The Jasper weekly courier. [volume] (Jasper, Ind.) 1858-1922, 1899-08-11
RAILROADS OVER BOCS.
Oevices Of Engsaeers for Crossfng
dangerous Marshes - Mud
Foundations.

The sinking Of a section Of the main
line Of the South Pacific Coast marrow
gauge) railroad a short distance south
of the bridge across the entrance 10 san
Leandro bay opens up new problem in
railroad engineering TO be solved. The
road bed trayerses the salt marshes bor-
dering the bay almost all the way from
Alameda to Alyiso, and in some parts
these marshes are very soft and cut in
every direction by sloughs. In many
parts the roadDed lies on a foundation
Of mud, to which there is apparently no
bottom; hut 20 long as there is 10 room
for the mud TO shift or no agent at work
undermining il the roadbcd stays in
place. The company has had much trou-
BILE. however. where the recent sub
sidence occurred. Ii has subsidized on
more than one occasion before. and il
has taken a lot of new material each
time 10 bring il up 10 grade. The diff
Guilty grows out OF the fact that the road
embankmont at that particular point is
swept at its base by swift tidal cur
rent. which undermines the soft mud
stratum and causes the roadbed to slip
ia "a hAia OAA VI 0if~ IL. ltdf al AAt ais
and ties hanging in the air. The trou-
besome current is said to have We
locity of Is or lC miles an hour. Ii is
intended 10 control IL BY damming the
source, thus holding the water brought
by the rising tide into the depressed
marsh land in the ne ehbor hood by pre-
venting its outflow.
ta march. IN ? ~, ~
San Francisco and ao acent bays have
perplexed railroad builders since early
days. In spots the mud is so deep that
attempts TO sound in 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-wherc the steam railroads serving
Oakland cross. there is al least 10 feet
of soft mud There the engineers were
forced TO rely on suction TO support the
trestling. and the spliced piles in the
middle of the First street railroad cross
ing are said TO he 40 feet in length and
are held solely by the suction of the
mud itself.
All the piling constituting the foun-
dation 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 in the lower Market
street building rest are held in place by
suction. SO powerful is this suction OF
the soft mud that a pile driven into il
so far cannot be budged by the strokes
u the heaviest triphammers used in pile
driving. and the end OF il Will broom un-
der the blows
The builders Of the California Pacific
railroad encountered much trouble with
a section of soft marsh land adjacent to
Suisun. Time after time the entire road
bed sunk not only out Of sight but out
Of sonndings also. and a sta BILE founda-
ton was only acquired after repeated
filling in, the lower stratum Of mate
rial being held in suspension. il is be-
lieved. in the body of the mud. suction
preventing il from suhsiding further
The engineer Of the Valley railroad
has made a mattress foundation for
the roadbed over the Martinez and san
joaquin marshes like the mattress
foundation which Capt. Eads adopted
for the levccs constructed by him at
the mouth of the Mississippi river.
These mattresses are made of brush
bound together with wire and laid on
the surface Of the marsh. Dre6gers
then lift the mud cut out Of the
trenches on either side and deposit it
on these mattresses, thus forming an
embankment that will carry when thor
oughly settled. many times the weight
IL will ever be required 10 carry. These
mattresses distribute the weight evenly
over so large an area Of the soft mud
unde rlying the marsh that il does not
perccptibly affect il. and the embank-
rnent is practically rs secure and ner-
manent rs if il were built on a founda-
-iu