A Radar History of World War II: Technical and Military Imperatives

Louis Brown

IOP, Philadelphia, 1999. 563 pp. $38.00 hc ISBN 0-7503-0659-9

When World War II is called "the physicists' war," the image evoked is of the mushroom cloud over Hiroshima. But nuclear weapons merely administered a horrific coup de grace to an already-defeated enemy. Radar, on the other hand, played a pivotal role in key battles that turned the tide of war in favor of the Allies, and for that, too, physicists can claim a fair share of the credit. Louis Brown, a nuclear physicist at the Department of Terrestrial Magnetism of the Carnegie Institution in Washington, DC, offers in this book a compendious and scholarly history of the development of radar.

The idea of using radio waves for echolocation dates back to the early years of the twentieth century, but it was not until the mid-1930s that all the key elements were in place: transmitters and receivers in the meter-wavelength band, modulators capable of generating microsecond pulses, and high-speed cathode-ray tubes to display the results. Most of these developments were byproducts of civilian work on broadcast television. At that time, laboratories in the US, Britain, Germany, and the USSR had all begun radar experiments on a modest scale. Japan did not take notice until 1941, but then hurried to catch up. As a result, all of the principal belligerents in the war entered it with some capability in radar.

Only Britain, however, had thought through the tactical use of radar in a real battle situation. This was a product of the vision of Air Vice-Marshal Hugh Dowding, who conceived a system based on the "Chain Home" (CH) radar network, linked to filter centers that evaluated the picture and relayed it to the fighter squadrons within minutes. Although many factors played a role in the 1940 battle of Britain, Brown concludes that in this closely-fought combat the British edge in radar proved decisive. He feels, however, that radar has been given too much of the credit for Allied victory in the antisubmarine battle of the Atlantic. In the naval war in the Pacific, though, it gave the US Navy a significant advantage.

CH was obsolescent from the day it was installed, in comparison to the meter-wave equipment already available in the US and Germany at that time. CH operated in the 10­15-meter band, which cursed it with poor resolution and high noise levels. This was a consequence of the technological conservatism of Robert Watson Watt, the British physicist who headed up its development. Watt chose to go for, as Brown reports, ". . . third best, because second best takes too long and best never comes." But second best, meter waves, was already available from Britain's EMI television laboratories, and best came as soon as 1940, with the development of the cavity magnetron. This device had been independently invented (but not exploited) a few years previously in the USSR, Switzerland, and Japan.

With Britain's limited resources fully committed, a fateful decision was made to bring the US into the picture via the celebrated "black deed box" that carried a magnetron across the Atlantic in September 1940. The Americans moved quickly. The Radiation Laboratory opened in 1940 at MIT under the leadership of Lee DuBridge. A staff was hastily recruited, much of it from the nuclear physics community, and work began by mid-December. Within three months an airborne prototype was flying. Close cooperation with the existing radar programs of Bell Laboratories, the Army Signal Corps, and the Naval Research Laboratory created a formidable presence in radar development.

Complementary to the radar effort was the push for the proximity fuse, essential for effective antiaircraft fire. Work on the fuse began at the Carnegie Institution under the leadership of Merle Tuve. As the work expanded, it came under the aegis of Johns Hopkins University, creating the Applied Physics Laboratory. By war's end over 22 million fuses had been produced, at a final unit cost of only 18 dollars.

By 1943 the Allies could call upon a wide variety of radars specialized for early warning, battle management, airborne search, night interception, bombing, and gun aiming. At the start of the war, antiaircraft batteries had to expend more than ten thousand rounds for every plane they brought down. By its end the combination of the Rad Lab's tracking radar, Bell's electronic analog gun director, and the proximity fuse assured that once a hostile aircraft was locked in a radar beam, its fate was sealed.

Germany offers a case study in squandered opportunity. By 1938, meter-wave radars of excellent quality were available, largely developed in private industry and sold to the armed forces. But it took a long time for radar to gain acceptance from the High Command. Hitler and Göring disdained it as a mainly defensive weapon. Besides, they harbored a deep mistrust of scientists and engineers. Interservice rivalries and the hidebound traditions of the officer corps also hampered progress. It was not until 1944 that an air defense system as effective as Dowding's went into operation in Germany, and a few months later it was trumped by the arrival of long-range fighter escorts.

The USSR may well have had the lead in radar technology in 1934. But this advantage was dissipated through bureaucratic fragmentation, disinterest at the top, and the disappearance of key personnel in the purges of the late 1930s. Crude early warning radar did play a role in the air defense of Leningrad and Moscow. In any event, however, radar could have had little impact on the titanic land battles that ultimately crushed the German war machine.

Wartime radar work brought significant peacetime dividends. New hardware and manufacturing capacity facilitated the rapid spread of television, FM radio, and VHF and microwave communications. Radar itself made all-weather air and sea travel routine. And today most kitchens in the developed world boast a cavity magnetron, dedicated to such mundane tasks as warming up leftovers.

Brown provides an excellent appendix, outlining the scientific basis of radar in terms a lay reader can easily comprehend. Unfortunately, the writing of the main body of the text is of uneven quality, occasionally marred by mangled sentences and misused homonyms. For this I must fault the publisher more than the author: The computer has not yet rendered redundant the honorable profession of editor. A work of this importance deserved more careful treatment. Nevertheless, Brown tells a fascinating story, and this book can be hard to put down.

Robert H. March
University of Wisconsin
Madison, Wisconsin

The Invention That Changed the World: How a Small Group of Radar Pioneers Won the Second World War and Launched a Technological Revolution by Robert Buderi. Touchstone Books, 1230 Avenue of the Americas, New York, New York 10020, 1997, 575 pages, $16.00 (softbound).

The terms military technological revolution and revolution in military affairs are popular in Air Force and Department of Defense journals. Many pundits subscribe to a belief that revolutions drive rapid increases in military capability. Others rely on the position that all technological changes are merely evolutionary in character. For readers of either disposition, it is indisputable that the invention of radar and its incorporation in air combat in World War II was a significant, if not pivotal, step in changing the nature of warfare.

The Invention that Changed the World does a fine job in tracking the creation and integration of a rather remarkable device frequently taken for granted: radar. Buderi, a former technology editor for Business Week and author of articles found in a variety of magazines, wrote this book with a style that reads more like a story than a detailed historical analysis. This makes his work, though containing an extensive bibliography, difficult to cross-reference due to the lack of footnotes. However, it remains an enjoyable and a rich account of scientific history that is accessible to a variety of audiences.

Most interesting for airmen and military enthusiasts alike is Buderi’s tale of the personalities and innovations that led to successful integration of radar into combat applications. Featured prominently in his World War II discussion of radar development were the scientists of the Massachusetts Institute of Technology’s Radiation Laboratory, the “Rad Lab.” Tracing the interactions of the principal scientists, Buderi illuminates an interesting historical case study for civilian-military cooperation in the development of war-fighting technologies. Unfortunately, he tends to oversell their impact on the war effort with his assertion that this “small group of radar pioneers won the Second World War.” Although a significant contributor to the greater war effort, neither the quality nor the quantity of radars in World War II supports the absoluteness of Buderi’s bold proposition that the “Rad Lab” scientists won the war.

Buderi better supports his proposition that the radar scientists helped launch a technological revolution. If a military technological revolution is a terrific leap in war-fighting capability, the institution and operational testing of radar in World War II certainly showed hints of an emerging “revolution.” In World War II, night-radar intercepts, early radar warning, and pathfinder bombers blazed the trail for more dramatic contemporary capabilities. For example, radar has made possible all-weather flight, stealth, terrain-following at night, and a host of other military and aerospace applications that arguably have now changed the nature of war to truly be a 24-hour-a-day enterprise. Moreover, the civilian spin-offs have had tremendous impact in scientific and commercial applications.

Overall, Buderi’s The Invention that Changed the World is a well-written and entertaining story of technology development with many implications for Air Force readers. He blends his tale of history, civil-military affairs, and human interaction in an entertaining yet not oppressively academic fashion. Though a bit oversold, many of the individuals whose stories are recounted in this book truly made an outstanding and long-lasting impact. Was radar a harbinger of a technological revolution—or was it simply a product of evolution? You decide.