The watchman and southron. [volume] (Sumter, S.C.) 1881-1930, 1922-12-09

now. The Santee river, the Wateree.
the Savannah span near Augusta
and the new bridge over the Savan-
nah river near Savannah. In an
article in The Manufacturers Rec
ord, Robert G. Thomas. editor of
the South carslina highway bulletin
and engineer in charge Of records,
writes interestingly of these pro-
seets The article deals principally
with the Santee River bridge and
includes "a number of pictures Of
the work. It brings out many in
teresting facts about the progress
being made
she article follows:
There are now under way in
South Carolina four major bridge
projects, the Santee River bridge,
the Wateree River bridge. the
Savanann River bridge near Au-
gnsta, Ga and the bridge over the
Savannah river near Savannah, Ga.
! Sansee River Bridge.
Ono Of the great rivers Of the
South IS the 5Santee. Formed by
the confluence. q few miles below
Columbia, Of the Congaree and the
Eaterec,s it reaches the sea near
tie center Of South, Carolina's coast
line between Charleston and
Georgetown. With its various
tributaries It drains most of the
state and part Of North Caro-.
lima, about Is. 600 square miles al
together. Bordering the river on
each side are thickly tinabered
swamps four or more miles wide.
separating an important section OF
the state and preventing free
raFei between the two portions,
There IS a highway bridge over
the Congaree at Columbia, and
over the Wateree there is one at
Camden and one almost completed
between Columbia and Sumter. but
there is no highway across the
santee.
TO remedy this situation, there
now under construction Cbegun
June 21, 1929 a bridge over the
Santee and a causeMay across the
sMamp. near ST. Stephens, a town
about SIS miles above the mouth OF
the river. at the site the main
channel is about $50 feet wide and
sne swamp is nearly four miles
wide. Ia order to reduce the main
tenance charges to a minimum al
structures. except the main span,
are Of reinforced concrete. The
beidge IS to have an 1S-foot road
5 way ana will be above the highest
kaown water. AS the Santee is a
nayigab1e stream. a 63 foot draw
saan is provided, The main chan
Hfsl crossing has enc $50 foot steel
Trough truss swing span and two
1aa0 foot steel through truss fixed
spans on concrete piers.
The approach trestles have a
total length of about ssoe9 feet.
There are seven trestles of lengths
and positions such as. to provide
for the most effective discharge of
the fIoed waters. These trestles
alternate with earth embankments.
The plans provided for two types
Of structure, one type having "a IL
foot concrete beam spans on con-
crete pile bents, the other pedestal
type, having 36 IL foot concrete
beam spans on cast in place bents
on timber piles. The later, how
ever. have been used to a small
extent only
There are four precast piles to
the bent. the two outside piles
being put up with. a batter. These
piles are cast on the nearest high
ground. in yard which contains
10 forms. They are left in the
forms one week and then allowed
TO season one month before driy-
ing. The trestles were designed
for a live load of two i5-ton trucks
Hith 25 per cent. allowance for inn
pacts. The embankments are to be
( . feet. high. have a total length OF
! I33.200 feet. and viii require $780,
{ 600 cubic yards Of earth.
material for the fills is being
taken from borrow pits outside the
smamps. Progress is being made
on the fills on the Williamsburg side
Of the river. which requires 10000
cubic yards. The fills on the Berke-
ley side inveive the excavation OF
SS8.9o0 cubic yards Of material
from a As acre borrow pit. Under
energetic superintendence with
standard gauge equipment this part
of the work is proceeding rapidly,
and the average OF about 10000
\ cubic yards q month will probably
be maintained to the end.
sIn all there are now. as this
is written. 10000 cubic yards OF
earth fill IN place: four river piers
are completed and the draw span
erected; 490 concrect piles have
been driven and $50 concrete piles
have been cast: and the decks for
70 spans OF trestle have been pour
ell.
To Protect Trestics.
in order to protect the trestles
from the heavy drift carried by the
gantee in flood. a strip Of land 225
sset wide is provided on the up
stream side of the right of way. on
which the timber is to remain
standing 50 long as protection 20
the trestles is necessary
Wooden ratings are to be used