Richmond daily times. [volume] (Richmond [Va.]) 1850-1853, 1851-05-27
SURVEY OF JAMES RIVER.
Report of Houard Stansbury, u. S. Civil Eng

SURVEY OF JAMES RIVER.
Report of Houard Stansbury, U s. Cira Eng inee,
| [coNoLuDED.l
Colonel Baldwin proposed three plans to remedy the
| evil. The flrst was, to construct dam with a lock
at some analogous point below all the distractions
of height suffic lent to raise the water t danfh of al
times sufficient for navigation.
The second was 10 construct etties at those place,
where deeper water is wanted and 10 leave the water
thus contracted, to wear out the channel. Wharves Of
piers TO be connected with and at right angles tn
the piers, to be parallel with each other and viii
the of the current, in order to give steadines
and direction to the force thus intended to be applied
The objection urged against these plans at the Time
they proposed, the very great expense VIII nt
the adoption OF either OF them would involve 1t is in
my opinion, we'll ounded and the first plan especially
is liable to others which are no less weighy The same
causes which have operated to form the obstruction a.
II now exists, would not be removed, nor in the least
degree diminished, but would continue TO act with in
creased force and rapdity, from the very means taken
to remedy the evil; Tor by the erection of the proposed
DAM the daily action OF the ebb tide there very stronp)
upon the lighter articles lodged upon the bar-the effect
OF which has been to postpone the elevation of the bar
| above low water mark-wouId be entirely prevented
A pool OF still water would be formed which would
present sudden and efieetua check to the CIR
rent from above, than the tide itself; in consequences of
which, much more rapid accumulation of the parti-
ces brought down would be occasioned, than can now
possibly lake place; that the pool thus formed al.
though it might, tor me effect the desired object.
would soon be filled up, until reached that point where
the transporting power OF the would again be-
| come superior to the resistance opposed 10 it. which
would be about the present depth The navigation
would then be no better than it is now while the ex-
| increased tenfod.
| The formation of a series of jetties would, without
DOUBT materially increase the depth OF water but to
render the improvement perfect, great number of
! them would he required many of which would have
to be erected in deep water. uncertain foundations
and, being transverse 10 the direction of the stream
would be exposed 10 the full force OF heavy freshets
UnulA Of ha
costly that the policy of restoring 10 such mode Of
| improvement, before other and simpler means shall
| have been aten pied, may well be doubted.
But one another plan remains to be consdered which
is to deepen the channel by dredging, so as to allow
vessels that up as high as Warwick to pro-
coed up to Richmond. 1t is believed that such mode
OF Improvement, it it do not entirely remedy the evil
will at all events, do much towards effecting that de-
! sirable object.
The depth of water required for vessels of the first
class s seventeen feet estimated that least
hall OF the foreign trade OF Richmond is now carried
on in briggs or ships OF less than four hundred tons bur-
den, drawing not more than fourteen or fifteen feet all
OF which can come up as high as Warwick fully laden
Of the remaining halt, which transported in ships of
six hundred tons, drawing sixteen seventeen feet
loaded, large proportion, say three-iourhs could
now be put on board such ships at Warwick and the
below that place. Now, by deepening the channel be-.
tween Warwick and Richmond, so as to allow vessels
which are able to come up 10 the former pass all the
way up the latter the whole trade in vessels of four.
teen feet draught and ourths OF the trade in veg
sells OF seventeen eet daugh would at be relieved
| from the Inconvenience and burdens to which they
are at present subjected. Some remarks upon the
amount of This tax submitted in succeeding part
Of this report.
To effect this very desirable object propose the
employment oftwo dredging machines to be occupied
mel entirely through the Richmond bar nine feet deem
at low water; by which means passage will at once
be opened for vessels OF thirteen feet draugh up to the
wharves at Rockets The dredging machines can
pmuIOVeU dor,tI, Of
ieet at low water or fifteen feet at high WATER to such
parts OF The river as require it, This may be effected
with greater ease and expedition than has been gener.
ally imagined.
By critical examination Of the chart it will be per.
eeved that exclusive OF the Richmond bar and about
tive hundred yards between that and the Warwick
bar, nine feet is TO be found all the way up to point
opposite the lower end of the island one mile below
the lower wharf at Rockets. Above that point seven
and for at least half the distance, eight feet are nb
tanned. So that, to reduce the bottom to uniform
depth nine feet at low water requires only an exca
cavation below the Richmond bar OF w feet tor five
hundred yards and above it TO carry the improve
ment quite to the mouth of the James River canaD an
average excavation OF one foo tor mile and half
10 open passage through the Richmond bar, one |
hundred yards in width, and fifteen feet in depth at
high tides, will require The removal of S2,727 cubic
yards; and TO reduce The bottom the same depth IN
TO the mouth OF the canal IL 400 yards |
Some rock is found in the bed OF the river in the i'm
mediate vicinity of Rockets !, appears to be of the
which is soft granite. In parts especially near
the steamboat wharf, the rock lies detached masses
not adherng to- but simply lying on, the bottom of the
river: and may be removed wilhou. difficulty. In one
spot forms part OF the river bed and will have to be
reduced and broken up BY OF heavy bars oGron
applied vertically; tor which purpose the power OF the
dredging machine can be applied with great effect.
In reducing the bottom TO uniform level it will be
proper 10 commence the work OF dredging at Rich |
Inond, The earth which is removed may be deposited
IN creek or bayou separating the large island just be-
low the city from the main land This would have |
forcing w
that passage into the main channel thereby mere asing
Its depth and the velocity OF the current and prevent
lng the sane s AMY tendency to too rapid
result from the removal OF the Richmond bar. row
OF sheetpiling should be driven across The bayou to
prevent the earth there deposited from being washed
wise happen. Being thus retained ia its place it would
very soon be covered with vegetation, which would
project 1t from any future action OF the current.
! ne 99nly o9ec'!on 10 the mode OF improvement
proposed Inc lear that may prove temporary ben.
EFT ony that the channel thus opened will soon fill up
or, do not, that another bar will be formed below
the present one, by which the navigation would be
equally obstructed: Tor TO the entire practcabity
OF removing the distractions within reasonable time
and at moderate expense, doubt can, | think, be
entertained; am inclined to the opinion, however,
than might al first be supposed. The bar which ia
the principal obstruction has been forming for long
series OF years. yet, from all the information l could
gather, it does appear to be increasing y OMEN
ing channel through it, and closing the bsyou be.
tween the island and the shore, above the current in
stead OF beng spread as al present over a wide fiat
VII naturally flow through the passage opened for it,
and that with increased power ard velocity tending
continually to enlarge and deepen the opening. II is
true that the PARTICLES which would otherwise be pre-
cpitated here may be carried further down and form
another bar below but this objection is equally appi
cable, and, indeed, with greater force to the improves
nent by Jeles-as, in the case, provision is made
Tor the disposal OF the earth removed and in the other
40 such provision is made and it is beyed that by The
timely and constant use of the dredging machine, ali
erous danger om this cause may be- entirely super
sded,
Alter completing this part OF the Improvement the (.
obstruction at Harrison's bar should next be removed
which will open uninterrupted navigation for vessels