Chapter 10 a

 

Petersburg, October 28, 2 PM

 

The Grand National was the sport version of a machine that began its existence as about the most ordinary car that could be built.  It was targeted at the market of commuters and mothers.  While the job of commuting daily up to an hour each way was a substantial task for a car, the real wring out came when Mommy had to drive the children to school on a cold morning.  Mommy’s interest was in getting there quickly – things are always late – and not getting the children excited by racing the engine.  She would learn just how hard she could mash on the accelerator without shifting the car into a lower gear and just when she could lift off a fraction to shift the car into a higher gear.  And this is the way she always drove.

 

Under the circumstances of a cold day, high power settings and low engine speed, a normally aspirated automobile engine will gulp as much cold dense air as it is capable of, particularly if the car has been asked to deliver peak performance before the engine itself is hot, as is usually the case.  That meant the greatest amount of oxygen possible is in the cylinder at the moment of ignition, and with proper admixture of fuel, the forces developed in the engine are at an absolute maximum.  Add to that chuck holes and unpredictable traction on recently salted roads.  If anyone can break an engine, Mommy can. 

 

With a hungry market for its work, the engine developed into an extremely tough mechanism.  It had crank shaft, connecting rods and cylinder walls beefed up for the challenge.

 

Then one day they decided to try using a computer to regulate the amount of fuel put into the engine under such extreme conditions.

 

Now as an internal combustion engine gathers speed, at a constant open throttle setting, at first the torque – the force delivered by the engine – rises.  Then an engine speed comes when the carburetor cannot deliver an optimal amount of air-fuel mixture in the time during the engine cycle when the intake valves are open, and the amount of energy released per ignition falls.  The torque falls, but the power keeps rising, since the engine is delivering more cycles per second.

 

For maximum power the engine is run in the high end of its designed speed range.  But it is not developing maximum torque.  That happens at slower engine speeds, and any engine must be tough enough to handle maximum torque or it will promptly destroy itself.

 

Under the control of the computer, the engine of this car had a torque curve that ran straight across.  It could deliver maximum torque in any part of its performance range.  The greatest effort a laboring engine must make is to use its power to propel the car forward.  But part of the power must be used to accelerate the moving parts of the engine itself.  And as the car runs through its gears these parts must be accelerated repeatedly.  The car must work hard to get out of its own way.

 

With a normal toque curve, the car at maximum horsepower is accelerating metal it is not actually using.  Not so the Grand National.  It uses all its strength all the time. 

 

The result was a car that would out accelerate other cars that had more horsepower, less weight and were better streamlined.  By the time the five were roaring out of Randleman, high end exotic cars routinely were computer controlled, but the vans never had a chance.

 

James headed south for a few miles, took a dirt road at right angles, picked up a parallel road and turned north again.  After a time James decided it was time for trouble to show up and pulled off the road to lurk behind a hedge.  In a few moments a white van went roaring past.  James pulled back onto the road and continued north.  As they crossed the Deep River Bridge he began to whistle an old spiritual.  The river must have made a glorious waterfall before it was dammed and tamed.

 

No more vans appeared.  They pulled off the road briefly so Ivan could retrieve his shirt and then got onto interstate eighty five going north. 

 

By early afternoon they got to the Petersburg battlefield, and Jon sat in the car completing his decoding and making a second copy.  It was a wonderful car, but it was not so convenient for doing paperwork while rolling as the van had been.  The others set out to explore the battlefield.

 

It had been one of the many battles between the Confederate Army of Northern Virginia and the Union Army of the Potomac.  The Union command was looking for a way to exploit their greater resources and win while reducing the amount they had to expose their troops to “Lee’s Meatgrinder  Everyone knew how horrific it was to send men marching toward a Southern position and how the rebel troops refused to attack where defensive preparations were strongest.

 

So they decided to dig a tunnel and blow the rebel line up.  With monumental labor the sappers dug their way all the way across the battlefield and placed kegs of gunpowder under the Southern position.  They did their work well.  Even today you can see why it is called, “The Battle of the Crater.”  The blast hole cleanly split the southern defensive works. 

 

But as the sappers dug, the Southern soldiers heard it and reported it.  Men were sent to dig listening chambers close enough to the advancing tunnel to eavesdrop on the unfolding events.  This accomplished two things.  For one thing the Army of Northern Virginia knew exactly when the charge was set and the fuse ignited.  For another thing the chambers absorbed some of the shock of the blast, although by no means enough to prevent the opening of an enormous hole in the ground.

 

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