140 COLLAPSE OF TEXAS TOWER NO. 4 



in the original design. We liave estimated tlie importance of tliese stresses and 

 find that percentagewise they do not greatly affect the overall strength of the 

 panel involved, but nevertheless there is some decrease in the factor of safety 

 and it can be said that, had the loss of the original braces not occurred, we would 

 have had a more perfect structure strengthwise. 



We do not believe that the replacement connections affect the rigidity. 

 Very truly yours, 



MoEAN, Proctor, Mueser & Rutledge, 

 Theodore M. Kuss. 



Mr. Kendall. Was that difficulty that was ascertained as a result 

 of the underwater inspection treated as a design deficiency, or as a 

 construction deficiency ? 



Commander Foster. Construction deficiency, sir. 



Mr. Kendall. At whose expense were the T-bolts installed? 



Commander Foster. At the contractor's expense. 



Mr. Kendall. No additional allowance was made to the contractor 

 for any work in connection with that? 



Commander Foster. He did some work at the time with regard to 

 an oil leak, which I believe we did allow. But the repair of this brace, 

 he did. 



Mr. Kendall. Commander, do you have a T-bolt in fi'ont of you 

 there, so we shall know what we are talking about, and tell us briefly 

 how you would install this ? 



Commander Foster. I think we have a sketch here that showed the 

 specification for installing this bolt. May I refer to it? 



Mr. Kendall. Yes, sir, you may. 



Commander Foster. Our problem here, of course, was that we could 

 not get into the inside of the caisson. Horizontal slots were cut 

 through the collar, through the skin of the caisson, which would per- 

 mit the entrance of the T-head in a horizontal position, after which 

 it was rotated to the vertical, which brought it in bearing up against 

 the caisson skin or the leg skin, and the nut tightened up to a pre- 

 determined torque, 



Mr. Kendall. Just to go back for a moment, there is a memorandum 

 from Captain Husband with reference to this matter, w^hich states 

 that it is not considered that the contractor is obliged to provide the 

 alternate T-bolt installation on this leg without extra reimbursement. 



Commander Foster. I recall that letter, sir. 



Mr. Kendall,. So with reference to replacing the Dardelet bolts with 

 T-bolts, that was not treated as a construction deficiency ; is that right ? 



failure of collar connection with dardelet bolts treated as 

 construction deficiency 



Commander Foster. Yes, it was, sir. There is maybe a little point 

 here that should be clarified. 



The contractor was required to install the brace with the Dardelet 

 bolts originally shown, which he did. Hewing very close to the line, 

 when we sent him back in there to fix it, theoretically he should prop- 

 erly have installed the Dardelet bolts. 



However, this could not be done. The holes were outsize. Another 

 means had to be found. He was willing to install the T-bolts, which 

 we felt were equal, if not better than the others, so he agreed to install 

 the T-bolts. However, in our letter to the Air Force, we were not 



