COLLAPSE OF TEXAS TOWER NO. 4 175 



Mr. Kendall. A^^iat was the purpose of that ? 



Mr. Crockett. The procurement officer from the Air Force base, 

 representing the Air Force at the particular tower, requested that we 

 do an emergency examination because of erratic motions, oscillations, 

 that the tower had generated, and also peculiar noises throughout 

 A caisson. 



Mr. Kendall. In other words, you were employed by the Air 

 Force on this occasion because they experienced excessive motion, 

 and were also hearing noises under water ; is that correct ? 



Mr. Crockett. That is correct. 



Mr. Kendall. You made the underwater survey ? 



Mr. Crockett. Yes, sir. 



Mr. Kendall. "V\niat was the significance of your findings ? 



Mr. Crockett. We found at this time, in examination of all the 

 brackets and pin structure connections, that we had an aggravated 

 wear from being within tolerance at the minus 23 -foot level, and 

 progressing to an inch and an inch and one-eighth. 



This measurement of an inch or an inch and one-eighth is taken by 

 motion in the pin, an external motion in the pin, rather than a meas- 

 urement between the pin diameter and the keeper plate diameter, the 

 hole diameter. Consequently, it could be plus or minus one-sixteenth, 

 something like this. 



Mr. Kendall. This is at the minus 23- foot level you are talking 

 about ? 



Mr. Crockett. Yes. 



Mr. Kendall. Was that on all planes ? 



Mr. Crockett. Reasonably. Through the AB section, we found 

 a gi-eater amount of wear. I would have to refer to the record to 

 distinguish one pin from the other. 



Mr. Kendall. ^Yhat was the condition of the pins in the lower 

 braces, that is, in the remaining portions of the tower ? 



Mr. Crockett. This lower panel [indicating], we found the pins 

 were in their original tolerance. There appeared to be no motion 

 whatever to them. As we increased to the minus 75-foot level, we 

 found that they had slight wear; at the minus 25-foot level they had 

 almost double that wear. We found a half-inch to five-eighths of an 

 inch on the 75-foot panel, and as I say, an inch to an inch and one- 

 eighth in the minus 25-foot panel. 



Mr. Kendall. What about the lower panel ? 



Mr. Crockett. That appeared to be stable in its tolerance. 



Mr. Kendall. The greater wear was in the top level of bracing ? 



Mr, Crockett. Yes, sir. 



Mr. Kendall. And the wear diminished as the braces went lower ? 



Mr. Crockett. Yes, sir. 



Mr. Kendall. What did that indicate ? 



Mr. Crockett. It would appear from the motion of the tower that 

 the excessive motion was creating an excessive wear. This wear was 

 generated over a period of some 14 or 15 months from being within 

 tolerance up to and inclusive of an inch to an inch and one-eighth. 



Mr. Kendall. Would you say that was substantial deterioration? 



Mr. Crockett. I most certainly would. 



Mr. Kendall. In addition to that, what else did you find on that 

 survey ? 



