The farmer and mechanic. [volume] (Raleigh, N.C.) 18??-19??, 1911-05-30

cables at the stern and noiu the 'eSSeI
back, keep it from moving too IaSt anu
stop il when the gates are cleared. AS
nearly every accident in lock operation
in the past has arisen from Vesseis
passing through under their own
power. the electric towing locomotives
practically insure absolute saIe'y.
But. with that characteristic oe-
termination to eliminate every poSSlpic
chance OF accident. Chief Engineer
GOethals has gone even further IheTe
will be two sets of gates at every F1tai
point in the lock system, so that II,
by any remote chance, a vessel SnOula
ram down one set there still would be
another to protect the lock. IneSe
double gates at vital points move IN
unison. SO that there are always two
effective safeguards. Should a vessel
break away from the towing appar-
atus or otherwise become uncontrolled
it might. one time in many thousands.
succeed in battering down n gate.
Should it do 50 there is still not a
lance in a million that it would ram
down the second one.
But suppose it did-the canal locks
will be prepared for it. A large can
tilever bridge will be mounted on a
pivot base on the middle wall at the
upper end of the uppermost lock. In
case everything went wrong and the
rotC1 11ou1o - 0AAAA
the locks at a destructive speed Of
about twenty-eight feet a second, this
bridge would be turned across the lock
and a set OF wicket Orders, made or
the hardest nickel steel, would be let
down, one end fast to the bridge n
the other end engaging an offset in
the lock DOR. Each Of these Orders
would make a sort Of perpendicular
railway, on which huge sheets of steel,
oo,,nfo6 an y o11-hoor ino rO1larS 1JOn1H
be let down to check the current.
When all the wicket girders and all
the sheets of steel are in position they
will make a steel dam which Will ef-
fectively restrain the flood. There is
such an emergency dam at the Sau1t
Ste. Marie canal. and although it a
grown rusty by disuse, it was most eff
fective when am accident occurred
there some time since.
The gates by which the water level
in the locks will be regulated are
ponderous affairs. their weight vary
ing from 500 to 500 tons. Each gate
is composed Of two leaves, hinged to
the sidewalks Of the locks like an or
binary pair Of one-Way double doors,
except that they do not shut straight
across the channel, but come together
like a flattened V, with the apex point
ing upstream. Forty-six gates of two
leaves each will be required in the lock
system. They will be opened and clos
ed by a huge arm weighing 10000
pounds, n having a diameter of six
teen inches.
The work Of building the six locks
required for the canal is proceeding
with unexampled dispatch. 1t requires
over two million barrels of cement and
as many cubic yards Of stone and of
sand to build the locks at Gatun. Prac-
tjC9IIE the S1n1Q MONT will hn rn-
CURED for the Pacific locks. The
work at Gatun was twenty months old
May l, n the locks are approximate
ly two-thirds. completed. Those on the
Pacific side are also going forward at
a surprising speed. The sand for the
concrete is taken from islands in the
Atlant1c and the Pacific by dredging,
and the @ from Porto Bello and
Ancon. The Porto Bello plant can
crush six thousand two-horse loads Of
rock a day. The concreting materials
for Gatun are brought to that point
through the canal on barges' under
tow.
The concrete handling plant at Ga
tun is the largest of it's kind In the
world. Huge clam shell buckets car
ried on big cableways, n operated
entirely by machinery. unload the sand
and rock from the barges without the
lifting Of a single shovelfu1 by hand
1t is loaded on automatic electric cars,
in exact proportions. and is carried to
the big concrete mixers which handle
more than two two-horse- loads at a
time. The cars on the electric rail-
way, which is a double tracked, cir
'cular railway. need no motorman. BY
means Of a governor or rhetostat, the
current is SO regulated h la their speed
is kept constant at about three miles
an hour.
When the concrete mixers finish
their task the concrete is dumped into
big buckets mounted on flat cars
drawn by small electric locomotives.
These haul two buckets to a point un-
der a big galloway, where they are
lifted off by machinery and carried to
the point where they are needed in the
lock construction. When the loaded
buckets are taken from the cars,
empty ones are substituted and the