42 COLLAPSE OF TEXAS TOWER NO. 4 



Senator Saltonstall. All right. Now let me ask you just one 

 final group of questions. 



It was my understanding that tower 4 was different from the other 

 two towers because the superstructure had to be floated out there and 

 jacked up, and was not put out there on top of the legs ; is that correct? 



Mr. Anderson. May I just change that wordology a little bit. It 

 is not because the tower was floated out. It was because of the de- 

 sign of the leg and truss system, as some call it, or, as I choose to 

 call it, the beam construction of the platform itself. And it was the 

 design of that which made it necessary for us to make minor changes 

 in the design of the platform itself — not the fact that it was floated 

 out. 



Senator Saltonstall. Well, you mean that the superstructure, for 

 which you were responsible for designing, was sufficiently different 

 because of the structure of the underpinning and the legs, and the 

 method of putting them together was not the same as with the other 

 two towers. 



Mr. Anderson. That is correct ; yes, sir. 



Senator Saltonstall. Now, did the placing of the superstructure 

 onto the legs, in the case of tower 4, in your opinion, weaken, in any 

 way, the legs on which it was to rest ? 



Mr. Anderson. I want to be sure I understand your question. Sen- 

 ator. 



Senator Saltonstall. What I am trying to bring out is this : Was 

 there any difference, because of tlie difference in design of the legs, 

 as to the strength, overall, of the structure due to the means by which 

 the superstructure was put on top of it ? 



Mr. Anderson. The fact that the superstructure was put on top 

 of it I would not say was a factor in the strength. The leg system 

 was designed to take the weight which would be involved in the plat- 

 form that was going to be placed on top of the legs, or rather on top 

 of the beam structure which tied the legs together. 



Senator Saltonstall. Well, I am not an engineer and it is very 

 difficult for me to state these questions clearly. Is it not true that 

 some of the support or some of the structural braces had to be dif- 

 ferent on tower 4 than on the other two towers when they were being 

 put in place? 



Mr. Anderson. They were different. 



Senator Saltonstall. All right. Now, could you point out which 

 ones were different ? Does it show on the model ? 



differences between the towers 



Mr. IVIiNNiCH. The difference in the towers is shown by the two 

 models you have here. All of this bracing is absent in Texas towers 

 No. 2 and No. 3. There was no bracing in these. It would be those 

 legs, with this platform. 



Senator Saltonstall. Tower 4 in its structure was sufficiently dif- 

 ferent because of the braces, and the braces would cause greater wave 

 resistance and resistance to water currents and everything else than 

 those three colmnns on the model of Texas tower No. 2. 



Mr. MiNNiCH. Well, yes, sir. That is true. But, even though the 

 braces pick up more resistance, they are also more effective struc- 



