페이지 이미지
PDF
ePub
[graphic]

Estimated cost of making the channel of Merrimac River navigable between Mitchell's Falls, below Lawrence, Mass., and Manchester, N. H.-Continued.

Locks and crib

work,

Ledge.

Bowlders.

Dredging

To be blasted.

To be hoisted.

Obstructions.

Cost.

contin Total + 10% for engi.

and
neering
gencies.

Price per cubic

yard.

Canal wall.

Cubic yards.

Locks.

Price per

ton.

Price per cubic

yard.

Price per

ton.

Cubic yards.

Tons.

Tons.

$22, 000

$10, 800

12 $30 00

54
300

24,000

29, 025

BETWEEN NASHUA AND MANCHESTER, N. H.-continued.
Cromwell's Fall's
Cromwell's Falls, with dam.
Cromwell's Falls, rocks in
Old Hildreth
Rock off Natticook Brook
Rocks below Souhegan River
Rocks at Reed's Ferry.
Moore's Falls
Rocks above Moore's Falls
Rocks at foot of Darrah's Rips.
Rocks below Darrah's Brook
Rocks off Darrah's Brook.
Jew Rock
Rocks at head of Darrah's Rips.
Little Cohass Falls
Bar above Ram Rock,
Goff's Falls
Goffs Flls with dam.
Short Falls
Rocks below Griffin's Falls
Griffin's Falls
Rocks at Baker's Island.
Merrill's Falls.
Bar below Factory Bridge.

11, 250

20,000
28,000
20,000
15,000

10, 010
8, 660
4, 725
28, 125

20,000

Total

5 00

4, 69830 00 149, 000 102, 595 $140, 955

4, 192 $20 960

2 50 6 00

3,580 $10, 740

3 00

3, 340 10, 945 $74, 020

498, 270

RÉSUMÉ.

1. To extend the present 47-foot channel from head of Mitchell's Falls to Lawrence lower lock

$11,000 2. To provide 4-foot navigation from Lawrence Dam to Lowell (and Pawtucket Canal), including improvement of Hunt's Falls..

225,000 3. To clear the river of obstructions between Pawtucket Dam at Lowell, Mass., and Nashua, N. H

8,000 4. To provide slackwater navigation above Nashua to Manchester, N. H., for 3 feet draught......

304,000 Total cost of improving the channel of the river for 50 miles from head of Mitchell's Falls, below Lawrence, Mass., to Manchester, N. H.......

548,000 In concluding my report upon this interesting work, I desire to acknowledge my obligations to the hydraulic engineers on the river, Mr. H. F. Mills, of Lawrence, Mr. J. B. Francis, of Lowell, and Mr. Hobbs, of Manchester, who placed all the valuable information in regard to the river in their possession at my disposal, and to their courtesy I owe in a great measure what success I shall have had in placing the information obtained by my own investigations before you in presentable shape. Very respectfully, your obedient servant,

SOPHUS HAAGENSEN,

Assistant Engineer. Bvt. Brig. Gen. GEORGE Thom,

Colonel of Engineers, U. 8. .

B.

UNITED STATES ENGINEER OFFICE,

Boston, Mass., October 15, 1881. GENERAL: I have the honor to forward to you a project for the improvement of Merrimac River, between Lawrence and Mitchell's Falls, Massachusetts.

The parts of the chart (200 feet to an inch) obtained throngh Mr. Mills gave hori zontal contours for each foot above and below the Essex Company's datum plane, which is 7.87 feet above the United States Engineer's datum plane, which datum plane is 10 feet below B. M. on Ring Bolt Rock (near foot of Mitchell's Falls).

By means of the profile of the river slope I have, from the horizontal contours, constructed the slope contours on those parts of the river which I did not survey myself. I made independent soundings from the lower locks in Lawrence to a point 5,000 feet below, including Andover Bar, and also at Gage's Ferry, covering there 3,200 feet, and reduced my soundings to the game slope.

On comparing the profile of the surface of the river with the profile sent me with your letter of October 12, I find the slope assumed by me as mean low-water to be within 0.2 feet of the 10.30 a. m. slope above the Upper Falls, or at the foot of Kimball's Island (the same slope to which you refer in your last report); this (mean low-water) stage would give 4.9 feet (see accompanying profile) in the shoalest part of the Upper Falls Channel, and I have, therefore, adopted five feet depth on the two shoals for the dredging which would give a depth corresponding with that which obtains in the falls below.

To continue this depth up to the lower locks in Lawrence (about 5 miles) would require : ESTIMATE FOR IMPROVEMENTS ABOVE MITCHELL'S FALLS AND BELOW LAWRENCE,

MASSACHUSETTS.

1. Gage'Ferry Shoal, 7,000 feet above Upper Falls :
a. Dredging from 3.8 feet to 5.0 feet a channel 1,440 feet in length, 60 feet in

width, about 2,100 cubic yards of gravel and cobble-stones, at $2.50.... $5, 250 b. Point of Ledge, 800 feet below and on the westerly edge of the channel,

removal from 3.1 feet to depth of surrounding bottom, 5.5 feet, about 16 cubic yards, at a cost of $30 per cubic yard ....

480 c. Point of Ledge, at the upper easterly edge of channel, removal from 0.4

feet to depth of surrounding bottom 4.2 feet, about 12 cubic yards, at $30 per cubic yard

360 2. Point of Ledge, in mid-channel, 4,500 feet above Gage's Ferry : Removal from 1.7 feet to depth of the surrounding bottom, 7.8 feet, about 22 cabic yards, at $30 per cubic yard

660

3. Andover Bar, 3,000 feet below lower lock in Lawrence:
Dredging from 3.4 feet to 5.0 feet a channel 760 feet in length, 60 feet in

width, about 1,240 cubic yards of gravel and cobble-stones, at $2.50 per
cubic yard....

$3, 100 4. Removal of bowlders at mouth of Spicket Rirer, 400 feet below entrance to lower locks, 20 tons, at $5 per ton..

100 Engineering and contingencies

1,050 Total cost of improvement...

11,000 The miter-gill of the lower lock in Lawrence is 2.4 feet above the plane of proposed improvements, or does not allow more draft than 2.6 feet at mean low-water, with mill-water in the river.

In order to carry navigation above Lawrence with the draught available below, it would be necessary to add another lock in front of those already existing at Lawrence, with its miter-sill 2.4 feet lower than the present one. Even if this would be done, the canal leading to slackwater above Lawrence Dam is not practicable for that class of boats or craft which could pass the river below; the streets, water-mains, gas-mains, &c., cross the canal on bridges, which leave only 3 feet space between them and the ordinary canal level. To provide these bridges with suitable draws, and to carry gas and water pipes in syphons below the canal bottom, is a work the cost of which you did not authorize me to make the necessary investigations for.

The only feasible way to extend navigation beyond Lawrence appears to me to build a canal and locks on the south side of the river. Very respectfully, your obedient servant,

SOPHUS HAAGENSEN,

Assistant Engineer. Bvt. Brig. Gen. GEORGE THOM,

Colonel of Engineers, U. S. A.

C.

UNITED STATES ENGINEER OFFICE,

Boston, Mass., November 9, 1881. GENERAL: I have the honor to forward to you a tracing of the map of Hunt's Falls and adjoining parts of the Merrimac and Concord rivers.

The map, which is drawn to a scale of 1:2000, exhibits a set of small black figures; these give the elevations of the bottom in feet and tenths above the United States Engineer's datum plane. The larger blue figures give the soundings referred to the slope of the river in an ordinary low-water stage with mill-water running. To this same slope the blue and red contour lines (respectively 4 feet and 2 feet) are parallel.

The upper and lower monuments have been placed by commissioners to settle rights of flowage by the Lawrence Dam; my levels (and located points) connect with these monuments as well as with the city B. M., and the locks and canals B. M. on the south shore.

By using the time when the mills in Lowell were shut down, and the areas above the 4-foot contour in lower portion (those above the 2-foot in the upper part) consequently were dry, I obtained the true elevations of the bottom; in the same stage of the water it was practicable to sound, as the fall was then concentrated on a few points and the chutes nearly level (see profile of low-water with no mill.water). From these elevations combined with the slope observed the soundings at each line have been computed.

of the area between the “distributing main of Lowell Water Works" and the line 0, marked on my chart, a very elaborate survey existed in the Proprietors of Locks and Canal, Office in Lowell; which chart Mr. J. B. Francis kindly permitted me to copy, and from which that part of my chart has been constructed; the P. L. & C.'s zero being reckoned as +58.47 feet above the United States Engineer's datum plane. Since that survey was made, some excavation has been done by the P. L. & C., mainly consisting in the removal of bowlders from the natural channel.

By sounding above the falls I found part of line O changed to some extent, and it may be possible that a close survey would show the 2-foot contour to have fallen back (as suggested by a red dotted line) in this upper portion of the upper chute; however, not so changed as to warrant a resurvey for this present examination and preliminary estimate of improvement.

Below the extent of this chart to Lawrence Dam, there appeared no obstructions to a 4-foot channel, in the form of bars; only scattered bowlders will have to be removed to make a navigable 4-foot channel to the foot of Hunt's Falls; here is a fall of 11 feet (10.84) in a length of 5,700 feet, mainly on two chutes, with a pool between.

Directly above the falls is the junction of the Merrimac with the Concord River, from which the Pawtucket Canal allows barges of 3 feet draught to be carried through Lowell to the river above Pawtucket Dam.

Immediately above the junction of Concord River, the city fronts on a deep-water basin in the Merrimac River. This basin would be the natural place for wharves and storehouses, should navigation be extended from Lawrence to Lowell; and with this in view the proposed improvements have been planned.

The scheme for making Hunt's Falls navigable, as adopted on the plan, is substantially the same as that carried out in Mitchell's Falls below Lawrence, namely, the excavation of straight channels through the chutes.

The velocity of current would, however, greatly exceed that in Mitchell's Falls; while in the latter place the current through the completed channels has a velocity of 37 knots per hour, the velocities (observed in my survey) in the chutes of Hunt's Falls range from 4 to 5 knots per hour, which, of course, would be increased by opening of artificial channels. To stem this current would probably not be possible for any steamboat with a tow of laden barges; but stationary engines might be placed on the shores in the axis of the excavated channels, and the barges warped over the falls. This is even now resorted to in Mitchell's Falls.

The channels estimated for have a width of 50 feet. The upper channel has this width throughout, while the lower ledge channel is flaring towards the pool, and at its lower end a basiu is to be cleared to allow the barges to swing into the direction of the channel axis.

To connect the Pawtucket Canal with the cbannels excavated in Hunt's Falls and the basin above, it would be necessary to dredge through the rapids in Concord River, as shown on the plan.

ESTIMATE OF THE COST OF MAKING MERRIMAC RIVER NAVIGABLE BETWEEN LAWRENCE

AND LOWELL FOR A DRAUGHT OF FOUR FEET IN ORDINARY LOW-WATER STAGE, WITH MILL-WATER RUNNING.

1. Between Lawrence Dam and the foot of Hunt's Falls: Removal of scattered bowlders in the channel....

$5,000 2. In Hunt's Falls: a. In lower chutc:

To procure a swing-basin and channel of a least width of 50 feet, with a

depth of 4 feet; removal of 4,4664 cubic yards of ledge, at $30 per
cubic yard..

133, 995 b. In npper chute: Dredging a channel 50 feet wide, 4 feet deep after excavation, requir

ing 8,620 cubic yards, scow measurement, at $6 per cubic yard. 51, 720 3. In Concord River:

Dredging a channel of least width of 50 feet, and 3 feet deep, 2,325 cubic
yards, scow measurement, at $6 per cubic yard..

13,950 Engineering and contingencies

20,335

Total cost

225,000

An alternative project has been considered, namely, to provide slackwater navigation through Hunt's Falls by means of two sets of locks and canal walls, the walls extending from the lock to the next level above and following the shore as near as practicable. This project has been drawn on the plan and profile in red.

By placing the npper lock higher up in the pool and including the whole of the northerly chute in the canal (as suggested in the plan by broken red lines), a saving in the length of canal wall could be made, as well as an insignificant amount of excavation for channel. But the effect upon the water-power in Lowell in thus contracting the area of river section would, I think, favor the adoption of the location along the north shore, which would not materially rednce the section; a small excavation in the flats, say from F to C, would compensate for shutting off the lower portion of northerly chute.

To make this work permanent it would be necessary to build those structures of solid granite masonry; in the upper river, similar works constructed of timber cribs have been totally demolished by ice-freshets. The cost of this work is estimated as follows: a. Lower Lock and Canal: 1,645 running feet of wall, containing 3,832 cubic yards of masonry, at $ 0 per cubic yard ....

... $76, 640 To clear a channel 30 feet wide inside canal wall, requiring an excavation of 788 cubic yards of ledge, at $5 per cubic yard

3,940 b. Upper Lock and Canal: 2,640 running feet of wall, containing 5,970 cubic yards of masonry, at $20 per cubic yard ...

119, 400 Riprap apron, 3,520 tons, at $1.50 per ton

5,280

To clear a channel 30 feet wide inside canal wall, requiring the excavation of 1,500 cubic yards of gravel and bowlders, at $3 per cubic yard..

$4,500 Engineering and contingencies.

20, 240 Total ...

230,000 To compare this with previous estimate (for channels), items 1 and 3 of that estimate should be added to the above total. Very respectfully, your obedient servant,

SOPHUS HAAGENSEN,

Assistant Engineer. Bvt. Brig. Gen. GEORGE THOM,

Colonel of Engineers, U. S. A.

D.

LETTER OF HON. J. F. BRIGGS.

MANCHESTER, N. H., November 1, 1881.

MY DEAR SIR:

In Manchester onr population is now over 36,000, and is fast increasing. We are at the mercy of one line of railroad, or, in other words, all our railroads are under one management. Freights are very high (particularly coal), and a subject of universal complaint. Years ago the freight for the valley of the Merrimac came via Middlesex Canal to Lowell; thence by the river to Concord. Our people believe that by a small expenditure of money some arrangement might be made at the falls at Lawrence, Lowell, and others on the river. We might carry coal and heavy freight in barges or flat-boats towed by light-draught steamers to and from Newbury port. We use 75,000 tons of coal annually in this city alone, and the products of our factories and other manufacturing establishments are largely sent to New York. If this river could be again utilized it would be a great benefit to our city and other towns upon the river.

My object in asking the survey was to obtain what facts I could, for the purpose, if possible, of adopting some system of improvement of this river that will relieve the business of this community of the unjust exactions of these railroad corporations, Yours, truly,

J. F. BRIGGS. Brig. Gen. GEORGE THOM.

A 25.

SURVEY OF LINN HARBOR, MASSACHUSETTS.

UNITED STATES ENGINEER OFFICE,

Portland, Me., December 31, 1881. GENERAL: I have the honor to submit the following report on the survey of Lynn Harbor Massachusetts, called for by the act of Congress approved March 3, 1881, “making appropriations for the construction, completion, repairs, and preservation of certain works on rivers and har bors, and for other purposes.

This survey was inade under my direction in July last by Mr. Sophus Haagensen, assistant engineer, and a map of it is herewith submitted, showing the results of the survey, together with the works projected for the improvement of the harbor.

Lynn Harbor is distant about 10 miles in a northeast direction from Boston, Mass. It is a sheet of water about 3 miles in extent from north to south, and bas an average width east to west of about 14 miles, being limited on the east by the peninsula of Nahant and Long Beach, and on the north and west by the city of Lyun and Chelsea Beach. The greater

« 이전계속 »