Honolulu star-bulletin. [volume] (Honolulu [Oahu, Hawaii]) 1912-2010, 1913-09-10

ScFlDe.
A simple definition of lock IS a
walled chamber between TWO bodies of
water of different levels have gates ut
either end, in which il is possible tol
confine vessels while they are being
raised or lowered from one level tol
another by allowing water TO flow in
or out OF the lock chamber.
The method Of raising or lowering
the level of the water in the lock
chamber varies on different lock ca
nails. The lock chambers on most OF
the old canals are emptied or filled
through sluice gates that slide up and
down in the lock gates themselves.
This system, however, caused a great
deal of surging of the water at that
end of the lock at which 1t was flow
ing in or out, and the system that has
been adopted on the Panama Canal
was designed with the idea of avoiding
this disturbance OF the water in the
lock.
All the locks ON the Panama Canal
have two parallel lock chambers, sep-
arated by center wall The water is
brought in or out of these chambers
eter passing lengthwise of the lock
through the center and side walls.
Branching out from these tunnels at
right angles and running out under
the lock floor are laterals, and these
laterals communicate with the lock
chamber through openings in the lock
floor. The flow of water in or out of
the lock is controlled by the gate.
valves located at both the upper and
lower ends OF the feed tunnels. In or
der to raise the water in the lock
chamber the valves at the lower end.
are closed and the ones at the upper
end opened. The water then flows
from the upper level into the lock.
passing down tho tunnel in the side
wall, and out through the laterals UNI.
der the floor, coming up through the
openings in the floor. 1t continues to
flow in this way until the elevation of
the water in the lock chamber is the
same as that of the water above. To
lower the water in the lock the proc-
ess is simply reversed. The upper
valves are closed and the lower ones
opened. The water then flows out
from the lock chamber and, passing
back through the same tunnels that
brought it in, seeks the level of the
water below. So that in order to
raise a vessel from one level to anoth-
Ter the level of the water in the lock
chamber is brought to the same level
as that at which the vessel stands.
The lock gates are then opened, the
vessel passes into the chamber, and
the gates are closed Water is then
allowed to flow into the lock until the
vessel is raised to the level of the up
tper body of water, and with the same
level on both sides of the upper gates
those gates are thrown open, the yes
Isel passing out at, asgreater. elevation
than that at which it entered the lock.
The big tunnels passing through the
side walls are the main operating
| tunnels, the one through the center
wall being an auxiliary used to assist
in filling the lock during the aatter
part of the operation, thereby increas-
ling the volume of the inflow at the
time when the velocity of the water
lentering the lock from the side wall
tunnels is decreasing, keeping up in
that way an average rate Of filling
| which would amount to about two feet
per minute So that at Pedro Miguel,
where the lift is 30 feet, a vessel
would be raised from one level to the
other in Is minutes. The desired rate
of filling can be kept up for the 600
foot and 400-foot locks by the side Gull
vert only 1t is probable that the GEN.
! ter wall tunnel will be used only in
case of the 1,O00-foot 1ockages.
Interesting Facts and Figures
Length of canal from deep water
to deep water, miles ...-...... .50h
Length from shore line to shore
Y line, miles ..ss.. ......es........ ~
Time of transit through complet-
| ed. canal, hours =. 10 to II
Time of passage through locks, ;
hours -. .............s...a.
Bottom width of channel, maxi
mum, feet 1000
Bottom width of channel, mini
mum, miles, Culebra Cut, feet. 300
Locks, in pairs :. IL
LOCKS, usable length, feet ....... 1000
Locks, disable width, feet ........ 10
Gatun Lake. area, so. miles ...... 164
Gatun Lake, channel depth,
feet .... 30 to 40
Culebra Cut, channel depth, feet. 40
Excavation, estimated total, cubic
yards :. 212.504, 13S
Excavation, amount accomplish
ed to Jan. Z, 1913, cubic
yards ...............18 S, 2S0s 312
Excavation by the French, cubic
Nh
Excavation by French, useful to
present canal, cubic yards. 20, sos, 600
Excavation by French, estimated
/ value TO canal .$25, 3S8.240
Value Of all French property ...-
............ .$42, 799 ,S26
Concrete, total estimated for ca
nal cubic yards ........ 1000, 600
Weight of cubic yard of con-
crete or earth, pounds 49,. 1000
Relocated Panama railroad, esti
mated cost :. s., 900 900
Relocated Panama railroad, length
miles - =
Maximum grade on Panama rail-
road, per cent l. %