and wing accelerations, skin-temperature rise, and
mal inputs were realize. then for the Ivy tests.
elevator position.
the case of Shot 1, where the yield was slightly
greater than the maximum probable, good results
were obtained. The aircraft sustained only minor
The aircraft participated in every shot of the
Castle series. The limiting condition on the aircraft
was either 190 percent of the design limit allowable
physica} damage, and the results indicated that sufficient information was recorded to meet the project
bending moment on the horizontal stabilizer or 2
400 F temperature rise on the 0.020-inch magnesium
skin on the elevators.
In
objectives.
For Shots 1 through 5, the
These data indicated that predictions of
aircraft skin response to thermal inputs from highyield weapons were over-conservative. They also
aircraft was positioned at time zero in a tail-to aspect for one of the two limiting conditions, whichever
indicated the need for a hetter undurstanding of the
was critical for the maximum predicted yield of the
parameters involved in skin responses to thermal
flux: e.g., convective and conductive cooling, as
device concerned. For Shot 6, the aircraft was
positioned ir a head~on aspect for conservative valucs
of bending moments. Data obtained from a head-on
well as the possible variance of absorption coefficients with change of incident angle of thermal inputs.
orientation were the first experimental verification
of theoretically predicted responses and. although
conservative. were nevertheless extremely valuabic
and necessary for a complete evaluation of aircraft
Project 6.4 “Proof Testing of AW Ship Countermeasures” (WT-927), Bureau of Ships und Naval
Radiological Defense Laboratory; G. G. Molumyhy,
CAPT, USN, Project Officer.
response to nuclear explosions.
The maximum useful incremental peak temperature measured was 250 F rise on the 0.020-inch
magnesium skin on the undersurface of the elevator
during Shot 5. The theoretical overpressure criteria
of washdown countermeasures on Ships and grounded
level of 0.50 psi was attained safely on Shot 1, al~
though considerable sheet-metal damage resulted
The maximum gust load ineasured was in incremental
fectiveness of ships structures, (3) the tactical radiological recovery procedures on ships and grounded
airerart, and (4) the extent of interior contamination
The principal objectives were:
aircraft, (2) the determination of the shielding ef-
beading moment on the horizontal stabilizer of approximately 80 percent of Jesign limit load.
and su:taniiity of ventilation protective devices
aboard ship.
The
predicted responses of the critical skin areas to the
Two remotely controlled ships, orc protected by
a washdown countermeasure, were guided throush
thermal) inputs received were conservative, but suf-
ficient data werc obtained tc enable 4 more realistic
empirical and theoretical determination of the delivery
cupabilities of the B-36.
regions of contaminated fallout.
Special structuru
configurations, Loiler ar ducts, ventilation test
compartments, and aircraft werc installed on both
chips to act as contaminant-collecting surfaces.
Recoraing gamma~radiation detectors, uir ga.nplers,
Project 6.2b ‘Thermal Effects on B-47B Aircralt
in Flight’ (WT-926), Wright Air Development Center;
C. L. Luchsinger, Project Officer
Project 6.2b was a continuation of the experimen-~
tation begun on Ivy to determine the effects, princi-
particle and differential faflout collectors, surface
samples, and postshot radiation surveys were used
to suppiy data cn the extent of contamination.
These data showed that {i was possible for person-
pally thermal, of nuclear detonations on a B-47
aircraft in flight.
,1) the evaluation
The Castle results, when combined
with previous data, will modify existing theories relating the B~47 response to thermal inputs.
nel to receive lethal radiation dosage aboard un-~
protected ships and shipboard aircraft if used opera-
tionally.
Washdown effectiveness on ships and
aircraft not in flight was eslimated to be 90 and 95
percent based on dosage and dose rute, respectively.
Distance and shielding by the ships structures resulted in attenuation fractions ranging from 0.2 in
The Ivy B-47B, with additional instrumentation,
participated on all but Shot 5 of the Castle series.
Recorded data included total thermal-input energies,
intensities, and spectra as well ag overpressures,
skin temperature response, and flight attitudes.
The aircraft was flown and maintained by WADC personnel who were also responsible for instrumentation
compartments close to weather surfaces to 0.001 in
interior compartments below armored ducks, with
respect to levels observed on weather decks.
On
unprotected ships and grounded aircraft, excessively
long pemods of repetitious decontamination were
and aircraft position determination. The average effectiveness of instrumentation for the series was 93
percent.
required to achieve satistactory radiation levels:
The aircraft was positioned on each shot to receive
sufficient thermal energy to raise the temperature in
the 0.020-inch skin on the ailerons to 370 [I above
ambient. Assigned positions in space were computed
on the basia of the maximum probable yield rather
than the most probable. In most cases, higher ther-
114
when a washdown countermeasure had been in operation, very little effort wags needed to make the ship
or aircraft sabitable.
Very little contaminant entered
either the boiler air system or ventilation systems
For contaminating events of the type encountered
in these tests, it appeared that:
(1) washdown coun-
termeasures will cnable ships and operational planes