The San Francisco call., 1908-12-21
WALL
IN DANGER
FROM TIDE
Doom of 10000 Feet of the Old
Fashioned Structure Is
Proclaimed
Assistant State Engineer Points
Out Insecurity of Water
Front Buildings
Settling of the Foundations Now
Threatens Equilibrium OF
Warehouses
Half Million Required to Repair
Damage Already Done by
Bad Construction

'"HE tides of the bay OF San
francisco are eating their way
- into the eity's water front.
They have been at the insid-
ious work for years and the doom of
10000 feet of old fashioned sea wall
has been. officially proclaimed. These
facts are revealed in the report OF
Assistant State Engineer Ralph A.
Barker, made public yesterday. Barker
points out the faulty construction that
has brought danger to a stretch of
structures from Mission street to
Jones street
Surface Giving Way
In places the sea wall has sunk
from three to FIVE feet. Big holes are
appearing in the streets where the
surface is giving way to the action OF
the unseen waters. Settling founda-
tions are threatening the eqsilibrium
OF warehouses and along the affected
strip the ferry building probably owes
its survival from the disaster OF 1906
to the fact that the seawall section
under the big structure was built ae-
cording to more modern ideas and OF
more resistant material
The sinking portion of the wall cost
the state $1,520,00O to build. 1t is
estimated that $5OOOOO will be re-
quired for repairs of the damage al
ready done by the tides and to insure
against further action of the waters
Barker has system OF construction
to recommend which he says will
keep the bay where it belongs.
Construction Faulty
The seawan referred to by Barker
extends from Mission street to Jones'
street and is known as Section A. B, 1.
2. 3, A. 5. s. and s. Speaking OF the
work. Barker says In his repsrt-
'This kind of seawan is not entirely
satisfactory, its principal faults being
that it allows the free flow OF the tide
through it. which carries away the
fill behind the wall. and makes 1t diff
ficult to maintain the thoroughfare
thereon. 1t is also faulty from the
fact that il ia difficult to obtain a
foundation which viii prevent the set
tlement OF the wall by the method
described. All OF the seawall. with tho
exceptions OF Sections sa and SO, has
settled considerably. taking down with
it the wharves which 1t supports and
causing much inconvenience and un-
sfghtliness. It viii be my policy to-
recommend the construction in-future
of a seawan which shall be impervious
to the tides and shall have a founda-
ton in which no settlement win occur
Sinking Increases Cost
Two additional sections. Nos. IL and
docks and costing In the neighborhood
Of s2s1.500. are included In the report.
but these have not been complstsd-
There is no immediate danger at
tached to the settlement OF the sea-
wallP said Barker yesterday. 'but the
sinking viii add greatly to the cost OF
maintenance of the whole work.
Warehouses are affected by tha
sinking and so are the streets. Big
holes are torn in the streets by the
settling. and the greatest damage has
been done in that manner.
TN many of the sections along the
front the seawall has sunk from three
TO five feet. In other places it sunk
only a few inches below the original
height. but the entire seawau is set
Ting
The Work Old Fashioned
-Of course the walls have been
constructed on hard bottoms. but the
work is old fashioned and will not
stand the wear and tear that new
concrete seawalls can stand I would
suggest that an entirely different type
of seawalI of concrete or other modern
material be constructed Concrete sea-
walls will cost trifle more. but as the
old style rock seawall needs extensive
repairs each year. the concrete walls
are cheapest in the end"
The method of construction that has
been followed in the building OF
the seawalI consists of first dredging
trench about 100 feet in width. to ths
hard bottom or as near substantial