  And it’s amazing what can float considering how heavy these ships can be.  But thanks to Archimedes’ principle all we have to do to make the biggest and heaviest ships float is too keep them watertight.  Keeping them less dense than the water that makes them float.  Even if we fail here due to events beyond our control we can isolate the water rushing in by sealing watertight compartments.  And keep them afloat.  So our ships have never been safer.  In addition we have far more detailed charts.  And satellite navigation to carefully guide us to our destination.  Despite all of this ships still sink.  Proving the need for something that has changed little since 14th century Genoa.  Marine insurance.  Because accidents still happen.  And ship owners and merchants still need to protect their wealth.

www.PITHOCRATES.com

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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.

www.PITHOCRATES.com

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