CHAPTER XV

THE CULEBRA CUT

Popular interest always has centered chiefly in the excavation phase of canal construction, losing sight of the fact that the locks, dams, and breakwaters call for an expenditure of $85,643,000.  The Culebra cut has been exploited more than any other feature of the canal, yet it was estimated to cost $80,481,000, or five million dollars less than the features just enumerated.  Even the dredging of fifteen miles of sea-level channel has received little publicity, and this was to cost no less than $30,906,000.

The physical aspects of the dry excavation doubtless account for this singling out of one feature by the public mind.  However stupendous the laying of concrete might be in the locks, or the sucking up of mud by the dredges, they are not as impressive as cutting through a mountain chain.  They are prosaic operations compared with the picturesque attempt to change geological conditions.  In the Culebra cut, Man was wrestling with Nature, whereas, in lock-building, he merely is playing the role of mason.

One finds in government work that the chief aim seems to be to plan two employees where only one worked before, and the canal organization is the least overworked set of employees in the world, but in the excavation phase of the government work the organization has attained as great efficiency as any private contractor could have attained, under the conditions adopted in the Canal Zone.  World records for steam shovel performances have been broken by government employees in Panama under adverse circumstances.

The Culebra cut is nine miles long with a curve for nearly every mile.   At these curves, the cut is widened to permit the ships to pass easily.   Always the chief problem has been one of transportation, or how to keep empty cars in front of the steam shovels constantly, in a canyon only three hundred feet wide.   In a working day of eight hours it has been found possible to keep the steam shovels working only about six hours, because of this circumscribed field of operations.

Naturally the 75 miles of track in the Culebra cut must be shifted constantly as the excavation work carries the levels down.  This keeps the track shifters and hundreds of men at work day and night.  During the maximum operations in the Cut, 6,000 men were employed in the daytime, while at night 400 men worked to keep the steam shovels in repair, to replenish their coal bins, blast more material for the shovels, and otherwise to get the Cut in shape of the next day's activities.

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About 100,000,000 cubic yards were to be removed to complete this part of the canal, or practically half the total excavation.  On June 1, 1912, the beginning of the last year of work, there were 7,399,615 yards left to be removed, which would have been out by January 1, 1913, at the rate of excavation, if it had not been for the slides.   To this had to be added 6,000,000 yards from that source, or more than 14,000,000 yards to be removed in order to get the Cut in shape for the passage of the first ship.   It was decided then to keep the 38 steam shovels at work and operations at full blast until July, 1913.

For the whole length of the Cut, the average depth from the surface to the proposed bottom of the canal was about 120 feet, the highest point on the center line of the canal being at Culebra between Gold and Contractor's hills where excavation has gone down 272 feet.  After the soil had been removed for a short depth, solid rock was struck and to January 1, 1913, 54,504,150 pounds of dynamite were used in blasting, or the staggering total of 27,252 tons.  The lay mind thinks of a pound of dynamite as impressive, but its use in the canal work has been bewilderingly heavy.

The following table shows the amount of dynamite used for the nine years of American operations:

1904 and 1905
1906
1907
1908
1909
1910
1911
1912
1913

.....
.....
.....
.....
.....
.....
.....
.....
.....

500,000 lbs.
1,400,000 lbs.
5,087,000 lbs.
6,822,000 lbs.
8,270,000 lbs.
10,403,000 lbs.
9,501,850 lbs.
8,533,000 lbs.
3,986,500 lbs.

Most of the explosive has been used in the Culebra cut.  It is estimated that a pound of dynamite will break up 2.14 cubic yards of rock and earth, and as much as 26 tons has been set off in one blast in the canal.  Stringent rules have prevailed to prevent accidents, and while deaths from this cause have run into the hundreds the handling of this amount of dynamite has been distinguished for the small number of fatalities.  In September, 1908, a steam shovel dug up a bushel of dynamite left by the French in 1887, but it had lost its potency.  The largest single shipment of dynamite to Panama was 846 tons received on June 27, 1911, without an accident in loading or unloading from the steamer.

All through the day drills, operated by compressed air, are boring into the rock in the Cut for 24 feet.  A small charge of powder is set off at the bottom of these holes to enlarge them for the real charge of as much as 200 pounds.  Then after the men have quit for the noon hour, or after five o'clock in the afternoon, the charges are set off by electric current.  It sounds like the steady booming of artillery in the Cut.   Many persons have been killed by being struck by rocks hurled long distances in these blasts.  The next morning the steam shovels find plenty of food for their hungry jaws, which bite off four or five cubic yards at a dip, swing around and drop the six or seven tons upon the cars.  Frequently they lift rocks so heavy that the cars are broken.

For 150 to 175 trains a day loaded with excavated materials leave the Culebra cut for the dumps.  A great deal has gone to build the mighty Gatun dam; much has been used in reclaiming nearly 400 acres from the ocean at Balboa, the Pacific terminal; the new Panama Railroad has required millions of yards in making fills; and the breakwater at Balboa also has taken a considerable amount.  What could not be usefully employed has been wasted on dumps.  The average haul from the Cut has been twelve miles, but as much as thirty miles must be traveled by some of the dirt trains.  Twenty flat cars constitute a train and one car can be loaded by a shovel in two and half minutes, or with seven scoopsful of earth and rock.  When the trains get to the dumps, an unloading plow is drawn by a steel cable over the flat cars, sweeping the material off the side which is open.  The spreaders are pushed over the track to shove the material to one side and down the embankment.  Track shifters later come along and move the track over to the edge of the fill.  Between 1,000,000 and 1,500,000 yards have gone out of the Culebra cut every month, except one, since December, 1907.

The employees are carried from the various towns to their work in the cut, or on the locks and dams, by labor trains.  The largest labor train in the world was operated out of Panama to Pedro Miguel until July, 1912, when it was divided into two sections.   These trains bring them to their homes, or the hotels, for the noon meal, consuming from ten minutes to half an hour in the journey.  But as the rest period at noon is for two hours in the Canal Zone, ample time for eating is allowed.  Tourists go through the Cut on a special train that costs the government a great deal of money because of the disarrangement of dirt train schedules, every minute a shovel is kept idle thereby costing Uncle Sam a pretty penny and making the men swear because they may be sweating for a record day's work.

In the month of March, 1909, more dirt was taken out than in the first twenty-two months of operations.  The excavation in one month usually exceeds an amount equal to the Pyramid of Cheops, which is 750 feet square and 451 feet high.  The canal force of 1909-1910-1911 would have dug and finished the Suez Canal.  March, 1911, retains the record for the greatest excavation in the cut, when 1,728,748 yards were removed, and this also is the record month for excavation for the whole canal, with a total removal of 3,327,443 yards.  The average daily output of steam shovels rose from 500 yards in 1905, when only dirt was handled, to 1,500 yards in 1911, when rock predominated.   The cost in the Central division has ranged from 10 cents a yard to 91 cents a yard, with an average of 91 cents, from 1904 to 1909, and fell to 51 cents in 1911-12.

Rains interfere with the excavation work in the Cut, reducing the output in the rainy season several hundred thousand yards a month.  During the downpours, operations must be suspended, but the Cut has been dug at a slant on both sides of the mountain system, so that water is drained out of it by gravity, running out at both ends.  Rivers which crossed the line of the canal have been diverted by digging new channels for them.

The precise date when the canal was half dug, in the year 1910, cannot be fixed until the water is turned into the Cut and dredges begin handling the slides, after ships are using the canal, but on a basis of 221,000,000 yards excavation, it was half done about July 1, 1910.  Slides make a revision of the estimates almost a monthly task for the Chief Engineer.  The Culebra cut was half finished about July 1, 1910.

Almost at the wind-up of operations the canal diggers made the highest records for excavation.  On April 11, 1912, forty-four steam shovels took out 68,505 yards in the cut, which is the record for one day in that division.  Steam shovel No. 257 working at Gatun took out 5,554 yards in one day, the highest record in the Canal Zone for one shovel, the date being May 2, 1912, and in August, 1912, the same shovel made a record by removing 86,844 yards in 26 working days.

That part of the Central division which is little mentioned, extends from the Gatun locks to the entrance of the Culebra cut, about twenty-three miles.  Only about 12,400,000 yards had to be excavated to complete this channel as it follows the Chagres River valley from about sea-level to Bohio, then the level rises until it reaches 48 feet above sea-level at the Cut.  From Gatun to Obispo the Chagres River crossed the line of the canal twenty-three times.  In the same distance the Chagres River has 26 tributaries, the more important ones being the Gatun and Trinidad rivers.  All contribute to the great Gatun Lake.

The slides, which have been accurately and inaccurately exploited in the press, represent the steep sides of the Culebra cut breaking off and falling down into the excavated part.  Even where the Cut has been sunk through solid rock these slides occur, as the rock formations of the Isthmus are brittle and dissolve to dust after exposure to the atmosphere.  An attempt was made to prevent slides of plastering the sides of the Cut with concrete, but the experiments were futile.  There are between fifteen and twenty important slides on both sides of the nine-mile Cut, the largest being on the West side of the canal near the town of Culebra, and embracing 63 acres.   Around the towns of Culebra and Empire are many smaller slides that have given much trouble to the engineers.  Steam shovels, locomotives, and flat cars have been caught in these slides, but, singularly, few lives have been lost.

Sometimes the pressure on the sides of the canal operate to make the earth bulge up in the bottom of the Cut.  Division Engineer Gaillard devised the plan of terracing the sides of the Cut to relieve this pressure with the result that much extraneous material has been prevented from sliding into the cut.  Engineers who formerly stood stanchly for the sea-level type of canal, after seeing the slides of the present 85-foot level lock type, are forced to admit that the attempt to sink a cut through the isthmus for a sea-level channel would be attended by such prodigious earth movements, necessitating such an inestimable additional excavation, as to make it well nigh impossible.  For a sea-level can the Culebra cut would have to go 85 feet deeper than in the present plan, which would require both a wider bottom and indefinitely wider surface opening, and then the slides would be immeasurably greater than at present.  The best year's work in the Culebra cut was 16,586,891 yards.  Slides first and last have added more than that amount to the total estimate of excavation for the division.  Yet the increase in efficiency of the organization has enabled the workers to handle the extra amount within the time and cost estimated for taking out the original yardage.

Three methods of excavation have been employed in digging the seven miles of sea-level channel on the Atlantic side and the eight miles of similar channel on the Pacific side.   Steam shovels dug down on the Atlantic side to forty feet below sea-level, with great dikes to hold out out the water, and dredges have done the remainder of the excavating.  On the Pacific side, in addition to dredges and shovels the hydraulic method has been used.  This method consists of playing a powerful stream of water on the earth and draining the water with the soil in a fluid state to a selected dump which has been boarded, the water being drained off when the mud has deposited.  The Atlantic entrance required an excavation of 47,523,000 cubic yards and the Pacific entrance 58,287,000 yards.  On July 1, 1912, the former lacked 8,592,773 yards of completion and the latter 18,348,176 yards of completion.  Of the amount removed to July, 1912, from both channels—78,868,134 yards—steam shovels excavated only 14,016,409 yards, but it was decided to remove most of the remaining material in the Pacific channel by steam shovels during the remainder of 1912 and in 1913, to about July 1st, when it is planned to take the great dredge Corozal through the channel, and locks up into the Culebra cut for the work of handling slides and silt after the water is turned into the cut, in preparation for the passage of the first ship in September.

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The following table shows the excavation year by year in the Culebra cut, from May 4, 1904, to May 4, 1913, a period of nine years of American operations:

From May 4, 1904 to May 4: 1905
1906
1907
1908
1909
1910
1911
1912
1913
_____
9 yrs.

648,911 cu. yds.
1,250,570 cu. yds.
4,861,895 cu. yds.
11,285,217 cu. yds.
13,955,753 cu. yds.
14,886,427 cu. yds.
15,925,976 cu. yds.
16,446,313 cu. yds.
14,754,155 cu. yds.
_________________
94,015,217 cu. yds.

By calendar years, the excavation in the Culebra cut is as follows, to September, 1913:

1904
1905
1906
1907
1908
1909
1910
1911
1912
1913

243,472 cu. yds.
914,254 cu. yds.
2,702,991 cu. yds.
9,177,130 cu. yds.
13,912,453 cu. yds.
14,557,034 cu. yds.
15,398,599 cu. yds.
16,596,891 cu. yds.
15,314,978 cu. yds.
9,200,000 cu. yds.
_______________
99,015,217 cu. yds.

For the whole canal, the excavation year by year since 1904 was as follows:

May 4 to December 31,

1904

243,472 cu. yds.

January 1 to December 31,

 

 


January 1 to August 31,

1905
1906
1907
1908
1909
1910
1911
1912
1913

1,799,227 cu. yds.
4,948,497 cu. yds.
15,765,290 cu. yds.
37,116,735 cu. yds.
35,096,166 cu. yds.
31,437,677 cu. yds.
31,603,899 cu. yds.
29,258,852 cu. yds.
13,653,564 cu. yds.
________________
205,933,379 cu. yds.

The above table estimates the excavation by the time the first ship is scheduled to pass through the canal.  Terminal works at Balboa requiring more than 8,000,000 yards excavation, and finishing details of the canal channel proper, will bring the total excavation, by January 1, 1914, when the canal is expected to be in regular commercial use, to 221,000,000 cubic yards.

It will be noted that the calendar year 1908 marks the highest record for annual excavation since the Americans began, overtopping the nearest year's record by more than two million yards.  It also represents the amazing increase of two and a half times the output of the year 1907, just preceding it, the explanation of which is found in the fact that the long period of preparation has been passed in 1907 and the great canal organization, built up by Mr. Stevens, struck its stride and plunged dynamically at the natural obstacles.

The year 1908 recorded the greatest annual excavation in the Atlantic division, the year 1909 the maximum excavation in the Central division, and for the Pacific division the highest annual excavation was in 1910.

In the late spring of 1912, the press in the United States exploited the discovery of volcanic formations in the bottom of the Culebra cut.  The engineers have not been alarmed by these vaporous emissions, which in July, had about stopped, and were caused, according to the Commission geologist, by the warm atmospheric effect upon pyrite material.  A great variety of colored stones are found in the blasted material in the Cut, and when cut and polished make attractive ring settings and other souvenirs.   One crystal-like stone has been found hard enough to cut glass.  Not coal or other usable minerals have been struck in the excavations.

In the first plans for relocating the Panama Railroad, it was designed to run the tracks on the edge of the Cut at an elevation of 10 feet above the water level, but the slides made this impossible.  The new line was placed well back from the Cut away from the probability of slides.  An observation tower used by thousands of tourists, back of the town of Culebra, for viewing operations in the Cut, was removed in June, 1912, just in time to prevent its sliding into the cut, and in August two slides near Empire threw 1,200,000 yards into the Cut, or more than a month's work.

It will be a time of mingled emotions when the canal employees stand on the side of the Cut, in 1913, and watch the waters of Gatun Lake creep up and cover the scene of 9 years' work, and then to watch a ship pass in an interoceanic trip that has been the dream of four centuries.