William Macfarland Patton.

A treatise on civil engineering online

. (page 118 of 145)
Online LibraryWilliam Macfarland PattonA treatise on civil engineering → online text (page 118 of 145)
Font size
QR-code for this ebook

to various ports over the Cape Horn route will be from 8000 to
14,000 miles.

The plan proposed was a canal mahitained at the level of high
tide in the Pacific. The canal is to be fed entirely from the Pacific
A canal of the usual width and section, with a depth of 25 feet for
the greater portion of the distance, and a tunnel of 7 miles iu
length, 100 feet wide, and 115 feet high through the Cordilleras.
The excavation will be mainly through rock, covered a few feet ia
depth with loam. A tidal lock having a wall elevation of 45^ feet
on the Pacific, a lift lock being required on the Atlantic side to
raise vessels to the level of the water in the canaL

1127. The only two routes, however, that have at all met with
popular favor are the Panama and Nicaragua. The Panama route
has been the favorite with the French and the Nicaraguan one with
the Americans. It is not the desire or purpose of the writer to
disparage the one or advocate the other. But he will try to gi?e
the facts as they have been presented and occurred. The unfor-
tunate condition of the Panama route is such that at present at
least there is but little encouragement for even its most ardent ad-
vocates. And the results obtained correspond so fully with the
predictions made, that a common i^ipression prevails that this route
is impracticable. The facts are as follows:

1128. The Panama CanaL — M. de Lesseps, the builder of the
Suez Canal, by the ability, energy, and skill displayed in the con-
struction of the Suez Canal as a purely sea-level canal, in the face of
the most violent opposition, discouragements, and dire predictions of
failure, immortalized his name, and so far as he himself is concerned
the breath of scandal and slander has been repressed in connection
with the facts developed.

He, no doubt, overestimating his own ability, underestimating
the difficulties, confiding in friends who ultimately betrayed their
trust, and who doubtless misrepresented the facts and conditions,
conceived the idea of building a sea-level canal similar in every
respect to the Suez Canal, and convinced himself, as he said, "that
unless the Atlantic and Pacific can be united by simply piercing the
Isthmus from sea to sea without Ipcks, as at the Suez Canal, the
proposed scheme cannot possibly succeed as a commercial enter-
prise, because of the inadequacy of a canal with locks to pass the
traffic that will frequent it, and also of the uncertainty of sufficient
water to supply the lockage and the evaporation." He easily con-

Digitized by


0AKALI3. 1397

Tinced the French people, whose confidence he possessed to a degree
Toachsafed to few, before or since.

It has been openly proclaimed that this gigantic work was under-
taken without sufficient and proper surreys and examinations, in
ignorance of the conditions existing and of the difficulties to be
encountered, and under the belief that a sea-level canal was en-
tirely practicable, and that the cost would be reasonable. The
facts, howcTer, were soon discovered to be so far different from
those stated, that the original plan had to be radically changed.
Instead of a flat sandy country, as between the Mediterranean and
Red Seas, in which the vise of tides were insignificant and almost
-equal, with no torrential streams which would deluge the country
and destroy in one night, works costing millions, it .was realized
that there was a rugged, mountainous country to build over; moun-
tain streams, especially the Chagres River, whose sudden and high
:flood8 rendered the construction of the canal impracticable until this
stream could be absolutely controlled during periods of floods — a
work of gigantic proportions in itself; and that the difference in rise
of tide in the two oceans varied from 12 to 20 feet or more, necessi-
tating beyond question both tidal and lift locks; and further, the
objection raised to the employment of locks, namely, want of water-
supply at the summit, was shown to be of no value, as ample water
could be stored to supply all the demands of the canal. An im-
mense mountain barrier had to be pierced with a tunnel, having
great width and clear height. The projectors were either ignorant
of these things or ignored them. The following is a partial record
of what followed.

The rovite selected was the narrowest width between the two
oceans — a distance of about 46 to 50 miles. A cross-section of the
canal similar to those already given, having a bottom width of 72
feet, top-water surface of 131 feet, with two berms 6 5 feet each a
little below the water surface, and the usual depth of water from
26 to 30 feet. These small dimensions were taken in order to save

For the purposes of traffic these dimensions were evidently too
small. At the water surface 197 was the least that should have
been considered, and even with this width, as at Suez, the canal
would have to be enlarged at no distant day.

In addition, the character of the material to be excavated, when
not rock, was of the most treacherous and uncertain kind. The
trenches were liable to be filled up by the soft, flowing material as

Digitized by



fast as they could be excavated. It was impracticable to form any
estimate of the amount of the material that would have to be
handled^ or to maintain any definite widths and depths.

The climate is considered one of the most oppressive and un-
healthy in the world.

Enormous sums of money, however, were expended in purchas-
ing the necessary plant, numbers of large and expensive dredges
were purchased. Actual work commenced in 1883, and according
to the estimates the work was to have been completed in five yearv
namely, in the year 1888.

In the year 1884 reports showed 1104,000,000 cash expended,,
liabilities $153,000,000. May 1st, 1885, less than one tenth of the
excavation was done, — 12,376,500 cubic yards out of a total now
estimated at from 125,000,000 to 150,000,000; original estimate
from 80,000,000 to 100,000,000 cubic yards. No suitable founda-
tion for the Chagres River dam had been found at a depth of 60
feet below the surface. The estimated cost of the completed canal
was at this time $600,000,000, original estimate about $120,000,000.

In the year 1887 less than one quarter of the excavation done;
cost to date $180,000,000. The work done was mainly on the less
expensive portions of the work, and the great Culebra cut hardly
commenced. Supposed final cost $800,000,000. The damming or
diversion of the Chagres River was not commenced, nor even a plan
decided upon.

In the year 1888 the determination was reached to abandon
the construction of a sea-level canal, and to pass through the sec-
tion of greatest excavation by a temporary high-level canal, with &
series of huge iron locks at either end. The level of the canal was
from 125 to 150 feet above the sea-level. This was recommended
as only a temporary expedient to reduce the immediate cost of con-
struction and the time required for completion. Ultimately this
high-level canal was to have been lowered, so that the canal would
in time become a sea-level canal, as originally intended. There is
some doubt and conflict of testimony as to the extent of the work
executed on this plan, which is, however, a matter of but little
moment to any but those who had subscribed to the stock of the
company, as the entire enterprise shortly collapsed. The works
have been abandoned, and recent reports state that there is but
little evidence of the nature and character of the work'done, except
A few large dredges and other machinery partly submerged in the
old excavations.

Digitized by




1129. In 1889 a pamphlet was published by a French engineer,
O. Sautereau, a colaborer with M. de Lesseps in the construction
of the Suez Canal, and freely consulted with by him in regard to
the Panama Canal. M. Sautereau seems, however, to haye favored
the !Nicaraguan route, and to have condemned in unmeasured terms
the proposed construction of a sea-level canal at Panama. What
has been said above is more than confirmed in this pamphlet, and in
fact no severer criticism has been made of the Panama route by any
American than is to be found in the pages of this pamphlet, written
by a French engineer.

He, however, advocated for both the construction of the Panama
or Nicaraguan route the formation of a great interior lake (see Fig.
416^), forming a long level reach entered from either ocean by




Fig. 416^

means of a single lock, at most two locks, on the Atlantic side,
having a lift of 100 feet or more, called by him " Les !6cluses a
grande Denivellation,'^ between which was to be " le canal trans-
form6e en lac int^rieur.^'

Some of the novel features in this proposed plan are interesting
and instructive, especially as only at a very recent date M. Bartissol

Digitized by



has proposed to revive the construction of the Panama Canal by
adopting at least a part of M. Sautereau'sidea. What follows is
taken from M. Sautereau's pamphlet, entitled "Le Canal de Panama
transform^ en lac interieur/'

The modified plan of M. de Lesseps consisted in the constmc-
tion of five locks on each side of the mountain, with level reaches
between each two locks. According to the report mentioned, the
expenditure had amounted in 1889 to $266,000,000, and to complete
the canal as proposed $114,000,000 more was estimated as required,
and to carry out the ultimate purpose of lowering the level of the
canal to that of the sea $190,000,000 more, and in the end they
would find themselves in this position: *'with a mass of water re-
tained by a dam without stability [cansistance], the dam of the
Chagres at Gamboa, and which, suspended above a narrow canal
in which would be passing or assembled [engages] a number of ves-
sels, would become a perpetual danger to navigation^' (transited
from the French by the writer).

" It is certain that the proposed project does not constitute an
acceptable solution, and that its execution will never respond to the
immutable principles laid down by M. Ferdinand de Lesseps. It is
not doubtful that, in order to triumph at Panama, as at Suez, over
all obstacles, it is necessary to abandon the traditions of the school
and the antiquated projects of the eleves of the school of Talabot
and d'Enfantin, and proceed to take examples from nature.

*'The Strait of Gibraltar, that is to say, a direct opening from sea
to sea, has served as an example for the execution of the Suez Canal.
The communication established by nature at the other extremity of
the Mediterranean, with an intermediary basin, the Sea of Marmora,
which unites the ^gean with the Black Sea, ought to be the
type in order to establish the interoceanic canal (at Panama w

" To dam the Chagres at Buhio-Soldado with a single lock hav-
ing a high lift, which will inundate the superior valley, and raise the
water-level sufficiently in order to admit the flood -water of the
Chagres in the canal; to dam the Eio Grande on the side of Panama
by a second lock of the same type, and cut the cnlebra with a trench
197 feet wide at water surface in the interior lake^ — such is the
solution that alone can give to the interoceanic canal conditions of
navigability comparable to those thrt are given by the Suez Canal.
Each lock to have two chambers, one for ascending and the other
for descending vessels. The masonry to be in a full compact mass,

Digitized by


CANALS. 1401

containing 450^000 cubic metres^ that would not be disturbed by
the trembling of the earthy so frequent in that country. Such an
arrangement would assure the passage of 40 ships a day^ whereas
the proposed plan would only admit of the passage of 10 ships in
the same time.

''These works^ one on each side of the mountain, can be built in
one or at most two years, at a cost, for both together, of not over

This construction then provides a sea-level canal from each ocean
to the locks, in which vessels easily reach these locks ; they are then
lifted by one lift to the level of the water in the interior lake. The
estimated total cost on this basis was about $80,000,000.

" The Culebra attacked by the Chagres by means of galleries
tunnelled through it at the level of the bottom of the canal, through
which the water of the lake or basin on the Atlantic slope will be
forced to flow towards the Pacific Ocean, carrying with it all mate-
rial easily excavated, as well as those constantly thrown into it by
blasting, and disposing these materials on the low plane bordering
the ocean — by this means the Culebra would be levelled in a year

" The high locks and dams are placed where the limestone and
hard sandstone first crop out, the valley of the Chagres being very
narrow at these places; and the effect will be, with locks having a
rise of about 100 feet, and with a diversion dam to raise the level
of the Chagres to this same level, that the valley will be inundated
up to the approaches of the Culebra, and there will be created a lake
which will be extended from 9^ to 12^^ miles in the valley of the
high Chagres, forming a liquid surface of several miriaraetres square,
covering virgin land and without inhabitants. A similar effect will
be produced on the Pacific slope. The distance through the solid
Culebra from water to water will be reduced to about 5 miles.

" Thus ample water-supply will be secured to supply the locks
and replace loss by evaporation, which would be difficult, if not im-
practicable, by the other plan without the use of steam-pumps.

" The excavated material can readily be removed by transports.
The Chagres River, the most formidable obstacle^ to the execution
of the works, forever subdued and enslaved, will become the prin-
cipal assistant (adjuvant) of the canal, instead of a constant menace
to the construction and maintenance of it. The excess of water in
time of floods will be spread over the surface of the lake, and
allowed to escape by diversion channels as may be deemed necessary.

" In the locks, each chamber will be about 650 feet in length ^
between the crates, in width 66 feet, andjj> depth a bout 138 feet."

Digitized by



The details of constmetion of the locks, gates, etc., are set forth
fully in the pamphlet. The aboTe is translated by the writer front
the French.

Such is the latest scheme for the construction of the Panama
Canal. Whether work will ever be resumed on this route is at
present a matter of doubt.

The following is a brief account of the suggestions and plans^
of M. Bartissol:

1130. M. Bartissol's method for completing the Panama Canal
is similar in many respects to that of M. Sautereau, described ia
paragraph 1129. He, however, proposes the construction of two
locks on each side of the Culebra cut, with a total lift of 75
feet, instead of the one lock with a lift of 135 feet. He therefore
forms an interior lake of much lower surface leveL He also pro-
poses to use the waters of the Chagres river to remove the material
to be excavated in the Culebra, but in a somewhat different manuer.
He proposes to control the waters of the upper Chagres by dams
and reservoirs, and lead the water in an open channel to the line
of the canal. He then proposes to build a conduit 13 feet in diam-
eter, starting just inside of the side slope of the complete canal,
towards the Pacific. The length of this conduit to be about 6J
miles, lined throughout with masonry or metal, and having a uni-
form slope of 1 in 1000. At intervals along the canal shafts are to
be excavated, opening into the conduit, for the purposes of throw-
ing the excavated material into the conduit; there it is to be taken
by the water flowing through the conduit at a velocity of 10 feet
per second, and deposited where desired.

The conduit is to be filled to the height of 10 feet with the water.
The duty of the conduit is estimated at 30 cubic metres per second
(I cubic metre = 1.31 cu. yds.), or about 1,000,000 cubic metres in
a day of 10 hours., with 100 shafts and 400 cubic metres of debris
thrown in each. The day's work would represent a cube of 40,000
cubic metres of d6bris, or 4 per cent of the total flow. According
to the experiments of Ouillemain and Durand-Glaye :

A velocity of 0.5 feet per second will carry the heavier clay;
" " 0.65 " ** " " fine sand;

" " 2.28 " « « « small gravel;

« " 5.86 " « « " flat stones;

'' " 5.31 " *< « stones 4 inches in diameter;

It '^ 7 5 *^ '' '' '^ 8 '^ '^ *^

Digitized by



M. Duponchel says a stream of water with a velocity of from.
6.5 to 10 feet per second carried 23 per cent of its own volume in
rock material, and that in a conduit of circular cross-section the
material would not only be carried forward by rolling, but it would
be in a state of complete suspension, and there would be but
little friction on the sides of the canal. Similar results were ob-
tained in a 20-inch pipe at the Culebra. M. Bertissol claims that
by this method the canal can be completed in four years, at an
expense of $100,000,000.

This proposition was declined, as being uncertain in its result,,
and not sustained by any precedent.

In Fig. 416^ (a) is shown a map of the railway and proposed
Panama Canal connecting the Atlantic and Pacific oceans at Colon
and Panama respectively; and in Fig. 416i^ (b) is a profile alon^ th&
axis of the canal, showing the two portions of sea-level canal at the
ends, and the interior lake formed by single locks, one on each side
of the culebra, having a lift of great height, as described above.
The drawings are readily understood from the foregoing discussion
and description. Instead of the single locks as shown, the last plan of
M. de Lesseps contemplated several locks on each side of the culebra.

1131. Tlie Nicaraguan Canal. — The year 1888 was no less noted
for the closing period of work on the Panama Canal than it waa
for the commencement of actual work on the Nicaragua Canal.
Careful preparation was made for this work by careful surveys and
examinations, and so far as practicable by plans and designs of the
work to be done and of the manner of doing the work.

The route of the canal is from San Juan del Norte, or Greytown,
on the Caribbean Sea, to Brito, on the Pacific Ocean, a distance of
169.8 miles; but of this distance there is only 29 miles of actual
canal excavation. The remaining distance is by free navigation of
the San Juan River, Lake Nicaragua, and the basins of the rivers
Descado, San Francisco, and Tola. (See Fig. 417 for plan and

The lake is a body of water 2600 square miles in area, with a
drainage area of 8000 square miles, and a mean daily fiow through
its outlet, the San Juan River, of 1,272,153,600 cubic feet — consider-
ably more than is necessary for the works it is to feed. The San
Juan River will be navigated for 64.5 miles, and the lake for 56.5
miles. The summit level, 110 feet above the sea, will be maintained
for a distance of 150 miles, beginning at the eastern divide, some 16
miles west of Greytown, and continuing to the west side of the

Digitized by




Tola basin, less than four miles from the Pacific Ocean. The ascent
from the level of the sea on the east side to the summit level will be
effected by three single locks, and on the west side by one double
lock and one single lock. Those portions of the line in river, lake,
and basin will have width and dei)th sufficient to render navigation


Fig. 417i (a\

almost as convenient as on the high seas. The cross-sections of
the excavated canal will have a depth of 30 feet, width at water
surface of from 174 to 288 feet, and bottom width from 80 to 120

The harbors are to be improved by means of breakwaters and
piers, and the eastern and western extremities of the canal are to be
widened and deepened to afford convenient access, safe anchorage,
and dockage. The rock cut to be made is 3 miles long, with an
average depth through that distance of 149 feet. The cost of this
excavation is estimated at $12,000,000. A dam at Ochoa, 1255 feet
in length on its crest and 52 feet high, will convert the upper 64.5
miles of the San Juan Eiver into an extension of the lake. The

Digitized by


CANALS. 1405

dam at the extremity of the Tola basin^ near the Pacific^ will be
2100 feet long on the crest and 71 feet high.

For impounding the waters to form the San Francisco basin
five dams will be required, varying in length from 1200 to 170O
feet, but of no great heights, and some secondary embankment
along the crest of the impounding ridge from 5 to 30 feet in height.

This arrangement is a substitute for a single dam of 6000 feet
in length, intercepting the Kio San Francisco near its junction with
the San Juan.

There will also be a dam and a waste-weir at the east end of the
Descado basin. It was believed that the work could be completed
in six years, at a cost of $50,000,000. Latest estimate, $100,000,000.

The climate is not at all unhealthy. The necessary labor can be
drawn from the neighboring States, which will also supply all the
fresh provisions needed. There is an abundance of excellent timber^
stone, clay, sand, and limestone found along the line.

The locks are to be 650 feet long between the gates, 70 feet
elear width between side walls. The locks will be built of concrete
and masonry.

The estimated traffic is 6,000,000 tons. With a toll-rate of $2.5(>
per ton, the income would be sufficient to pay the interest on a
capital of $200,000,000. The saving of distance from principal
points on the Atlantic and Pacific will be very considerable. The
following table gives the distances by several routes between some
points of importance:

Table LXXIXa.


By By , By Cape rvRimk.

Panama. Cape Horn. Bonne Espefanoe. '^^ ovio^
From Havre to—

San Fraociaco 8.000 15,000

Canao(Lima) 7.000 11.600

Valparaiso 8,000 10.000

Yokohama 11,400 17.000 18.000

Sbangbai 13.000 16,000 12.000

HougKong 18,600 16,500 11,000

From New York to—

aan Francisco 6.000 14.900

Callao 4.000 11.000

Valparaiso 5,000 9,800

Shanghai 11,000 15,000 14,000

Digitized by



M. Sautereau also suggests the employment of locks with high
lifts for the Nicaragua Canal. He recommends on the Pacific slope
a single lock with a fall of ahout 109 feet at Flor, and on the At-
lantic slope two locks and dams (deux eduses barrages), the one of
42.6 feet fall and the other of 65.6 feet, which will be suflScient to
overcome the difference of level between the oceans and the lakes.
The adoption of these locks reduces the works to their simplest ex-
pression, and admits of making all the necessary excavations bj
means of hydraulic forces arising from the excess of the water in
the lake. It admits of the utilization of the old bed of the San
Juan River without the resort to manual labor or mechanical ap-

The question as to the number of locks is not only one of cost,
but also of time and expense of passing through them.

The following analysis of cost of locks is given for what it is
worth, as indicating the lines upon which comparisons can be made.
This was made in connection with the Nicaragua CanaL

Assuming locks 600 feet long between gates, TO feet clear width,
and 25 feet draught: in locks of different sizes, and well propor-
tioned in capacity for doing the necessary work, approximately pro-
portional to the product of areas and draught, the following data
and dimensions are usually given :

Total length of side walls 700 feet.

" " "lock floor 700 "

" height of side walls = lift -+- draught -+- 4 feet.

Length of thin portion of wall 652 **

Width or thickness on top of thin portion of wall 10 **

Width or thickness at bottom of thin portion of wall = 10
feet + 22^ of height.

Length of thick portion of wall 148 **

Thickness at top of thick portion of wall 15 **

" " bottom of thick portion of wall, 15 feet + 32j<

of height.

Length of mitre wall on curve 75 **

Height of mitre wall on curve, lift + 12 feet.
Thickness of mitre wall, two-thirds lift.

On this data the following estimate of cost is made on the basis
of cut-stone masonry, cut stone with rough backing, and with con-
•crete; only details for the least expensiye and most expensive ar-

Online LibraryWilliam Macfarland PattonA treatise on civil engineering → online text (page 118 of 145)