The citizen-Republican. (Scotland, Bon Homme County, S.D.) 1???-19??, 1904-09-01
WORK OF DEEPENING
BEDS OF Big RIVERS
Recent Successful Engineering Ex-
Veriments Made On the Mis-
3sippi River.
DREDGEB0ATs, PORTABLE IETTlEs
PAINS SrhsS 10 Taken by the Gov
crnmsnr to\akeep Rivers Open
for Navigation.-Appara-
tus Described.

ST. Louis Glcbe-Democrat: Major
Thomas H. Hanbury, in charge of the
corps of engineers engaged in Missis-
sippi improvement in this district has
just completed his annual report to
the chief of engineers for the fiscal
year ending June so, in which some
interesting and successful expert
ments with jet drcdgeboats and port
able ]jettics are described.
During the past two low water
seasons" says Major Handbury, EEK
periments have been made with cheap
devices designed to concentrate the
water at shoal places and, by increas-
ing its velocity. induce a scour that
VIII give Il depth of channel sufficient
Tor the passing needs Of navigation,
these devices to be removed as soon
as they have effected their object or
the river has risen. The results OBJ
tanned last season were very crafty
ing and nave led to the adoption of a
system which may be briefly described
as follows: Having determined upon
the direction that should be given 10
the getty In order to produce the best
results and admit Of the easiest posi-
BILE construction, piles are driven firm
~ into the bed of the river along this
line at distances apart varying from
ten to twenty feet, depending upon
the depth of water and the strength
OF current. In extreme cases, instead
OF single piles, clumps of two or three
may be driven. Along these piles at
q proper distance above the water sur
face other piles are made fast longitu-
dlnally either by wire or rope. They
are to support the upper ends of cor
rugated sheet steel panels, the lower
ends OF which are to rest upon the bot
tom of the river. Each panel is ten
feet in width, measured in the Girec-
ton of the jetty, and from ten to
twenty feet long, depending upon the
depth of water in which it is to be
used. 1t is made of No. il United
States standard gauge corrugated
sheet steel. Suitable links or cleyices
are provided for handling the panels.
To prevent scour taking place along
the lower edge of the panels, and thus
permitting them to swing through be-
tween the piles, a mattress from eight
to ten feet wide is made by placing
small fascines side by side. This is
tied to the lower edge of the panels
and sunk with. AT the end of the low
water season the ~jetties are removed.
The panels are taken out, cleaned,
painted and stored. The piles are
also removed, to be used in future
work.
WORK WITH PORTABLE JETTIES
During the last low water season
portable jetties were constructed and
removed in the following localities:
Turkey island, 1850 feet; Ste. Gene
We've, 1,460 feet; Shinneman's 1000
feet; Goose island, $50 feet, and
Hecker's bend, 1850 feet, making in
all $3.50 feet. The field expenditures
for this work amounted to S~15,sO1.25,
equal to $2.41 per lineal foot. Add to
h proportionate expenses for
plant, repairs, deterioration, towage,
officers, engineer depot, etc, which
amount to S13,049.O6 or, $1,9s per lin
cal foot, the total cost wa S25, 850.3I,
or $4.4o per lineal foot. The cost of
the piles and panels not recovered was
S2,499.27, an average of IS cents per
foot. Had these been recovered the
total cost per lineal foot would have
been S4.o2.
In each Of the localities where let
ties were constructed, except at Sew
enty-six landing, their effect was has
tened by the aid Of No. / jet dredge
OF the steamer General Abbot. The
channel depth was increased from one
to three feet at points as follows: At
Turkey island, two and three-fourths
feet; Ste. Genevieve, one foot; Sew
enty-six landing, two feet; SHINE
mans three feet; Goose island, one
and one-half feet, and Hecker's bend,
n foot. These measures are after
allowances has been made for differ
ences in the stage Of water. The least
channel depth at any of these locali-
ties where the jetties were removed
was eight feet.
1.-THE foregoing facts and figures
fully demonstrate that it Is practi-
cable, within reasonable limits of ex-
penses, to maintain a navigable chan
six feet in depth at all stages of
watch between ST. Louis and the
mouth of the Ohio river by means of
portable j%etties, aided by dredges, pro-
yided that the permanent contraction
works now in process of construction
be maintained and proceeded with,
n there is every reason to believe
that a channel depth of eight feet can
be maintained by this means, when
the whole reach Of the river has been
permanently contracted within the
limits contemplated in the project for
its general improvement"
THE JET DREDGEBOAT.
In his last annual report, Major
Hamburg gave a brief description of
a jet dredgeboat then in process of
construction. This boat" he SAYS,
was completed and commenced oper
atoms about September 1 on the APP
proach of low water. From this date
until the end of October, when the
river commenced to rise, it was in
Work was done by 1t at
Ha~rrisonville crossing, Calico island.
Stanton Towhead, Grand Tower bend
and Shinneman's. At all of these To-
caities the channel was materially
improved by its operations, the depth
being increased from one to three
feet. This outfit consisted of the
dredgeboat, a quarter-boat, a pile driv-
q barge with supply of coal and
piles and one of the steam tenders.
dredge was furnished with a dou-
bic crew during q part Of the time
that it vas in service, in order that
It might be operated night and day.