Whirlwind - Barrett Tillman [108]
Gray was likely the last Canadian killed in action in World War II. Admiral Sir Philip Vian lauded his “brilliant fighting spirit and inspired leadership” and nominated him for a posthumous Victoria Cross, Britain’s highest honor. The presentation was made to Gray’s parents in Ottawa in February 1946. It was the sixteenth VC awarded a Canadian in World War II; only the second for a Fleet Air Arm aviator.
With the sacrifices of fliers such as Hawes and Gray, the harbor war largely ended on August 9, the same day that continued a rain of ruin upon Japan undreamt of by even airpower’s most flamboyant visionaries.
CHAPTER EIGHT
“A Most Cruel Bomb”
THE WEAPON STREAKED down through six miles of sky, accelerating to its terminal velocity at 32 feet per second. From the instant the 8,800-pound bomb left the belly of a bomber with the radio call “Dimples 82,” an irrevocable sequence had begun.
Ordnance engineers had computed that the most damage would be inflicted upon the target by an explosion 1,900 feet above ground level. The Mark 1 weapon’s fusing was designed accordingly. As the device dropped from Dimples 82, an electrical plug was stripped from an aircraft socket, beginning a timer delay of fifteen seconds, at which point the bomb’s onboard battery kicked in. The electrical circuit activated a barometric altimeter that sensed the outside atmosphere as the blunt-nosed shape plummeted through the 6,000-foot mark. For utmost precision, a radar-controlled detonation was required. Therefore, at the designated height the barometer actuated four radar altimeters, all linked to one another. When at least two registered 1,900 feet altitude, the ignition sequence began.
The workings of the device, though requiring twentieth-century precision, were centuries old in principle. The Mark 1 was a simple “gun” concept built around a six-foot tube containing a gunpowder charge that fired a six-and-a-quarter-inch diameter uranium slug at a “target” four inches in diameter. The 85-pound projectile smashed into the 56-pound target at 1,000 feet per second. Ten-thousandths of a second later, compressed between tungsten-carbide reflectors, the entire U-235 assembly reached critical mass and erupted in a chain reaction, the nuclear fuel feeding upon itself.
Almost perfectly aimed by a twenty-six-year-old bombardier, after a forty-three-second fall from 31,000 feet the bomb missed its aim point by fewer than 200 yards. There, southeast of the juncture of two rivers, it burst with the energy of approximately 15 metric tons of TNT.
First came the light—red-hued purple—then the heat, vastly searing in its intensity as the raging fireball surpassed 5,000 degrees Fahrenheit. Beneath an enormous blast wave exceeding 12 pounds per square inch, a stone and concrete building at ground zero was either vaporized or driven vertically into the earth.
The resulting firestorm measured two miles across, jumping both natural and man-made barriers. Where the rampaging blast overpressure leveled buildings, the ravenous fire consumed most of the ready-made fuel in its path. Further out, where more buildings survived than collapsed, the effects were diminished by distance. However, humans died beyond that radius, from blast, flames, and the invisible killer called radiation. The exact number of dead will never be known.
Its mission accomplished, Dimples 82 banked away from the destroyed city of Hiroshima, having completed a process that began with a letter from a scientist to a politician six years before.
Gadgets and Firecrackers
On August 2, 1939, Albert Einstein wrote President Roosevelt, citing “recent work by E. Fermi and L. Szilard . . . [which] leads me to expect that the element uranium may be turned into a new and important source of energy.”
The German-born physicist postulated a nuclear chain reaction producing enormous amounts of power. He said, “This new phenomenon would also lead to the construction of bombs,” though he