Freeland tribune. (Freeland, Pa.) 1888-1921, 1902-02-05
THE GREATEST ELECTRIC SPAN.
It is Nearly a Mile Long and 1t Carries
Power to San Francisco.

More remarkable than the Niagara
Falls electric plant is one in the in
terror of California on the Yuba River,
200 miles from San Francisco. The
California plant has water wheels of
greater capacity than any others of
the kind in the world, and its genera
tors are the largest machines Of the
type ever constructed. The generated
electricity, moreover, is carried farth-
er before it is used than such power
has ever been carried elsewhere. To
get the electrical energy to its destina-
ton one of the most remarkable
achievements in the history of engin-
eering has just been completed.
The Straits of Karquines, across
which it was necessary to carry the
electric power il the best market was
to open to it, connect San Pablo and
Suisan bays, which together form the
northern part of San Francisco Bay.
Through this comparatively narrow
channel the entire central region of
the State of California is drained, and
in addition there is an ocean tide of
about five feet, so although the water
is more than 100 feet in depth there is
at all times a heavy and dangerous
current. Experiments proved that
while it was barely possible that
telegraph or telephone cable might be
laid in these waters, the laying and
operating of the huge wire ropes de-
signed as tunnels for the passage of
electrical power current was out Of
the question. The straits are about
mile wide.
"If power cables cannot be laid un.
derneath the water, why not suspend
them aboveI" said the engineer, and,
accordingly, the construction of a gi
gantic suspension bridge consisting OF
four cables was begun.
Two slender steel towers, each as
high as an ordinary Office building.
We're reared on opposite points of land
overlooking this mile-wide waterway.
The United States Government, in
granting permission for the crossing,
stipulated that the cables should be
suspended at least 200 feet above the
surface Of the water, since the peak
OF the highest mast of the Shenan
doah, the largest vessel OF the Amer
lean merchant marine, is 1874 feet
above the waterline.
The bluff on the north side of the
straits on which the tower is erected,
Is 162 feet above extreme high tide,
and the great steel skeleton itself is
225 feet in height. The tower on the
south shore is not in itself so lofty as
the other but being perched on higher
ground its top is fully eighty feet
higher than that of the other tower.
The erection of these towers probably
called for more daring On the part of
the men who built them than any sky
scraper that was ever constructed.
There is variation in temperature
of about sixty degrees at the Straits
of KarQuines, and this will cause a
variation of fully five feet in the sag
of the great cables. The cables are
made of steel, and are each nearly an
inch in thickness, there being about u
score of wires in the twisted strand.
For each cable there has been proyid-
ed an anchorage in the form OF q mass
Of concrete almost as large as an
ordinary room, and the great wire
rope is wound around Il wheel cou.
pie Of feet in diameter.
Four cables span the Straits Of Kar-
quines, but only three are in use at
any one time, the fourth being held
in reserve. This enables the cables
to be cleaned or repaired at any time,
ard it would be difficult to imagine
more exciting task than that OF the
man who must travel out over the ex-
panse of water in tiny car suspend
cd from the cable, which &c greases
as he slowly glides below it.
Strangely enough, the cables move
less on windy day than on q per-
fectly quiet one. On morning when
the air is still a person can put his
hand on the cables and feel continu.
GUS jarring movement, whereas, if he
takes hold of the same cable when a
breeze is blowing he will find it free
from movement.
Prior to the erection of the cables at
the Karquines Straits the longest span
on the North American continent for
carrying electric power over water
was that Of an electric lighting CON-
pany in British Columbia, which
spanned the Columbia River in a
stretch OF 1900 feet. Inasmuch as
this new California wonder swings
through the air for three times that
distance, it is the most remarkable
structure OF the kind on the globe
New York Sun.
Disinfect Rag Dolls.