Waterwheel, Rotational Motion, Reciprocal Motion, Steam Engine, Internal Combustion Engine and Hydraulic Brakes

Posted by PITHOCRATES - December 5th, 2012

Technology 101

To Keep People on Trains they Undercharge Passengers and make up the Difference with Government Subsidies

We built some of our first factories on or near a river.  Where we could use that river’s current to turn a waterwheel.  To provide a rotational motion that could do work for us.  We transmitted that rotational motion via a main drive shaft through a factory where it could drive machinery via belts and pulleys.  Once we developed the steam engine to provide that rotational motion we could move our factories anywhere.  Not just on or near a river.  Giving us greater freedom.  And permitting greater economic growth.  As we put those steam engines onto rails.  That transported freight and people all across the country.

Trains are nice.  But expensive.  To go anywhere on a train you need train tracks going there.  But train tracks are incredibly expensive to lay.  And maintain.  If you ever stared at a set of train tracks you probably noticed something.  There aren’t a lot of trains going by on them.  When a train stops you when you’re running late or bringing home dinner it may feel like trains are always stopping you.  But if you parked at those same tracks for a few hours you wouldn’t see a lot of trains.  Because even the most polished rails (the more train traffic the more polished the rails) are unused more than they are used.

This is why trains are very expensive.  Tracks cost a lot of money to lay and maintain.  Costs that a railroad has to recoup from trains using those rails.  And when you don’t have a lot of trains on those rails you have to charge a lot for the trains that do travel on them.  A mile-long train pulling heavy freight can pay a lot of revenue.  And make a railroad profitable.  But passenger trains are not a mile long.  And carry few people.  Which means to make money on a passenger train you’d have to charge more for a ticket than people would pay.  To keep people on trains, then, they have to undercharge passengers.  And make up the difference with government subsidies.

A Crank Shaft and Combustion Timing takes Reciprocal Motion of Pistons and Converts it into Rotational Motion

This is why people drive places instead of taking the train.  It’s far less expensive to take the car.  And there are roads everywhere.  Built and maintained by gas taxes, licenses and fees.  And if you’ve ever driven on a road you probably noticed that there are a lot of cars, motorcycles, trucks and buses around you.  With so many vehicles on the roads they each can pay a small amount to build and maintain them.  Which is something the railroads can’t do.  Only trains can travel on train tracks.  But cars, motorcycles, trucks and buses can all travel on roads.  This is why driving a car is such a bargain.  Economies of scale.

To operate a train requires a massive infrastructure.  Dispatchers control the movement of every train.  Tracks are broken down into blocks.  The dispatchers allow only one train in a block at a time.  They do this for a couple of reasons.  Trains don’t have steering wheels.  And can take up to a mile to stop.  So to operate trains safely requires keeping them as far apart from each other as possible.  Traveling on roads is a different story.  There are no dispatchers separating traffic.  Cars, motorcycles, trucks and buses travel very close together.  Starting and stopping often.  Traveling up to high speeds between traffic lights.  With motorcycles and cars weaving in and out among trucks and buses.  Avoiding traffic and accidents by speeding up and slowing down.  And steering.

Driving a car today is something just about anyone 16 and older can do.  Thanks to the remarkable technology that makes a car.  Starting with the internal combustion engine.  The source of power that makes everything possible.  Just like those early waterwheels the source of that power is rotational motion.  But instead of a river providing the energy an internal combustion engine combusts gasoline to push pistons.  A crank shaft and combustion timing takes that reciprocal motion of the pistons and converts it into rotational motion.  Spinning a drive shaft that provides power to drive the car.  As well as power all of its accessories.

The Friction of Brake Shoe or Pad on Steel slows the Car converting Kinetic Energy into Heat

The first cars required a lot of man-power.  It took great strength to rotate the hand-crank to start the engine.  Sometimes the engine would spit and cough.  And kick back.  Breaking the occasional wrist.  Once started it took some leg-power to depress the clutch to shift gears.  It took a little upper body strength to turn the steering wheel.  And some additional leg-power to apply the brakes to stop the car.  In time we replaced the hand-crank with the electric starter.  We replaced the clutch and gearbox with the automatic transmission.  We added power steering and power breaks to further reduce the amount of man-power needed to drive a car.  Today a young lady in high heels and a miniskirt can drive a car as easily and as expertly as the first pioneers who risked bodily harm to drive our first cars.

The internal combustion engine can spin a crankshaft very fast and accelerate a car to great speeds.  Which is good for darting in and out of traffic.  But traffic occasional has to stop.  Which is easier said than done.  For a heavy car moving at speed has a lot of kinetic energy.  You can’t destroy energy.  You can only convert it.  And in the case of slowing down a car you have to convert that kinetic energy into heat.  When you press the brake pedal you force hydraulic fluid from a master cylinder to small cylinders at each wheel.  As fluids cannot compress when you apply a force to the fluid that force is transmitted to something than can move.  In the case of stopping a car it is either a brake shoe that presses against the inside of the car’s wheels.  Or a caliper that clamps down on a disc.  The friction of brake shoe or pad on steel slows the car.  Converting that kinetic energy into heat.  In some cases of excessive braking (on a train or a plane) the heat can be so excessive that the wheels or discs glow red.

So as the internal combustion engine and the brakes play their little games of speeding up and slowing down a car the rotational power of the crankshaft drives other accessories.  Such as power steering.  Where a belt and pulley transfers that rotational power to a power steering pump.  The pump pushes fluid to the steering gear to assist in turns.  Another belt and pulley connects an alternator to the crankshaft to produce electricity to provide power for the car’s electrical systems.  And to charge the battery so it can spin the automatic starter.  Another belt and pulley connects another compressor to the crankshaft.  This one for air conditioning.  That allows us to alight from our cars shower-fresh on the hottest and most humid days of the year.  And, finally, antifreeze removes the heat of combustion from the internal combustion engine and transfers it to a heating core inside the passenger compartment.  Allowing a warm and comfortable drive home during the coldest of days.  As well as keeping our windows free of snow and ice so we can see to drive safely on our way home.  Through bumper to bumper traffic.  Something we do day after day with the ease of doing the laundry.  Thanks to the remarkable technology that we take for granted that makes a car.



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