Manual Hand Brake, Dynamic Braking and George Westinghouse’s Failsafe Railway Air Brake

Posted by PITHOCRATES - July 17th, 2013

Technology 101

Getting a Long and Heavy Train Moving was no good unless you could Stop It

Trains shrank countries.  Allowing people to travel greater distances faster than ever before.  And move more freight than ever before.  Freight so heavy that no horse could have ever pulled it.  The only limitation was the power of the locomotive.  Well, that.  And one other thing.  The ability to stop a long and heavy train.  For getting one moving was pretty easy.  Tracks were typically level.  And steel wheels on steel rails offered little resistance.  So once a train got moving it didn’t take much to keep it moving.  Especially when there was the slightest of inclines to roll down.

Getting a long and heavy train moving was no good unless you could stop it.  And stopping one was easier said than done.  As trains grew longer it proved impossible for the locomotive to stop it alone.  So each car in the consist (the rolling stock the locomotive pulls behind it) had a manual brake.  Operated by hand.  By brakemen.  Running along the tops of cars while the train was moving.  Turning wheels that applied the brakes on each car.  Not the safest of jobs.  One that couldn’t exist today.  Because of the number of brakemen that died on the job.  Due to the inherent danger of running along the top of a moving train.  Luckily, today, all brakemen have lost their jobs.  As we have safer ways to stop trains.

Of course, we don’t need to just stop trains.  A lot of the time we just need to slow them down a little.  Such as when approaching a curve.  Going through a reduced speed zone (bad track, wooden bridge, going through a city, etc.).  Or going down a slight incline.  In fact slowing down on an incline is crucial.  For if gravity is allowed to accelerate a train down an incline it can lead to a runaway.  That’s when a train gathers speed with no way of stopping it.  It can derail in a curve.  It can run into another train.  Or crash into a terminal building full of people.   All things that have happened.  The most recent disaster being the Montreal, Maine & Atlantic Railway disaster in Lac-Megantic, Quebec.  Where a parked oil train rolled away down an incline, derailed and exploded.  Killing some 38 people.  While many more are still missing and feared dead.

Dynamic Breaking can Slow a Train but to Stop a Train you need to Engage the Air Brakes

Trains basically have two braking systems today.  Air brakes.  And dynamic braking.  Dynamic braking involves changing the traction motors into generators.  The traction motors are underneath the locomotive.  The big diesel engine in the locomotive turns a generator making electric power.  This power creates powerful magnetic fields in the traction motors that rotate the axles.  The heavier the train the more power it takes to rotate these axles.  It takes a little skill to get a long and heavy train rolling.  Too much power and the steel wheels may slip on the steel rails.  Or the motors may require more power than the generator can provide.  As the torque required to move the train may be greater than traction motors can provide.  Thus ‘stalling’ the motor.  As it approaches stall torque it slows the rotation of the motor to zero while increasing the current from the generator to maximum.  As it struggles to rotate an axle it is not strong enough to rotate.  If this continues the maximum flow of current will cause excessive heat buildup in the motor windings.  Causing great damage.

Dynamic breaking reverses this process.  The traction motors become the generator.  Using the forward motion of the train to rotate the axles.  The electric power this produces feeds a resistive load that draws a heavy current form these traction motors.  Typically it’s the section of the locomotive directly behind the cab.  It draws more than the motors can provide.  Bringing them towards stall torque.  Thus slowing their rotation.  And slowing the train.  Converting the kinetic energy of the moving train into heat in the resistive load.  Which has a large cooling fan located above it to keep it from getting so hot that it starts melting.

Dynamic breaking can slow a train.  But it cannot stop it.  For as it slows the axles spin slower producing less electric power.  And as the electric current falls away it cannot ‘stall’ the generator (the traction motors operating as generators during dynamic braking).  Which is where the air brakes come in.  Which they can use in conjunction with dynamic braking on a steep incline.  To bring a train to a complete stop.  Or to a ‘quick’ stop (in a mile or so) in an emergency.  Either when the engineer activates the emergency brake.  Or something happens to break open the train line.  The air brake line that runs the length of the train.

When Parking a Train they Manually set the Hand Brakes BEFORE shutting down the Locomotive

The first air brake system used increasing air pressure to stop the train.  Think of the brake in a car.  When you press the brake pedal you force brake fluid to a cylinder at each wheel.  Forcing brake shoes or pads to come into contact with the rotating wheel.  The first train air brake worked similarly.  When the engineer wanted to stop the train he forced air to cylinders at each wheel.  Which moved linkages that forced brake shoes into contact with the rotating wheel.  It was a great improvement to having men run along the top of a moving train.  But it had one serious drawback.  If some cars separated from the train it would break open the train line.  So the air the engineer forced into it vented to the atmosphere without moving the brake linkages.  Which caused a runaway or two in its day.  George Westinghouse solved that problem.  By creating a failsafe railway air brake system.

The Westinghouse air brake system dates back to 1868.  And we still use his design today.  Which includes an air compressor at the engine.  Which provides air pressure to the train line.  Metal pipes below cars.  And rubber hoses between cars.  Running the full length of the train.  At each car is an air reservoir.  Or air tank.  And a triple valve.  Before a train moves it must charge the system (train line and reservoirs at each car) to, say, 90 pounds per square inch (PSI) of air pressure.  Once charged the train can move.  To apply the air brakes the engineer reduces the pressure by a few PSI in the train line.  The triple valve senses this and allows air to exit the air reservoir and enter the brake cylinder.  Pushing the linkages to bring the brake shoes into contact with the train wheels.  Providing a little resistance.  Slowing the train a little.  Once the pressure in the reservoir equals the pressure in the train line the triple valve stops the air from exiting the reservoir.  To slow the train more the engineer reduces the pressure by a few more PSI.  The triple valve senses this and lets more air out of the reservoir to again equalize the pressure in the reservoir and train line.  When the air leaves the reservoir it goes to the brake cylinder.  Moving the linkage more.  Increasing the pressure of the brake shoes on the wheels.  Further slowing the train.  The engineer continues this process until the train stops.  Or he is ready to increase speed (such as at the bottom of an incline).  To release the brakes the engineer increases the pressure in the train line.  Once the triple valve senses the pressure in the train line is greater than in the reservoir the air in the brake cylinders vents to the atmosphere.  Releasing the brakes.  While the train line brings the pressure in the reservoir back to 90 PSI.

This system is failsafe because the brakes apply with a loss of air pressure in the train line.  And if there is a rapid decline in air pressure the triple valve will sense that, too.  Say a coupler fails, separating two cars.  And the train line.  Causing the air pressure to fall from 90 PSI to zero very quickly.  When this happens the triple valve dumps the air in an emergency air reservoir along with the regular air reservoir into the brake cylinder.  Slamming the brake shoes onto the train wheels.  But as failsafe as the Westinghouse air brake system is it can still fail.  If an engineer applies the brakes and releases them a few times in a short period (something an experienced engineer wouldn’t do) the air pressure will slowly fall in both the train line and the reservoirs.  Because it takes time to recharge the air system (train line and reservoirs).  And if you don’t give it the time you will decrease your braking ability.  As there is less air in the reservoir available to go to the brake cylinder to move the linkages.  To the point the air pressure is so low that there isn’t enough pressure to push the brake shoes into the train wheels.  At this point you lose all braking.  With no ability to stop or slow the train.  Causing a runaway.

So, obviously, air pressure is key to a train’s air brake system.  Even if the train is just parked air will leak out of the train line.  If you’re standing near a locomotive (say at a passenger train station) and hear an air compressor start running it is most likely recharging the train line.  For it needs air pressure in the system to hold the brake shoes on the train wheels.  Which is why when they park a train they manually set the hand brakes (on a number of cars they determined will be sufficient to prevent the train from rolling) BEFORE shutting down the locomotive.  Once the ‘parking brake’ is set then and only then will they shut down the locomotive.  Letting the air bleed out of the air brake system.  Which appears to be what happened in Lac-Megantic, Quebec.  Preliminary reports suggest that the engineer may not have set enough hand brakes to prevent the train from rolling on the incline it was on when he parked the train for the night.  On a main line.  Because another train was on a siding.  And leaving the lead locomotive in a five locomotive lashup unmanned and running to maintain the air pressure.  Later that night there was a fire in that locomotive.  Before fighting that fire the fire department shut it down.  Which shut down the air compressor that was keeping the train line charged.  Later that night as the air pressure bled away the air brakes released and the hand brakes didn’t hold the train on the incline.  Resulting in the runaway (that may have reached a speed of 63 mph).  Derailment at a sharp curve.  And the explosion of some of its tank cars filled with crude oil.  Showing just how dangerous long, heavy trains can be when you can’t stop them.  Or keep them stopped.


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Thomas Edison, Patents, Intellectual Property Rights, Nikola Tesla, George Westinghouse, DC, AC and the War of Currents

Posted by PITHOCRATES - March 27th, 2012

History 101

Thomas Edison protected his Intellectual Property Rights with over 1,000 Patents

Thomas Edison was a great inventor.  A great entrepreneur.  But he wasn’t a great scientist or engineer.  He was home-schooled by his mom.  And didn’t go to college.  But he read a lot.  And loved to tinker.  He grew up in Port Huron, Michigan.  At one end of the train line that ran between Port Huron and Detroit.  Where he sold newspapers and other things to commuters during the Civil War.  Then he saved the life of some kid.  Pulled him out of the way of a runaway boxcar.  The kid’s dad ran the train station.  Out of gratitude for saving his son’s life he taught the young Edison Morse Code.  And trained him to be a telegraph operator.  He mastered it so well that Edison invented a better telegraph machine.  The Quadruplex telegraph.  Because he liked to tinker.

What made him a great entrepreneur and not a great scientist or engineer is that his inventions had a commercial purpose.  He didn’t invent to solve life’s great mysteries.  He invented to make money.  By creating things so great that people would want them.  And pay money for them.  He also had an eye on production costs.  So he could build these things the people wanted at affordable prices.  For if they were too expensive the people couldn’t buy them.  And make him rich.  So his inventions used technology to keep production costs down while keeping consumer interest high.  Because of the profit incentive.  But the POSSIBILITY of profits wasn’t enough to push Edison to set up his invention lab.  Where he employed a team of inventors to work full time inventing things.  And figuring out how to mass-produce inventions that made everyone’s life better.  He needed something else.  Something that GUARANTEED Edison could profit from his inventions.  The patent.  That gave the patent holder exclusive rights to profit from their invention.

Inventors and entrepreneurs spend a lot of money inventing things.  They do this because they know that they can file a patent when they invent something that people will buy.  Protecting their intellectual property rights.  So they alone can profit from the fruit of all their labors.  And Edison was one of these inventors.  One of the most prolific inventors of all time.  Filing over 1,000 patents.  Including one on the incandescent light bulb.  Which was going to replace gas lamps and candles.  And provided a need for another new invention.  Electric power distribution.  Something else he spent a lot of time tinkering with.  Producing electrical generators.  And an electric power distribution system.  Which was going to make him an even richer man.  As he held the patents for a lot of the technology involved.  However, he was not to become as rich as he had hoped on his electric power distribution system.  Not for any patent infringements.  But because of a mistreated former employee who had a better idea.

Thomas Edison and George Westinghouse battled each other in the War of Currents

Nikola Tesla was a brilliant electrical engineer.  But not a great entrepreneur.  So he worked for someone who was.  Thomas Edison.  Until Edison broke a promise.  He offered a substantial bonus to Tesla if he could improve Edison’s electric power generating plants.  He did.  And when he asked for his bonus Edison reneged on his promise.  Telling the immigrant Tesla that he didn’t understand American humor.  Angry, Tesla resigned and eventually began working for George Westinghouse.  An Edison competitor.  Who appreciated the genius of Tesla.  And his work.  Especially his work on polyphase electrical systems.  Using an alternating current (AC).  Unlike Edison’s direct current (DC).  Bringing Edison and Tesla back together again.  In war.

Direct current had some limitations.  The chief being that DC didn’t work with transformers.  While AC did.  With transformers you could change the voltage of AC systems.  You could step the voltage up.  And step it back down.  This gave AC a huge advantage over DC.  Because power equals current multiplied by voltage (P=I*E).  To distribute large amounts of power you needed to generate a high current.  Or a high voltage.  Something both DC and AC power can do.  However, there is an advantage to using high voltages instead of high currents.  Because high currents need thicker wires.  And we make wires out of copper or aluminum.  Which are expensive.  And the DC wires have to get thicker the farther away they get from the generator plant.  Meaning that a DC generating plant could only serve a small area.  Requiring numerous DC power plants to meet the power requirements of a single city.  Whereas AC power could travel across states.  Making AC the current of choice for anyone paying the bill to install an electric distribution system.

So the ability to change voltages is very beneficial.  And that’s something DC power just couldn’t do.  What the generator generated is what you got.  Not the case with AC power.  You can step it up to a higher voltage for distribution.  Then you can step it down for use inside your house.  Which meant a big problem for Edison.  For anyone basing their decision on price alone would choose AC.  So he declared war on AC power.  Saying that it was too dangerous to bring inside anyone’s house.  And he proved it by electrocuting animals.  Including an elephant.  And to show just how lethal it was Edison pushed for its use to replace the hangman’s noose.  Saying that anything as deadly as what states used to put prisoners to death was just too deadly to bring into anyone’s house.  But not even the electric chair could save Edison’s DC power.  And he lost the War of Currents.  For Tesla’s AC power was just too superior to Edison’s DC power not to use. 

Nikola Tesla was a Brilliant Engineer who Preferred Unraveling the Mysteries of the Universe over Business

George Westinghouse would get rich on electrical distribution.  Thanks to Nikola Tesla.  And the patents for the inventions he could have created for Thomas Edison.  If he only recognized his genius.  Which he lamented near death as his greatest mistake.  Not appreciating Tesla.  Or his work.  But Edison did well.  As did Westinghouse.  They both died rich.  Unlike Tesla.

Westinghouse could have made Tesla a very rich man.  But his work in high voltage, high frequency, wireless power led him away from Westinghouse.  For he wanted to provide the world with free electric power.  By creating power transmitters.  That could transmit power wirelessly.  Where an electric device would have an antenna to receive this wireless power.  He demonstrated it to some potential investors.  He impressed them.  But lost their funding when they asked one question.  Where does the electric meter go?  Free electric power was a noble idea.  But nothing is truly free.  Even free power.  Because someone had to generate that power.  And if you didn’t charge those using that power how were you going to pay those generating that power?

Edison and Westinghouse were great entrepreneurs.  Whereas Tesla was a brilliant engineer.  He preferred unraveling the mysteries of the universe over business.  Tesla probably suffered from obsessive-compulsive disorder.  Think of the character Sheldon Cooper on The Big Bang Theory television sitcom.  He was a lot like that character.  Brilliant.  Odd.  And interested in little else but his work.  He lived alone.  And died alone.  A bachelor.  Living in a two-room hotel room in the last decade of his life.  Despite his inventions that changed the world.  And the fortunes he made for others.  Sadly, Tesla did not die a rich man.  Like Edison and Westinghouse.  But he did live a long life.  And few men or women changed the world like he did.  A brilliant mind that comes around but once in a millennium.


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LESSONS LEARNED #72: “Moms are a lot like CEOs. Only with more responsibility, longer hours and less pay.” -Old Pithy

Posted by PITHOCRATES - June 30th, 2011

A Genius may have a Brilliant Idea, but it’s an Entrepreneur that brings it to Market

A CEO is a lot like an entrepreneur.  They’re both a cut above the rest.  And can do what few can do.  Bring two worlds together.  The theoretical world inhabited by great thinkers and inventors.  And the practical world inhabited by people who act.  Who take the things the great thinkers and inventors create and give them to us.   There is a difference between the people that inhabit these worlds.  And most can only live in one or the other.  But CEOs and entrepreneurs can live in both.  That’s what makes them special.  Thinkers and inventors possess a genius of theoretical creativity.  But they can do little with their idea.  The action people can build great things (cars, airplanes, buildings, power plants, cell phones, etc.) but only from a construction plan.  Someone else has to have an idea and think and create the construction plan before they can build.  These are the two worlds.  The genius.  And the builders.  And it is the CEO and entrepreneur that bring these two worlds together.

Nikola Tesla was a genius.  A brilliant theoretical thinker.  He created the world in which we live.  But do you know who he is?  What he created?  Probably not.  Unless you’re a Croat.  Because there are probably a lot of statues of him in Croatia. Because he was born there to Serbian parents.  He eventually moved to America.  Got a job with a guy name Thomas Edison.  Who didn’t appreciate his genius.  Or his one particular ‘crazy’ idea.  But George Westinghouse did. 

That ‘crazy’ idea is the AC power we use today.  Thomas Edison was building DC power plants and a DC electric grid.  Despite all the failings of DC distribution (DC power doesn’t travel far requiring lots of generating plants, different voltages have to have their own generating plant, large power loads require very thick and expensive copper wires, etc.).  There was already a DC electrical infrastructure.  And it was Edison’s.  Which he wanted to expand because it would pay him well.

But Tesla’s AC system was better.  Because it could use transformers.  One power generating plant could provide power at a variety of voltages.  You just needed a transformer to get the voltage you wanted.  Also, electrical power is the product of voltage and current.  High power, then, requires either a high voltage or a high current.  High currents require thick, expensive copper wires.  So high voltage was the way to go.  It allowed power to travel farther over thinner wires.  Therefore, it required fewer generating plants.  And a single electric grid (not one for each voltage).  AC power was much more economical than DC power.  And George Westinghouse saw that.  And took Tesla’s brilliant idea and built the AC power generation and distribution system we use today.

The Business of Beautiful, Estée Lauder

You see, Tesla was at home in the lab.  He was a scientist.  Not a salesman.  That’s why he wasn’t an entrepreneur.  Because, just like being a CEO, you need sales skills to be an entrepreneur.  Because you are the number one sales person in your business.  And Edison and Westinghouse were great salesmen.  That’s why they brought a lot of Tesla’s great inventions to market.  And why Tesla did not.  He was just not a sales person.

But Estée Lauder was.  She was always selling.  And creating.  She was the classical entrepreneur.  Her uncle was in the chemistry business making beauty products.  Which fascinated her from a young age.  He taught her the chemistry.  Taught her how to make the products.  How to use the products.  And she did.  Loved them.  And started selling them.  With a passion.

She started creating her own products.  Using her own kitchen as her laboratory.  When not tending to her two sons.  She demonstrated how to use her products.  Gave away free samples.  And sold.  She was always selling.  She started out small.  By herself.  From these humble beginnings she grew to dominate the industry.  She was relentless.  She worked herself to the premier counter space in department stores by redefining the way cosmetics were sold.  Starting with Saks Fifth Avenue in New York.  She visited each counter to ensure they were meeting her high standards.  She gave away free samples.  She demonstrated.  She touched.  Personally applying products on customers.  That’s why when you walk into a department store you’ll see the Estée Lauder counter first.  And you’ll see all the counters selling the same way.  Giving away free samples.  Demonstrating products.  Showing how to apply products.  The Estée Lauder way.

One Smart Cookie, that Mrs. Fields

Debbi Fields liked to bake cookies.  She married young at 19.  To a Stanford graduate.  And aspiring financial consultant.  And about a year later decided to go into the cookie business.  After an incident at a party with her husband and a lot of his snobby associates.  She apparently mispronounced a word.  Said ‘orientated’ instead of ‘oriented’.  A snob pointed out her faux pas.  Sending her home in tears.  Didn’t much like that experience.  And decided to be something more than a ‘just’ a housewife.  Not that there was anything wrong with that.  And she would love being a housewife.  She would raise 5 daughters.  And add another 5 stepchildren in a second marriage.  But the snobs in her husband’s circle did look down on that particular institution.  It was so old fashioned.  It wasn’t progressive.  It wasn’t what people in their circles did.  So they acted like real asses.

Yet they liked her cookies.  Loved them.  Her husband would take them to work.  Where they were a big hit.  Soft and chewy.  Gourmet.  They were different.  When she asked them if she should go into the cookie business, they said it was a bad idea.  The conventional wisdom said crispy cookies were the way to go.  People didn’t want to buy soft and chewy.  They said as they stuffed their mouths with soft and chewy cookies.  And there were others who told her not to do it.  Even her husband doubted her.  But he loved her.  And would support her. She had no business experience.  But she was a hard worker.  And believed in what she was doing.  She got a bank loan to open a cookie store.  Not so much because the banker believed in the business idea.  But because of the good character of her and her husband.  Whatever the outcome, the bank was willing to take a chance.  Because, success or fail, they knew they would repay the loan.

She opened her first store in a mall food court.  Did not sell a single cookie.  Until she used the Estée Lauder sales method.  She gave away free samples.  People tried.  And people liked.  Soft and chewy was a hit.  She grew the company.  Added more stores.  And made a lot of money.  She was very hands on to maintain the quality.  Again, like Estée Lauder.  She visited her stores.  To make sure they maintained her high standards.  Which is why she refused to franchise.  She was too worried about losing that quality.  Which is what made Mrs. Fields cookies better than the competition.  Her husband computerized her operation.  Adding a computer at each store.  All wired to the Internet and tied into her headquarters.  It was state of the art technology.  Allowing more growth.  While retaining full control.  The growth was fast.  Too fast.  The hands-on management didn’t work well with so many stores.  The debt started to pile up.  And then a recession hit.  Her expensive gourmet cookies became too expensive.  And people stopped buying them.  To save the company she had to sell 80% of it.  And the new owners changed the business model.  Franchised stores.  And bumped Debbie Fields from CEO.  But she remained chairman of the board.  And though only a minority shareholder, the business Debbie Fields created continues on.  Her only mistake was being so successful so fast.  And if you’re going to have a fault that’s not a bad one to have.  By the way, don’t forget that she did all of this while raising 5 daughters.  Which probably made the running of the multi-million dollar business the easy part of her life.

Entrepreneurs, CEOS and Moms

Entrepreneurs and CEOs.  They’re a different breed.  They can be both brilliant thinkers like Nikola Tesla.  And aggressive sales people like Thomas Edison and George Westinghouse.  Such as Estée Lauder.  And Debbie Fields.  These mothers dominated their industries.  And set the bar for everyone else.  Lauder built an empire that dominates still.  Fields use of technology to streamline operations is a model for business efficiency at Harvard Business School.  Two of America’s most successful entrepreneurs and CEOs.  And both were moms first.


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