the U boats waited for a freighter to come along. If its torpedoes missed, another ship would be along soon. A submerged submarine was about the slowest craft at sea. It couldn’t catch up with or even keep up with the slowest freighter. Convoys eliminated the steady stream of ships steaming across the Atlantic. U boats had to wait a long time between targets, and when a convoy appeared, it was guarded by naval ships. If the U boat were not positioned just right, it might miss all the ships in the convoy, and it was too slow to make up for poor positioning.
In the next war, the submarines were bigger, faster, and sturdier, but their enemies had something new, too. The British called it asdic; the Americans called it sonar. Basically, sonar sends beeping sounds into the water and listens for echoes caused by other objects in the water. An experienced sonar operator could distinguish between the echoes from a U boat or a whale. The convoy escorts also had better hydrophones, and whales don’t make engine and propeller noises.
Locating subs was also helped by another, more sophisticated method of detection: radar. Radar used radio waves instead of sound waves, but it, also, relied on echoes. The first important use of radar was in the Battle of Britain.
Britain had radar stations all along its shore. They were able to locate German planes long before they were in sight, allowing the British fighter command to concentrate its interceptors to meet the threat. The Germans had a primitive form of radar and had no idea that the British had any, much less the more advanced form they were actually using.
British scientists continually improved their radar devices. They made some small enough to be installed on ships. That further complicated life for subma-riners. Radar could “see” in the dark, and it could “see” at much longer distances than human eyes. Submarines could no longer travel on the surface at night in safety, as they once did. It got worse. Radars became precise enough to “see” periscopes; they became small enough to install on airplanes. In daylight, unseen planes swooped out of the clouds and bombed surfaced submarines. At night, a surfaced submarine could be located by a plane and bombed before its crew even knew they were under attack. Airborne radar became operational in 1943, the year a German writer called “the year of the slaughter of the U boats.”
The miniaturization of radar went on. One result was the greatest advance in artillery in the 20th century: the proximity fuse (see Chapter 19). For the first time in history gunners could explode their shells, whether for antipersonnel ground fighting or for antiaircraft fire, at the optimum distance from the target, and do it without failure.
Radar and sonar were the first of a great array of detection devices that are at the heart of many of our modern “smart” weapons (see Chapter 50).
Chapter 44
The Fires of War: Thermite, Napalm, and Other Incendiaries
On the night of March 9, 1945, as the B 29s took off from Guam, war was raging everywhere. In Europe that day, American forces had taken the Ludendorff Bridge at Remagen, crossing the border of Germany for the first time. The Red Army had entered Germany and had trapped half a million German troops in a pocket against the Baltic Sea, but there were still months of fighting ahead. In the United States, the American Office of War Information was desperately trying to perpetuate the myth, based on Roosevelt’s promise to Churchill, that American forces were concentrating on defeating Germany first, after which they would turn to Japan.
Actually, there was no such concentration on Germany by American forces.
That propaganda line, politically correct at the time, has unfortunately been accepted by some later writers. That makes it sound as if Japan was a paper tiger that collapsed like a punctured balloon as soon as we were able to turn away from Germany. And that supposition ignores all the toil, blood, and hero-ism of the American forces that pushed Japan almost to the breaking point while their contemporaries were helping to defeat Germany. The British forces did concentrate on Germany, certainly. Germany was a near, clear-and-present danger. But, although the largest part of the U.S. Army was in the European and Mediterranean theaters, almost all of the major ships of the U.S. Navy — aircraft carriers, battleships, cruisers, and submarines, and most of the Marine Corps — were in the Pacific and had been for three years. Guam itself, the base of these super-heavy B 29 bombers, had been retaken from the Japanese less than a year before this. At the same time, at the Battle of the Philippine Sea (also known as the Great Marianas Turkey Shoot), the U.S. Navy had broken the back of Japanese naval air forces and dealt a heavy blow to the Imperial Navy. A few months later, on October 24 and 25, 1944, the United States struck an even heavier blow at the Battle of Leyte Gulf. Japan lost four aircraft carriers, three battleships, 10 cruisers, and nine destroyers as well as 500 planes, and U.S. forces began the reconquest of the Philippines. They had gone from there to Iwo Jima on the doorstep of Japan — almost, in fact, one of the Japanese home islands. By this time, Japan had no airframe factories, almost no shipping, hardly any oil, and hardly any planes on the home islands.
The B 29s soared over the Pacific on a route that had been used many times before. They were heading for a target so far away such a bombing mission would have been unthinkable early in the war. Enough 29s had already flown this route, though, to have wiped out some of Japan’s strategic industries such as airframe factories and oil refineries. The Japanese had managed to disperse other industries all around their country, but that didn’t matter now. The Americans were after cities. Tonight’s target was the huge Tokyo-Yokohama metropolitan area.
The bombers swooped to low altitude as they approached the Japanese coast and unloaded their deadly cargo over the port city of Yokohama and the Japanese capital, Tokyo, then returned to Guam after experiencing hardly any resistance. Behind them, 16 square miles of homes and businesses were ablaze.
They had created a fire storm — the biggest one in history.
A fire storm occurs when a conflagration becomes so big and hot that it creates a powerful updraft over the center of the fire, consumes all the oxygen in the affected area, and draws so much cool air to the center of the fire that winds reach gale force. The winds make the fire more intense. The heat in Tokyo was so intense that the water in the city’s canals boiled. In places, the fire took all the oxygen out of the air. Many of those caught in the firestorm, even though sheltered from the flames, suffocated for lack of oxygen. In this raid, some 86,000 people — almost all civilians (men, women, and children) — died.
In June 2004, John Yoo, a law professor explaining some memos (which he helped write) defending the use of torture on prisoners in the Iraq War, said,
“This is an unprecedented conflict with a completely new form of enemy that fights in unconventional ways that violate the very core principles of the laws of war by targeting civilians.”
The weapon that made possible conflagrations such as the Tokyo-Yokohama fire and the fires that destroyed all of the largest cities of Japan was based on an incendiary substance known and used by every American: gasoline. It was jel-lied by mixing it with aluminum naphthenate, a naphtha-based soap, and aluminum palmate, a palm-oil-based soap. The thickened gasoline clings to whatever it touches and burns more fiercely. It was also used in American flamethrowers during World War II. Because of the thickening, flamethrowers projected in a narrow stream with greater range than would have been possible with gasoline.
The jet of fire could be made to ricochet around corners. Newer fire bombs use a liquid, not a gel, called napalm B, composed of polystyrene, benzine, and gasoline. It is said to burn three times longer than the older mixture and cause more destruction.
The idea of napalm bombs came from fighter-bomber pilots who discovered that if one of their auxiliary gas tanks were dropped while still loaded, it ignited spontaneously. That made it a potentially deadly weapon, and substitut-ing napalm for aviation gas made it even more deadly. Most napalm bombs were quite large, in contrast to the thermite bombs that initiated this horrible form of warfare, first by the Germans, then by the British.
Thermite, too, is a combination of common materials — powdered aluminum and ferric oxide — better known as rust. Neither component, though, is generally considered a fire-starter. Thermite had been used to an extent in the First World War when German zeppelins bombed cities. At that time, it formed the center of a cone of resinous material bound with tarred rope. In the Second World War, the Germans used thousands of 2-pound bombs that
