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Aug 09 2010

Pique the Geek 20100808: Automobiles Then and Now, Part One: Overview

(10 pm. – promoted by ek hornbeck)

With the near release of the Nissan Leaf and the Chevrolet Volt, both 100% electric driven automobiles, I thought that it would be appropriate to reflect on the history and technology of the automobile.  Actually, the Volt also has an internal combustion engine on board, but that engine runs a generator, so both of these cars are exclusively driven by electric motors.

The engine to generator concept is not at all new, as practically all big Diesel locomotives are driven that way.  There are significant advantages in using electric motors to propel vehicles, even if they are powered by on board generators.  We shall get to that in future.

This is the first part of a several (yet to be determined) part series.  This overview will look at the history of the automobile, the evolution of the car from very primitive beginnings to what we now have, and some speculation as to what the future holds.  Future installments will go into some detail about the different major systems in cars, how they originated, how they work, and how they have changed over the years in a more Geeky fashion than this overview.  Next time we shall discuss engines (or, for electric cars, motors).

Most authorities agree that the automobile originated in the 1880s in Germany, and also that Karl Benz designed and built the first commercially successful automobile in 1885, using a four stroke internal combustion engine.  However, others had demonstrated automobiles (as differentiated from locomotives, which run strictly on rails) as early as 1801 when the first steam powered road vehicle was demonstrated.  Also, in 1881 usable electric car was demonstrated in France, thus making the electric car older than the internal combustion engine one.

As a matter of fact, electric cars were very common around the turn of the 20th century, because they were simpler and more reliable than internal combustion ones.  However, internal combustion engines and other power train components improved significantly in the late 1910s so that electric cars were little produced after 1920.  The biggest problem at the time for electric automobiles was their limited range because of physical limitations of the battery packs.  In 2010, the biggest problem for electric automobiles is their limited range because of the physical limitations of the battery packs.  The more things change, the more they remain the same.  In the 1900s, there were limited recharging stations even in large towns and none in rural areas.  This problem remains to this day, except rural areas have electricity.

Without getting too deep into Geeky detail that will come next week, it takes an overnight charge for the Leaf or the Volt to travel around 40 to 50 miles.  The Leaf claims to have a 100 mile range and requires 20 hours at 120 volts or 8 hours at 240 volts to recharge it.  Commercial “fast charge” filling stations require 30 minutes, but with damage to the battery pack, which weighs 660 pounds.  The Volt has a 375 pound battery pack and no fast charge option and is claimed to have a 40 mile range.  However, at that time the engine starts and runs the generator, both recharging the battery and powering the motor at the same time until the batteries are up to the designated charge state.  The difference is that with the Leaf, once you run down the batteries, you are stopped (for a minimum of 30 minutes if you happen to make it to a high voltage charging station), where with a Volt the engine starts and you keep going.

The first models of what are pretty much considered to be cars were three wheeled affairs, then Benz decided to add a second wheel in the front and that became practically universal.  A three wheeled automobile is technically much simpler to build, but the instability required the second from wheel.  The exact same thing happened a hundred years later when all terrain vehicles (ATVs) were introduced.  They were first three wheeled, but safety regulations soon required the forth one.

Early cars were often steered with a tillar on the single front wheel rather than a steering wheel, and some early four wheeled ones were steered that way as well.  The steering wheel was developed in the 1900s and soon became the standard method.  One reason is that a tillar is direct coupled to the wheels, so half a turn was all the travel that it had, requiring significant strength to operate and producing huge changes in direction for just a small movement.  Steering wheels can be geared to the wheels, so less effort is required and smoother steering results.

From the very first, automobiles were designed to run from diverse power sources (but only one source in a given vehicle).  Steam, gasoline, alcohol, Diesel fuel, and battery power have all been used.  In the first couple of decades of the 20th century, all of these methods were being built.  As a matter of fact, the Stanley Steamer had better take off power than most other designs, but required that coal or wood be put in the firebox from time to time, making it inconvenient to say the least.  Liquid fuels in internal combustion engines became the fuels of choice for a plethora of reasons.

First, liquid fuels are extremely energy dense, so a reasonable amount will carry you a long way.  For example, in my 1998 Windstar with a 20 gallon fill up, I can go over four hundred miles.  20 gallons of gasoline weighs about 125 pounds, much less than the battery packs on either the Volt or the Leaf.  Second, liquid fuels are actually quite cheap (I wrote an installment wherein I showed that, adjusted for inflation, the cost of gasoline is quite comparable to that in 1964).  Third, they are easy to handle, easy to transport, easy to dispense, and easy to meter into the intake ports of an engine.  Forth, the infrastructure for manufacturing and distributing liquid fuels was easier to develop than others.

Petroleum won out over alcohol because it was at the time (and is still, by many accounts) cheaper to produce than alcohol.  It offers another couple of advantages as well.  Both gasoline and Diesel fuel are more energy dense than alcohol for one, and does not soak water from the atmosphere like alcohol does.  As a matter of fact, vehicles designed to run on E85 (85% alcohol, 15% gasoline) are specially designed to avoid the corrosive effects of alcohol to fuel systems.  Alcohol, however, does have excellent anti-knock properties, and we shall discuss that more next time.

The shape of automobiles has changed dramatically since invention.  The first ones were based on the horse drawn carriage, hence the name horseless carriage, through high center of gravity cars, then streamlined, and now to the low center of gravity, highly aerodynamic vehicles of today.  As the center of gravity got closer to the road, stability increased.  I know from personal experience that the Model “T” Ford was extremely easy to turn over (I never did turn it over, but I came close several times).  I guess I should admit that it was a 1919 Model “T” Ford on which I learnt to drive.  No, I am not that old, but my father and I restored one when I was little and he taught me to drive it when I was 13.

Other then the recent changes in power sources, the most significant change in the automobile is safety.  Mercedes-Benz has long been an innovator in this area, pioneering the crush zone construction that reduces driver and passenger impact energy during a collision.  Seat belts were a big innovation (remember when they were called safety belts?), followed by the shoulder belt.  I maintain that is absolutely nuts to operate a vehicle without wearing belts.  About the same time of seat belts came the padded dashboard, reducing injury from impact with it.  Until then, most dashboards were metal and/or wood.  Next came air bags (that do not use air at all) in the front, and now side curtain air bags.  By the way, it is an urban myth that the convertible went out of production in the United States because of rollover regulations.  This is not true, although the expense of building convertibles that would meet the standards was pretty high.  With better technology, convertibles are back.

Materials of construction have evolved tremendously over the years, from the wooden, steel, and cast iron ones early on to fiberglass bodies of Corvettes, to aluminum engine blocks, to the substitution of lots of plastic for previously metal parts.  Most of these changes have been for the better, but some of the early plastic substitutions were inferior to the metal pieces that they replaced.  With better resins, this problem is largely solved and modern polymers are in many cases much better than the metal ones that they replaced.

Whilst I am not a futurist, here is where I see the automobile headed for the near term.  First, the trends will be towards smaller, more efficient cars because of costs involved in driving them.  More hybrids and electric cars will be produced, but battery technology is still not where it needs to be.  The lithium used in batteries is also a problem, since that is not a lot of lithium.  Fortunately, it can be recycled.  The total electric car will not be feasible until power packs (I hesitate to use the word battery, since batteries might not be the answer) are developed.  Less and less steel will be used, being replaced with lighter materials even if they cost more.  The internal combustion engine will be used for a long time to come, but I suspect it will be more like the Volt, being used to drive a generator.

I am not sure that we will ever do away with the automobile completely (and I include SUVs, pickup trucks, and vans in this category) simply because they fulfill a purpose not available with mass transit, especially in a nation as spread apart as the United States.  However, I do see a day when alternatives are better than they are now.  Not having cars is not withing the realm of reality in our lifetimes, and probably not even in that of our grandchildren (I do not have any, yet).  Nor do I see the day of the George Jetson flying car for many a day to come.  We have enough trouble driving in three dimensions (counting time, since timing is critical to safe driving), let alone four.  We have enough trouble looking front, rear, right, and left and adding up and down would overwhelm even the best of drivers if the number of cars on the road were now in the air.

Well, you have done it again.  You have wasted another perfectly good set of photons reading this low horsepower excuse for a post.  And even though Mike Huckabee will have Tommy Chong on his extremely right wing Fox “News” Channel show and treat him with respect after he reads this, I always learn much more than I could ever pretend to teach writing this series.  WOW!  Huck must have read my mind, because he did just have Chong on his show and treated him with respect.  Good one Huckabee for that!  Thus, please keep comments, tips, recommendations, questions, and corrections coming.  Remember, no science or technology subject is off topic here.

I will hang around for Comment Time until comments dry up, and shall return tomorrow around Rachel for Review Time if you miss commenting tonight.  Thanks for your input.

Warmest regards,

Doc

Crossposted at Dailykos.com and at Docudharma.com  

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