The times dispatch. [volume] (Richmond, Va.) 1903-1914, 1912-11-18
axes ieDOrt.

Work. though In view OF tho fact that
Il 10 dated September 10. last the ng-
,, ures regarding excavation. placing OF
| concrete. erection OF dams and locks
and subsidiary works are not as re-
| cent a. those contained in the regular
monthly reports. Naturally. the most
| interesting feature OF the report re-
iatss to the operations in the great
Culebra Cut. Here. great landsldes.
I, many ranking with an Alpine avalanche
in magnitude. have 20 increased the
| amount OF material to be excavated,
that were II not found possible steadily
to reduce the cost per yard OF dredging
and steam shoveling through the grow
ing expertness OF the employees and i'm
proved engineering methods. the total
| cost OF excavation would have been
vastly greater than the estimates. Dur
ing the las, year nearly Is.500,O00 cubic
yards Of earth were taken out Of this
cut, leaving nearly 100000 to be dis
placed before the canal can be opened.
The damage caused by the slides may
be appreciated from the fact that
nearly 100000 yards Of earth exca-
waited was so composed. or nearly So
per cent of the total excavation.
There Is only one way to deal with
these slides. and that Is to dig them
out AZ they occur though some help
Is gained by terracing the upper bankA
That Is because the geological forma-
ton changes SO frequently and sud-
denly that no other effective treat
ment has been found. So unstable Is
the earth that the material In one part
Of the cut begins to move on An incli-
natin a. low a. one on seven, owing
to the mass OF stratiaed rock sliding
over as layer OF Ignite. One slide
now In motion near the bridge Of Gu
Zebra covers An area OF sixty-three
acres. from which 2.710.00o yards have
| already been removed. leaving l.3oo.-
600 still to be handled.
no less than fifty acres on the oppo-
site side Of the canal The result Of
these earth movements. which are quite
exceptional in engineering practice. has
been to leave the canal in dts deepest
portions with very fiat slopes. The
encouraging feature OF the heavy
work at that point is found in the
statement in the report that none OF
the slides which occurred during the
year would have interfered with the
passage Of ships had the canal been
in operation"
Rans Int Zig Figures.
Already the appropriations made by
Congress for the canal have run into
big figures, the total up to June 81
last being $293.561.46S. and since that
date there have been additional appro-
priations, exclusive Of those for forti-
fications amounting to s2S.ss0.000. max
ing the grand total $322.54l.4e8. On
June 80, of all these appropriations.
the engineers had expended 50 per
cent OF the total estimated cost Of the
canal
OF even greater interest from an en-
cheering point Of view than the vast
but commonplace work Of excavati IN
in Culebra Cut was the work Of con-
structing the great locks at 9atun
and Miradores and Pedro Miguel, for
there many novel problems have been
solved and lock machinery constructed
Of special designs Of a magnitude never
before heard Of. For instance, SO big
are the valves at the side of the locks
that test showed that 1t required
a pull Of over ten tons on the stem
to open one Of these valves. All OF
this " ork is done electrically. and here
again the engineers were confronted
with new difficulties. Owing to the
peculiar climatic conditions on the 18th
mus. with tropical heat and extreme
humidity. and the deteriorattns effect
of these conditions on the insulation
Of electrical machinery. the ordinary
Insulation proved unreliable. and the
engineers found 1t necessary to make
a great number of experiments, no less
than sixteen sample motors being pitted
against one another. 1t was an awful
test for dynamo and motor builders
to have their machinsS required to op-
crate for a period OF ten days in
building flied with steam at temper
allure Of SO degrees centigrade and
having the motor cases filled with
water for five hours at 30 degrees.
But finally the American motor build
ers responded. and suitable apparatus
IL being installed
Thus electric motors under tests are
now swinging the great gates of the
canal each Weighing very many tons
and as tall and broad as q great sky.
scraping building. in the remarkable
time Of one minute and forty-edght
seconds. Incidentally It appears that
to make these gates the iron workers
must drive and head 5.750.00o rivets.
The pivots Of these great locks are
being made OF . special grade OF steel
to protect them against corrosion
very necessary precaution In view OF
the fact that they viii always DO sub
merged In sea water after the canal
Is open. To guard against galvanio
action zinc rings are also placed on
the bronze bushings.
ssVplying the Power.
To supply the power to operate the
gates and siu!ce valves In the locks
and furnish current for the monster
electric locomotives which are to tow
the steamships through the locks
great hydro-eIcctric station 10 beins
erected adjacent &c the spillway III
.Gatun dam There are three 2.cse
k.lowat; water turbines and three 1900
kiIowatf senerators. with suitable ex-
citers and o.her auxiHaries- There
will be enough available water from