98 COLLAPSE OF TEXAS TOWER NO. 4 



of 1954, and the early part of 1955, about December and January, 

 we AYere called in and advised that the design engineers had come 

 up with a scheme, and would we look at it with the purpose of erecting 

 it. We did. And we said, "Yes, the scheme is all right, we go along 

 with it, subject to certain changes and we would like to discuss them, 

 over a series of conferences." The first tower. No. 2, had bracing in 

 it. We objected to the bracing. Our experience had given us the 

 knowledge that the tower could be built differently, without bracing, 

 by reinforcing the legs, restudying the bottom condition, and putting 

 your penetration into the ocean floor to such depth that you had what 

 we call fixity at this point and up here, and the column was strong 

 enough to withstand the sea action. Your brown mark, is where 

 the ground line on the ocean fioor starts. That was agreed on as 

 being around 50 feet. The legs were stiffened up, steel was made 

 thicker, and bracing was eliminated. The use of bracing was a 

 serious objection on our part. But the engineers, the design engi- 

 neers, were very cooperative and everybody put their best effort forth 

 to come up with the solution. 



Senator Saltonstall. Mr. Chairman — did you say 50 feet in the 

 ocean floor ? 



Mr. DeLong. It is 48 to 50 feet — into the ocean bed. The ocean 

 bed is actually here. 



Senator Saltonstall. Is that rock or sand ? 



Mr. DeLoxg. Sand. 



Senator Stennis. Mr. DeLong, it will make it clearer for the record 

 and also for tliose present if you will make it clear that you are point- 

 ing to the model before you. 



Mr. DeLong. Yes, sir. 



Senator Stennls. That model has three legs without any bracings? 



Mr. DeLong. That is correct. 



Senator Stennis. That is the model for tower No. 2 ? 



Mr. DeLong. Yes, Texas tower No. 2. 



Senator Stennis. It will be better, when you say "here" if you 

 will indicate that you are pointing to the brown part, the lower part. 

 Remember that as iDest you can. 



Mr. DeLong. Yes, sir. The reason that I go back on tower No. 

 2, is because some of the principles of tower No. 2 go over into tower 

 No. 4. It was also decided that a 10-foot diameter leg was sufficient 

 strengthwise, but that the portion that would go into the ocean floor — 

 that ts the brown portion — should be larger, and that was increased 

 to 15 foot diameter. 



water depth is deciding factor in use or BRACING 



Then there was considerable concern about erosion — sand cutting 

 away the steel and so forth. Therefore, it was left approximately 1 5 

 feet, I believe, above the ocean floor, the same diameter, steel and 

 concrete and so forth, to provide for erosion or sand scour over a 

 period of time, which could wear the steel away and things like that. 

 But when you get to a certain stage of water depth, this freestanding 

 column is inadequate, and roughly the rule of thumb, is that of 

 about 100 feet — taking into consideration the conditions that you 

 have in the Atlantic, the storms, the sea and so forth, that you have 

 to cope with. So, therefore, when you get to a hundred feet or over, 

 you have to do something else, for example, use bracing. 



