Fixing the Sky

by James Rodger Fleming

  Reminiscent of the later distinction between cloud physics and weather modification—perhaps also between basic research and practical applications—MIT researchers were quick to point out that fog research, not fog control, was their ultimate aim: “The end result, whatever the practical application of local fog dissipation, has been a substantial increase in knowledge of the physical properties of fog and of the means for conveniently determining these properties, as well as a more thorough quantitative knowledge of the transmission of electromagnetic waves through fog, whether they be radio, light, or long infrared.”37

  Still, the list of institutions acknowledged for their support in the MIT report reads like a who’s who of the military–industrial complex in 1934: Colonel Green for the use of his estate; the American Philosophical Society for a research grant; and the U.S. Navy Bureau of Aeronautics, the U.S. Army Air Corps, and the Bureau of Air Commerce of the Department of Commerce for their support. Huge amounts of chemicals were provided free of charge by the Michigan and Columbia alkali companies and the Dow Chemical Company. Edison Electric of Boston lent the experimenters a large power transformer. This combination of government, commercial, and private philanthropic support was part of a persistent pattern of patronage (6–7).

  It is undoubtedly true that a 30-foot-high barrier made of metal pipes and stretched across a runway is dangerous to airplanes landing and taking off, especially in conditions of low visibility. Houghton’s chemical mix, although promising, was also impractical, being dangerous and corrosive. More substantial was his basic research on the formation and evaporation of small droplets, on the optical properties of fog, and on the search for possible hygroscopic chemicals to disperse it. Houghton’s greatest contribution, however, involved the idea that cloud physics research, as distinct from but related to operational weather modification, had a place in the modern university.

  FIDO: A Brute-Force Method of Fog Dispersal

  Foggy weather kept aviators grounded in World War I, but by 1921 British meteorologist Sir Napier Shaw discussed the possibility of clearing fog at an airfield by heating it, concluding, “I would not like to say it is impossible with unlimited funds and coal.” He noted, however, that “air in the open is very slippery stuff and it has all sorts of ways of evading control that are very disappointing.” 38 Professor Frederick A. Lindemann (later Lord Cherwell) agreed with Shaw and chose to emphasize blind landing techniques. Other possibilities, although none of them were proved, included sprays of electrified water, air, or sand (Warren), chemical treatments (Houghton), vigorous fanning, and coating rivers with oil. Yet the brute-force technology of heating the runway was the only one certain to work—although it appeared at the time to be prohibitively expensive.

  In 1926 Humphreys estimated that it would require the combustion of 6,600 gallons of oil (or 35 tons of coal) an hour to clear a layer of fog about 150 feet thick from a typical airfield—a cost that he deemed far too large. David Brunt, Shaw’s successor at the Imperial College of Science and Technology, revisited the issue in 1939. He estimated that clearing a layer of fog about 300 feet thick would require an average temperature increase of 3.5°C (6°F) (twice this at the ground) and suggested that smokeless burners supplied by an oil pipeline along an airfield could be designed to do the job. Brunt’s ideas were field-tested in the winter of 1938/1939, but the results were not promising.39

  As World War II escalated, fog became an obstacle to successful bombing raids. With more raids scheduled, a surging accident rate, and the large number of flying hours lost to fog, the problem became one of “extreme urgency.” In 1942 Prime Minister Winston Churchill directed his scientific adviser, Lord Cherwell, to address the matter and issued the following statement: “It is of great importance to find means to disperse fog at aerodromes so that aircraft can land safely. Let full experiments to this end be put in hand by the Petroleum Warfare Department with all expedition. They should be given every support.”40

  Under the leadership of Britain’s minister of fuel and power, Sir Geoffrey Lloyd, and Major-General Sir Donald Banks, the scientific research establishment and industry joined forces to tackle the problem. The Petroleum Warfare Department (PWD), an agency created in 1940 to consider “the possibilities inherent in the use of burning oil as an offensive and defensive weapon in warfare,” was charged with developing a reliable, if expensive, brute-force method of clearing fogs over airfields, a system it called Fog Investigation and Dispersal Operation. FIDO was one of the most spectacular but least publicized secret weapons of the war. According to Banks, “We had been making vast preparations to cook the Germans. We would see whether we could cook the atmosphere!”41

  It was a massive undertaking. The FIDO project brought together pilots, engineers, fuel scientists, industrialists, government bureaucrats, and meteorologists. Given the urgency of the situation, normal research and development plans were shelved in favor of an all-out attack by research teams from the National Physical Laboratory, Imperial College of Science and Technology, Royal Aircraft Establishment, Armament Research Department, and such industries as the Anglo-Iranian Oil Company, Gas Light and Coke Company, General Electric, Imperial Chemical Industries, London Midland and Scottish Railway, and the Metropolitan Water Board. According to Lloyd, the project director, “each was told to get on with the job with the fullest support and freedom of action.”42

  First Successful Tests

  FIDO consisted of a system of tanks, pipes, and burners surrounding British airfields and designed to deliver petroleum that, when ignited, raised the ambient temperature by several degrees—enough to disperse fog and light the way for aircraft operations. The first large-scale test of a FIDO system was conducted in a field and did not involve aircraft takeoffs or landings. With strong radiation fog predicted for the morning of November 4, 1942, the FIDO team assembled at Moody Down, Hampshire. An 80-foot fire escape ladder was positioned between two FIDO burners 200 yards in length and 100 yards apart. As a local fireman climbed to the top of the ladder, he disappeared into the fog. When the burners were lit, the fog began to clear and the fireman came into view. To verify the result, the burners were turned down and the fog reappeared. The burners were again ignited, and the fog dissipated. With typical British reserve, it was reported that Lloyd “almost whooped for joy” (emphasis added).43

  On the same day, experiments were also conducted at the airfield in Staines, Surrey, using coke-burning braziers shuttled by miniature rail cars along tracks paralleling the runways. While an even denser fog was cleared with less smoke, the coke took longer to light and required more effort to replenish. Gasoline was much easier to pipe to airfields and ultimately became the fuel of choice for FIDO. The urgency of the situation did not allow much time for further experimentation and research. As a result, the petroleum burner setup at Graveley airfield, Hertfordshire, served as the prototype for other FIDO systems ultimately installed at fourteen Royal Air Force (RAF) fields.

  On February 5, 1943, Air Vice Marshal Donald C. Bennett landed a Gypsy Major at Graveley in a midday FIDO light-up. Thirteen days later, in the first night test, he again landed, in a Lancaster. Although it was not foggy, visibility was poor. Bennett recounted seeing the blazing runway when he was still 60 miles out. As he made his approach, he recalled, “I had vague thoughts of seeing lions jumping through a hoop of flames at the circus. The glare was certainly considerable and there was some turbulence, but it was nothing to worry about.”44 Except wildfires. A demonstration test for aircrews on February 23 resulted in grass, hedges, trees, and telegraph poles near the burners going up in flame. All hands, in addition to local bomb spotters and fire companies, were called in to fight the blaze. The first opportunity to land an aircraft in actually foggy conditions occurred in July 1943. A thick fog, approximately 300 to 400 feet deep, blanketed the runway, with visibility less than 200 yards. The FIDO burners were lit at five o’clock in the morning, and within seven minutes, an area 1,500 yards long and 200 yards wide was clear
ed of fog. Aircraft were then able to land successfully at fifteen-minute intervals.45

  The futurist Arthur C. Clarke once witnessed a FIDO test in Cornwall:

  The runway was lined on either side with a double row of pipes—four or five miles in all—which conveyed gasoline to long rows of burners. When they were in action, they consumed fuel at the awesome rate of 100,000 gallons an hour and formed multiple walls of flame the full length of the runway.

  At night, with the fog rolling in from the Atlantic, a FIDO operation was like a scene from Dante’s Inferno. The roar of the flames made speech difficult; such an updraft was created that small stones on the edge of the runway were picked up and tossed around by the air currents. The yellow walls of fire, taller than a man, stretched away into the foggy night as far as the eye could see. The miles of burners pumped heat into the air at the rate of 10 million horsepower, cutting a long, narrow trench through the fog down which the retuning bombers found their way to the ground.

  I have known nights when the fog was so thick that visibility was less than ten feet; but standing in the middle of the runway, with the flames roaring on either side, you could see the stars shining overhead. FIDO worked by brute force, and the development of radar made it obsolete, but it did show what could be done if the incentive was sufficiently great.46

  The view from the cockpit was especially exhilarating. Although airmen were thankful for the safety that FIDO provided, they described their first experiences of landing between FIDO burners as frightening. One veteran pilot, echoing Clarke’s description, likened it to a descent into hell, remarking that it seemed as if he “was over [the enemy] target once more ... [and] that the whole place must have caught on fire.”47

  FIDO Becomes Operational

  FIDO actually worked. It allowed British and Allied aircraft to take off and land in conditions of poor visibility when the Germans were grounded (figure 4.6). The urgency that Churchill demanded had been met, and FIDO was quickly serving the duty of guiding RAF and Allied airmen home safely. Pilots returning to foggy England after a mission could see the airfield glowing in the distance, beckoning them home to a lighted, fog-free airport. They could also save valuable time getting their shot-up planes and exhausted (and possibly wounded) crews on the ground. Because of FIDO, the Allies could launch patrols and air raids and return their planes safely when enemy aircraft were grounded due to poor visibility. RAF Coastal Command aircraft on anti–U-boat patrol used FIDO frequently. On one occasion, a lost Lysander aircraft landed on a runway that had been cleared of fog. When FIDO was turned off, fog once again enveloped the aircraft. Reportedly, the pilot wandered across the tarmac for quite some time before finding the control tower.

  4.6 Boeing B-17 Flying Fortress, 493rd Bomb Group, landing in England with the aid of FIDO, November 16, 1944. Note the giant flames behind the airplane. (NATIONAL ARCHIVES PHOTO A9004, DETAIL)

  The success of FIDO was presented to a war-weary public as almost a miracle. Newspapers proclaimed it as a lifesaver and a triumph for British aviation. Those involved in administering the project credited FIDO with shortening the war and saving the lives of up to 10,000 airmen. Military historians are fond of invoking “the fog of war” as they struggle to reconstruct events. In the case of England, the fog was literal. An ice fog persisted during the opening days of the Battle of the Bulge, when FIDO supported Allied aviation. But during the long campaign, the weather cleared and much of the tactical air support came from the Continent, not England. Thus contemporary evaluations of the overall success of FIDO in “shortening the war” may have been somewhat optimistic and self-serving.48

  The Aftermath of FIDO

  FIDO proved to be one of the innovation success stories of World War II. It was a crash research program that became operational; it saved lives and equipment; and it definitely gave the edge to Allied aviation during the last two years of the war. But FIDO was feasible only under the desperate conditions of wartime. Bomber Command, its chief beneficiary, credited it with introducing a “revolutionary change in the air war,” but its success was never replicated. When the FIDO system was ignited at an airfield, up to 6,000 gallons of gasoline were burned during the time required to land one aircraft. By comparison, a Mosquito bomber might burn between 10 and 20 gallons of fuel during its landing approach. It is estimated that during the two and a half years that FIDO was in operation, airfields that used it consumed a total of 30 million gallons of gasoline. Such expenditures were justifiable only when national survival was at stake. Ironically, FIDO’s success was due in large part to the brilliant but modest British defense engineer Guy Stewart Callendar, who was the first scientist to attribute the enhanced greenhouse effect to the burning of fossil fuels, who designed key components of the system (including the trench burners), and who was one of the patent holders on the massive FIDO fuel burner.49

  After the war, a FIDO system was planned for London’s Heathrow Airport, but it was never installed. For a time, FIDO systems were maintained at the Blackbushe and Manston RAF bases, but according to one 1957 estimate, the cost of running a FIDO installation was prohibitively expensive—₤44,500 an hour. Experiments using jet engines installed along runways to heat and disperse fog at Orly Airport near Paris and in Nanyuan, China, met with mixed results. The main technique for dealing with fog, developed after the war, was not weather or cloud modification but the widespread use of instrumented landing techniques.50

  The Airs of the Future

  On July 11, 1934, Willis R. Gregg, chief of the U.S. Weather Bureau, presided over the dedication ceremony at the air-conditioned house at the Century of Progress World’s Fair in Chicago. It was the Midwest’s hottest summer to date, with temperatures that day in St. Louis reaching 100°F (38°C), but Chicago, cooled by a breeze from Lake Michigan, reached only a moderate 82°F (28°C). It was a dust bowl year, with little rain and the average regional temperatures soaring 5 to 10 degrees above normal. Gregg’s theme, broadcast over NBC Radio, was weather control, and he began by discounting the “fantastic methods” of the professional rainmakers “who have boasted of their abilities to end drouths by the simple expediency of setting off a few explosives,” or of those charlatans who “would mount receptacles containing small quantities of chemicals on poles or platforms in the vicinity of the drouth stricken areas, and then trust to the law of averages and Old Mother Nature to come through with rain at the psychological moment so they may collect rain-making fees.”51 He deemed the prospects for controlling outdoor weather “rather slim” for a great many centuries to come.

  Gregg’s focus was on the control of indoor weather, on display that day in the air-conditioned house, where there was “no necessity for suffering from weather discomforts.” Of course, indoor air-conditioning really began before recorded history, when people sought shelter from the storm to keep them dry and warm. Roofs, doors, windows, screens, fireplaces, stoves, and furnaces function either to keep out undesirable elements like rain, wind, and pests or to allow in or provide desirable elements such as shade, light, and heat. In hot climates, traditional practices of ventilation and evaporative cooling have long served to moderate heat, if not moisture. The inner atmosphere of the show house of 1934, however, had been refrigerated and dehumidified by mechanical means, the science of thermodynamics, the engineering that has come to be known as HVAC, and the power supplied by electricity. According to Gregg, conditioning this indoor air was solving “the one thing that actually has the most lasting effect upon the human body and human activity—weather, if only in a small way.”52 Gregg, speaking from the front porch of the house, speculated about the possible, if impracticable, project of refrigerating an entire city mechanically, but he did point out, prophetically, that air-conditioning would allow cities to expand in areas formerly considered too hot for comfort. He might be amazed today to see air-conditioned mega-malls and domed stadiums, but not really, since even then air-conditioning was becoming more and more popular. On his inspection tour out west, t
hrough the dust bowl region, Gregg, at least on occasion, traveled on air-conditioned trains, slept in air-conditioned hotels, and ate in air-conditioned restaurants. He spoke of air-conditioning in relief of hay fever and of living in it from cradle to grave, citing the hospital incubators supporting the Dionne quintuplets, born in May of that year in Canada, and the growing trend for air-conditioned funeral parlors. His weather bureau office in Washington, D.C., however, was not air-conditioned; it had high ceilings and fans that helped alleviate the oppressive heat somewhat. The federal government followed liberal leave policies during heat waves.

  But what about the outside air? In the summer of 1938, Gregg sent letters to his colleagues asking them to speculate on what the meteorological profession might look like in fifty years. Most of the responses focused on scientific and technological advances in forecasting. Some emphasized the growing importance of upper-air measurements using radiosondes and broadcasts that would allow “records to be flashed to all parts of the world.” Charles Franklin Brooks foresaw remote sensing of the atmosphere using ultra-high-frequency radio transmissions. J. Cecil Alter suggested that “sky-sweeping robots of electric eyes will explore the upper atmosphere for air mass demarcations, depths, direction and velocity movement, moisture content, and other factors. Zigzag tracings or photographic replicas, automatically registered, will be made of the shape of the course of the refracted ray from the electric eye, as it passes through different air masses.”53 Humphreys wrote of “robot reporters—instruments that not only keep a continuous record of the weather elements, but which, at the touch of a button, or automatically at regular intervals, also tell all about the weather there at the time” (215). These predictions were largely realized through the development of weather radar and other forms of remote sensing. Also, in 1939, George W. Mindling foretold, in doggerel, of the “coming perpetual visiontone show” of perfect surveillance and perfect prediction using television and infrared sensors, a technology instituted in the TIROS (Television Infrared Observation Satellite) meteorological satellite program in 1960: