The herald., 1894-09-30
would lead to still more rapid shoal-

| 1890 ~
ing.
DEFECT AT SAN PEDRO.
Unfortunately at San Pedro the break
water had to be either connected with
the shore or built with an opening about
1000 feet wide to accommodate vessels
and the shore currents. II the latter
plan were adopted the southwest swells
(and they are the principal ones to pro-
teot against) would enter freely, and
with marked and annoying distur bsnce.
into the harbor, striking at an angle
against the whsrves, if built out to deep
water. Under such conditions the har-
Dor could not be considered protected in
any sense OF the word. The area actually
protected beyond the four and a half
fathom line would be very restricted and
of but little value to commerce. An ex-
animation OF the email chart of this
harbor accompanying House Elk. Doc.
No. Al. with the direction of the swell
shown on it, will convince anyone OF the
| correctness OF the above statement.
SERIOUS DILEMMA.
The board OF 1892 recognized the se-
rious dilemma in which they were placed,
and considering it bset, no doubt, to
take the hazardous risk of the harbor
| filling up by the action OF closed
| break water, recommended it in order to
escape the other serious alternative.
At Santa Monica, or Port Los Angeles,
the conditions are favorable to easily
meet both of the above conditions of
ocean swells and currents. There will
be ample area between the AZ fathom
low water curve and the breakwater.
This area is nearly mile wide, suffi-
cient for handling vessels in and out Of
the wEarves and at the same time admit
OF the anchoring and maneuvering in
the harbor, if required. of large num-
ber of vessels.
HARBoR AREA AT PORT LOS ANGELES.
The protected area between the AZ.
fathom curve and breakwater built on
the 9fathon curve and $3.50 feet long, as
designated by the board OF 1891, is over
750 acres, which would accom- mmodate
from $50 to 800 vessels at one time, in
addition to those lying at wharves ex-
tending to the Al -fathom curve. 1t is
of interest to know the distance from,
say, the 3fathom curve to the AZ.
fathom curve, as this gives the measure
OF usefulness of the hsrbor for wharf
purposes for all craft, large and small.
The distance averages 400 feet, and is
eS tended, without unduly interfering
with the harbor area, to the 81 fathom
curve, If thought best. which would give
an average length of wharf room be-
tween this curve and and the 3-fathom
curve of about 2800 feet. Offering over a
mile OF wharf room on each wharf. The
easy, uniform slope eeaward is one of
the advantages of this harbor. West
ward of the end of the hreskwater there
is Tree open space three-fourths of q
mile wide for navigation and the unob-
structed movement of the ocean cur
rents.
DIsADvANTAGEoUs CONDITIONS.
At San Pedro the conditions are not
as advantageous; the shore line is not
parallel to the breskwater and the mouth
OF the river, and the jstties required to
maintain channel OF about IL feet into
an inner harbor of restricted dimensions
occupy much OF the useful area and a
considerable part OF the shors line.
The board OF 1892 feared that the pile
wharvss to be built at Santa Monica out
to deep water would cause deposit and
fhRShioots haS hot ahare fe t5s esf Rs bpt
wharf at Port Los Angeles. extending
nearly mile into the sea and about l30
feet wide for quite distance near the
sea end, has been in place about one
year, sufficiently long to test this matter.
While at Port Los Angeles | detected q
slight deepening at the end of the wharf;
since then careful soundings have been
made at my request along the deep-water
portion of the wharf, and covering over
one-third OF its length, to determine this
question.
THE MATTER OF sHoALINa.
The comparative record of depth taken
at several dates, the last being April 5.
1894, slows slight increase of depth.
This, in my opinion, might have been
expected where material composing the
bottom ia abradable. The shore cur
rents require their normal section in
order to flow easily. II pile bents, as
obstacles to the free flow. diminish this
section, the currents at once will, by
slight increase OF velocity, remove the
material between the bents and thus re-
store the sectional area. This ia what
has happened, no doubt, at the Port Los
Angeles wharf. and the building OF other
wharves will not alter these conditions
or induce the currents to get along con.
tentedly with restricted areas.
CAPACITY FOR wHARvEs.
At Port Los Angeles the distance from
the shore to, say, the 4 2 fathom curve
is uniformly about one-hslf mile and
over ground suitable for building
wharves the entire length hbehind the
breakwater. At San PedroEitis one
half to fve-eighths of mile at the
westerly end of the harbor, but about
| Ia miles along the ea8terly portion, fur
nishing q convenient distance for wharf
construction at only one point. whore
| the Southern Pacific has built its wharf.
That the conditions for building out
the wharves at Port Los Angeles are
much more favorable than at San Pedro
is shown by the Two wharves already
built at each place by the Southern Pa
cifc company. At San Pedro the piles
had to be placed in openings blasted
into the rocky bottom by dynamite; at
Port Los Angeles the material is good
for driving piles.
SUB STRUCTURAL CONDITIONS.
They were driven from 10 to 20 feet
into the sea bottom. and into sufficiently
hard material to sustain any load re-
uuired. There ia no rock bottom and no
hidden dangers. The borings, also, out
to so feet of water show good holding
ground for anchors, the material being
clay, gravel in patches near the shore.
mud and sand. The material brought
up on the piles, whenever for any reason
they had to be Withdrawn, was stiff
pcud and sand and CLAW As shown bv tn e