The Coeur d'Alene press. (Coeur d'Alene, Idaho) 1906-1907, 1906-10-08

Eu6J Fails iuhHot Oeb D. - me
installation of beartrap gate, or
more properly speaking, a movable
dam Of the beartrap type, at the
north channel controlling works Of
the extensive power development by
the Washington Water Power com
pany AZ Post Falls, on the Spokane
river, has awakened considerable In
terest and speculation as TO the man
ner Of its construction and operation,
a. we'll a. It's history and develop
ment to It's present stage Of perfec.
tion, said w. @. Weeks, superin-
tendent of construction for the Wash
ington Water Power company. Con-
tinuing, be said:
AS FAR as Is known TO me the bear
trap dam at Post Falls Is the only
one Of It's kind In the Inland Empire,
and brief description and history Of
this gate and It's prototypes may be Of
interest To those connected with the
various power development enter
prises 10 the northwest, as we'll as to
those who take general interest In
things out Of the ordinary.
THE design and construction of
means for controlling the flow Of wat.
or IN sluicas, fumes and locks has
been given very close and detailed
study by European engineers for
many years, and II may here DO noted
with satisfaction that the beartrap
type Of movable dam, Is distinctly an
American invention, and, strange to
say was the direct result of the neoes-
atty 81 obtaining supply Of anthra'
cite coal TO operate wire mill in
1878.
"No gate or dam heretofore con-
structed was suitable To the purpose,
so Josiah White devoted his talents
20 constructing a movable dam which
could be- made 20 impond water In a
pool. and then fold up or collapse
sufficiently to allow coal harges TO
pass over Il with the rush OF water.
He devised such dam. and In order
10 demonstrate is practical workings
had small gate built In an expert.
mental sluice In Mauch Chunk creek.
Curious persons were evasively an
awered by the workmen that they
were building beartrap, and this
form Of dam has retained the name of
s'beartFap" ever since. A number OF
dams were built In tho river, supplied
with beartrap gates, and their use was
20 successful that they became Of
great Importance In hydraulic devel.
opment.
THE first boartrap dam consisted
Of two fiat. rectangular levers, three
levers having a width OF certain ra-
ito TO each oth0r and length equal
TO the width OF the sluioe they were
10 control. Tho total rise OF the dam
Is limited by means OF number Of
chains fastened to the under side of
the lower leaf, which coil mp ON the
bottom Of the chamber when the gate
h down. The successful operation Of
the device depends upon an unhal,
anced hydrostatic pressure ON the
levers OF the gate when the pressure
Of the water above the dam is admit
ted 10 the chamber beneath,
with the development of naviga
ton In tho United States came fur.
Their study Of beartraps A man OF
prominence, Ashbel WEIGH, came onI
boldly with his approval OF the typs
and We hear Of board Of United
States engineers recommending the
adoption of the beartrRp for dam a,
Beattyville ON the Kentnckey river,
m 1886.
Naturally a number OF improve
ments were proposed some OF which
we're variations, others alterations,
and some having distinct merit, The
development may be readily traced