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between Avery and Abner ledges is to form it by the deposit of granite rubble in the manner now adopted for the work in progress at the Delaware Breakwater. It is proposed to give the moud a width of 51 feet at mean low water and to form it up to that level by the deposit of random stone, so that the slopes shall be such as inay be established by the action of the sea, the heaviest stones to be placed on the exposed face of the structure. It is proposed to give the superstructure, above low water, a height of 18 feet and a top width of 20 feet, with slopes of about 1 on 1 on the sea side and 1 on oo on the inside, formed by the heaviest stones laid in position, the interior space to be filled with rubble. The cross section provisionally adopted by the Board is shown on the accompanying sketch. It is based upon a study of the storm-level . oped slopes of the breakwaters at Rockport and in Delaware Bay. Experience during the progress of the work may require the modifica tion of its forn and dimensions.
As before remarked, it was originally proposed to begin the construction of the southern brancli at Avery Ledge, the most exposed point of the line, in order to determiue the feasibility of this part of the work before committing the Government to further heavy expenditures. This reason no longer exists, a large sun having been already expended in the formation of the substructure. The Board is, therefore, of the opinion that the work of raising the breakwater to its full dimensions should be commenced at the northern end of the branch, at Abner Ledge, which is the least exposed portion of the line, and should be gradually extended until it reaches Avery Ledge. The experience obtained from this work, and investigations made during its progress, will determine whether the head of the break water at Avery Lege can be former of large natural or artificial blocks, or which of the other methods proposest should be adopted.
For the western branch of the breakwater, the Board, with its pres. ent information, is unwilling at this time to recommend any inethod of construction other than the rubble mound proposed for the southern branchi, although the average depth is so great that the structure will be of very great size below the level of sea action. Thie Board recommends for this branch the provisional adoption of the rubble method, with the cross section shown on the accompanying sketch. During the progress of work on the southern branch a thorough investigation should be inade of recent foreign practice, especially at the harbor of Boulogne, with a view to possible economy by the construction of a masonry wall above low water.
The project submitted by the Board is based upon the fact that the country in the vicinity of the work is covered with hills of syenite, containing extensive quarries, from which stone can be obtained at a low price. The rubble employed is the refuse of the quarries, and its removal has hitherto been a source of expense to quarry companies. It has been estimated that the four breakwaters built out from the shore near Rockport contain about 1,500,000 tous of this refuse material. In the preliminary project the local engineer estimated the cost of the rubble in the breakwater with the present means of production at 70 cents per ton; but he was of the opinion that if extensive quarries were opened at Gap Ilead, Gully Point, and Straitsmouth Island, and the rock broken out by large blasts, the work could be greatly cheapencil. The actual contract prices paid for stone have been 58,3 cents per ton in 1885, 71 cents per ton in 1886 and 1858, and 73,5 cents per ton in 1891. The Board believes that if a contract for a very large amount of stone, which would justify the opening of quarries specially
for its production, were authorized by Congress, the cost of this material would be greatly reduced.
This Board is further of the opinion that the breakwater can be com-
WM. P. CRAIGHILL,
S. M. MANSFIELD,
C. W. RAYMOND,
Major, Corps of Engincers. Brig. Gen. THOMAS L. CASEY,
Chief of Engineers, U. S. A.
OFFICE CHIEF OF ENGINEERS,
U. S. ARMY,
March 14, 1892. Respectfully submitted to the Secretary of War.
The project submitted in 1884, under which work has heretofore been carried on at this locality, provides for the construction of a continuous breakwater about 9,000 feet long, extending from Avery Ledge northwest to the 86-foot contour off Andrews Point.
The estimated cost of this work was $5,000,000.
The within project by the Board of Engineers proposing plan for substructure as well as superstructure of the entire breakwater is recommended for approval. It is the opinion of the Board that with liberal appropriations the breakwater can be completed with the section now recommended within the estimate submitted, viz, $5,000,000.
Thos. LINCOLN CASEY,
WAR DEPARTMENT, March 17, 1892. The within project is approved as recommended by the Chief of Engineers.
S. B. ELKINS,
IMPROVEMENT OF HARBOR AT GLOUCESTER, MASSACHUSETTS. This is the most important harbor between Boston and Portlaud, and is the principal resort for all New England fishing vessels. It is situated at the southeastern extremity of Cape Ann, 20 miles northeast from Boston. It is easily entered when the dangerous storms of this coast occur, and provides a secure, ample shelter for all classes of vessels, except from south winds, and from these a moderate extent of protected anchorage is afforded in the inner harbor.
It contains in the outer roadstead, the imer harbor, and in the channels connecting them, sufficient deep water for the most liberal demands of commerce, but the inner harbor and channel are obstructed by bowl. ders, ledges, and shoals, dangerous and inconvenient to shipping, and the outer harbor or roadstead is open to the action of all southerly winds.
A plan of the harbor was published in the Annual Report of the Chief of Engineers for 1887, page 506.
The first project formed for improvement was submitted January 20, 1871, and was based on the survey orderetl by act of July 11, 1870. (Report of the Chief of Engineers, 1871, page 869.)
This project proposed the removal of certain bowlders from the inner harbor at a cost of $10,608.20, and the construction of a breakwater from Eastern Point over Dog Bar to Round Rock Shoal, at an estimated cost of $ 194,148.65.
On November 10, 1884, Maj. C. W. Raymond, Corps of Engineers, by order of the special Board of Engineers that was considering the subject of the Sandy Bay Breakwater, submitted a project for two breakwaters at the entrance of Gloucester Harbor, one to cost $752,000 on essentially the same site as that proposed in 1871, and a supplementary one through Normans Woe Rock, to cost $607,000.
This project and estimate are published in the Chief of Engineers’ Report for 1885, page 534.
On January 20, 1885, it was recommended, in accordance with act of July 5, 1884, that a survey of the inner barbor and of the reef of Muscle Point be made, and that Babsons Ledge be removed to 21 feet at mean low water. (Report of Chief of Engineers, 1885, page 541.) In the annual report for this harbor for 1887 a general project for its improvement was submitted, based on the survey provided for by act of Congress approved August 5, 1886. (Chief of Engineers' Report, 1887, page 500.)
This project proposed to remove from the inner harbor 101} cubie yards of rock known to exist, and to dredge 216,000 cubic yards, scow measurement, at an estimated cost of $65,000; and to construct the breakwater, recommended in the project of 1881, that extends from Eastern Point to Round Rock Shoal, at an estimated cost of $752,000.
The total appropriations for this harbor to date have been $40,000.
Clam Rock had been reduced from 1 foot to 9 feet at mean low water; Pinnacle Rock, from S} to 16} feet, mean low water; rock off Pews Wharf, from 2 to 5 feet, mean low water; rocks off J. Friend's Wharf, from 13 to 17 feet, mean low water. All of the above rocks were reduced to the level of the surrounding bottom.
Babsons Ledge had been reduced from 11 to 14 feet, mean low water; no work had been done on the breakwater.
Two channels had been dredged in Harbor Cove, approximately parallel to the heads of the wharves; the east channel was 550 feet long; the west, 1,000 feet long; both were 40 feet wide and 10 feet deep at mean low water, except over a small ledge uncovered by the dredging off Parmenters Whart.
All the ledges obstructing the channel in the main harbor between Harbor Cove and Pews Wharf had been removed to the depth of the projected dredging in this part of the harbor, and a contract was in force with the Bay State Dredging Company to remove 40,000 cubic yards from Harbor Cove and the main harbor.
Operations under this contract were commenced in July, 1891, and satisfactorily completed in November, 1891; 47,298 cubic yards were removed.
At the date of this report the two channels in Harbor Cove are each 140 feet wide, 10 feet deep at mean low water, and the inner harbor has been improved from its entrance near Fort Point to the steamboat wharf, so that 15 feet depth at mean low water can be carried, except over four small ledges uncovered by the dredging near the Halibut Company's Wharf.
To complete the improvement will require an appropriation of $40,000 for dredging and $732,000 for the breakwater at Eastern Point. Of this amount $305,000 could be expended to advantage during the fiscal year ending June 30, 1894, in completing the proposed dredging and in commencing the breakwater.
The prospective advantages to commerce by the completion of the improvement are greater facilities and safety in the movement of vessels in the harbor, and a more safe anchorage for vessels seeking protection from southerly gales.
Gloucester Harbor is in the collection district of Gloucester, Mass., of which Gloucester is the port of entry.
The nearest light-houses are Ten Pound Island Light, in the harbor, and Eastern Point Light at its entrance.
The accompanying commercial statistics for the fiscal year ending June 30, 1892, have been furnished by the collector of customs at Gloucester, Mass.
The date and amount of appropriations for this work are as follows: Act ofJune 10, 1872
$10,000 August 5, 1886
5,000 August 11, 1888
10,000 September 19, 1890
15, 000 Total
40,000 Money statement. July 1, 1891, balance unexpended
$15, 351.40 June 30, 1892, amount expended during fiscal year
12, 013. 77 July 1, 1892, balance unexpended....
3, 307.63 Amount appropriated by act approved July 13, 1892
40,000.00 Amount available for fiscal year ending June 30, 1893.
43, 307.63 Amount (estimated) required for completion of existing project.. 752, 000.00 Amount that can be profitably expendeil in fiscal year ending June 30, 1894 305, 000.00 Submitted in compliance with requirements of sections 2 of river and
harbor acts of 1866 and 1867.
Amount of revenue collecteil, 1890, $50,461.23; 1891, $19,800; 1892,
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All classes of vessels frequent the harbor, from 5 tons to 1,500 tons; greatest draft, 24 feet.
The business of shipping salt to Nova Scotia, New Brunswick and Newfoundland has been established during the fiscal year.
Total number of vessels boarded during the year was 3,900.
IMPROVEMENT OF HARBOR AT MANCHESTER, MASSACHUSETTS.
Manchester Harbor is situated about 53 miles northeastward from the entrance of Salem Harbor, Massachusetts.
A chart of the harbor was published in the Annual Report of the Chief of Engineers for 1888, Part 1, page 466.
The outer sheltered roadstead contains, approximately, 300 acres, with 5 fatlioms of water.
The entrance channel from the roadstead to Proctors Point is everywhere at least 100 feet wide, at least 6.4 feet deep at mean low water, and is unobstructed.
At the “narrows," distant 1,400 feet inside of Proctors Point, the depth in the channel is reduced to 1.4 feet at mean low water; thence to the town wharves, a further distance of 2,500 feet, no low water channel exists. Near the town wharves the channel is crossed by the Boston and Maine Railroad (eastern division), on a bridge which is provided with a draw opening 28 feet wide.
The original project for the improvement of this harbor was submitted November 28, 1887. It was based on a survey provided for in the river and harbor act of August 5, 1886. It proposed to dredge a channel 60 feet wide, 4,000 feet long, and 4 feet deep at mean low water from Proctors Point to the town wharves, at an estimated cost of $14,300.
The total appropriations for this improvement to date have been: By the act of August 11, 1888
$2,500 September 19, 1890.
5,000 Total .... The expenditures to June 30, 1891, were $321.67. At that date operatio is were in progress under a contract with Messrs. Hamilton and Sawyer to dredge 22,000 cubic yards.
Work under this contract was commenced in Jue and satisfactorily completed in July, 1891; 22,052 cubie yards were removed; and, at the date of this report, the improved channel is 35 feet wiile, 4 feet deep at mean low water from Proctors Point to the railroad bridge, a distance of 2,900 feet.