Morning appeal. [volume] (Carson City, Nev.) 1877-1906, 1899-09-03
OVER THE MARSHES.
How Engineers Build Railroads on
Mud Foundations
B~otton,less Dogs Are Brfdgcd Over 10y
the Use OF Hrnsh M~attresses-
Some Difficult Under
tnEings.

The sinking Of q section of the main
line of the South Pacific Coast (narr6w
gaumc; railroad g short distance south
of the bridge acres the entrance 10 San
Leandro bay opens Up 4 new problem in
railroad en"ineerin" to be solved. IEC
roadbe3 traverses the salt marshes Dor
dering tue bay almost all h way from
Alameda to Alviso, and in some parts
these marshes are very soft and crt in
every direction by sloughS. In many
parts the r0adhCd lies On 2 foundation
OF mud. to which there is apparently no
bottom; but 50 long as there is no CON
for the mud to shiftor agents at work
undermining il the roaGbcd stays III
place, IT, company he's had much trou-
ble. however. where tha recent sub
sidence occurred. It las subsided IN
more ttan OUc occasion before, and it
has taken a lot Of new bacterial each
time to bring it up to grade. The diff
Guilty grows out Of the fact that the road
e~mbankment al that particular point is
swept at its East by a swift tidal cur
rent. which undPrmines the soft mud
stratum and causes the roadbed to slip
in a body out OF sight, leaving the rails
and ties hanging in the air. The 1rou-
blesomr current is said 10 have a We
locity Of Is or IL miles an hour. 1t is
intended to control it by damming the
source, thus holding the water brought
by the rising tide into the depressed
marsh land in the neighborhood by pre-
venting It's outflow.
The marshes in the neighborhood of
San Francisco and adjacent bays have
Dsrpiexed railroad builders since early
days. In spots the mud is so deep that
attempts to sound it have resulted in
the discovery of no bottom. At those
points on the north arm of the estuary
of San Antonia-that is, the arm con-
Meeting Oakland creek with Lake Mer-
ritt-where the steam railroads serving
Oakland cross. there is at least 10 feet
of soft mud. There the engineers were
forced to rely on suction to support the
trestling, and the srlioed piles in the
middle of the First street railroad cross
ing are said to be 10 feet in length and
are held solely by the suction OF the
mud itself.
All the piling constituting the foun-
dati0n Of the ferry building at the
foot of Market street and much of the
piling driven into the made land on
which the foundations OF most Of the
big buildings ii tie lower Market
street building resi- are held in place By
suction. So powerful is this suction Of
the soft mud titat . pile driven into il
so far cannot be budged by the strokes
of the heaviest triphammers used in pile
driving. and the end Of it viii broom I'm
der the blows.
The builders Of the California Pacifi,
railroad encountered much trouble with
8 section of soft marsh land adjacent t.
Suisun. Time after time the entire road
bed sunk not only Il Of sight but GU
# soundings also, and a stable founda
ton was only acquired after repeated
filing in, the lower stratum of mate
rial being held in suspension, it is be
lieved, in the body of the mud, suction
preventing it from subsiding further.
= The engineer of the Valley ~railroa'
has made a mattress foundation 70
l the roadbed over the Martinez and Sa,
Joaquin marshes like the mattres
, ~fcunIatlon which Capt. Eads adopte
FOR The Ievees constructed by him a
the mouth Of the Mississippi rive
These mattresses are made of brus
bound together with wire and laid o
! the surface of the marsh. Dredgei
- sAen lift the mud cut out of til
trenches On either side and deposit
on these mattresses, thus forming {"
embankment that will carry, when tt>
N1hly settled, many times the ~c;Ci
it will ever be required to carry. IE>t
mattresses distribute the weighr.vI@
over so large an area Of thc Sc; TT
underlying the marsh that /; dcea EC
p~erceptibly affect it. and thu tn.cGrI
- ment is practically as secure aEd &c
. nanent as If it were built on a found
ton Of rock.-San Francisco Chronicl