9. USAF Texas Towers 4

Texas Towers 4 (1957-1961) was one of the USAF Semi Auomatic Ground Enviroment (SAGE) radarstations built on platforms at sea. See TT 2 for further informaton about crew and equipment. TT 4 was destroyed in a storm.
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The tragedy of TT-4.
A problem of inherent stability at TT 4 overshadowed previous Texas Tower problems. Ever since TT-4 was towed to site in mid-1957, it had become an engineering nightmare. Whereas TT-2 and TT-3 stood in relatively shallow waters, TT-4 stood in water 2 or 3 times deeper. From the time it was erected, Texas Tower 4 wobbled when under stress caused by winds and waves. Hurricane “Donna” (September 1960) whirled in at forces exceeding design specifications: 132miles per hour winds and breaking waves exceeding 50-foot heights. TT-4, evacuated of all personnel 2 days before, survived “Donna,” but not without shaking and rocking a great deal from the impact. Part of TT-4’s superstructure was destroyed; worst of all, below-water bracings were fractured, cutting overall strength to 55% of what it had been built up to prior to “Donna.” Meantime, a maintenance crew of 28 (14 USAF and 14 repair personnel) were stationed aboard to perform repairs. On 14 and 15 January 1961, TT-4 was again caught in a storm with winds up to 85 miles per hour and waves up to 35 feet high. Finally, TT-4 collapsed. One of its three legs snapped in half; the remaining two thereupon broke and the platform, with all hands aboard, sank to the ocean’s bottom.

Demise of TT-2 and TT-3, 1961-1964. The tragedy of TT-4, as much as anything else, sealed the fate of TT-2 and TT-3. Both were immediately checked for safety and structural strength and phased out within a year.

Website explaining the Texas Towers system http://www.radomes.org/museum/documents/TexasTower.html

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