50 Weapons That Changed Warfare Page 14
European military attaches noted the destruction these guns achieved, but that didn’t impress their general staffs. Ferdinand Foch believed French elan and the bayonet was the key to victory. Lord Kitchner, who had seen the slaughter at Omdurman, thought that more than four machine guns to a battalion would be a luxury. The British had even used a few Maxim guns in the Boer War, but the Boers were not soldiers — just an irregular rabble. The trouble was that all the European officers had the romantic notion that wars are won by human valor. The machine gun made valor useless.
When war came in 1914, the European military expected a short war of movement and maneuver with heroic charges with the lance and bayonet decid-ing the outcome. Instead, the machine guns drove armies underground for four years of siege warfare broken only by the tank.
Chapter 28
Block that Kick!: Quick-Firing Field Pieces
National Archives from Army
Howitzer shelling Germans in 1944 recoils after firing a shot.
It really wasn’t like the movies. In films about the American Revolution or the American Civil War, for example, the muzzle-loading cannons fire, throwing out some smoke, and the gunners, who have been standing beside them and behind them, immediately reload and fire again. Actually, the guns of those days threw out a lot more smoke, because the film-makers don’t use full charges of black powder. And the real gunners didn’t stand behind the cannons and reload as soon as they fired. The recoil of the shot blew the gun back quite a few feet, and standing behind a heavy cannon when it fired was a good way to keep from growing old. The movie cannons don’t recoil, because they really don’t fire shot or shell. Property-owners in the vicinity would take a dim view of cannonballs holing their roofs or shells exploding in their gardens.
Before the cannon could be fired again, it had to be swabbed out with a wet “sponge” (actually a wad of wool on the end of a ramrod) to kill any sparks that might be in the gun. Otherwise, the powder charge might ignite and drive the ramrod through the gunner before he had a chance to load the shell or cannonball. Swabbing took some time. Even more time-consuming was the need to realign the gun. The gun crew had to manhandle the cannon back to its original position and aim it again. Even a comparatively light gun such as the 12-pounder “Napoleon” of the Civil War weighed more than a ton, and aiming the gun usually involved lifting the trail of the heavy carriage to swing the gun around.
By the Civil War, another problem had appeared. Rifles had become so accurate at long range that using artillery at traditional ranges had become almost suicidal. Artillery could no longer be used in the front line with the infantry. The gunners stood in the open, and there was nothing to give them protection from enemy rifle fire. Recoil made it impossible to hide behind the gun.
The latter part of the 19th century was a period of tremendous progress in artillery design. One prime objective was to increase the effective range of cannons. Another was to increase their speed of fire. Achieving both of these objectives meant overcoming recoil.
One way to increase the range was to fire guns at a higher elevation. Most of the cannons until this time were what artillerymen technically call guns — comparatively heavy, long-barreled weapons that have a higher muzzle velocity than the shorter barreled howitzers and mortars and fire their projectiles on a flatter trajectory. If a gun could be elevated to fire on a higher trajectory, its projectiles would go farther. But more of the recoil would be directed down at the carriage. That proved to be too much strain on the old wooden carriages. Gun makers switched to metal carriages, particularly steel carriages. Steel, much stronger than bronze, cast iron, or wrought iron was just starting to become available in large quantities at reasonable prices. Krupp pioneered making gun barrels from steel. Steel barrels could handle heavier powder charges, which also increased range.
Rifling a cannon barrel also increased its effective range. The main problem was getting a hard iron or steel shell or solid shot to “take” the rifling. Various methods were tried, including casting lugs on the shell that would fit in the grooves of the rifling. The method finally adopted was surrounding the projectile with a band of softer metal, usually a copper alloy, that the “lands,” the raised portions of the rifling, could bite into. That, and another soft metal band that rode above the lands, sealed the bore so that none of the expanding gas from the explosion of the propelling powder charge leaked around the projectile. Before that, muzzle-loading cannons had to allow for “windage.” The projectile had to be smaller than the bore. On the 12-pounder Napoleon that difference came to.01 inches. The absence of windage increased both the range and accuracy of the cannon. So did the fact that rifling made a projectile travel nose-first. Rifled guns could use an elongated projectile, one much heavier for its diameter than a round ball. This increase in “sectional density” meant that an elongated projectile had far more range than a round one with the same muzzle velocity.
It’s much easier to load a rifled cannon from the breech than from the muzzle. The use of steel and improved breech blocks made breech-loading so attractive that muzzle loading practically disappeared except for small trench mortars. Two types of breech block were used. One was a sliding block of steel; the other resembled a small, extremely thick bank vault door that was locked by an interrupted screw surrounding it.
There were three types of ammunition for breech-loading cannons — fixed, semi-fixed and bagged. Fixed ammunition resembled a rifle cartridge, with the shell fitted into a brass cartridge case containing the propelling charge. Semi-fixed also had a brass cartridge case, but the powder charge, packed in bags, could be varied to vary the range. With bagged ammunition, the shell was loaded first then the powder charge in one or more bags. Fixed ammunition and semi-fixed ammunition depend on the brass cartridge case expanding when the propelling charge is ignited. That seals the breech against escaping gas. To use bagged ammunition, the interrupted screw breech block has a “obturation pad” on its inner face that expands when the propelling charge explodes. To use the sliding breech block with a bagged charge, a gunner inserts a separate copper sealing ring behind the bagged propelling charge.
Steel, breech-loading, rifled guns were a huge step forward. They had more range and far more accuracy than their predecessors. But when makers like Hotchkiss and Krupp advertised their quick-firing field pieces they were using a bit of hyperbole. They still hadn’t dealt with that old devil, recoil. After a gun fired, the gunners had to push it back into position and aim it once more. Only if someone found a way to keep the gun in position and on-target during firing, could the cannon be truly said to be quick-firing.
Inventors came up with a variety of systems to hold the gun in place. On sailing ships, guns were allowed to roll back a certain distance, then the motion was stopped by a thick rope attached to the gun. Gun crews then used other ropes and pulleys to haul the cannon back to its gunport. If the restraining rope broke, however, you would have the proverbial “loose cannon on the deck” — a most undesirable situation. In some fortresses, guns were allowed to roll up a steep ramp. Gravity then repositioned them. One ingenious device, also used in fixed fortifications, was the disappearing gun. The gun was in a concrete-lined pit below the surface of the earth. Machinery raised it to firing position with the aid of counterweights. When the gun fired, the recoil returned it to its pit. An enemy would have only a brief glimpse of the gun before it fired and disappeared. Airplanes made the disappearing guns obsolete, but they were still used in U.S. coastal defenses in World War II.
Recoil was easier to treat in forts than in the field. Some designs attempted to absorb recoil with rubber buffers, but rubber wore out quickly, froze in cold weather, and wasn’t all that effective at any time. The 15-pounder field piece the British used in the Second Boer War had a “recoil spade” attached to the carriage axis. The spade was attached to a steel spring fixed to the carriage trail.
Gunners dug the spade into the ground. When the gun fired, the whole gun and carriage rolled back
, but the spring drew it back to position — more or less. It sounds better than it worked. The spade itself did not stay immobile. The recoil pulled back the arm to which the spade was attached, changing its angle to the ground, so the gun never returned to exactly the same spot.
The first field gun to solve the recoil problem was the French 75 mm Model 1897. A retired officer, Commandant de Port, modified a German invention to produce the system upon which all modern recoil systems are based. The “French 75,” as American World War I veterans called it, had a barrel that could slide back but that was attached to a piston in an oil-filled cylinder. When the gun barrel recoiled, the piston pushed the oil through a small orifice and into a second cylinder. That oil pushed back a floating piston in a second cylinder, compressing the air in that cylinder. Squeezing the oil out of the first cylinder absorbed much of the energy of the recoil; compressing the air in the second cylinder took care of the rest. Air is an extremely elastic material. When the gun’s motion stopped, the compressed air reasserted itself, bringing the gun back into firing position. The trail of the gun carriage had a spade that was planted in the ground to keep the gun carriage from moving. The gun was ready to fire another shot immediately. Because the gun carriage didn’t move at all, it was possible to hang a bullet-proof shield on the gun. That was a great boon to gunners. It also made possible the U.S. World War II experiment of attaching “cannon companies” to the infantry. The cannoneers worked right up with the riflemen, providing close-in support with their 105 mm howitzers. That was dangerous work, to be sure. But without the shield, it would have been suicide.
The recoil mechanism also made it much easier to dig in artillery pieces, a practice that was common in both world wars, Korea, and Vietnam. Without something to absorb their recoil, guns of the power of those used in modern wars would have to roll back a long way, so digging them in would require an enormous pit.
The French 75 used fixed ammunition. When a gunner opened the breech, the brass cartridge case was automatically ejected, and another round could be loaded. A trained crew could fire 30 shots a minute from the 75 — faster than most infantrymen could fire a bolt-action rifle. The M1897 75 mm was the standard French and American light artillery piece all through World War I and for many years afterwards. The French were still using it in World War II.
Every field gun in the world and most of the naval guns and the big siege guns copied the recoil system introduced on the French 75. As a result of the speed of fire it made possible, artillery was far and away the greatest killer of all guns used in World War II. Artillery and mortars killed two thirds of all the soldiers who died in that war. Speed of fire was especially important to antiaircraft guns. German antiaircraft fire during World War II probably shot down more Allied planes than German fighter planes, and in Vietnam antiaircraft guns destroyed 91 percent of all American planes lost in combat.
Chapter 29
The 1st Stealth Weapon: The Submarine
National Archives from Nav.
Torpedoed Japanese destroyer sinks while being photographed through the periscope of a U.S. submarine.
On the night of September 6, 1776, a small group of men on the shore of New York harbor silently lowered a most peculiar-looking object into the dark water. The strange contraption was made of two solid curved pieces of wood closely fitted together to form a waterproof joint. It had a hand-cranked propeller, a rudder at the rear, and another propeller on its upper surface. One man, Ezra Lee of Old Lyme, Connecticut, had entered through a hatch at the top. Lee planned to propel his strange craft to the British 64 gun frigate H.M.S Eagle, dive below the surface when the got near the British flagship, attach an explosive charge to the ship, and leave as fast as he could.
The peculiar craft, named the American Turtle because it looked like a turtle tipped over on one side, was the brainchild of Captain David Bushnell, an engineering officer in the Continental Army. When he was 29, Bushnell had sold the farm he inherited and attended Yale, where he studied science for four years.
When the Revolution broke out, he joined the Continental Army. With the help of another Yale scientist, he designed an underwater bomb with a time-delay mechanism. When the preset time was up, the mechanism activated a flintlock that set off the charge. That led Bushnell to consider some means of getting the bomb to the enemy. The British ships had lookouts watching the water at all times. Even at night, it was unlikely that a rowboat or canoe could get close enough to one of their ships to attach a bomb. And it was almost certain that the inevitable noise of the attaching work would attract attention.
The only sure way would be to approach under water.
So Bushnell designed Turtle. The boat would travel most of the way to its target with its hatch open and just above the surface of the water. Driven by a hand-cranked propeller it would be too slow to make a noticeable wake. When it got near the British ship, Turtle’s pilot would use the upper propeller to force his craft below the surface. The bomb was attached to a screw on the front of the submarine that could manipulated from inside the craft.
Bushnell’s brother, Ezra, volunteered to bomb H.M.S. Eagle. He had piloted the submarine for weeks in waters where no British were to be found. But at the last minute, Ezra Bushnell fell ill. Ezra Lee volunteered to take his place although he had much less experience with Bushnell’s invention. With the hatch open and barely above the surface, Lee slowly made his way to the British ship.
In a modern reproduction of Turtle, built for a television documentary, the pilot found it was easier to move the boat by sculling with the rudder than cranking the propeller. An earlier reproduction, built for the U.S. bicentennial celebra-tion reportedly worked as intended. Whatever method he used, Lee got near Eagle and dived. In addition to the difficulty in handling a brand-new weapon of war and the danger that the British would learn what he was doing, Lee was working under a serious deadline. The timing mechanism of the bomb had already been activated. He tried to drive the screw into the hull of the ship, but Eagle was sheathed in copper below the waterline to foil barnacles. The screw wouldn’t penetrate the metal. Lee tried again and failed. Time was running out.
Lee jettisoned his bomb and moved away. The floating bomb exploded with a shocking flash and bang. The British ships hauled in their anchors and hoisted their sails.
On shore, David Bushnell roundly cursed the unfortunate Lee. Then he and his party loaded Turtle into a sloop to take it back to New England. A British warship chased the sloop and sank it.
After the Revolution, Bushnell petitioned the Continental Congress for some form of recognition or compensation. But, although General George Washington said in 1784, “Bushnell is a man of great mechanical powers, fertile in invention and a master of execution,” Congress ignored him. Bushnell moved to France and tried to interest the French in his submarine. He failed, although he apparently interested another American, Robert Fulton, inventor of the steam-boat. Fulton launched another submarine, called Nautilus, in France in 1800.
Fulton, who had received a commission in the French Navy, almost succeeded, but at the last minute Napoleon decided that underwater warfare was also underhanded and cancelled the sale.
Bushnell had returned to the United States in 1795 but, disillusioned, he had changed his name and moved out of New England. It was only after his death in 1824, that residents of Warrentown, Georgia, learned that “Dr. Bush,” who taught science and religion at the local academy, was really David Bushnell, the Revolutionary inventor.
Bushnell’s submarine was not the first one, but it was the first to be used in war. The first sub was built in England in 1620 — the year before the Pilgrims landed — by a Dutchman named Cornelius van Drebbel and tested in the Thames.
After Bushnell and Fulton’s boats only Americans seemed to have any interest in submarines. Both the Union and Confederacy used submarines in the Civil War. In 1862, the U.S. Navy purchased its first sub, the U.S.S. Alligator, to plant mines (“torpedoes” in those days) in Confederate
harbors. Alligator sank in April, but it was followed by several other submarines. Alligator carried two air purifiers, a chemical means of producing oxygen, and a bellows-driven ventilation system. The Confederacy also had a fleet of submarines. One of them, the C.S.S. Hunley, sank the U.S.S. Housatonic, the first time a submarine ever sank an enemy ship. But the blast also sank Hunley.
After the war, John Holland, an Irish immigrant, and Simon Lake, a New Jersey foundry owner’s son, continued to work on submarines. Holland at first was financed by the Feinians, an Irish secret society dedicated to winning Irish independence from Britain. In 1881, he launched a submarine called Feinian Ram, intended to end Britain’s command of the sea. It needed further work, but Holland and the Feinians quarreled and the society cut off its financial aid.
Holland continued working and built a boat named Holland IV, which won a U.S. Navy award for submarine design. The Navy was not yet ready to buy a submarine, though. Holland designed more boats and sold Holland VI to the navy, which renamed it U.S.S Holland in 1900. Holland was powered on the surface by an internal combustion engine, which also charged storage batteries.
When submerged, it ran on an electric motor. That system was used by all modern submarines until the advent of nuclear power. In the meantime, Lake had been designing other subs. In 1898, he launched Argonaut, which sailed from Norfolk to New York, becoming the first submarine to travel a significant distance on the open sea. Argonaut, which had wheels beneath her hull, was also equipped to roll along the ocean floor. Lake also invented even-keel hydro-planes, ballast tanks, divers compartments, periscopes, and twin hull design — all of them essential to modern submarines.