Blowing in the Wind

A remarkable tale – The Japanese Fu-Go

There are some remarkable stories from the WW2 period, and this is one of those. Who could have imagined that a few schools girls participated in the mass production of the world’s first Intercontinental ballistic missile? And who could imagine that one of those early ICBM’s very nearly derailed the production of the very bomb which later flattened Nagasaki and hastened the end of the WW2? Who would believe that these ballistic missiles were all transported without any rocket power from Japan to America’s West Coast? Well, there you go, that is what we will read about today and it is all about the Japanese Fu-Go bombs, a subject the Americans kept under tight wraps right through the war, so much so that even though many hundred balloons landed, only one newspaper report was published at that time.

So much has changed since the war and the world is a different place, many good things came out of it, but I guess those who lived through those harrowing years saw things in a different way. Anyway we have to start with the Pearl Harbor event when a surprise Japanese attack devastated the naval base in Hawaii on Dec 7th, 1941, drawing America into the war. The distances between mainland America and Japan were too great for retaliatory air attacks, and intercontinental missiles did not exist. But retaliation did occur and this was the ‘Doolittle raid’ carried out in April 1942 when 16 B-25 bombers took off from the USS Hornet positioned some 620 miles off Japan’s coast. The planes took off with an intent to bomb Tokyo and other industrial centers, without returning to their origin. 

The Japanese neither anticipated the raid nor detected the B-25’s as they swooped in and dropped some armaments on their targets, later flying on towards the Chinese mainland. None of these planes ever landed at the right destinations, but all the crews bailed out. It was not a very destructive mission, but it was one intended to strike a psychological blow and prove to the Japanese that they were not invincible. The Japanese lost a lot of ‘face’ in this incident and retaliated by attacking Americans near Midway islands but lost their naval carriers and the battle itself to some smart American air bombing.

Following this, the Japanese planned revenge and decided to attack the American mainland with a simple plan, launch balloons attached with incendiary and anti-personal bombs and land them in US cities and forests. It was easier said than done, with no precedence, and took two years of scientific work to create a solution. The concept was awe inspiring and its potential to start fires, even deliver chemical weapons with ease had the potential to affect US morale. Air raids happened usually after some advance warning, but balloon attacks would be silent, undetected by radar. The devilish concept had only one flaw, it depended entirely on what was not so well known to the rest of the world in those days, the existence of jet streams. The Japanese used the jet streams between Japan and America to swiftly deliver the balloons arbitrarily over 6,200 miles of ocean, to destinations on the US west Coast. The limitation was that these air flows occurred only during the latter half of the year when the US west coast experienced winter, and the forests were not necessarily dry enough for large forest fires. But let’s get to all that later.

The program was called the Fu-Go (it is assumed that Fu stood for Fusen meaning balloon). By March 1943, the first test balloons were tested, initially capable of covering some 600 miles, planned to be launched from submarines in the Pacific Ocean. During this period, they developed expansion valves to counter Hydrogen expansion and contraction due to day night temperature changes, but it was quickly clear that the subs were going to be diverted for other crucial purposes. The only method left was to use high speed jet streams 30,000 feet above, between Nov and March and the Japanese estimated that on an average they could achieve this transpacific flight in an average of 60 hours. The balloon size was fixed at 33 feet, and the skin was made up of glued layers of tissue paper. At its mouth, shroud lines supported a tray with the control mechanisms and the bombs, and a ballast comprising many sandbags dropped with explosive slugs triggered by slow burning fuse. 

The system itself was ingenious and some types battery operated and complete with telemetry, but I would rather not get into the finer details for they would quickly lull the lay reader into a deep slumber. The system also included a self-destruct mechanism after the balloon had completed its tasks and dropped the bombs. Two types were made, one made of paper, called Type A and a second by the navy using rubber infused silk, called the Type B, though the latter quickly became impracticable and unpopular with the scientists.

Mass production was the next challenge. The paper for the balloons came mostly from the kozo mulberry tree while the glue to stick paper layers came from a type of potato. Panels of paper so formed were glued to make the balloon envelope. All this work was done by some 150 plus Yamaguchi high school girls who were asked not to wear any hairpins, trim their nails and wear socks, and to work with gloves. After short class hours , they got together to prepare the balloons. The school girl team wore white head bands with the emblem ‘Student special attack force’. Even with this kind of raw material and labor, the cost of a balloon was still quite high, some $2000 each.

A regiment was formed and trained to launch the balloons from Honshu’s eastern shores. Between 3rd Nov 1944 and April 1945, close to 9,300 balloons were launched, lesser than the planned number of 15,000. Each balloon carried close to 35 kgs of bombs. A few balloons had radios instead of bombs, and they were tracked by a radio unit, but that was possible only for about 30 hours of flight and not beyond.

The first balloon was sighted by the US navy two days later floating in the Californian coast waters. Starting from the very first sighting, followed by many more and after analyzing its potential effect on population morale, America decided to clamp down on any press releases or reports on this new weapon, using strict censoring laws. It was a brilliant decision.

Perhaps due to lack of spies in US as most Japanese persons in US had been interned following the Pearl Harbor attack, the Japanese balloon team had no choice but to scan for newspaper reports to check how their weapons fared. No reports reached them. As it transpired, the balloons did not create any havoc and there was only one recorded case of causalities, in May 1945.

By Dec 1944, the US military had started analysis and potential countermeasures. Initially there was disbelief, thinking they were weather balloons off course since the payload was radio equipment, but once the bombs were noticed on some intact balloons which came down, they knew it was a brilliantly conceived weapon riding the high winds. A couple of projects were instated with planes (firing special bullets) and spotters to ensure detection of balloons before they entered the US and Canadian land borders. Fear of forest fires and the prospect of biological warfare agents prompted this. Analyzing the sand bag ballast, they quickly established that the balloons indeed originated from Japan.

Interestingly even in 1945, the concept of using Jet streams and the fact that it was seasonal was not well known in the US, despite Japanese scientist Ooishi’s published papers on the very subject dating back to 1925.

But one eager reporter did report a Dec 1944 incident at Wyoming and this was repeated in a Chinese newspaper which the Japanese obtained, amid much exultation. They gleefully published several false news articles aimed at their readers stating how the Japanese had achieved thousands of causalities with their balloon bombs, how they had started fires in cities and farms, and how they would execute the next plan of using balloons to send millions of Japanese troops to conquer America.

The Americans were busy on the other hand, perfecting their secret weapon to bring about an end to the war. The Western fronts were coming under allied control, the Nazi’s were being clobbered and it was time to bring Japan to their knees. The race to build the A bombs was on.

Brigadier General Leslie R. Groves, charged with the construction of industrial-size plants for manufacturing plutonium and uranium established the Hanford Engineer Works (HEW), codenamed "Site W". The B reactor manufactured by Du Pont went critical in Sept 1944 and the first batches of Plutonium was under production for a critical test being planned by Robert Oppenheimer and team at Los Alamos.

What followed relates to my field of work which is power systems protection and control. So, I hope you will forgive my enthusiasm with the forthcoming description.

The reactors housed at the Hanford facility were fed from the Midway 230/115 kV substation built in July 1942 located midway on the  double circuit lines from the Bonneville dam in Oregon and Grand Coulee dam in Washington terminating at this station. The substation is located near Vernita on the Columbia River Northwest of Richland. It was the existence of Midway s/s and the Bonneville-Coulee transmission lines which factored in the selection of the Hanford Site. By 1944, the Midway Substation began furnishing the Hanford Works with an estimated 75,000 to 150,000 kilowatts of electricity in what BPA personnel referred to as the "mystery load" because of the secrecy surrounding its ultimate use.

The HEW facility had been running round the clock and producing fissile material for the upcoming nuclear test. But what happened on March 10th, 1945 was totally unexpected, considering that the site was top secret and no laymen knew of the detailed goings on at Hanford, including its workers (some thought it produced toilet or sand paper, until its secret was revealed later in August).

Let us go to the operator on duty at Midway s/s who witnessed a fault occurrence. He recorded thus after carrying out what he had been trained to do.

1523 hrs, A66 Bonneville #2 line relayed H.Z relay on A phase, 2 zone C phase, 1 & 3 zone, Line dead. 1523 1/2 Line hot. 1524 Closed OCB A 66. 1525 Reported to dispatcher Kirkman, cause of trouble unknown

Without getting into engineering mumbo jumbo talk, I will explain what happened. A phase to phase fault on that power line, was picked up by the protective relay as it should, which then tripped the circuit breaker to clear the flow of fault currents. 30 seconds later, the remote end breaker which had tripped, was closed by BPA and a minute later, the Midway operator reclosed the local circuit breaker. The transient fault had cleared and things were back to normal on the high voltage lines. But due to the short system overload or disturbance, voltage relays at the reactor distribution system tripped, shutting down the plant.

At the HEW plant, it created a furor as the cooling systems shut down and the reactors SCRAM’d (emergency shut down). Furious telephone calls ensued between the top brass, nothing was recorded on paper while the reactors went out of service for an extended period. Some mentions can be seen that it took almost 3 days after the reactor’s shutdown, before they could get them back to normal production, though the largest of the three reactor outages was not more than 68 minutes.

Capt. Johnson reported to his boss Col. Mathias the same day of a statement from the FBI Agent in Yakima, WA, detailing that a farmer living approximately 15 miles south of Toppenish, WA, had reported that a balloon had struck a High Voltage line running across his property at about “3:30 PM.” Upon striking the wires, the balloon burst into flames. It was later concluded that this fault was, indeed, the 1523 hours event logged at Midway (But fortunately the balloons did not explode).

Col Mathias recollected thus in a 1986 interview to SL Sanger - Well that was enough, we had it rigged you know. If the power went off, the emergency rods that were suspended above the pile through a series of wells would drop down in and with the cobalt just knock out the radioactivity and the flux. And it shut down the reactor. And when I read about it the next day, I was delighted. They found out the reason was they knew what had happened and started the thing up again. It took about three days to get up to full speed again. But we never had guts enough to test that under a full load. We did not know for sure that that device we had as an emergency shutdown would work. So, this proved it for us. It did work. And I used to say, this is the first damage done by direct enemy action in this country.

The Japanese had struck a critical military installation, albeit unintentionally, at just the right time, but only just so and with little impact. Nevertheless, they would not find out that this had happened, it was not mentioned or investigated.

It was not the only balloon to land near HEW. A second balloon landed nearby, the very same day, two hours later in what was termed as the ‘Cold creek landing’. Quoting Burt Pierard who still conducts tours at the plant - one Hanford Security Patrolman and one U.S. Army MP whipped out their pistols and mercilessly gunned down a helpless, landed Japanese Balloon (although it was being dragged by the wind across the ground toward the same Transmission Line involved earlier).

The balloon settled down about 5:51 PM at a spot ¾ mile west of the Yakima Gate and ¼ mile south of the old highway 11A (Highway 24 today), near the headwaters of Cold Creek. The previously mentioned patrolman and MP were 2 of the first 3 people to arrive at the scene and observed the balloon dragging its apparatus toward the power line so they used their guns to deflate it. They then took up positions 300 yards away to keep other arriving personnel away and organize them into a circular guard position. They also had several workers heading home who stopped to see what was going on and were encouraged to move on and say nothing to anyone else. They held these positions until the Army arrived to take over, at about 8 p.m.

The Hanford works, surviving the ICBM balloon attacks, chugged on through the rest of the war, doing what it was meant to do, produce fissile material for A bombs. America was however worried that some of these balloon bombs might by sheer coincidence, land on critical targets such as the Boeing factory 200 miles farther in WA and hastened watches and counter measures as we read previously.

On the very same day, 10th March 1915, Americans commenced firebombing Tokyo (Operation Meetinghouse). Approximately 15.8 square miles of Tokyo was destroyed, and some 100,000 people are estimated to have died in the operation. Sixty-three percent of Tokyo's commercial area, and 18 percent of its industry, was destroyed. An estimated 267,000 buildings burned to the ground.

On 5 May 1945, five of his children and Elsie, the wife of Rev Michel were killed near Lakeview, Oregon, by a balloon bomb which exploded as they dragged it from the woods. That was the first and last case of human causality due to the balloon bombs.

The balloon attacks stopped abruptly in May. After the war, the US rounded up many of the people behind the program and it became apparent that Hydrogen plants had been hit by American bombing in the first place, secondly there were paper shortages and finally they concluded that the entire Fu-Go program was continued only to keep the baying domestic populace in Japan satisfied of Japanese retaliation underway, after the humiliating Doolittle raid and more recent air raids. As the attacks in Japan increased, all focus was directed towards defending Japan while the Fu-Go operation tapered off and died.

From 4th November 1944 to 8th August 1945, 285 balloon "incidents" were recorded, including 120 balloon recoveries; 32 balloon recoveries including bombs; 20 balloons downed but not recovered; 28  independent bomb incidents; and 85 related incidents. Though brilliant in concept, the initiative failed as the balloon was an uncontrollable weapon. Some balloons are still out there in the deep forests and potentially active, one was discovered as recently as 2014. The NY times statement though ironic was on the dot, they said - For once the American kept their mouths shut. Japan was kept in the dark about the fate of the fantastic balloon bombs because Americans proved during the war they could keep their mouths shut. To their silence is credited the failure of the enemy's campaign.

In July 1945 the Trinity experimental nuclear explosion test was conducted, successfully using the HEW manufactured plutonium. Dr. Oppenheimer, on whom had rested a very heavy burden, grew tenser as the last seconds ticked off. He scarcely breathed. For the last few seconds, he stared directly ahead and then when the announcer shouted "Now!" and there came this tremendous burst of light followed shortly thereafter by the deep growling roar of the explosion, his face relaxed into an expression of tremendous relief.

He explained later quoting the Bhagavad Gita - I remembered the line from the Hindu scripture, the Bhagavad Gita; Vishnu is trying to persuade the Prince that he should do his duty and, to impress him, takes on his multi-armed form and says, 'Now I am become Death, the destroyer of worlds.' I suppose we all thought that, one way or another.

The B reactor then produced the required weapons grade Plutonium for the ‘Fat Man’ Nagasaki bomb. On August 6th 1945, a modified B-29 dropped the uranium (from the Oak Ridge works) based "Little Boy" on Hiroshima. Another B-29 dropped the plutonium based "Fat Man" on Nagasaki three days later. The bombs devastated their targets. Japan surrendered to the Allies on August 15th, six days after the Soviet Union's declaration of war and the bombing of Nagasaki.

The real reason for the surrender may not have been the bombs themselves, and we can discuss this another day. But imagine for a moment the consequences, if the balloon had landed by chance on the top secret Hanford plant and its breeder reactors!

Japan's H World War II Balloon Bomb Attacks on North America - Robert C. Mikesh
Hanford B reactor museum association – Newsletter, Vol 20, issues 1 & issue 2 - 2014, Burt Pierard’s articles  - Midway s/s, Japanese balloon bombs
Fu-Go - The Curious History of Japan's Balloon Bomb Attack on America - Ross Coen
Manhattan, The army and the atomic bomb – Vincent C Jones
Power to the People: Construction of the Bonneville Power Administration's 'Master Grid', 1939-1945 - Craig Holstine (The Pacific Northwest Forum Second Series Volume I, Number 2, Pages 35-46 Spring, 1988)

With special thanks to Burt Pierard and his paper on the March 10th event and the BPA network.

Note: Jet streams as I understood, blow in narrow bands with widths of a few hundred miles and thicknesses of less than 3 miles. You will observe that they blow from west to east due to Earth's west-to-east rotation, combining with its north-south temperature gradients. Commercial aircraft may opt at times to ride a jet stream and reach their Eastern destinations faster, using less fuel. But there are some problems as well, a consequence of encountering edges of a jet stream is what is known as clear air turbulence or CAT. The great circle route in the picture is the shortest air route between Japan and US.

The eccentric Japanese scientist Wasaburo Ooishi, who discovered it, chose to publish his many papers on the subject in the Esperanto language, which was unpopular and hardly understood those days. Jet streams were researched and re-documented by others, after the war towards the 60’s. For details, read OOISHI'S OBSERVATION - Viewed in the Context of Jet Stream Discovery, BY JOH N M . LEWIS

Midway s/s 1945 -, courtesy vintage tri-cities
Fu-Go Balloon bomb, Jet streams – Wikipedia