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Report of the Secretary
of War, with Lieutenant Colonel Long's plan and estimate for the repair of
the Cumberland dam |
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31st congress, 1st session
[ SENATE. ]
Ex. Doc. No. 14.
REPORT OF THE SECRETARY OF WAR,
with
Lieutenant Colonel Long's plan and estimate for
the repair of the Cumberland dam.
January 16, 1850.
Read, ordered to lie on the table, and be
printed.
War department, Washington, January 12, 1850.
Sir: In compliance with the resolution of the Senate of
the 3d instant, I have the honor to transmit herewith, a communication of
the Colonel of the Corps of Topographical Engineers, submitting a copy of
the report, plan, and estimate of Lieutenant Colonel S. H. Long, in
reference to the repairs of the Cumberland dam.
I have the honor to be, very respectfully, your
obedient servant;
GEO. W. CRAWFORD,
Secretary of War.
Hon. M. Fillmore,
President of the Senate.
Bureau of Topograhical Engineers,
Washington, January 12, 1850
Sir: I have the honor to submit to your consideration a
copy of the report, plan, and estimate of Lieutenant Colonel S. H. Long, in
reference to the repairs of the Cumberland dam, called for by a resolution
of the Senate of the 5th instant.
Lieutenant Colonel Long evidently counts in his report
upon the services of the steam dredge-boat Lavaca. This boat was built
under his superintendence for the quartermaster's department, was turned
over to that department in January, 1849, and while descending the
Mississippi during the month of September, 1849, was snagged and lost.
Such a boat, with the requisite scows for receiving,
transporting, and unloading the dredged material, cannot safely be estimated
to cost less than twenty thousand dollars. The boat Lavaca, without
the scows, cost upwards of seventeen thousand dollars.
The estimate of Lieutenant Colonel Long will, of course, be at fault to
some extent, as the contemplated services of this boat cannot now be had.
Respectfully, sir, your obedient servant,
J. J. ABERT,
Colonel Corps Topographical Engineers,
Hon. Geo. W. Crawford, Secretary of War. |
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Office of W. R. improvements,
Louisville., December 20, 1848.
Sir: In addition to
the communications heretofore submitted in relation to the difficulties in
the way of navigating the Ohio river, at and near the Cumberland dam, I have
now the honor to submit the results of a survey recently made in that
vicinity, under my direction. The survey was made by C. A. Fuller, esq., one
of my assistants, and may be relied upon as accurate and authentic for the
particular stage of the river at the time of making it, which was about one
foot above extreme low water.
The information previously given by river men and
others professing a thorough knowledge of the hindrances to navigation, at
the place in question, established a general belief that at least two
distinct breaches had been made in the dam, and that these crevasses must
either be blocked up, in order to keep open the low water channel between
Cumberland island and the Kentucky shore, or that one of the breaches must
be enlarged by removing a considerable portion of the dam, and thus opening
a passage for ascending and descending boats.
It now appears that no breach whatever has been made in
the original dam, extending downwards from Dog island, 2,270 feet; but that
the dam throughout this distance, which included the most formidable of the
breaches alluded to, remains entire and unbroken, and retains its original
form and position as perfectly as when first constructed. The other breach
alluded to occurred between the lower end of the dam, as above designated,
and the head of Cumberland island, where the dam appears to have been but
partially completed, and was not sufficiently deep and broad to resist the
undermining influences of the current.
It also appears that the main difficulty in the way of
navigation is owing to the accumulation of sand, and the enlargement of the
bar, situated on the Kentucky shore, opposite to the head of Cumberland
island; the growth of which has been such as to block up the Kentucky
channel, and effectually obstruct the passage of the water on that side of
the river in a low stage.
The accompanying chart will show the form and position
of this formidable bar, and various other features affecting the navigation
of this part of the river.
The bar, by which the Kentucky channel is obstructed,
is represented on the chart as extending along the Kentucky shore, from D to
N, more than three-fourths of a mile, and stretching entirely across the
head of the Kentucky channel, and to the distance of more than one thousand
feet past the head of Cumberland island, into the Illinois channel. The
width of the bar, from the Kentucky shore to the head of the island, is
about fifteen hundred feet; and the distance from the lower extremity of the
present dam to the head of the island, is upwards of a thousand feet; the
whole of the bar, except a narrow channel, about one hundred feet wide, in
the immediate vicinity of the lower end of the dam? having been elevated, at
the time of the survey, from a few inches to four or five feet above the low
water surface of the pool formed by the dam, or about two feet, on an
average, above that level.
The water surface above the dam was three and a half
feet higher than that below the dam. The greatest depth of water in the pool
above the dam in its immediate vicinity, as indicated by the soundings, was
about 10 feet. The depth across the crest of the dam varied from zero to
three feet, as |
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shown in section No. 1 of the drawing, and the
greatest depth in the narrow channel at the lower end of the dam was six
feet. The water of this channel, after passing the end of the dam, occupied
a much broader and shoaler space, and was conveyed off through several
winding channels, in which the depth did not exceed one foot, and neither
of which was navigable for a loaded skiff. Accordingly, all ascending and
descending boats were compelled to pass over the crest of the dam, at the
hazard of being stranded upon the rocks of which it is composed; and with
respect to the ascending boats, at the enormous trouble of surmounting a
cascade of three and a half feet perpendicular pitch.
The bar about midway of Dog island, on its easterly
side, is a ledge of rocks rising about two feet above the surface of the
upper pool at the time of the survey. The distance from this bar to the
lower end of the dam (from B to H on the chart) is four thousand feet, and
the soundings along the line vary from three to twenty-one feet, giving an
average depth of about ten feet on the entire line. Hence the construction
of a new dam along this line, as suggested in a former report, is obviously
unadvisable, especially when considered in connexion with the stability and
permanency of the old dam.
The position of the old dam is correctly indicated by
the line extending from the point K, on Dog island, through the points e d,
c b, and a, to H, its lower extremity. The irregular portion called the V,
is indicated at b c d, and e. An extended profile or section of the dam,
showing the crest line, the depths of the water on the crest, &c., &c., is
exhibited in section No. 1 of the drawings, as above referred to. The
subdivisions of the profile, indicated by the small letters a, b, c, &c.,
are intended to show the portions into which it has been found convenient to
divide the profile, in order to facilitate the computations for the
enlargement and repairs of the old dam, which are proposed to be effected
by increasing the width of its base, and raising the crest to a uniform
elevation. The computations relating to the case, which embrace merely the
quantities of stone required for enlarging and strengthening the several
portions into which the dam has been divided, are exhibited on the same
sheet under the head of “explanations of plan.” The amount thus obtained is
8,082 perches.
As before remarked, the soundings recorded on the line
from B to G indicate the depths of the water along that line. The same line
continued, first crosses a dry bar rising about two feet above the water
surface of the upper pool) and then a narrow channel contiguous to
Cumberland island, and terminates at A, on the margin of the island.
From A to H, the lower end of the old dam, embracing a
distance of fifteen hundred feet, it is proposed to construct a new dam on
the plan of the old one, with the addition of crib-work, if found necessary
and advisable. The entire dam thus prolonged from Dog island to Cumberland
island, embraces an aggregate length of four thousand and fifteen feet. The
quantity of stone required for the new dam is estimated at 10,818 perches,
and the aggregate quantity for both dams at 18,900 perches.
A material feature in the contemplated improvement is
the opening a channel two hundred feet wide on the upper side of the new dam
and contiguous to it, from the point M to the point L, where it will unite
with the channel still remaining open along the margin of Cumberland island.
The excavation of this channel may be effected by the use of |
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the dredge boat Lavaca,* and mud scows properly
constructed for this purpose. The quantity of sand, &c., to be removed in
the formation of a channel to the depth of three feet below the low water
surface, is computed at 59,260 cubic yards, or for a depth of four feet
71,112 cubic yards. By opening this channel, and preserving a free passage
of the water through it, the growth of the sand bar through which it is to
pass may be effectually checked, and a navigable communication kept open
between the island and the Kentucky shore, leading from the head of the
island directly into the mouth of Cumberland river.
With respect to the probable cost of effecting the
objects herein contemplated, I take leave to subjoin the following estimate
:
18,900 perches of stone, procured, delivered, and deposited along the line
of the dam, at $1 50 per perch -
$28, 350 00
59,260 cubic yards sand, &c., removed from
channel across bar, 3 feet below water surface, at 12 1/2- cents per yard -
7, 407 50
Crib-work along the crest of the dam for
protection against ice, drift, &c., say 4,015 lineal feet, at $1 50
-
6,022 50
Superintendence and contingencies (including
casualties)
8, 220 00
Amount
50,000 00
For any further views
that may be required in relation to the condition and aspect of the river at
and near the Cumberland dam, I beg leave to refer to the accompanying chart,
and also to my former reports on this subject, dated September 22, 1845, and
April 6, 1848.
I have the honor to be, sir, very respectfully, your
obedient servant,
S. H. LONG,
Lt. Col. Top. Eng.j Super't W. R. Improvements.
Col. J. J. Abert,
Chief Top. Engineers, Washington, D. C.
*This boat has been lost since the date of this
report. She was snagged and lost on descending the Mississippi.
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