62 HAUPT — METHODS OF IMPROVING OCEAX BARS. [May 3, 



METHODS OF IMPROVING OCEAN BARS. 



BY LEWIS M. HAUPT. 



{Read May 5, 1901.) 



In an official report on the "Brunswick Outer Bar, Georgia," 1 

 the U. S. Engineer now in charge of that work presents an elabor- 

 ate analysis of five methods available for creating navigable 

 channels: (a) by the use of dynamite; {l?) by a single jetty ; (c) 

 by a single curved breakwater ; (jf) by twin jetties ; and (e) by 

 dredging; from which he concludes that the last is "probably" 

 the most economical and hence he recommends that " the Govern- 

 ment should own and operate such sea-going dredges as are neces- 

 sary and not call upon contractors for such work at all." 



Inasmuch as the history of maritime works is replete with the 

 failure of dredging machines to create and maintain deep channels 

 in the open ocean and that the analysis and conclusions as to the 

 methods are so erroneous as to facts and results, the writer feels im- 

 pelled, in the interest of the public service, to submit a brief 

 review of some of the cases cited therein, with a view of bringing 

 out the truth more clearly. 



i. Dynamite. 



On this subject the author of the report, although having had 

 no experience in the use of dynamite, concludes as follows : 



"Fourth. The channel produced (at Brunswick, by use of dyna- 

 mite) has no advantage of permanence over a dredged channel of 

 similar size and location, which could be produced for about one- 

 twelfth of the cost of the present channel." The unfortunate part 

 of this comparison and assertion is that the " channel produced " is 

 the result of dynamite aided by dredging, and is not therefore such a 

 channel as might have been secured by dredging alone, for it is a 

 curved channel with flat slopes constructed by aid of natural forces 

 and which is larger than the channel contracted for and unusually 

 permanent. None of these things would be true of a dredged 

 channel in the open sea, unprotected by jetties or regulating works. 

 As no dredged channel of similar size and location exists as a basis, 

 no comparison can be made as to cost at this site ; but a thorough 

 analysis of other efforts to secure deep channels elsewhere shows 

 that this effort of the contractor has been far less expensive, both for 



1 See Document 355 H. R., 56th Congress, 2d Session. 



