PUZZLE IN PANAMA — BOWMAN 425 



To eliminate the problems at Lagarto, two other Chorrera routes 

 with Atlantic terminals near those of the present canal in Limon Bay 

 were studied, followed by the next logical idea of shifting the Pacific 

 terminus from Chorrera to the vicinity of Balboa on the present canal. 

 Thus the Panama Parallel Route came into being. 



A common element of all these routes was a crossing of Gatun Lake 

 that would be blocked off by barrier dams, which would also provide 

 flood protection from the various lake-feeding streams. By digging 

 the other sections of the canal first, the resulting spoil could be used to 

 build the dams, after which the Gatun Lake sections could be exca- 

 vated in the dry behind their protection. 



This idea has great appeal, its principal drawback being, of course, 

 the tremendous dam-building job involved, since the total barrier dam 

 length would exceed 14 miles. A conventional cross section of say 

 100-foot top width would not be too serious, but if this were increased 

 10, 20, or 30 times to provide security against modern weapons, grave 

 doubts arise as to the advisability of the scheme. Nevertheless, once 

 built, it would undoubtedly represent a reasonable solution of the 

 problem that Congress set up. In the final analysis, also, it will have 

 to compete with one of the Panama conversion plans on the basis of 

 cost. 



THE SITUATION SUMMARIZED 



What then are the possibilities of solving this puzzle in Panama? 

 Wliat considerations must be resolved to come up with a recommenda- 

 tion for a canal that will best meet the requirements of security and 

 ample capacity set up by Congress? Among the obvious ones are 

 sound engineering, practicable construction, and minimum possible 

 cost. To which must be added resistance to or possible protection 

 from the destructive effects of present and future weapons of war. 

 Adding up these considerations as they apply to each of the proposals 

 and then comparing the results is the present task of the investigators. 

 It is futile, and it would be improper, to anticipate or speculate upon 

 their conclusion, but a few applicable facts will serve to summarize the 

 situation as it now exists. 



There are four routes removed from the present canal and three in 

 the vicinit}^ of it whose merits must be weighed. Of the former, three 

 are sea-level routes whose yardages, estimated on a 1 : 1 bank slope 

 assumption are as follows: Atrato-Truando, 1,590 million; San Bias, 

 1,520 million; and Caledonia, 1,260 million. What these yardages 

 would prove to be were sufficient knowledge available to use geological 

 slopes in estimating them is problematical, but they would increase 

 rather than diminish judging from the Panama Conversion Route; 

 using 1 : 1 slopes, this plan required 688 million yards, which increased 

 to 917 million when geological slopes were applied. 



