Tabulated statement of cost of work at Flood Rock, Hell Gate, East River, New York, during fiscal year ending June 30, 1882. Pumping. Ventilating. Timbering. Cost, drilling Addition to perma Repairs to plant and buildings: Material Wages Operating expenses: Material Wages Total expenses Total cost per cubic yard of rock, brok. en: Galleries, full size. Headings, 10 by 6 feet. Stoping linear foot: $7,290 53 1,075 89 $900 71 358 63 $3, 565 12 953 26 $856 77 2,876 79 762 21 14, 207 31 633 22 1, 484 68,10, 157 68 3,310 02 10, 067 97,200, 109 94 Scow hire. Cost of 2" drill..$0 05. 2 12.3 $30 75 per Transportation. Surveying. Superintendence. Total. Remarks. Tabulated siatement of amount of work done at Flood Rock, Hell Gate, East River, New York, during fiscal year ending June 30, 1882. REPORT OF MR. ROY STONE, ASSISTANT ENGINEER. UNITED STATES STEAM DRILLING SCow, SIR: Regarding the operations of the United States steam drilling scow under my charge, I have the honor to report that work was continued on the reef near North Brother Island from July 1, 1881, the date of my last report, to November 28, 1881, and resulted in the complete removal of that reef to the plane of 26 feet below mean low-water. In trausmitting the usual tabular statement I take pleasure in noting a still further reduction of about 10 per cent. in the cost of drilling, making it less than one-fourth that of the years prior to 1879. I have this season carefully compiled the full cost of breaking the rock, including drilling, cost of powder and blasting appliances, time of blasting, and a full share of all general and incidental expenses, and find it to be, per cubic yard, $3.81. In the averages of cost in the statement only the column of totals should be regarded below the cost per linear foot of hole drilled, as the work prior to July 1 was mainly drilling and blasting, and the rock broken was removed subsequently, so that both periods are necessary to a fair average. The rock was removed altogether by divers, and the cost of removal is necessarily large; but as the divers were constantly guided by a horizontal sweep-rod, showing the 26-foot plane, and removed no rock below that plane, this work was probably more economical than dredging, which must have taken a great amount below the plane. The rock at North Brother, like the Heel Tap, crumbles readily to sand, and the divers were much assisted by a small induction-tube, operated by the small pump on deck. Through this tube several hundred yards of sand were carried off the reef and the stones left clear for chaining, &c. Without the tube the work could not have been finished this season. If a large pump, capable of using with the best economy the full power of the boiler, is placed upon the scow so that an induction-tube of about 18 inches diameter can be successfully worked, I shall look for excellent results in the next season's work. The scow was placed in winter quarters on November 29. A careful examination, made by your order, shows the hull to be in good, sound condition, except as to portions of the deck and ends, which can be readily repaired by the regular force of carpenters and seamen. I have the honor to be, very respectfully, your obedient servant, Col. JOHN NEWTON, Corps of Engineers, U. S. A. ROY STONE, Assistant Engineer, Superintendent. Tabular statement of operations on reef near North Brother Island. Operations, &c. Cubic yards of rock removed. Total number of feet drilled. Average depth of holes Size of drilling bit. inches. Average number of feet of holes drilled by each machine per shift of eight hours Average cost of sharpening a drill. Average number of feet drilled to each sharpening. Average cost of linear foot of hole drilled, including placing of scow, lowering of dome, expenses of drilling, cost of sharpening drills, expenditure of steel, hoisting up dome after drilling operation, and heaving off scow. Number of drill-hole blasts. $0 63 14 Amount of powder for drill-hole blasts ..pounds.. Average number of pounds of powder to each cubic yard of rock removed (including surface blasts) IMPROVEMENT OF BUTTERMILK CHANNEL, NEW YORK. The project and estimate for this work was submitted March 27, 1880, as an indorsement upon a communication of the Hon. Levi P. Morton to the Chief of Engineers. The contract made October 20, 1880, with Henry Du Bois was completed in November, 1881, 126,285 cubic yards, measured in place, having been removed at 35 cents per cubic yard-a depth of 26 feet at mean low-water having been obtained on the side of the shoal next to the Brooklyn piers for a distance of about 2,400 feet in length and about 250 feet in width. Under the appropriation of March 3, 1881, of $60,000, a contract was made with Henry Du Bois & Sons on October 15, 1881, at 22 cents per cubic yard, measured in scows, for continuing the dredging of the shoal. Under this contract there have been removed 91,260 cubic yards of material. The channel in its original condition was obstructed by a large shoal, with a minimum depth of 93 feet at mean low-water, which lay in the direct track of navigation, too near the wharves of Brooklyn for the safe passage or maneuver of large vessels. 'The originally adopted project for the improvement was the removal of a sufficient portion of this shoal to the depth of 26 feet at mean lowwater, and thereby to increase the depth and width of the channel. The amount expended to the close of the fiscal year ending June 30, 1881, was $25,421.01. The removal of a part of the shoal at that date gave proportionate relief to vessels going to the Brooklyn wharves. The amount expended during the fiscal year ending June 30, 1882, was $37,386.28, and greater benefit has been obtained by the increase in width of the deepened channel. The amount available, $57,192.71, with additional appropriations, may be profitably expended during the fiscal year ending June 30, 1883. The estimated amount required for the entire and permanent completion of the work of improvement in accordance with the approved and adopted project is $20,000; but owing to the large and unexpected advances in the cost of dredging since the first estimate was made, it is not unlikely that $90,000 will be required. This work is in the collection district of New York. The nearest port of entry is New York City. The amount of revenue collected during the fiscal year ending June 30, 1882, $152,774,062.32. The nearest light-house is Robbins' Reef. Amount of commerce benefited by the completion of this work is about $1,500,000 daily. For dredging 570,000 cubic yards ORIGINAL ESTIMATE. $140,000 00 $88,978 99 July 1, 1882, amount expended during fiscal year, exclusive of outstanding liabilities July 1, 1881 $31,786 28 July 1, 1882, outstanding liabilities.. 7,920 00 39,706 28 July 1, 1882, amount available... 49, 272 71 Amount appropriated by act passed August 2, 1882 60, 000 00 Amount available for fiscal year ending June 30, 1883..... 109, 272 71 20,000 00 Amount (estimated) required for completion of existing project... 30,000 00 Abstract of bids for dredging Buttermilk Channel, New York Harbor, opened September 28, 1881. Henry Du Bois & Sons. Abstract of contract for dredging Buttermilk Channel, New York Harbor. The survey of this work was directed by the act approved June 23, 1874, and on February 18, 1875, I reported a project and estimate for the improvement of the river from Randall's Island to the Hudson River. The commissioners appointed by the supreme court of the State to inquire the right of way for the proposed cut or canal to connect the Harlem and Hudson rivers are, I have understood, ready to report the result of their difficult and complicated task to the court. The lines of the improvement, as laid down by the Engineer in charge, are as follows: 1. Below the Harlem or Third Avenue Bridge the outer pier and bulkhead lines, as laid down by the park department, are adopted. |