Decorah public opinion. (Decorah, Winneshiek County [Iowa]) 1895-1928, 1910-03-30

i crosses. Track moving is done
principally by an immense track
shifter' which performs the work
\ of 500 men, 1t is an immense der
I rick mounted on a steel car, with
projecting arm 10 which hooks are
attached, by which section of the
/ track is raised and moved.
The great Gatun dam, which fills
the opening between the hills at
Gatun, through which flows the
Chagres river, is virtually noun
tain in itself, and has received
worldwide attention. 1t rests on
impermeable material of sufficient
supporting power, and consists Of
great water-tight center or core,
in proper proportion and deposited
by hydraulic force through great
pipes between the upper and lower
sides or toes" of rock. 1t is said
to be sixteen times as strong as is
necessary to withstand the pressure
against it. Located in the dam is
great spillway. a concrete-lined
opening cut through a hill of rock
along the line of the dam near the
center, supplied with gates of suit
able design to allow the lake to be
regulated in case of high water.
The locks are built in an excavation
at the east end of the dam, in rock,
and afford means for passing vessels
in and out of the lake on the At
lantic side.
,ne dam is 9,O4O feet long, one
and one-eight miles, 2,100 feet wide
at the base, 400 feet at the water
line, 100 feet at the top, 115 feet
high. Only 500 feet of it will be
subjected to the pressure of 50 feet
of water from the lake.
Work on the locks at Gatun is
we'll under way, the upper locks be-
ing about half completed. we should
say The plans for all the locks are
practically the same. They are
made in pairs, side by side for ships
passing in either direction, 1000
feet long and 10 feet VIDE. Each
lock consists of a chamber, walls
and bottom of concrete, and water
tight gates at the end. The level
of water in the locks is regulated
through openings in the bottom. by
the operation of valves in the side
and center walls, which permit
water to flow in and out of the
locks by gravity There will be two
gates at the upper end and two at
the lower end, operated simultane-
ously, for double safety Another
safety device is an immense chain
stretched across the lock near the
surface of the water and passed
around fixed capstans on the walls.
This will arrest a 10000 ton vessel
moving at the rate of six miles per
hour, and will be used to prevent
accidents, such as have occurred at
other locks. Vessels will be towed
through the locks by electric loco
motives. The gates will be massive
steel structures feet thick, 65 feet
long, and from AZ to 80 feet high.
They will weight 800 to 600 tons
each. intermediate gates will be
used in the locks to save water, if
desired, in locking small vessels
through, the gates being so fixed
that the locks may be divided into
chambers $50 and $50 feet long,
respectively. Ninety-five per cent
of all vessels are less than 600 feet
long. The base of the locks is solid
concrete Is to 80 feet in depth, and
the side walls of the locks 81 feet
in height. The locks have capa-
city of As lockages per day. The
canal and locks may be used night
and day. The channel of the canal
will be lighted at night by electric
lighted buoys.
AT Pedro Miguel and Miraflores.
on the Pacific side of the lake, the
locks are similar to those at Catun.
The dams at Pedro Miguel are not
large. 1,40O feet long en- the west
side and $50 feet long en- the east
side. At Miraflores the west dam
is 1900 feet long and the east dam
500 feet long.
The great concrete mixing plant
at Gatun was one CT the most inter-
esting sights on the canal. Broken
stone for concrete is brought from a
large quarry and crushing plant at
Porto BellO, IS miles east of Colon
and sand from Nombre de Dios, be-
yond. Over 1000 yards of concrete
is laid daily. Cement comes from
the United States in two large
steamers bought for that purpose,
each carrying $4,000 barrels. About
100000 barrels will be used. It
is all the Atlas Portland cement.
An eiectric tramway system is used
for operating the mixing plant. The
cars run mainly underground. Pass
ing the sand and crushed rock sup