Measures for Progress: A History of the National Bureau of Standards

THE RADIO PROXIMiTY FUZE 393
Actually, tests of two fuzes were made at that time, the radio fuze
developed by Diamond and Hinman's group and the photoelectric fuze by
Taylor and Astin. Functionally, the photoelectric fuze was excellent.
Equipped with a photoelectric cell and lens and triggered by its sensitivity
to changes in light intensity, the fuze detonated its projectile when an object
passed between a portion of the lens and the sky. Drawbacks of the fuze
were its dependence upon light, making it useless at night, and its tendency
to anticipate its target as sunlight moved into and out of the lens. With the
help of the Bell Telephone Laboratories, methods for solving both difficulties
were found, but the success of the radio fuze finally led to suspension of the
photoelectric project in October 1943.81
For the tests in June 1942, construction of both radio and photo.
electric fuzes for the Army rocket began on small-scale production lines at
the Bureau and at Westinghouse. More than a thousand of the two fuzes
were made in the Bureau's model shops, "bugs" were ironed out at the prov-
ing ground, and late that year, as complete specifications for the fuzes went
to industry, full production began.. Under procurement for the Signal Corps
by agreement with Army Ordnance, almost 400,000 of each type were turned
out in 1943 and an additional 400,000 of the radio fuzes before the end of
the war.82
While the radio fuze for the rocket was primarily designed for use
against aircraft in its limited use overseas it functioned equally well from air-
planes and from ground rocket launchers against troops and gun emplace.
ments. Its most spectacular use was in multibarreled projects mounted on
the General Sherman tank, the 60 VT-fuzed rockets, released in 6 seconds,
completely smothering the target area with their concentration of projectile
Well before the end of 1942 the fuze program had completely out-
grown the laboratory in which it began overflowing into a number of tempo.
rary structures put up in the open area across Van Ness Street. Upon the
assignment of additional fuze types and other ordnance projects to the group
that December, the Bureau organized the sprawling units into the ordnance
development division, under the direction of Harry Diamond, for better
administration of the work.
A month later Army Ordnance renewed its original request for a
radio fuze for bombs. The bomb fuze was not, as originally planned, to
be used against enemy battleships—the Bismarck, Scharnhorst, Prinz Eugen,
L .
ninetiart pp. 111—112; A. V. Astin, ed., Photoelectric Fuzes and Miscellaneous
Projects," vol. 3, Summary Technical Report of Division 4, NDRC (Washington, D.C.,
1946), p. 20.
83
Hinman, pp. 15—17, 31; NBS War Research, p. 21; Baxter, pp. 239—240.
p. 17.