--FIRST -PREV NEXT-
No one loves a siege. (Am I repeating myself?)
By the end of August 1864, the Union had settled down to besiege not one, but two Southern cities: Richmond and Atlanta. Granted, the Atlanta siege was new, but Richmond had been under siege since late Spring, at the conclusion of the Overland campaign. As I said before, sieges combine all the things least enjoyable about campaigning: you have all of the danger of active engagement, plus all of the boredom of garrison life. And into that, you can add the rampant disease of so many men quartered so closely together.
It sometimes sounds odd to the modern ear, but up until fairly recently, disease claimed more lives in wartime than did enemy action. A Union soldier was more likely to fall to cholera, fever, or some other illness than he was to fall to a Confederate Minié ball. Scientists were beginning to understand the link between germs and disease -- Louis Pasteur was wrapping up his landmark experiments at almost this exact time in 1864 -- but they had not yet applied this knowledge to military sanitation or medicine. It had long been known that a clean soldier was a healthy soldier, and that if you dig your latrines just so it holds off the sickness longer ... but they did not yet know why.
All that said, the siege of Atlanta was less than a month old, and Sherman didn't think it would last much longer. He knew that the Confederate army under John Bell Hood didn't have much in the way of supply stored up in Atlanta, and if he could manage to destroy his last rail link with the outside, he'd have to abandon Atlanta in short order.
Here we begin to see the payoff of two Union strategies: first, the long-range strategy of isolating the Confederacy; and second, the "attack everywhere" plan that kept the Confederate armies from supporting one another. The first essentially guaranteed that no Confederate force had any more than a few days' supplies on hand at any given time, and the second guaranteed that a hard-pressed Confederate army could not depend upon support or reinforcement. Armies that were based at or near a major city, such as the Army of Northern Virginia at Richmond, could draw upon considerable supplies ... but were essentially immobile. Armies like Hood's, on the other hand, either had to have a steady source of supplies or had to keep moving. Atlanta had no fortifications like those that had been built up around Richmond, nor did Atlanta have any natural defenses like Vicksburg. So hunkering down in Atlanta wasn't a real option.
So it was, then, that when Sherman's army threatened Hood's last rail link at Jonesborough, Hood was forced to come to its defense. Hood sent two corps under General Hardee to keep Sherman from cutting him off. But Hood seriously underestimated how much force Sherman was willing to commit to this effort.
Of his seven infantry corps, Sherman sent six. And a Union corps was larger than a Confederate corps to begin with.
If this had been 1862 or 1863, the Battle of Jonesborough probably would have been a bloodbath. But the survivors of 1862 and 1863 had learned the value of maneuver. And they also learned when to cut their losses. Hardee's two corps made a stand as long as they could, but were forced to yield or be destroyed.
For Hood, it may as well have been six of one or a half-dozen of the other. With Sherman's army in Jonesborough, his position in Atlanta was no longer tenable. If he stayed put, he'd be crushed. So on September 1st, Hood's army retreated from Atlanta, destroying all stores of military use beforehand.
That night, Atlanta burned.
The next morning, Sherman and his army arrived. "Atlanta is ours, and fairly won," he exulted in a message to President Lincoln. It was the best news Lincoln had received all summer. It was the best news anyone in the Union had received all summer. The capture of Atlanta had several effects.
First, the capture and reduction of an important supply center would have long-ranging implications for the Confederate war effort. The already-precarious Confederate supply system would now be in truly dire straits. Worse still, from Atlanta, Union forces could threaten the most valuable, most productive agricultural areas.
Second, it was an important symbolic victory. Vicksburg had cut the Confederacy in half. The capture of Atlanta had gone halfway towards doing it again. This was a boost to Union morale, and a dreadful blow to Confederate morale -- what was left of it. The first half of 1864 was a dreadful slog, with no end in sight. That had changed. With the capture of Atlanta, and the measurable progress that represented ... well, that's not victory, but you can see it from there.
Lastly, and perhaps most importantly, it provided a powerful boost to Lincoln's re-election chances. McClellan's candidacy was predicated upon a negotiated peace. Why negotiate, when the matter is so very nearly settled? Sherman's victory at Atlanta took the wind out of McClellan's sails. He'd still have his partisans, of course; he'd still have a fair share of people who'd had enough. But the voters still in the undecided middle were now going to be that much harder for him to win.
For now, though, Sherman needed to take time to reorganize his army, and figure out what he was going to do next. A plan was taking shape ...
... a plan that would be the biggest gamble of his life.
Friday, August 29, 2014
Friday, August 01, 2014
Faster
We chafe at limits.
We don't like being told something is impossible, even -- or maybe especially -- if it is. Virtually anytime someone says "it can't be done", you can find someone willing to put the matter to the test. And whatever can be done, you can be sure someone's on the prowl looking for a way to do it better. A way to go higher, or farther, or faster.
For most of human history no one ever traveled faster than a horse could gallop. The steam engine changed that. Man got his first taste of higher speed in 1804, when Richard Trevithick built his "Puffing Devil" steam locomotive. Towards the end of the century, the first automobiles were built, and were soon faster than locomotives themselves.
It's understandable and perfectly excusable if you think that electric cars are a recent innovation, but that's actually not the case. The first land speed record held by an automobile, set in 1898 by the French vehicle Jeantaud Duc, was set by a car with an electric motor. Steam engines were too heavy, and gasoline engines too unreliable, so in the early days of the automobile electric engines were the motors of choice. That didn't last very long, though. Four years later, a steam-powered car overtook the electics with a then-blistering speed of 75 miles per hour. Lest you think that steam was making a comeback, it was displaced in mere months by a gasoline-powered car driven by the American driver William Vanderbilt. This would begin an American dominance of land speed records that would last ... oh, about five years. A Frenchman would take the lead in 1909, and then an Englishman in 1914. The English would hold the record for a while. Almost fifty years, in fact.
Their dominance came to a temporary end for two reasons. First, they were hitting a hard limit with what could be accomplished with wheels. Second, some might say that the Americans ... cheated.
First, the problem. If we go back a few years, I wrote about the maximum speed a running man could achieve. It's the same basic principle with cars. You can only drive the wheels so hard before they start slipping. You can make the tires extra-sticky, you can hold the test on the most favorable ground possible, but there's only so much direct drive can do. Which means ... you have to do something that isn't direct drive.
Purists would call what comes next cheating. If direct drive doesn't give you enough satisfaction, you heed the maxim "everything's better with fire", and use a jet engine, or better still, a rocket.
Which is exactly what Craig Breedlove did in 1963. Granted, the Spirit of America only raised the speed record from 403 to 407 miles per hour, but it showed what a jet-powered car could do. Two other Americans would yank the record away from Breedlove before he came back to the ring with a new and improved Spirit, this one called Sonic 1, built around an engine from an F-4 jet fighter. He set a record at 555 miles per hour, then broke his own record a few weeks later when he hit 600 miles per hour. The record rested comfortably in his hands for about five years. Then, Gary Gabelich comes along with the Blue Flame, a rocket-powered car that hit 622 miles per hour in 1970. This is where the record would stay for another thirteen years. It would stay there, because engineers were beginning to reach another problem.
Compressibility becomes a huge problem when you get that close to Mach 1. That's true for any vehicle. That's doubly true for a vehicle that has to maintain contact with the ground. The shock wave really wants to get between you and terra firma, which would be ... a problem. And not "a problem" as in "this is a really sticky equation," but "a problem" as in "holy mother of God, I've been flipped like a pancake at 700 miles per hour." Only there'd be a lot more screaming and loss of bladder control involved. It would take some high-power computational wizardry to figure out how you build a car that can go that fast without killing its driver.
Richard Noble started the climb up that steep hill in 1983 with the Thrust 2. This car, built around a Rolls-Royce Avon jet engine, hit 633 miles per hour. Nowhere near Mach 1, but it did claim the record. Noble would spend another fourteen years designing and building its successor, Thrust SSC, powered not by one, but two Rolls-Royce Spey turbofan engines. Power was only half the problem. Control was the other half. Thrust SSC has a triangular control surface on its aft fin, to help keep the vehicle on the ground during high-speed runs. Appropriately enough, the car was driven by a Royal Air Force fighter pilot, Wing Commander Andy Green. And in October of 1997, Thrust SSC broke the sound barrier.
That's where the land speed record stands. There are a couple of teams at work trying to beat it, but no one's succeeded yet. It's the longest gap between broken records, and it's liable to stay that way for a while.
But don't feel too bad for rail-based vehicles, so unceremoniously left behind in 1898. They got the last laugh. In 2003, at a test range near Holloman AFB, a four-stage rocket sled pushed its payload to the staggering speed of 6,416 miles per hour -- EIGHT AND A HALF times the speed of sound -- as a test of the High-Speed Test Track.
It's ... gonna be a while before anyone drives that fast.
We don't like being told something is impossible, even -- or maybe especially -- if it is. Virtually anytime someone says "it can't be done", you can find someone willing to put the matter to the test. And whatever can be done, you can be sure someone's on the prowl looking for a way to do it better. A way to go higher, or farther, or faster.
For most of human history no one ever traveled faster than a horse could gallop. The steam engine changed that. Man got his first taste of higher speed in 1804, when Richard Trevithick built his "Puffing Devil" steam locomotive. Towards the end of the century, the first automobiles were built, and were soon faster than locomotives themselves.
It's understandable and perfectly excusable if you think that electric cars are a recent innovation, but that's actually not the case. The first land speed record held by an automobile, set in 1898 by the French vehicle Jeantaud Duc, was set by a car with an electric motor. Steam engines were too heavy, and gasoline engines too unreliable, so in the early days of the automobile electric engines were the motors of choice. That didn't last very long, though. Four years later, a steam-powered car overtook the electics with a then-blistering speed of 75 miles per hour. Lest you think that steam was making a comeback, it was displaced in mere months by a gasoline-powered car driven by the American driver William Vanderbilt. This would begin an American dominance of land speed records that would last ... oh, about five years. A Frenchman would take the lead in 1909, and then an Englishman in 1914. The English would hold the record for a while. Almost fifty years, in fact.
Their dominance came to a temporary end for two reasons. First, they were hitting a hard limit with what could be accomplished with wheels. Second, some might say that the Americans ... cheated.
First, the problem. If we go back a few years, I wrote about the maximum speed a running man could achieve. It's the same basic principle with cars. You can only drive the wheels so hard before they start slipping. You can make the tires extra-sticky, you can hold the test on the most favorable ground possible, but there's only so much direct drive can do. Which means ... you have to do something that isn't direct drive.
Purists would call what comes next cheating. If direct drive doesn't give you enough satisfaction, you heed the maxim "everything's better with fire", and use a jet engine, or better still, a rocket.
Which is exactly what Craig Breedlove did in 1963. Granted, the Spirit of America only raised the speed record from 403 to 407 miles per hour, but it showed what a jet-powered car could do. Two other Americans would yank the record away from Breedlove before he came back to the ring with a new and improved Spirit, this one called Sonic 1, built around an engine from an F-4 jet fighter. He set a record at 555 miles per hour, then broke his own record a few weeks later when he hit 600 miles per hour. The record rested comfortably in his hands for about five years. Then, Gary Gabelich comes along with the Blue Flame, a rocket-powered car that hit 622 miles per hour in 1970. This is where the record would stay for another thirteen years. It would stay there, because engineers were beginning to reach another problem.
Compressibility becomes a huge problem when you get that close to Mach 1. That's true for any vehicle. That's doubly true for a vehicle that has to maintain contact with the ground. The shock wave really wants to get between you and terra firma, which would be ... a problem. And not "a problem" as in "this is a really sticky equation," but "a problem" as in "holy mother of God, I've been flipped like a pancake at 700 miles per hour." Only there'd be a lot more screaming and loss of bladder control involved. It would take some high-power computational wizardry to figure out how you build a car that can go that fast without killing its driver.
Richard Noble started the climb up that steep hill in 1983 with the Thrust 2. This car, built around a Rolls-Royce Avon jet engine, hit 633 miles per hour. Nowhere near Mach 1, but it did claim the record. Noble would spend another fourteen years designing and building its successor, Thrust SSC, powered not by one, but two Rolls-Royce Spey turbofan engines. Power was only half the problem. Control was the other half. Thrust SSC has a triangular control surface on its aft fin, to help keep the vehicle on the ground during high-speed runs. Appropriately enough, the car was driven by a Royal Air Force fighter pilot, Wing Commander Andy Green. And in October of 1997, Thrust SSC broke the sound barrier.
That's where the land speed record stands. There are a couple of teams at work trying to beat it, but no one's succeeded yet. It's the longest gap between broken records, and it's liable to stay that way for a while.
But don't feel too bad for rail-based vehicles, so unceremoniously left behind in 1898. They got the last laugh. In 2003, at a test range near Holloman AFB, a four-stage rocket sled pushed its payload to the staggering speed of 6,416 miles per hour -- EIGHT AND A HALF times the speed of sound -- as a test of the High-Speed Test Track.
It's ... gonna be a while before anyone drives that fast.
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