Operation CASTLE's 15 MT Bravo early fireball with Compton Effect lightning, March 1, 1954

Thursday, February 6, 2014

Section 2, Operation HARDTACK Military Effects Studies (1958): High Altitude

Technicians readied a remote camera boom for technical photography.

Cameras were vital where people couldn't be during atmospheric nuclear tests, especially for safety reasons.

Lessons were learned during the BRAVO shot in March 1954, that caused massive damage the Eninman Island A base at Bikini Atoll, over 12 miles (19 km) away from the device B.

Bracers were constructed for the 29 June, 1958, 8.9 MT OAK test, to prevent buildings from collapsing. Power sources were sandbagged against tsunami flooding effects:

Operation HARDTACK I 1958
DNA 6038F
Blast gauge:


 MV Acania was part of a science project measuring signal attenuation through high altitude bursts.

MV Acania later served again during the DOMINIC I Fishbowl tests in 1962.

Radar trailers, like this suspected (Signal Corps Radio) SCR-584 Mod II microwave system, were everywhere during HARDTACK I. The 584 was developed by MIT during WW II, and subsequently.

Was this trailer originally brown or green? Input is welcomed.

This materials test pod was subjected to a 3.8 megaton thermonuclear environment at high altitude.

Both scenes were B&W still photos of this pod. Part of the photographer's label is to the bottom right of the lower image.

Darkening to the right of the pod, along  the transverse (90° to the length) axis of its casing, was caused by intense X-ray burns at 23,000 feet (7 km) from the warhead.

TEAK was fired at 10:50 PM, 1 August.

ORANGE took place at 10:30 PM local Johnston Island time, 12 August.

Operation HARDTACK I 1958
DNA 6038F

The (above) probe was likely a lower altitude probe, farther from the warhead's detonation altitude. A clue is an apparent lack of X-ray surface scorching, unless an overexposure masked it. Nevertheless the scientist used only light, disposable handling gloves..

Operation HARDTACK I 1958
DNA 6038F

Free neutron absorption from the W-39 thermonuclear warhead of the TEAK test caused this probe to become radioactive.

Pods were sequentially dropped in the pattern of this diagram.

Instrument pods at the base of a Redstone missile before takeoff

Considering that these missiles also lifted the NASA Mercury space capsules less than 3 years later, the small diameter of the Redstone was barely large enough to fit a capsule that could carry an astronaut.

Technicians secured the instrument pods to the Redstone.

Among the data collected by the pods were exposure readings at various distances from the weapons explosions:

Lethal radiation exposure rates span enormous distances high above the Earth, because of the low absorptivity of the low density atmosphere. Readings in this diagram scale to millirems per microsecond.

1 μ sec = 1 millionth of a second

Those nasty yellow lines in the left image scan vertically through the scene. Removing them is a real problem.

The bangs from these 3.8 megaton (each) high altitude explosions were extremely loud at the island launch site, yet originated from the thin air above.
.1 PSI = 150 dBSPL (decibels sound pressure level)
.18 PSI = 155 dBSPL

Rabbits were mounted in surface and airborne stations, for flash studies on the eye, a pressing concern for the military during that time.

 A land test over sand is seen above, while the lower image was located on a ship.

Those instruments to the upper right were photocell sensors for measurements of overall exposure at this station:

MATS (Military Air Transport Service) delivered much of the airborne shipments of cargo and test animals to the staging sites.

For TEAK, these stations were located:
  1. Johnston Island
  2. USS De Haven (DD-727), 70 nautical miles (130 km) from Johnston Island
  3. USS Hitchiti (ATF-103), 350 nmi (649 km) away from J.I.
  4. 2 B-36s flying at 15 000 feet (4.57 km), 350 nmi (649) km from surface zero
  1. USS Boxer (CVS-21), 50 nmi (93 km) from Johnston Island
  2. USS Epperson (DDE-719), 65 nmi (120 km) from J.I.
  3. USS De Haven (DD-727), 120 nmi (222 km) from J.I.
  4. 1 C-97 aircraft, 205 nmi (380 km), at 24 000 feet (7.31 km) from J.I.
Remarkably, Johnston Island was excluded from ORANGE surface animal testing sites, since the island reached 500 °F (260 °C) for some seconds, therefore requiring remaining brush and other combustibles to be removed before the test.

The doctor used an opthalscope to examine each eye.

A close-up view of the commander:

Each rabbit was then carefully photographed for weapon optical effects on the retina and macula. 

This was a remarkably messy cut (above), with so much color-bleeding and hotspots.

More work needs to be done to recover the color of the uniform.

Photographic sequence, starting with the eye open at the camera flash:

The blink reaction:

Scientific data for analysis were central to the objectives of all nuclear tests. TEAK, at approximately twice the altitude burst height, had a very short pulse lasting milliseconds, due to the very thin atmosphere at 250 000 feet (76 km). There was little atmosphere to support a fireball.

TEAK from an aircraft near Johnston Island:

The image below needs another run, to turn the grey sky between the ground the cloud base to a blue color.

TEAK's 3.8 megaton W39 device burst at 250, 000 feet/50 miles (80 km) above the Johnston Island launch pad, 1 August, 1958. Both NEWSREEL tests were near midnight. TEAK's firing was under heavy cloudcover with some openings to the sky above. The flight time was 3 minutes.

A spectacular display of TEAK was observed from the Hawaiian Islands, 700 nmi (1,297 km) away.

The USS Boxer launched the YUCCA test balloon from its stern while maneuvering to keep the relative air motion on the deck to less 10 knots.

A Sikorsky H-34 helicopter was parked to the bottom right.

YUCCA's 1.7 kiloton W25 nuclear device was lofted inside this casing, with a long trail of radar tracking reflectors and data telemetry instruments hanging below it. In all, the entire balloon and bundled instrument package was 80 feet (24.4 m) long at launch. It was released at 11:25 local time.

The W25 device detonated at 82, 250 feet/16.3 miles (26.2 km) altitude, 28 May, 1958, at 14:40.


 The YUCCA cloud sequence improved (above) over its original appearance:

From Operation HARDTACK I 1958, DNA 6038F:

No comments:

Post a Comment