mean low water. In addition to this amount the city of Providence has expended upward of $90,000 in dredging the harbor, mainly above Fox Point. Under date of February 18, 1878, I made a report in regard to the improvement of Providence Harbor and the channels of approach to it. This report was printed as Sen. Ex. Doc. No. 34, Forty-fifth Congress, second session, and is part of this report. By act of Congress approved June 18, 1878, $50,000 was appropriated for the improvement of this river and bay. This it is proposed to expend in dredging a channel 23 feet deep in the shoalest part of the present channel, the work to be done by contract after advertising in the usual mannar. By the same act of Congress $5,000 was appropriated for the removal of Bulkhead Rock. This rock is on the side of the deep channel of the river, about 24 miles below Fox Point. It lies in the path of vessels beating in or out of the river, and should be removed. In my former reports upon this obstruction I have estimated for its removal to a depth of 18 feet at mean low-water, at a cost of $5,000. At that time 18 feet was the governing depth, but with the depths of the proposed channel this should be removed down level with the bottom, about 20 feet at mean low water. To do this will probably cost $10,000, and as it can be done cheaper by making the depth required at once, it is thought advisable to reserve the present amount until another appropriation for the river is made, when the work can all be done at once. Providence is in the Providence collection district, and that place is a port of entry. The amount of revenue collected there during the fiscal year ending June 30, 1878, is $171,553.79. MONEY STATEMENT. Improvement of Providence River and Narragansett Bay. Amount appropriated by act approved June 18, 1878... $50,000 00 July 1, 1878, amount available... 50,000 00 Amount (estimated) required for completion of existing project... Amount that can be profitably expended in fiscal year ending June 30, 1880. 450,000 00 100,000 00 Improvement of Providence River-Removal of Bulkhead Rock. July 1, 1877, amount available.... $74 98 Amount appropriated by act approved June 18, 1878.. 5,000 00 July 1, 1878, amount expended during fiscal year. 5,074 98 74 98 July 1, 1878, amount available.... 5.000 00 Special Report on Improvement of Providence River and Narragansett Bay, Rhode Island.* OFFICE OF THE CHIEF OF ENGINEERS, WASHINGTON, D. C., February 25, 1878. j SIR: I beg leave respectfully to return herewith the resolution of the Senate of the United States of the 31st January last That the Secretary of War be directed to furnish to the Senate any informa tion in his department relative to the improvement of Providence River and Narragansett Bay, with an estimate of the cost of such improvement. And, in obedience to its requirements, to submit the inclosed copy of a report on the subject from Maj. G. K. Warren, Corps of Engineers, to whom it was referred. This report is very full, and conveys all the information contemplated by the resolution. It will be seen that the improvement which, in the opinion of the Harbor Commissioners of the State of Rhode Island, is demanded by the interests of commerce, consists in making a channel of 23 feet in depth at mean low water from Providence to the sea, and they estimate that the whole amount of dredging required for this purpose will be about 3,501,640 cubic yards, at a cost of $500,234.29. In this estimate no allowance for rock-excavation is made, though it will in all probability be in some places required. The order in which the work of improvement should be executed is, in Major Warren's opinion, first, to make the deep channel for ocean steamers from Providence to the sea; then to proceed with the work of widening the channel, &c. The cost of this deep channel he estimates at $100,000, and deems it to be in the interest of economy to appropriate the whole sum at once. I concur in Major Warren's views. Very respectfully, your obedient servant, A. A. HUMPHREYS, Brigadier-General and Chief of Engineers. HON. GEO. W. McCRARY, Secretary of War. REPORT. ENGINEER OFFICE, UNITED STATES ARMY, GENERAL: I have the honor to submit the following report in obedience to your letter of instructions, of February 2, transmitting a copy of the resolution of the United States Senate, made on January 31, and also in obedience to your Printed as Sen. Ex. Doc. 34, Forty-fifth Congress, second session. letter of February 7, transmitting a resolution of the United States House of Representatives, passed on February 5, both in regard to the improvement of Providence Harbor, Rhode Island, and the channels of approach to it. The House resolution requires a report "based on examinations and surveys made by the Coast Survey or other departments of the Government," which, as far as I know, are as follows: In the year 1872, under an act of Congress, I made a survey from Fox Point to Field's Point (see Annual Report of Chief of Engineers for 1873, page 969), and estimated the cost of dredging off the point of Long Bed, for which $10,000 was appropriated, and the point dredged off in the summer of 1873. In 1874 the United States Coast Survey made a new survey which also covered this portion of the harbor, and a copy of the map was furnished the Rhode Island Board of Harbor Commissioners, which copy I have consulted. There is as close agreement in the result of the two surveys as could be expected, so that, as a basis for an estimate of quantity of material to be removed in this part, nothing more is desired. There is some uncertainty as to the amount of rock that may be encountered, but this cannot be definitely determined except as the dredging is being carried on. During the past summer, upon application of the Governor of Rhode Island, the President of the United States appointed Rear-Admiral Daniel Ammen, Chief of the Bureau of Navigation, United States Navy, Prof. Henry Mitchell, United States Coast Survey, and myself, members of an advisory council to the Board of Harbor Commissioners of Rhode Island, and this council had several meetings with the Harbor Commissioners to consider the improvement of Providence River and Harbor. The harbor proper is taken to comprise the part between Fox Point and Field's Point, a distance of about 8,800 feet. Through about 2,800 feet of this there is ample channel depth. Through the other 6,000 feet the depth, in places, shoals to 14 and 15 feet, and at the upper end to 12 feet at mean low water. This limits the size of the vessels that can reach the wharves. The mean rise of the tide is about 4 feet. In regard to the improvement of this portion the Advisory Council give the following opinion to the Harbor Commissioners: present In a port like Providence, employed for miscellaneous commerce, the greatest good to the greatest number is to be secured by a channel of 18 feet depth at low tide. In order, however, not to exclude vessels of greater draught, we recommend that the channel should have a central pathway of 23 feet depth, 150 feet wide. The form of channel that would meet these requirements and have the most permanent slopes, would have the following widths, naturally, between its contours in light alluvium: 23 feet depth, 150 feet wide. We recommend that this channel should be carried from the city to Field's Point, following generally the present channel below Fox Point; and using the above table as a guide as far as possible for computing the amount of material to be removed (and not as a convenient plan of dredging), we find from the origi nal hydrographic sheet of the Coast Survey (1326 A), executed in 1874, that the necessary dredging would then have been two and one-quarter millions of cubie yards, bank measurement. The average length of vessels likely to seek this harbor, if improved, may be set down at 150 feet, and these, with average draught of 18 feet, would require 54 feet of cable, giving her radius of swing room 202 feet. These vessels, anchored most carefully on both sides of the channel proposed, would leave 321 feet gangway for the passage of other vessels. If anchored with only the ordinary care (but still under supervision of a harbor-master) the width of the gangway would sometimes not exceed 150 feet. It is assumed that so few vessels of extraordinary draught would be in port at the same time that the harbor-master could so arrange them as to avoid having any two of them in the same section. It is proper to regard the vessels as lying transversely to the direction of the channel, because during the season when the largest fleet visits this port winds from the west-southwest and southwest prevail. In providing for anchorage-room on either side of the gangway rather than excavating a special basin for anchorage, it has been borne in mind that the whole channel in the absence of vessels at anchor will be useful for the passage of vessels under sail, and that this channel traversed by tidal currents will be less likely to freeze up than a sheltered basin, or more easily broken out when frozen. The Harbor Commissioners have also made an estimate of the amount of material to be removed to make a channel 23 feet deep at mean low water, and 400 feet wide, with an additional width each side of 200 feet, gradually shoaling up to a depth of 10 feet at mean low water. The amount is 1,421,720 cubic yards. But in their communication to me dated February 8, transmitted herewith, they adopt the plan and estimate of the Advisory Council. In order to secure the depth of 23 feet at mean low water below Field's Point, dredging must be done at Pawtuxet Shoal and at Gaspee Shoal. The Harbor Commissioners' estimate for the amount to be removed at these two places, is upon the design to make the channel 23 feet deep and 400 feet wide and 200 feet each side, shoaling up to 10 feet. At Pawtuxet Shoal, cubic yards. 733,686 46,000 In order to allow vessels to enter and leave Providence direct by the western entrance to Narragansett Bay, drawing 23 feet at mean low water, another shoal must be removed just above Rocky Point, which the Harbor Commissioners estimate to amount to 424,824 cubic yards. Vessels using the middle entrance to Narragansett Bay, would not have to pass this shoal near Rocky Point. The foregoing quantities are bank measurements; measured in scows, the quantity would be increased by one-third. To recapitulate, we have now the following estimates of quantities: ESTIMATE OF ADVISORY COUNCIL. Fox Point to Field's Point, cubic yards, bank measurement. 2,250,000 3,000,000 $428,571 ESTIMATES OF HARBOR COMMISSIONERS. Fox Point to Field's Point, cubic yards.. 1,421,720 733,686 No rock is included in the foregoing estimates, and although some will undoubtedly have to be removed, as, for instance, Bulkhead Rock, this is comparatively a small item. This improvement, when made, will be permanent. The improvement desired will, at present prices, cost about $500,000. The importance of doing this is so well set forth in the accompanying communication made to me by the Board of Harbor Commissioners that I have nothing to add on this point.* The first improvement to be undertaken is to make the deep channel for ocean steamers, from Providence to the sea, and let the widening for anchorage and for a beating-channel for sailing vessels follow. For making such a channel 200 feet wide and 23 feet deep at mean low water I have estimated would require: From Fox Point to Field's Point, 434,000 cubic yards, measured in scows. At $1 for 7 yards, this would cost... $87,000 13,000 $100,000 To cut through the shoal near Rocky Point 200 feet wide and 23 feet deep at mean low water would require the removal of 300,000 cubic yards, measured in the scows; and inasmuch as this shoal can be avoided by using the middle en. trance to the bay, it is not an important obstruction. It now has a ruling depth of 18 feet at mean low water. All the estimates below Field's Point are based solely upon the United States Coast Survey charts, on one of which, sent herewith, the proposed channel is marked. If the revenue of the Government will allow such an expenditure in one year it would be best to appropriate the sum of $100,000 in one year, so that the benefit may be at once obtained. Providence is in the Providence collection district, and is a port of entry. The revenue from customs, during the fiscal year ending June 30, 1876, was $182,352.57. The United States in former years has expended about $56,500 on improvement of this harbor. Very respectfully, G. K. WARREN, Major of Engineers, Brevet Major-General, U. S. A. BRIG. GEN. A. A. HUMPHREYS, Chief of Engineers, U. S. A. * This communication was printed in the Second Annual Report of the Harbor Commission. |