Savannah morning news. [volume] (Savannah) 1868-1887, 1881-08-18

Progress OF the WOrlk-The Report OF
Colonel Fremont. Assistant Engt-

We have the opportunity OF presenting
this morning copy Of the report made by
Colonel s. l.. Fremont, Assistant Engineer,
to;Major General Q. A. Gilmore, Lieutenant
Colonel of Engineers, noting the progress
OF improvements In the Savannah river for
the fiscal year ending June Both, 1881. The
report sets forth the following, and will, we
are sure, have careful perusal from all. who
appreciate the importance Of this work to
Savannah:
Improvements have been made at the fol-
ing places:
L. At the Cross Tides river.
2. At the channels along the old jetty and
Kings Island.
8 At the shoals at Garden Bank.
4. AT the new ship channel known as
"The Wrecks"
5. At the channel at the distractions near
Elba Island.
6. At the submerged dam in South Chan
mel.
z. At Screven's Point.
s. At Fig Island.
9. AT the Oyster Bed shoal near Red
10. At Tybee Knowl and St. Michael's
Channel.
IL. At the dry dock in st. Augustine
creek.
THE SUBMERGED DAM AT THE CROSS TIDES.
At the close of the last fiscal year the
contractor for this work had completed IT,
with the exception of placing 244.95 cubic
Yards OF rip rap stone Of the superstruc-
tive
This remnant was put in place during the
months Of July, August and November,
the last being laid on the 18Th Of November,
which completed the work.
This dam has withstood the most thorough
freshet tests that have been known in the
Savannah river In many years, and without
injury. The only injurious effect Of this
series of freshets has been in eating away
small portion of the Argyle Island shore,
at the end OF the dam. This was caused by
the eddying of the water produced by
the great volume passing through the open
ing Cor low place left in the wake) for the
purposes of navigation, and the consequent
strong current
This erosion has now been secured by a
mattress of brush one foot in thickness,
20 feet in width and 155 feet long, loaded
with one half cubic yard Of stone to each
lineal foot I'm length Of mat. This opening
should now be closed, or the dam raised up
to the general level, and the passage of
small vessels and flats made near the other
end of the dam, where the depth of the
river above and below is much less and the
force of the current correspondingly weak.
When this dam is raised up to the lowwater
line-as l think 1t should be at an early day
there will be no want of water in front of
the city of Savannah fer a water way and
anchorage eight hundred feet in width, as
desired by the business men of the city, who
look forward to its necessity within a rea-
sonably short time.
The new channel below the city south Of
the "Wreck" shoal has now assumed such
proportions, and the old channel has been so
well closed up, that no danger need be
apprehended from a large increase Of
the volume of water in front river. This
dam is no doubt the KEY to all improvements
of the water way above Fort Jackson.
THE CHANNEL AT KINGS ISLAND AND OLD
JETTY.
This channel, as shown by the soundlngs
heretofore transmitted, has not maintained
its originally dredged depth along the old
jetty, while that portion of it connecting
with the opening that was made through the
old jettY has increased in depth and width.
Dredging done in both braI chee OF this
+ channel since July LIST, 1880, amounts to
"a $40 cubic yards. The work was com
menced on the 10Th of October and CON-
pleted on the Sd day of December, 1880
think another crib seventy 20 feet in length
should be removed from the old jetty, Civ
ing a water way through that structure OF
l40 feet In width. The channels depth and
width from Kings Island to the Central
Railroad wharves have increased all the way.
THE sHoAL AT GARDEN BANKS.
The channel across this shoal has been
Nidened seventy five feet, giving with the
dredging done during the last fiscal year a
channel width Of $50 feet, with a low water
depth of sixteen feet, which has greatly re
lieved the difficulties of navigation at that
place.
The amount of material removed from
this shOal was Is, 813 cubic yards 1t is be-
lieved that the work of cutting away the
salient point of Fig Island, and deepening
the water In its front, will have beneficial
effect In removing this shoal.
THE SHIP CHANNEL AT THE WRECKS sHoAL.
The United States steamer Henry Burden
was employed IN this channel 10 July and
August, 1880, and removed 1909 cubic
yards OF matter therefrom.
This channel has maintained It's full depth
with the exception OF a small shoal formed
at the mouth of a rice field creek, which
| seems to cause perpetual deposit, and the
| only remedy so far is annual dredging. The
| creek must have an outlet into the river,
and its sedtmentarY character requires In
the channel greater volume and conse-
| quent Increased velocity of water to sweep
iG away.
THE CHANNEL AT THE INSTRUCTIONS.
This channel is near the head OF Elba
Island where the river is divided into the
North and South channels, and is obstructed
by sand shoal formed at the slack water
point of divergence OF the two channels. 1t
will continue TO be so formed until some
work is erected 10 aid the current Ia the
Northern channel in destroying any ten
dency to deposit sand there.
The quantity OF material removed from
this shoal by the United States steamer
Henry Burden, in August and September,
was Ii. 276 cubic yards.
THE SUBMERGED DAM IN SOUTH CHANNEL.
This dam was commenced during the last
fiscal year by the contractor, r. @. Mckay,
of Philadelphia, and 425 lineal feet of apron
dam was laid. In December of the present
year, his attorney, 4. G. Ross, recommended
the work and continued 1t In slow and
feeble manner until April 18Th, when it was
wholly suspended. The entire apron course
from high water to high water, was com
pleted in March, giving an aggregate length
of dam of ] ,461 feet. The mats for
a second course 12S feet in length were laid,
and from that point 1902 feet from high
water on the southern shore), the double
mats (second and third course combined)
This leaves about $50 feet of the double mat
to be laid to complete the dam according to
the original design-less than a weeks work
for a suitable force.
This dam consists Of an apron course of
logs IL inches In diameter and "a feet in
length, laid parallel with the direction OF
the current, and fastened together by
binders, drift-bolted to the logs and covered
with course OF stone six inches in thick
ness. UPon this apron course a sand course
OF similar construction, only fourteen feet
in width, is laid, and upon this a third
course 10 feet in width is placed.
For convenience in placing them, and 10
secure greater stability in the dam, after
passing beyond low water depth of feet,
the second and third courses are combined
and the logs OF both courses are fastened
together with drift bolts, and all the stone
of both is placed on the top of the two
courses. This dam stands the current there
very strong) perfectly, and is having the de-
sired effect upon the currents so far as it
has been completed.
The design in locating this dam was to
obstruct as little as possible the food tide
A,@u he oh 81 loA a.