Bat Bombs

   Posted by: John   in Random Stuff

From the Uncle John’s Slightly Irregular Bathroom Reader

In the days and weeks following the bombing of Pearl Harbor on December 7, 1941, a lot of people wrote letters to President Roosevelt.  Some wrote to express their sympathy with the victims or their outrage at the attack; others made suggestions about how to fight back against Japan.

One man, a dentist from Irwin, Pennsylvania, wanted to talk about bats.  His name was Lytle S. Adams, and he had recently been to the Carlsbad Caverns in New Mexico, home to one of the largest bat colonies in North America.  When Adams learned of the attack on Pearl Harbor, his thoughts returned to the bats he’d seen.  Could they be useful to the war effort?  He was convinced they could.

In his letter to the president, Adams explained that bats are capable of carrying more than their own weight in flight.  In many species, for example, the mother bat carries two or even three of her young as she searches for food.  If bats could carry their children, Adams reasoned, why couldn’t they carry tiny bombs?

The dentist’s plan went further: Bats hate sunlight, so if bats carrying time-delayed incendiary devices could be released over a Japanese city shortly before dawn, as the sun rose, the bats would seek refuge from the light.  Many would roost in the eaves and attics of buildings, a great number of which were made of flammable materials like wood, bamboo, and paper soaked in fish oil.  When the firebombs detonated, thousands of tiny fires would start in buildings all over the city.

Not only that, bats typically hide out of sight in hard-to-reach places, and that would make the fires difficult to detect.  By the time they were discovered, the fires would be well established but still small enough at first (each bat would weigh less than half an ounce, so the bombs would have to be small, too) that people would have a fighting chance to escape.  Casualties would be lower than with conventional firebombs, which weighed hundreds of pounds and engulfed entire buildings on impact, giving occupants no warning and no chance to escape.  For all their destructive power, Adams believed that “bat bombs” could be a more humane weapon of war than regular firebombs.

How many fires could be started with bats?  “Approximately 200,000 bats could be transported in one airplane,” Adams write, “and still allow one-half the payload capacity to permit free air circulation and increased gasoline load.  Ten such planes would carry two million fire starters.”

Perhaps the most impressive feature of bat bombs was not their destructive power, but the psychological impact they could have on the Japanese.  The bats would be dropped by planes before dawn, and by the time the bombs went off, the planes would be long gone.  Entire cities would ignite spontaneously and burn to the ground…with no warning and no explanation.

“The effect of the destruction from such a mysterious source would be a shock to the morale of the Japanese people as no amount of ordinary bombing could accomplish,” Adams wrote to Roosevelt.  “It would render the Japanese people homeless and their industries useless, yet the innocent could escape with their lives.”

How flammable were Japanese cities?  When a woman living in Osaka, Japan, knocked over her hibachi-type cook stove in 1911, 11,000 homes burned to the ground.  And it was raining.

President Roosevelt forwarded Adams’s letter to Colonel William J. Donovan, who would soon head the Office of Strategic Services, forerunner of the CIA.  “It sounds like a perfectly wild idea but it is worth looking into,” FDR wrote.  “This man is not a nut.”

Dr. Adams got the go-ahead to assemble a 20 person staff and begin working out the details on how such a weapon might be built.  What species of bats would be best?  What kind of firebomb would be used?  How would the device be attached to the bat?  How would the bats be dropped over cities?  There was a lot to figure out.  Here’s what they came up with.

The Bats

The researches decided early on that they would use a species called the Mexican free-tailed bat.  They weighed about half an ounce but were capable of carrying a load of as much as three-quarters of an ounce.  Tens of millions of them made their summer homes in caves in Texas and other southwestern states.  Just as important, these bats hibernated in the winter.  That meant they could be put into artificial hibernation so that the bombs could be attached, then kept in cold storage until they were ready to be released over Japan.

The Incendiary Bombs

Once of the researchers assigned to the project was an incendiary bomb specialist, a chemist named Louis Fieser.  He devised a tiny bomb that weighed a little over half an ounce and consisted of a timer and thin plastic capsule measuring three-quarters of an inch in diameter by two inches long, filled with a jellied gasoline he’d invented, napalm.

Initially the designers planned to attach a bomb to each bat’s chest with a piece of string and a surgical clip that mimicked the way baby bats latched onto their mother’s fur with their claws.  But that turned out to be too complicated, so they switched to a simple adhesive and just glued the bombs to the bats.

The “Bombshell”

If you just threw a bunch of hibernating bats out of an airplane, their fragile wings would break the moment they hit the airstream at 150 mph or else they would fall all the way to the ground and die on impact before they could emerge from hibernation.  So the researchers designed a protective bomb-shaped canister to put the bats into.   The “bombshell” was cigar-shaped and had fins, just like a regular bomb, except that it was filled with bats and was poked full of holes so they could breathe.

Inside the canister, the hibernating bats were packed into cardboard trays similar to eggshell cartons, and these cartons were stacked one on top of the other.  Each bombshell held 26 cardboard trays, each of which held 40 bats.  That meant each bomb would contain 1,040 bats.

How it worked

1)  The bombshell was designed so that when it was dropped from a plane, it would free-fall to an altitude of 4,000 feet, at which point a parachute would deploy, slowing its descent.

2)  When the parachute opened, the bomb’s outer shell would pop off and fall away.  The stacked cardboard trays, which were tied to one another with short lengths of string, would then drop down and hang from the parachute about three inches apart, like rungs on a rope ladder.

3)  As the cardboard trays dropped into position, a tiny wire would be pulled from the incendiary device attached to each bat.  Just like pulling a pin from a hand grenade, when the string was pulled, the firebombs would be armed and set to go off in 30 minutes, 60 minutes, or whatever the interval the bombers chose.

4)  The bats, now exposed to the warm air and floating slowly to the earth, would have enough time to warm up, emerge from their hibernating state, climb out of their individual egg-carton compartments, and fly away to seek shelter.

5)  When time ran out, the incendiary device glued to their chest would explode into flames, incinerating them instantly and setting fire to whatever structure they had taken refuge in.

A bombshell filled with bats and tiny firebombs sounded clever, but would it really work?  Dr. Adams’s team built a prototype, loaded it with 1,040 bats fitted with dummy bombs, and dropped it from a plane in a remote region outside Carlsbad Air Force Base in New Mexico.  The test went off nearly without a hitch: the parachute deployed, the trays dropped open, and the bats awakened from hibernation and flew off in search of shelter from the sun.

The only snafu was that the researchers misjudged how far winds would carry the bat trays.  Instead of landing in the middle of nowhere (the project was top secret, after all), the bats ended up flying to a ranch and roosting in the bar and ranch house.  The researchers caught up with the creatures half an hour later and collected them as the mystified rancher looked on (he never did learn what the bats were carrying or what they were for).

But the real proof of the power of bat bombs came later that day when Louis Fieser, the incendiary specialist, wanted some film footage of a bat armed with a live incendiary bomb actually exploding into flames.  He took six hibernating bats out of cold storage and set their bombs to detonate in 15 minutes, figuring that in such a short time, the bats would still be hibernating and wouldn’t fly away.

What Fieser failed to take into consideration was that on a hot New Mexico afternoon, the bats would come out of hibernation quickly.  All six bats woke up within 10 minutes, escaped, and roosted in the rafters of various buildings of the airfield where the test was being conducted.  Five minutes later the bombs went off, and every building on the airfield, the control tower, barracks, offices, and hangers, burned to the ground.

Believe it or not, bat bombs were found to be more effective than conventional firebombs.  One study concluded that a planeload of conventional firebombs would start between 167 and 400 fires, whereas a planeload of bat bombs would start between 3,625 and 4,748 fires. 

So how many bats died in combat during World War 2?  Not even one.  After spending 27  months and $2 million looking into the feasibility of bat bombs, the Pentagon canceled the program in March 1944.  The military claimed that the bats were too unpredictable to be useful, but Jack Couffer, a research scientist who worked on the project, has a different theory.  Couffer speculates in his memoirs that the government knew the Manhattan Project was making steady progress toward the world’s first atomic bomb, and the military decided to focus on that instead.

Which explanation is true?  Only the U.S. government know for sure.  Sixty plus years later, the reasons for the cancellation of the program, like the blueprints to the incendiary device itself, are still classified.

This entry was posted on Friday, March 26th, 2010 at 5:46 pm and is filed under Random Stuff. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

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