CHAPTER XXVIII 

 THE COST OF OPERATING DREDGES 



THE cost of dredging, like that of any other engineering work, 

 should be deduced from an accurate analysis of all the various 

 operations required for the work. Some of these expenses are very 

 apparent, recurring continuously in the execution of the work, 

 while others, and perhaps the most important, do not occur simul- 

 taneously with the work, but at long intervals between one 

 another, thus they are detected with more difficulty and in many 

 cases observed. 



Some engineers and contractors, in preparing estimates for public 

 works, rely almost exclusively upon the prices that were paid for 

 w r orks executed under almost similar circumstances, this method 

 of determining the cost of work very often leading to errors. Prices 

 will give but little idea of costs, unless the profit realized by the 

 contractor can be learned. Since such information can hardly be 

 obtained, it is evident that prices are hardly a guide for bidding 

 on new works. Besides, in dredging it is difficult to call work 

 similar, owing to the different conditions of depth, magnitude 

 of the improvement, quality of soil, whether the dredging is to 

 be done in the open or in sheltered places, the character of the 

 plant and other details. Useful information concerning the cost 

 of dredging may be obtained from the Annual reports of the Chief 

 of engineers of the United States Army. In them is given the cost 

 of various improvements in different sections of the country. There 

 are at present many government dredges engaged on difficult works 

 about the country. These dredges are handled by experienced 

 engineers and crews and their work may certainly give an approximate 

 idea of the real cost of dredging. But even such data should be 

 taken with great caution, owing to the fact that the reports frequently 

 do not include expenses which should be charged to the work. 

 Thus, for instance, the salary of engineers, the tugs or motor boats 

 for the service of engineers and crews, the cost for piers, the cost 



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