The New Orleans daily Democrat. [volume] (New Orleans, La.) 1877-1880, 1877-11-01
THE PROTECTION LEvEE.
what surveyor d'Hemeceurt Has to say
In Reply to Gen, Heauregard.

In Reply to Gen, Heauregard.
On Tuesday morning we gave brief state
ment Of Surveyor d'Hemecourt in reply to Gen.
Beauregard's letter the protection levee at the
lake and on the drainage Of the city, in which
the Surveyor asserted that Gen. Beauregards
reference to his proposition of protecting the
reveted levee must be the result Of misundsr-
standing Of his plan by the General.
Yesterday we had a formal interview with the
Surveyor, who had then carefully reviewed Gen.
Besuregard's letter.
La The course Of our conversation Mr.. diem
court said !" When the project of the lake pro-
lection evee was conceived, l was not officially
connected with The city. but as al engineer
was strongly opposed to IL not that doubted
lie merits, but because thought then as | do now
that before protecting and draining uninhabltable
swsmps thorough system OF drainage and pro-
lection ought to be established for that portion of
the city which is inhabited. / was, az l sm now,
OF the opinion that this could easily be- accom-.
plished.by using the Metairie and GENTLY ridges
aud placing locks and hood-gstes In all the canals
crossing them.
In spite OF what all engineers could do or Say,
the existing piece of lake shore lev was built,
think it should be maintained, especially at the
small cost which Ii is proposed to eKpend upon 1t.
'Well," we asked, show about your close piling
project which the General or.tieises2"
Mr.. D'Hemecourt-Ge Bsauregard evidently
confounds two OF my propositions. My original
proposition to construct a row Of double close
png, several feet out into the lake, in front Of
the protection .evee when that levee was intsot.
in may last, hence before the storm: and my
second proposition,
lr..Sx 1t ntxne AL thA Eeut tfna
the very grounds urged against it by Gen. Beau.
regard: q at lie, that the waves Of the lake upoa
recedipg from the inclined plane OF the levse
would excavate the bottom sand in the angle be-
tween the levee and the piling.
My present proposition Ia to cut the levee, CIV
ing Its outer slope an inclination OF fifteen de-
grees from the vertical line, instead Of its present
slope OF sixty or seventy degrees; to construct
Immediately In front OF the outward base OF the
eyee 30 cut 4 work composed as follows: q sheet
ping Of two rows OF overlapping cypress plaDks
two inches in thickness, resting against the 1evee
driven five feet into the bottom OF the lake, and
extending three feet and half above the Metal
RE Ridge level.
This sheet.piling il to be secured on two longi-
tudiual pieces, six by eight, braced with two
braces ~ each Of the old piles now existing 10
the old work, which are ten feet from centre to
centre. Three feet outside Of his sheet-piling is
TO be sunken row of close round Cypress, piles
not ees than ten inches in dianieter--driven
twelve feet into the bottom OF the lake. the tops
to be sawed off at the height Of the Mstairie
Ridge; the space between the sheeting and the
round plies to be filed in with fsscines, on top OF
which there shall be placed not les than tour
feet OF brickbas or ballast. Both the sheet
piling AMI close piling are to have an incline
equal to that of the levee.
rhs system, maintain will resist the effects of
any storm. have. 1 think. suffi GENTLY estab-
lished by Mr.. Lebeaus experiment at Milneburg,
made in 1912, its strength aud durability. The
cypress piles that were driven there thirty five
Years ago are az sound to-day. up to the low
water line, as they we're when they we're first
driven; and / think that can safely say that
nine tenths of them are yet standing up to their
original height
"Now please explain." we asked. "about the
statement OF MIR. Roy regarding the close piling,
which he says has been washed away at Milne
| burg, and which is referred to by Gen. Beaure-
gard in his criticism OF your plan2"
Mr.. d'Hemecourt-The error OF Gen. Beaure
gard ia not one in engineering; it ia the result Of
taking Mr.. Roy'a letter as basis. The Glove
| pilinR the sheet piling, the fascines and the
! bricks thrown in between them-the foundation
| OF my system-are still there, on the west side Of
the track Of the Pontchartrain Railroad, at Mil
neburg, as you have seen for yourself. The
works spoken Of by Mr.. Roy as having been exc
cuted by Mr.. Pandely were on the east side OF the
track aud were not constructed on the same
principle at all. They consisted Of q row OF
double sheet piling, by IL planks, driven twelve
| feet into the bottom OF the lake.
There may have been brickbats placed at the
footing of the planks, but there was no close
ping outside of these bricks. Hence the action
Of the waves striking against the vertical surface
OF the plank breakwater, the planks were under
mined and with the bricks, were washed away,
thus destroying the works attempted on the east
side OF the railroad.
the water will not wash away the works contem-
plated according to your SYSTEM"
| Mr. d'Hemecourt- two reasons. l. Be-
cause round pilings offer a non-refscting sur
face; Q. Because the waves beating through the
small interstIces between the piles take away the
sand, the vacuum being filed by the sinking of
the fascines and ballast; and when these fascines
and ballast shall have reached depth Of five feet
below the surface OF the bottom, there will be nc
more digging out by tia action OF the waves;
consequently the material under the surface Of
the water, being of an imperishable nature, the
lakeshore will be permanently fixed to the height
Of low water.
"But. we asked again. seen. Beauregard says
that he spprehends that you have not entire faith
in YOUR experiment, since you propose also to
test the efficacy of your protection plan by de-
posting ballast in layers between two rows Of
close niles aud pouring liquid cement therein (ol
as it is called, 'groutng) to fill the interstices
and solidify titus forming sold wall"
MIR. d'Hemecourt-I have never said anything
of the kind I have spoken of q ballast (not 1
concrete) wall, that might be constructed at {
cheaper rate than any other, Immediately behinC
the work I propose, because of the necessit.
otherwise of digging far bslow the water line t
establish the foundation of a wall. which woult
; be very costly and unsafe. In fact, assert tina
whatever work, whether a brick, concrete o
ballast wall, or earth levee, is built out in tn
water at the lake, must be protected at its bas
according to nv plan, unless the very expensive
! method Of bui ding wall with a foundation OF q
, least five feet below the bottom Of the lake i
t adopted, which. presenting still an even aud re
fecting surface, would yet be unsafe, as hav
, already said.
Its. therefore, .clesr that do not propose t
| construct wall by pouring liquid cement ore
the ballast to be put on top Of the fascines, be
tween the sheet and round piling. This clos
lpihng plan il ono proposition; the building Of |