The New Orleans daily Democrat. [volume] (New Orleans, La.) 1877-1880, 1878-04-12

been about 100 feet caved In since 1858. but there
Ia little, If any, caVing going on now, except In
two places -o1e about 3OD and the other about
200 feet long, Below station 30, there Is a till
Below Canal street from Morgan's wharf,
ut station 10 to station 100, distance OF
$1,000 feet, the bank needs more or less pro-
lection. 1t has, however, only been deemed
slope of the bank from Morgan's wharf to
Congress street, a distance Of 1900 feet, leaving
the remaining portion Of the city below that
point to be projected by new levee.
On the right bank the space through which
- to 176, below the locks. and from
station 296 to 476, above and at Algiers
a total length of 81 700 feet. The board, how
ever, does not deem it at present absolutely
necessary to apply the works Of protection to
| this entire stretch of bank, but only to por-
ton, embracing Nine Mile Point. The loca-
tions Of the different eavng banks at which
it is proposed to apply the works Of protection
can better be understood by reference to the
at the same time an inspection Of the index
and detailed maps will give all the informa-
ton respecting the depths Of water slope OF
bank, composition Of same, etc, much more
fully than can be indicated or enumerated In
| the report
The results OF the survey Of the banks show
that they are composed Of a hard blue mud
with intermediate soft strata. These soft
strata Outcrop at varying depths, as shown
on adjacent lines OF soundings. In some
cases they are quite regular, in others quite
irregular, as il deposited upon a slope. The
cavings result from the saturation of these
layers Of soft material, which are afterwards
| washed or cut out, causing the snperincum-
bent mass to fall or slide into the river This
caving takes place mostly upon a falling
river. the high water seeming to act by its
pressure in sustaining the bank These Soft
strata occur at various depths from near the
surfaceoto near the bottom Of the river, and
the greater or less amount Of cave seems to
depend upon their relative position.
| In order, then, to retain the bank in its nat
ural position, the remedy to be applied would
seem to be some method by which the cutting
out of the defective strata could be prevent
ed. This is best subserved by applying to
the bank a revetment extending SO as tl
cover the whole slope, or SO much Of it as Is
likely to be affected. The banks along the
city front present conditions not unfavor-
able to the successful application OF a pro-
ject, such as was outlined in our preliminary
report of November last. The general method
indicated there was to cover the slope Of the
| bank with a revetment OF brush and stone in
such shapes and forms as best suited the par
| ticular locality where it was to be applied.
! While much more costly applications OF
timber and stone might subserve the object
| In view, those of brush and stone in the shape
OF mating applied to the banks have the merit
that while suitable for the purpose, they
are comparatively. cheap, are durable, are
easily applied, and on account Of their plia-
bility can be well adapted to the irregular
slopes Of the banks caused by the caving. AT
the same time the carpeting OF the bank in
such manner causes no undue contraction
of the water way and allows the current tc
move along in it's natural course.
At the upper section OF the river at Carroll
ton, and on the right bank above AIgiers
where there are no wharves, it is proposed, In
accordance with the above views, to cover the
III, -
to distance out such that all defectivestrata
will be protected by a layer Of brush formed
into RATS and ballasted with stone sufficient
to keep them in position.
Along the section of the river from Nor
gan's wharf to the foot of Congress street, ii
is proposed to form bulkhead extending the
entire distance in line with the outer row Of
wharf piles by driving piles in pairs. the dis
lance between the centres of each pair being
six feet, and between the piles Of each pair
gether at low water and at the top. Between
the piles, and extending up and down stream
brush fascines are piled up to low
water mark, forming, so to speak, brush
wall. Above low water mark, on the outside
Of the piles, plank are placed extending tc
high water mark. From the foot of this row
of piles, extending out as far as may be
necessary to cover all defective strata, a
| layer Of brush and stone in suitable form Is
laid upon the slope. The object in not con-
as in the other districts, is that it has been
| found from experience that great difficulty
and expense will attend the removal Of the
great number of piles and timber work now
forming the wharves and occupying por.
ton Of the slope needing protection, and
which it would be necessary to remove were
1t determined to carpet the entire slope
adding considerably to the expense and more
than the circumstances would warrant
Statistics at the disposal of the board indi
cate that the largest interests involved are
In section 2, from MOrgan's wharf to Congress
street. 1t therefore seems expedient that
the proposed measures OF protection shoulc
be first applied to that part of the shore
Similar reasons indicate that the work on the
Carrollton section, No. /, should be next done
and, finally, that work above Nine Mile Point
on the right bank which is essential as a pro-
| lection to the works in section and the shore
| below.
The following are the estimates for the pro.
lection Of SO much Of the city front as the
board deems absolutely essential at the pres
ent time to the preservation Of the wharves
and harbor, though eventually the protection
| OF the entire front may have to be undertaken
These estimates being approximations, the
board has sought to make them sufficiently
large to cover all contingencies, leaving to the
engineer who may have charge OF the con-
struction Of the work certain latitude
whereby such changes as may appear neces,
sary, and as circumstances call for, can be
made as the work progresses.
| ESTIMATES.
Section 2, from Morgan's wharf to Congress
| street
Piles and planking at So SO per
running foot. ............ S47,475
Filling between piles, $500
| cords, at 50 so per cord $50 1880
Brush mating, 1900 feet long,
200 feet wide, in position
| and ballasted .... 146,025
| $4,000
| Contingencies ............ ... $4,000
-S235,O 0t
Section l. at Carrollton-
Brush mating, 5000 feet long,
200 feet wide sunk and bal
lasted, at $40 so per run
ming foot ...........S 179,4 400
Contingencies .............. 1860
- $4,000
| Section 8, Nine Mile Point
Brush mating, 1000 feet long,
200 feet wide, sunk and bal
lasted. at $40 50 DER run