COLLAPSE OF TEXAS TOWER NO. 4 259 



Mr. EuTLEDGE. We were asked by Commander Foster for our ad- 

 vice on the pin tolerances. The contractor had requested that the 

 specified tolerances be increased to the standard tolerance for this 

 type of construction, and we finally agreed that it could be increased 

 to the standard, which was one-sixteenth of an inch. 



Mr. Kendall. And one-eighth of an inch on the upper braces which 

 were to be lashed down ? 



Mr. KuTLEDOE. Yes, sir. Those pins, because of the method of con- 

 struction elected by the contractor, those pins had to be placed under 

 water. 



Mr. Kendall. Didn't that increase in the pin tolerances make it 

 even less rigid and permit additional motion ? 



Mr. Rutledge. We computed the motion that could be contributed 

 by such pin tolerances, and the result is in the order of four-tenths of 

 an inch horizontal motion at the top. 



Mr. Kendall. At the top of the platform ? 



Mr. Rutledge. Yes, sir. 



Mr. Kendall. Mr. Brewer testified that Mr. Kuss told him the tower 

 could move as much as 2 inches without taking up the known pin 

 tolerances. 



Mr. Kuss, is that correct ? 



Mr. Kuss. Mr. Brewer made a misstatement there. He said that 

 Mr. Kuss computed this. Now, I was in attendance at the meeting with 

 Mr. Brewer, and T\^e were having very general conversations. He 

 said, "Mr, Kuss, how much do you think the tower will move?" 



At that time I had no figures whatsoever, and I told him 2 inches. 

 My computations consisted of kind of waving a piece of chalk at the 

 blackboard. It was purely a guess. 



Mr. Kendall. It was a conservative guess, was it not ? Didn't the 

 studies show it moved as much as 3 inches? 



Mr. Kuss. His studies did, but w^e don't know that that was as a 

 result of pin tolerances or what. 



Mr. Kendall. It was platform movement, though ? 



Mr. Kuss. Yes. 



Mr. Kendall. If the pilings were considered necessary to a depth 

 of 48 feet at the time of the design of the tower, why is it that they 

 became unnecessary a few months later ? 



Mr. Rutledge. Sir, for foundations, it is quite common to have 

 caissons as an alternate to piles. We had 21 piles at the base of each 

 leg. 



Mr. Kendall. Forty- eight feet in depth ? 



Mr. Rutledge. I believe that they were to be 60 feet. These were 

 replaced by caissons 25 feet in diameter, and the original contemplated 

 depth was 20 feet embedment, and we analyzed this completely. 



The effect of the caisson 25 feet in diameter with full bearing, em- 

 bedded 20 feet, was completely identical to the piles. For this reason 

 we approved the contractor's request to change. 



Mr. Kendall. "V\'Tiat was the original embedment of the caissons? 



Mr. Rutledge. Twenty feet. 



Mr. Kendall. Did you increase the embedment when you eliminated 

 the pilings, or just what did you do to compensate for the elimination 

 of the pilings ? 



Mr. Ru'ri^EDGE. There was no embedment at the base of the legs, or 

 no enlargement at the base of the legs, with piles. 



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