War Through the Eyes of NBS (Room 1)

Besides the Bat Missile, NBS was involved in an assortment of other important military technology developments during World War II. This room seeks to provide brief glimpses of some of the other influential projects NBS participated in.

NBS began its war-related research as early as summer 1939, when NBS Director Lyman J. Briggs sent a memorandum to the Department of Commerce describing the services the Bureau could render "in the event of war." In fact, 90 percent of the Bureau's staff was already involved in war-related research when the Japanese attacked Pearl Harbor.

President Roosevelt authorized the creation of two significant organizations between 1939 and 1941:

• the National Defense Research Committee (NDRC)
• the Office of Scientific and Research Development (OSRD)

For the duration of the war, these two bodies assigned many of the Bureau's projects.

NBS's most high profile work centered around four distinct projects: the Atomic Bomb, the Radio Proximity Fuse, "Radio Weather," and development of the Bat Missile.

During the war years, NBS was located at its northwestern Washington, D.C. campus. Its average staff of 2,300 worked in some 20 major and 60 minor buildings. Pre-war laboratory work halted in many cases, as space was cleared to begin new military projects. New divisions were formed in collaboration with Navy and other military personnel.

NBS and the Atomic Bomb

NBS played a critical role in the initial steps of the Atomic Bomb project. In 1939, President Roosevelt appointed Lyman Briggs head of the committee responsible for investigating the possibility of utilizing the atomic fission of uranium in warfare. From that point until 1943, Briggs headed or was a member of the highest Atomic Bomb-related committee in the country.

Over the course of the war, 60 Bureau staff members engaged in work directly related to the Atomic Bomb project. Interestingly, the Bureau's involvement in this project was kept a complete secret from the non-associated Bureau members. In fact, because of the need for high security, the Bureau's annual reports during the war years excluded several dozens of projects. The official (and equally valid) reason for the decision offered by the Department of Commerce said annual report printing was cut back in order to save paper, manpower and printing funds.

NBS was involved in many phases of the project. It helped to devise improved ways of removing impurities from uranium and graphite. By removing the impurities, scientists could more effectively bombard the uranium with neutrons and set the chain reaction of molecules into action. NBS served as the project's central control laboratory for determining the purity of uranium used in the project and performed thousands of chemical and spectrographic analyses in the course of this work. NBS also developed the technique of "liquid thermal diffusion" for separating uranium isotopes.

The Radio Proximity Fuse

Through experience in World War I, the U.S. military recognized a bomb's explosion coverage increased dramatically when detonated a close distance above a target, rather than upon impact. In addition, many types of cover, such as foxholes and trenches, were more vulnerable in the case of air-bursting projectiles.

In late 1940, The National Defense Research Committee assigned to NBS the task of developing a fuse that would detonate a non-rotating projectile (such as a bomb, rocket, or mortar) when the projectile had come within a close proximity to its target. In December of that same year, eight NBS staff members began working on the project. Incorporating help from academic and private industry circles, NBS work on the proximity fuse would grow to incorporate more than 400 people.

This type of fuse is essentially a tiny radio sending and receiving station about the size of a 100-watt light bulb. When in operation, it continuously sends out radio waves. When the waves approach a sizable object - a ship, plane, building, other structure, or even open ground - they are reflected back to the fuse's receiver. As the projectile nears the object, the waves reach a sufficient intensity to indicate the object's effective proximity. The radio waves then operate an electronic switch, detonating the fuse and projectile above the object.

Development took the entire first half of World War II. Cautious of its new technology, the United States Military was determined to keep the fuse out of enemy hands. The first proximity fuses were used by fighter planes in early 1943 in the Pacific Theatre because there the projectiles were unrecoverable. The fuse was not cleared for general use in combat until December 1944.

The first major combat use of proximity fuses was during the pre-invasion bombardment of Iwo Jima in 1945. It was spectacularly successful, proving to be 5-20 times more effective than a projectile fitted with a timed or contact fuse. The fuse was altered to fit several types of artillery, and by the end of the war, more than 8 million fuses were produced.

NBS and the Radio

Aiding U.S. war efforts was not a new role to NBS. In World War I, the Bureau performed multiple research tasks, including extensive radio research. This work in the radio field produced two famous publications:

• An elementary textbook titled The Principles Underlying Radio Communication
• A radio reference book titled Circular NO. 74, Radio Instruments and Measurements

In the second Great War, NBS was at the radio research forefront yet again. While the work during World War I was more basic in nature, the work during World War II focused on radio propagation and ionospheric data issues.

The National Defense Research Committee appointed NBS to work on radio propagation in 1941 by assigning the Bureau two projects:

• a study of the correlation of direction-finder errors with ionospheric conditions
• the preparation of a "radio transmission handbook" to permit usable frequency calculations

NBS assigned L.B. Heilprin to the correlation task and Newbern Smith to the handbook task.

In 1942, the Combined Communications Board of the Combined Chiefs of Staff in Washington, DC created the Interservice Radio Propagation Laboratory and placed its headquarters at NBS. The duties of this new lab were:

• to centralize and disseminate all ionospheric and radio propagation data for the U.S.,
• to operate and sponsor operation of such ionospheric stations as were necessary to obtain the data,
• to cooperate and collaborate with the radio propagation organizations of other countries of the United Nations,
• to issue radio propagation information and predictions for the use of the armed forces and other cooperating agencies of the United Nations
• to train personnel of the armed forces in the use of ionospheric and propagation data
• to make special propagation studies and solve specific problems upon request

Besides these tasks, NBS scientists expanded their radio research into other realms. During this time, advances were made in microwave standards, radar countermeasures and wind measurement. NBS' involvement in the Interservice Radio Propagation Laboratory lasted for the duration of the war. next>>

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date created: May 21, 2001
date revised: October 18, 2004