COLLAPSE OF TEXAS TOWER NO. 4 7 



following dimensions. Texas tower No. 4 stood in 185 feet of water. 

 Each of its three legs were 252 feet long and 121^ feet m diameter, 

 made of 13/16 inch steel plate and braced by three tiers of 24 and 

 30-inch steel struts. The superstructure was a triangular platform, 

 661/^ feet above sea level, approximately 180 feet on each side. The 

 weight of the entire structure was some 7,000 tons. Its overall height 

 from the ocean floor to the top of the radomes was 345 feet, roughly' 

 that of a 30-story building. 



I shall now turn briefly to the history of Texas tower No. 4, from 

 when it passed to Air Force control m November 1957 to its tragic 

 collapse in January of this year. 



E^^NTS LEADING TO COLLAPSE 



The first notable event was in the summer of 1958, when the normal 

 motion of the tower increased to the point that hi September and 

 October, after Hurricane Daisy, the Navy made an miderwater inspec- 

 tion to ascertain the causes. The divers liired by the Navy found 

 some loose bracing connections at the —65-foot level on the shore- 

 ward, or A-B, side of the tower. In November, the original con- 

 struction contractor, J. Rich Steers, was recalled by the Navy to 

 correct these deficiencies. 



During the winter of 1958-59, before tliis work could be completed, 

 the tower underwent 5 storms, with maxhnum wmds of 90 miles per 

 hour and waves of 33 feet observed at the tower. 



Upon completion of the repairs in May 1959, there was a noticeable 

 reduction in the motion of the tower. An underwater inspection was 

 made by the Navy at that time, which established that the repairs had 

 been satisfactorily accomphshed. 



In the course of the winter of 1959-60, the tower was subjected to 

 4 more storms, with winds to 75 miles per hour and 35-foot waves 

 experienced at the tower. 



In the latter part of January 1960, personnel on the tower reported 

 underwater noises and abnormal motion. The Air Force thereupon 

 engaged the services of the Marine Contractors, Inc., the organiza- 

 tion which the Navy had previously used for this purpose, to make 

 another underwater investigation. This investigation, concluded in 

 February, disclosed that there were loose connections in the bracing 

 on the A-B plane at the — 25-foot and — 75-foot levels. 



Incidentally, on this model this is the 25-foot plane; this is the 

 — 75-foot plane. 



Senator Stennis. If you could have the model of the tower put up 

 higher, and have one of your aides point out the specific places you are 

 talking about, I think the committee, as well as the press, would have 

 a better chance to comprehend this thing. 



This is a model to scale of the Texas tower in question; is that 

 right? 



Mr. Chartk. It is a model. I would not say it was to scale. 



Senator Stennis. Well, approximately to scale. 



Mr. Chartk. The significant elements that might be pointed out 

 are, first of all, the A-B plane ; which we are talking about, which is 

 the plane in which the major difficulties were experienced; the brac- 

 ing at the —25-foot level, the —75-foot level, and at the —125-foot 

 level. 



