COLLAPSE OF TEXAS TOWER NO. 4 101 



Here is your waterline^ — the blue marking into the gray is your water- 

 line. So you have to think of the same problems that you have had 

 over here when you decided to go 48 feet into the ground and had 

 15-foot-diameter' enlarged lower cylinders, for the ground portion. 

 You have the same problem, because you have the same sea action. 

 You still have the sea. This is your new ocean floor. 



NEW FLOOR JUST BELOW WA^TE ACTION 



The stresses that you have here, less the w^ater depth — you have 25 

 feet here, so you have a smaller action floor to work on. You have 

 made it the best that you could, since you are making a new ocean 

 floor, always remembering that you had to put these bracings here 

 below the movement or the bottom of the wave to keep the resistance 

 of the legs against the sea down to a minimum. 



Now^, it became very important, then, that from here down this 

 structure was of sufficient strength and was anchored in the ocean in 

 such w-ay that it would act as it was — for it was designed as an ocean 

 floor up to here about 150 feet or something like that. 



PIN CONNECTIONS CONSIDERED POOR DESIGN 



We disagreed with pin connections because 



Senator Saltonstall. Would you repeat that, please ? 



Mr. DeLong. We disagreed with pin connections — pin connections. 



Senator Stennis. You mean you advised against the use of pin 

 connections ? 



Mr. DeLong. I would make it a little stronger. We just stated 

 positively that we did not want any part of it, any part of it. 



Senator Saltonstall. Mr. Chairman, would you be willing to let 

 me ask a question on that point ? 



Senator Stennis. Oh, yes ; yes. 



Senator Saltonstall. I want to get this question of erosion very 

 clear, Mr. DeLong. Now^, you said that column was made 15 feet in 

 diameter at that level, because of the danger of erosion. Now, am I 

 correct in believing that salt water causes erosion on steel, and if you 

 have two steel joints coming together such as these pin connections 

 then the size of your lower structure — what do you call that — pole or 

 what do you call that thing — a leg? 



Mr. DeLong. Leg. 



Senator Saltonstall. Is it not true that salt water causes erosion 

 where steel meets steel ? Am I right on that ? 



Mr. DeLong. Well, there are various ways of taking care of that, 

 Senator. You can use cathodic protection under water and above 

 water you can paint. Erosion, I think, has been used in a different 

 term here. Erosion is something caused by the elements, water and 

 so forth. 



Senator Saltonstall. But if you have a steel anchor cable, and you 

 connect that to a chain with a link, there will be erosion between that 

 steel cable and the iron chain connection in a year, will there not? 

 Now, that is caused by salt water. 



Mr. DeLong. Well, salt water causes erosion. 



Senator Saltonstall. Well, what I am getting at is that you built 

 the leg 15 feet in diameter to avoid the effect of erosion, (jidn't you? 

 That is what you just said. 



