Corduroy Roads, Positive Buoyancy, Negative Buoyancy, Carbon Dioxide, Crush Depth, Pressurization, Rapid Decompression and Space

Posted by PITHOCRATES - May 9th, 2012

Technology 101

Early Submarines could not Stay Submerged for Long for the Carbon Dioxide the Crew Exhaled built up to Dangerous Levels

People can pretty much walk anywhere.  As long as the ground is fairly solid beneath our feet.  Ditto for horses.  Though they tend to sink a little deeper in the softer ground than people do.  Carts are another story.  And artillery trains.  For their narrow wheels and heavy weight distributed on them tend to sink when the earthen ground is wet.  Early armies needing to move cannon and wagons through swampy areas would first build roads through these areas.  Out of trees.  Called corduroy roads.  It was a bumpy ride.  But you could pull heavy loads with small footprints through otherwise impassable areas.  As armies mechanized trucks and jeeps with fatter rubber tires replaced the narrow wheels on wagons.  Then tracked vehicles came along.  Allowing the great weights of armored vehicles with large guns to move across open fields.  The long and wide footprints of these vehicles distributing that heavy weight over a larger area.  Still, nothing can beat the modern rubber tire on a paved road for a smooth ride.  And the lower resistance between tire and road increases gas mileage.  Which is why trucks like to use as few axles on their trailers as possible.  For the more tires on the road the more friction between truck and road.  And the higher fuel consumption to overcome that friction.  Which is why we have to weigh trucks for some try to cheat by pulling heavier loads with too few axles.  When they do the high weight distributed through too few wheels will cause great stresses on the roadway.  Causing them to break and crumble apart.   

Man and machine can move freely across pretty much anything.  If we don’t carry food and water with us we could even ‘live off the land’.  But one thing we can’t do is walk or drive on water.  We have to bridge streams and rivers.  Go around lakes.  Or move onto boats.  Which can drive on water.  If they are built right.  And are buoyant.  Because if a boat weighed less than the water it displaced it floated.  Much like a pair of light-weight, spongy flip-flops made out of foam rubber.  Throw a pair into the water and they will float.  Put them on your feet and step into the deep end of a pool and you’ll sink.  Because when worn on your feet the large weight of your body distributed to the light pair of flip-flops makes those flip-flops heavier than the water they displace.  And they, along with you, sink.  Unlike a boat.  Which is lighter than the water it displaces.  As long as it is not overloaded.  Even if it’s steel.  Or concrete.  You see, the weight of the boat includes all the air inside the hull.  So a large hull filled with cargo AND air will be lighter than the water it displaces.  Which is why boats float. 

Early sail ships had great range.  As long as the wind blew.  Their range only being limited by the amount of food and fresh water they carried.  Later steam engines and diesel-electric engines had greater freedom in navigation not having to depend on the prevailing winds.  But they had the same limitations of food and water.  And when we took boats under the water we had another limitation.  Fresh air.  Early submarines could not stay submerged for long.  For underwater they could not pull air into a diesel-electric engine.  So they had to run on batteries.  Which had a limited duration.  So early subs spent most of their time on the surface.  Where they could run their diesel engines to recharge their batteries.  And open their hatches to get fresh air into the boat.  For when submerged the carbon dioxide the crew exhaled built up.  If it built up too much you could become disoriented and pass out.  And die.  If a sub is under attack staying under water for too long and the levels of carbon dioxide build up to dangerous levels a captain has little choice but to surface and surrender.  So the crew can breathe again.

Rapid Decompression at Altitude can be Catastrophic and Violent

Being in a submarine has been historically one of the more dangerous places to be in any navy (second to being on the deck of an aircraft carrier).  Just breathing on a sub had been a challenge at times while trying to evade an enemy destroyer.  But there are other risks, too.  Some things float.  And some things sink.  A submarine is somewhere in between.  It will float on the surface when it has positive buoyancy.  And sink when it has negative buoyancy.  But submarines operate in the oceans.  Which are very deep.  And the deeper you go the greater the pressure of the water.  Because the deeper you go there is more ocean above you pressing down on you.  And oceans are heavy.  If a sub goes too deep this pressure will crush the steel hull like a beer can.  What we call crush depth.  Killing everyone on board.  So a sub cannot go too deep.  Which makes going below the surface a delicate and risky business.  To submerge they flood ballast tanks.  Replacing air within the hull with water.  Making it sink.  Other tanks fill with water as necessary to ‘trim’ the boat.  Make it level under water.  When under way they use forward propulsion to maintain depth and trim with control surfaces like on an airplane.  If everything goes well a submarine can sink.  Then stop at a depth below the surface.  And then resurface.  Modern nuclear submarines can make fresh water and clean air.  So they can stay submerged as long as they have food for the crew to eat.

An airplane has no such staying power like a sub.  For planes have nothing to keep them in air but forward propulsion.  So food and water are not as great an issue.  Fuel is.  And is the greatest limitation on a plane.  In the military they have special airplanes that fly on station to serve as gas stations in the air for fighters and bombers.  To extend their range.  And it is only fuel they take on.  For other than very long-range bombers a flight crew is rarely in the air for extended hours at a time.  Some bomber crews may be in the air for a day or more.  But there are few crew members.  So they can carry sufficient food and water for these longer missions.  As long as they can fly they are good.  And fairly comfortable.  Unlike the earlier bomber crews.  Who flew in unpressurized planes.  For it is very cold at high altitudes.  And there isn’t enough oxygen to breathe.  So these crew members had to wear Arctic gear to keep from freezing to death.  And breathe oxygen they carried with them in tanks.  Pressurizing aircraft removed these problems.  Which made being in a plane like being in a tall building on the ground.  Your ears may pop but that’s about all the discomfort you would feel.  If a plane lost its pressurization while flying, though, it got quite uncomfortable.  And dangerous. 

Rapid decompression at altitude can be catastrophic.  And violent.  The higher the altitude the lower the air pressure.  And the faster the air pressure inside the airplane equals the air pressure outside the airplane.  The air will get suck out so fast that it’ll take every last piece of dust with it.  And breathable air.  Oxygen masks will drop in the passenger compartment.  The flight attendants will scramble to make sure all passengers get on oxygen.  As does the flight crew.  Who call in an emergency.  And make an emergency descent to get below 10 thousand feet.  Almost free falling out of the sky while air traffic control clears all traffic from beneath them.  Once below 10 thousand feet they can level off and breathe normally.  But it will be very, very cold.

Man’s Desire is to Go where no Man has Gone before and where no Human Body should Be

Space flight shares some things in common with both submarines and airplanes.  Like airplanes they can’t fly without fuel.  The greatest distance we’ve ever flown in space was to the moon and back.  The Saturn V rocket of the Apollo program was mostly fuel.   The rocket was 354 feet tall.  And about 75% of it was a fuel tank.  In 3 stages.  The first stage burned for about 150 seconds.  The second stage burned for about 360 seconds.  The third stage burned for about 500 seconds (in two burns, the first to get into earth orbit and the second to escape earth orbit).  Add that up and it comes to approximately 16 minutes.  After that the astronauts were then coasting at about 25,000 miles per hour towards the moon.  Or where the moon would be when they get there.  The pull of earth’s gravity slowed it down until the pull of the moon’s gravity sped it back up.  So that’s a lot of fuel burned at one time to hurl the spacecraft towards the moon.  The remaining fuel on board used for minor course corrections.  And to escape lunar orbit.  For the coast back home.  There was no refueling available in space.  So if something went wrong there was a good chance that the spacecraft would just float forever through the universe with no way of returning home.  Much like a submarine that can’t keep from falling in the ocean.  If it falls too deep it, too, will be unable to return home.

Also like in a submarine food and fresh water are critical supplies.  They brought food with them.  And made their own water in space with fuel cells.  It had to last for the entire trip.  About 8 days.  For in space there were no ports or supply ships.  You were truly on your own.  And if something happened to your food and water supply you didn’t eat or drink.  If the failure was early in the mission you could abort and return home.  If you were already in lunar orbit it would make for a long trip home.  The lack of food and hydration placing greater stresses on the astronauts making the easiest of tasks difficult.  And the critical ones that got you through reentry nearly impossible.  Also like on a submarine fresh air to breathe is critical.  Even more so because of the smaller volume of the spacecraft.  Which can fill up with carbon dioxide very quickly.  And unlike a sub a spacecraft can’t open a hatch for fresh air.  All they can do is rely on a scrubber system to remove the carbon dioxide from their cramped quarters.

While a submarine has a thick hull to protect it from the crushing pressures of the ocean an airplane has a thin aluminum skin to keep a pressurized atmosphere inside the aircraft.  Just like a spacecraft.  But unlike an aircraft, a spacecraft can’t drop below 10,000 feet to a breathable atmosphere in the event of a catastrophic depressurization.  Worse, in the vacuum of space losing your breathable atmosphere is the least of your troubles.  The human body cannot function in a vacuum.  The gases in the lungs will expand in a vacuum and rupture the lungs.  Bubbles will enter the bloodstream.  Water will boil away (turn into a gas).  The mouth and eyes will dry out and lose their body heat through this evaporation.  The water in muscle and soft tissue will boil away, too.  Causing swelling.  And pain.  Dissolved nitrogen in the blood will reform into a gas.  Causing the bends.  And pain.  Anything exposed to the sun’s ultraviolet radiation will get a severe sunburn.  Causing pain.  You will be conscious at first.  Feeling all of this pain.  And you will know what is coming next.  Powerless to do anything about it.  Brain asphyxiation will then set in.  Hypoxia.  The body will be bloated, blue and unresponsive.  But the brain and heart would continue on.  Finally the blood boils.  And the heat stops.  In all about a minute and half to suffer and die.

Man is an adventurer.  From the first time we walked away from our home.  Rode the first horse.  Harnessed the power of steam.  Then conquered the third dimension in submarines, airplanes and spacecraft.  We are adventurers.  It’s why we crossed oceans and discovered the new world.  Why we climbed the highest mountains.  And descended to the oceans’ lowest depth.  Why we fly in airplanes.  And travelled to the moon and back.  When things worked well these were great adventures.  When they did not they were horrible nightmares.  While a few seek this adventure most of us are content to walk the surface of the earth.  To feel the sand through our toes.   Or walk to the poolside bar in our flip-flops.  To enjoy an adult beverage on a summer’s day.  While adventurers are still seeking out something new.  And waiting on technology to allow them to go where no man has gone before.  Especially if it’s a place no human body should be.

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LESSONS LEARNED #24: “You cannot lobby a politician unless he or she is for sale.” -Old Pithy

Posted by PITHOCRATES - July 29th, 2010

BUILDING A RAILROAD ain’t cheap.  It needs dump trucks of money.  Especially if it’s transcontinental.  And that’s what the Union Pacific and the Central Pacific were building.  Starting during the Civil War in 1863 (the year Vicksburg fell and Lee retreated from Gettysburg).  The Union Pacific was building west from Iowa.  And the Central pacific was building east from California. 

For the most part, Protestant, English-speaking Americans settled Texas.  Mexico had encouraged the American colonists to settle this region.  Because few Mexicans were moving north to do so.   The deal was that the colonists conduct official business in Spanish and convert to Catholicism.  They didn’t.  These and other issues soured relations between Mexico and the American Texans.  The Republic of Texas proclaimed their independence from Mexico.  America annexed Texas.  Mexico tried to get it back.  The Mexican-American War followed.  America won.  Texas became a state in 1845.  And that other Spanish/Mexican territory that America was especially interested in, California, became a state in 1850.  Hence the desire for a transcontinental railroad.

The U.S. government was very eager to connect the new state of California to the rest of America.  So they acted aggressively.  They would provide the dump trucks of money.  As America expanded, the U.S. government became the owner of more and more public land.  The sale of new lands provided a large amount of revenue for the federal government.  (Other forms of taxation (income taxes, excise taxes, etc.) grew as the amount of public lands to sell decreased.)  Land is valuable.  So they would grant the railroad companies some 44 million acres of land (i.e., land grants) for their use.  The railroad companies, then, would sell the land to raise the capital to build their railroads.  The government also provided some $60 million in federal loans.

But it didn’t end there.  The federal government came up with incentives to speed things up.  They based the amount of loans upon the miles of track laid.  The more difficult the ground, the more cash.  So, what you got from these incentives was the wrong incentive.  To lay as much track as possible on the most difficult ground they could find.  And then there were mineral rights.  The railroad would own the property they built on.  And any minerals located underneath.  So the tracks wandered and meandered to maximize these benefits.  And speed was key.  Not longevity.  Wherever possible they used wood instead of masonry.  The used the cheapest iron for track.  They even laid track on ice.   (They had to rebuild large chunks of the line before any trains would roll.)  And when the Union Pacific and Central Pacific met, they kept building, parallel to each other.  To lay more miles of track.  And get more cash from the government.

PAR FOR THE COURSE.  When government gets involved they can really mess things up.  But it gets worse.  Not only was government throwing dump trucks of American money down the toilet, they were also profiting from this hemorrhaging of public money.  As shareholders in Crédit Mobilier.

Thomas Durant of Union Pacific concocted the Crédit Mobilier Scandal.  As part of the government requirements to build the transcontinental railroad, Union Pacific had to sell stock at $100 per share.  Problem was, few believed the railroad could be built.  So there were few takers to buy the stock at $100 per share.  So he created Crédit Mobilier to buy that stock.  Once they did, they then resold the stock on the open market at prevailing market prices.  Which were well below $100 per share.  Union Pacific met the government requirements thanks to the willingness of Crédit Mobilier to buy their stock.  The only thing was, both companies had the same stockholders.  Crédit Mobilier was a sham company.  Union Pacific WAS Crédit Mobilier.  And it gets worse.

Union Pacific chose Crédit Mobilier to build their railroad.  Crédit Mobilier submitted highly inflated bills to Union Pacific who promptly paid them.  They then submitted the bills to the federal government (plus a small administration fee) for reimbursement.  Which the federal government promptly paid.  Crédit Mobilier proved to be highly profitable.  This pleased their shareholders.  Which included members of Congress who approved the overbillings as wells as additional funding for cost overruns.  No doubt Union Pacific/Crédit Mobilier had very good friends in Washington.  Including members of the Grant administration.  Until the party ended.  The press exposed the scandal during the 1872 presidential campaign.  Outraged, the federal government conducted an investigation.  But when you investigate yourself for wrongdoing you can guess the outcome.  Oh, there were some slaps on the wrists, but government came out relatively unscathed.  But the public money was gone.  As is usually the case with political graft.  Politicians get rich while the public pays the bill.

(Incidentally, the investigation did not implicate Ulysses Grant.  However, because members of his administration were implicated, this scandal tarnished his presidency.  Grant, though, was not corrupt.  He was a great general.  But not a shrewd politician.  Where there was a code of honor in the military, he found no such code in politics.  Friends used his political naivety for personal profit.  If you read Grant’s personal memoirs you can get a sense of Grant’s character.  Many consider his memoirs among the finest ever written.  He was honest and humble.  A man of integrity.  An expert horseman, he was reduced to riding in a horse and buggy in his later years.  Once, while president, he was stopped for speeding through the streets of Washington.  When the young policeman saw who he had pulled over, he apologized profusely to the president and let him go.  Grant told the young man to write him the ticket.  Because it was his job.  And the right thing to do.  For no man, even the president, was above the law.)

THE FINANCIAL WORLD fell apart in 2007.  And this happened because someone changed the definition of the American Dream from individual liberty to owning a house.  Even if you couldn’t afford to buy one.  Even if you couldn’t qualify for a mortgage.  Even, if you should get a mortgage, you had no chance in hell of making your payments.

Home ownership would be the key to American prosperity.  Per the American government.  Build homes and grow the economy.   That was the official mantra.  So Washington designed American policy accordingly.  Lenders came up with clever financing schemes to put ever more people into new homes.  And they were clever.  But left out were the poorest of the poor.  Even a small down payment on the most modest of homes was out of their range.  Proponents of these poor said this was discriminatory.  Many of the inner city poor in the biggest of cities were minority.  People cried racism in mortgage lending.  Government heard.  They pressured lenders to lend to these poor people.  Or else.  Lenders were reluctant.  With no money for down payments and questionable employment to service these mortgages, they saw great financial risk.  So the government said not to worry.  We’ll take that risk.  Fannie Mae and Freddie Mac would guarantee certain ‘risky’ loans as long as they met minimum criteria.  And they would also buy risky mortgages and get them off their books.  Well, with no risk, the lenders would lend to anyone.  They made NINJA loans (loans to people with No Income, No Job, and no Assets).  And why not?  If any loan was likely to default it was a NINJA loan.  But if Freddie or Fannie bought before the default, what did a lender care?  And even they defaulted before, Fannie and Freddie guaranteed the loan.  How could a lender lose?

Once upon a time, there was no safer loan than a home mortgage.  Why?  Because it would take someone’s lifesavings to pay for the down payment (20% of the home price in the common conventional mortgage).  And people lived in these houses.  In other words, these new home owners had a vested interested to service those mortgages.  Someone who doesn’t put up that 20% down payment with their own money, though, has less incentive to service that mortgage.  They can walk away with little financial loss.

ARE YOU GETTING the picture?  With this easy lending there was a housing boom.  Then a bubble.  With such easy money, housing demand went up.  As did prices.  So housing values soared.  Some poor people were buying these homes with creative financing (used to make the unqualified qualify for a mortgage).  We call these subprime mortgages.  They include Adjustable Rate Mortgages (ARMs).  These have adjustable interest rates.  This removes the risk of inflation.  So they have lower interest rates than fixed-rate mortgages.  If there is inflation (and interest rates go up), they adjust the interest rate on the mortgage up.  Other clever financing included interest only mortgages.  These include a balloon payment at the end of a set term of the full principal.  These and other clever instruments put people into houses who could only afford the smallest of monthly payments.  The idea was that they would refinance after an ‘introductory’ period.  And it would work as long as interest rates did not go up.  But they went up.  And house prices fell.  The bubble burst.  Mortgages went underwater (people owed more than the houses were worth).  Some people struggled to make their payments and simply couldn’t.  Others with little of their own money invested simply walked away.  The subprime industry imploded.  So what happened, then, to all those subprime mortgages?

Fannie and Freddie bought these risky mortgages.  And securitized them.  They chopped and diced them and created investment devices called Collateralized Debt Obligations (CDOs).  These are fancy bonds backed by those ‘safe’ home mortgages.  Especially safe with those Fannie and Freddie guarantees.  They were as safe as government bonds but more profitable.  As long as people kept making their mortgage payments.

But risk is a funny thing.  You can manage it.  But you can’t get rid of it.  Interest rates went up.  The ARMs reset their interest rates.  People defaulted.  The value of the subprime mortgages that backed those CDOs collapsed, making the value of the CDOs collapse.  And everyone who bought those CDOs took a hit.  Investors around the globe shared those losses. 

Those subprime loans were very risky.  Lenders would not make the loans unless someone else took that risk.  The government took that risk in the guise of Fannie and Freddie.  Who passed on that risk to the investors buying what they thought were safe investments.  Who saw large chunks of their investment portfolios go ‘puff’ into thin air.

SO WHAT ARE Freddie and Fannie exactly?  They are government-sponsored enterprises (GSEs).  They key word here is government.  Once again, you put huge piles of money and government together and the results are predictable.  In an effort to extend the ‘American Dream’ to as many Americans as possible, the federal oversight body for Freddie and Fannie lowered the minimum criteria for making those risky loans.  Even excluding an applicant’s credit worthiness from the application process (so called ‘no-doc’ loans were loans made without any documentation to prove the credit worthiness of the applicant.)  To encourage further reckless lending.  Ultimately causing the worst financial crisis since the Great Depression. 

And, of course, members of Congress did well during the good times of the subprime boom.  They got large campaign contributions.  Some sweetheart mortgagee deals.  A grateful voting bloc.  And other largess from the profitable subprime industry.  Government did well.  Just as they did during the Crédit Mobilier Scandal.  And the American taxpayer gets to pay the bill.  Some things never change.  Government created both of these scandals.  As government is wont to do whenever around huge piles of money.  For when it comes to stealing from the government, someone in the government has to let it happen.  For it takes a nod and a wink from someone in power to let such massive fraud to take place. 

www.PITHOCRATES.com

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