Evening star. [volume] (Washington, D.C.) 1854-1972, 1906-02-19


IN Limon and Panama bays. Though differ
ing in details such work in no way affects
the type of canal and consideration of the
terminal harbors In connection herewith Ia
here unnecessary.
The sea-level canal proposed by the ma
jcrity consists of continuous, winding
waterway extending from Limon bay to a
properly constructed dam near Panama
bay. provided with duplicate locks near
Sosa HUI To overcome the difference in
Tidal hhci nations that exist at the two ex-
trcmities OF the canal. The canal prism has
81 depth ~ 10 feet. minimum bottom width
of 100 feet in earth and 200 feet in rock
with suitable side slopes for the former
and practically vertical sides for the latter
The foods of the Chagres are controlled by
dam built at Camboa to a height of 1870
feet above sea level provided with sluice
gates for regulating the discharge which
l. made through the canal Dams and
levees exterior to the canal. are provided
streams that cross the canal line. and for
preventing overfows in the vicinity of
Panama.
The EightyFive-Foot Level Canal
The sJ-foOt level canal recommended by
the minority has a dam across the valley
of the Chagres river. near Gatun, with a
crest i35 feet above sea level and so feet
above the normal water surface of the res
erVoir or inland lake that is formed. The
dam is provided with sluice gates for regu-
Ia ting the height of water in the reservoir,
thereby controlling the floods of the
Chagres. From Linon bay to this dam the
channel is 800 feet wide and II feet deep
mean tide. The difference of level from
tho channel at the foot of the dam to the
surface of the lake (S5 feeD Is overcome
by duplicate flights of three locks. The
total length of this waterway Is 30 miles.
extending from the Gatun dam to Pedro
Miguel At Pedro Miguel duplicate locks,
with one lift of 30 feet under ordinary con-
ditiCns connect the summit level with
another waterway. whose surface at nor
nal stage is 81 feet above mean sea level.
Thi. waterway is created by dams placed
across the valley of the Rio Grande and
adjacent depressions. and extends nearly o
miles TO Sosa Hill. Descent to the channel.
~ feet at mean tide, in Panama bay Is eff
fected by duplicate flights of two locks TO
the west of Sosa Hill.
Under the act of June IS 1902. Congress
requires that the canal across the isthrnus
'shall be of sufficient capacity and depth as
shall afford convenient passage for vessels
OF the largest tonnage and greatest draft
now in use and such as may be reasonably
anticipated.
This law in effect fixes the minimum
dimensions of the locks and the width and
depth of the canal prism. The high level
canal employs locks with 900 feet disable
lencth ~ feet width and 10 feet depth over
the inter sills somewhat smaller than the
tidal locks recommended for the sea level
type.
Two ships now building for the Cunard
lire Will be. when completed, the largest
afoat. Each is SO feet in length overall
and IS feet beam, with maximum loaded
posed locks Is capable Of floating vessels of
% per cent greater tonnage than the new
Cunarders. it is evident that the locks fully
comply with the requirements imposed by
Congress.
In the high level canal, a vessel of the
Dimensions noted would have, with the eX-
Ceptiou of the ~ miles where the width is
only 20 feet. ample leeway for safe uavtSa-
tIon and good speed. without objectionable
currents and without difficulties at the
points where changes In course are neces-
II. a ole No 10 1a.N4 -,
throughout except at the approaches. 1t is
true that the depth in the channel below
the Gatuu dam is forty-one feet at mean
tide ttidal range, two feet and in the chan
mel below the SosH locks. is forty-five feet
at mean tide (tidal range, twenty feet,
but additional depths in both approaches
because of the character of the bottom can
DE easily and economically secured by
dredging when demanded by the needs of
commerce
The Sea-Level Proposition.
With the proposed sea level canal condi-
tiJns are different The depth is but two
feet greater than the draft of the ship, not
sufficient to permit her to proceed under
her own steam except at great risk; twenty
one miles of the canal is not sufficiently
wide FOR two such ships to pass; currents
caused by the regulation of the Chagres
and by the flow of other streams into the
canal. and its many curves, combine to in
crease the difficulties and dangers of
navigation. In short the sea level canal
recommended Is not 'Of sufficient capacity
and depth to afford convenient passage
Tor vessels of the largest tonnage and
greatest DEPTH ard can be made so only
by materially increasing the depth and
width, and at considerable increase of
time ard money. If the suggested width of
$50 To 20 feet is the greatest width
economically permissible for a sea level
canal, the cost of the enlargement required
must De prohibitiye.
1, therefore follows that the high level
canal more fully meets the requirements
Of Congress.
The majority Of the board makes objec-
ton that locks are unsafe for the passage
az the great seagoing vessels contemplated
~ the act, due to the disastrous couse-
FuenceS That might result II the gates are
. injured by vessels entering; that the lifts
proposed are beyond the limit of prudent
design for safe operation and administra-
tive efficiency, that locks delay transit.
Lock navigation is not an experiment, all
the locks are duplicated thereby minimiz-
ing such dangers, and experience shows
that with proper appliances and regu-
1ftiOus the dangers are more imaginary
than real The locks proposed have lifts
Of about thirty feet, or less than these here
tofore advocated by engineers of such high
standing that the objection Is believed TO
be not well founded The delays due TO
loCbages are more than Offset by the great
er speed at whiC. vessels can safely nav
iglie jhe lakes formed by the dam than is
possible I'm the sea level canal. and the
Eumruts on this point in lie minority re
port seem TO me TO be the more weghty.
The advocates Of the sea level canal ex-
press doubt as to the stability of dams
al Gatum and at La Boca, II founded on
the natural soil. and advance the opinion
that mo such vast and doubtful expert
meut should be INDUCED in
The Dams Proposed.
il appears, however, that the dams pro-
posed are to he founded on impervious ma
terials. thereby conforming to the views or
the majority. and are to have such ample
Dimensions as TO insure the compression OF
the mud and clay rather than its dsplace
meut. Furthermore. the estimates include
an allowance for additional safeguards
against seepage IL subsequent detailed in
NestEatiOus show the necessity for extra
precautions. The construction OF earth
dams % retain water eighty-hve feet deep
IS not experimental, and. as the dams pro-
posed have greater mass and stability than
similarly constructed dams of greater
heights. tt appears that the approximations
20 the safety of the dams are uuneces-
SaTy.