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Page i Map Page ii Title Page Page 1 Page 2 List of Illustrations Page 3 Page 4 Foreword Page 5 Page 6 The Panama Canal Page 7 Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Page 24 Page 25 Page 26 Page 27 Page 28 Page 29 Page 30 Page 31 Page 32 Page 33 Page 34 Page 35 Page 36 Page 37 Page 38 Page 39 Page 40 Page 41 Page 42 Page 43 Page 44 Page 45 Page 46 Page 47 Page 48 Page 49 Page 50 Page 51 Page 52 Interesting facts and figures Page 53 Page 54 Page 55 Page 56 Page 57 Page 58 Page 59 Page 60 |
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Ja Nombre de ious I.C.C. S Pit' ISTHMUS WITH COMPLETED CANAL SCALE Miles 0 5 10 15 Kilometres 0 5 10 15 20 THE PANAMA CANAL A BRIEF ANDSIMPLE DESCRIPTION OF THE ESSENTIAL FEATURES BY WILLIAM M. BAXTER, JR. The Official Guide of the Isthmian Canal Commission ENLARGED AND ILLUSTRATED 1913 COPYRIGHT, 1918, BY WM. M. BAXTER, JR. LIST OF ILLUSTRATIONS. Page Culebra Cut, looking north from the Con- tinental Divide . . . . . . . . 8 Flat Arch in the Church of San Domingo, Panama . . . . . . . . . . . 14 Old French Locomotives, near Empire, Canal Zone . . . . . . . . . 16 Abandoned French Ladder Dredges . . . 18 Old French Excavation in Cut, near Empire 22 Steam Shovel Loading Rock for the Toro Point Breakwater . . . . . . . 28 Steam Shovel in Culebra Cut, buried under small rock slide, May 31, 1912 . . . 32 Slide of 300,000 cubic yards in the East Bank of Culebra Cut, August 21, 1912 34 Gatun Locks in Course of Construction . . 36 Cross-section of Lock Chamber and Walls, Gatun Locks . . . . . . . . . 40 Entrance to Upper Gatun Lock from the Lake . . . . . . . . . . . . 42 General View of the Pedro Miguel Lock . 44 Sanitary Drip Barrel . . . . . . . . 48 FOREWORD. The idea of the construction of a canal across the Isthmus has been the dream of all nations of the world ever since the day when Balboa first landed on the Isthmus in 1500. He had hardly set foot on dry land before he began the search for a natural waterway between the two continents. Failing to find anything of the kind, he had one of his followers, an engineer named Saavedra, prepare plans and surveys of an artificial water- way, but, after studying the subject for a period of more than ten years, he reported on the pro- ject as being impracticable. For over two centuries following this the project dropped from sight and it was not until the early part of the nineteenth century that the matter was again taken up. In 1814 Spain again under- took the consideration of a canal, but without any result. Following this both England and France became interested and made many studies and surveys of various routes. In 1835 the United States joined the list of those interested in the construction of a canal and had studies made of several of the feasible routes. It is interesting in this connection to know that, even before this time, Goethe had prophesied that the United States would eventually have to build the canal. In 1838 France secured a concession to build a canal, but allowed it to lapse through failure to do any work. In 1848 Messrs. Aspinwall, Chauncey and Stephens secured a concession from the Govern- ment of New Granada for the construction of a railroad across the Isthmus, which work they carried to a successful conclusion in 1855. For a while this road filled the demand for a trans- continental highway, but in 1870 the United States again became interested and entered into an agreement with Colombia for the construction of a canal; nothing was done, however, and in 1876 a Frenchman, Lieutenant L. N. B. Wyse, secured a concession to build a canal and it was his concession that was later transferred to the Universal Interoceanic Canal Company. This company began active construction work in 1881, but failed in 1888 and, although a new company was organized in 1894 it continued operations on a small scale, doing simply enough to maintain its franchise, until 1904, when it sold out to the United States. On April 23, 1904, the stockholders of the New Panama Canal Company formally authorized the sale of the company's property to the United States upon payment to the company of the sum of $40,000,000. The transfer of the property on the Isthmus was made May 4, 1904, the United States being represented by Lieutenant Mark Brooke, Corps of Engineers, U. S. Army. THE PANAMA CANAL. CULEBRA CUT, LOOKING NORTH FROM THE CONTINENTAL DIVIDE. THE PANAMA CANAL. THE CANAL ZONE. HE Canal Zone is a strip of land ten miles wide, five miles each side of the center line of the Canal, extending from the At- lantic to the Pacific. All told, it contains 436 square miles, of which the United States now owns about 363 square miles. The remainder is privately owned and was not acquired by the Government, as it was not needed for the con- struction of the Canal. If, however, this land should ever be needed, the United States can by its treaty right acquire, either by purchase or by the exercise of the right of eminent domain, any lands, buildings, water rights, or other properties necessary for the construction, maintenance, operation, sanitation, or protection of the Canal. The two cities of Panama and Colon, although within the boundaries of the Canal Zone, are ex- cluded from it and are under the Government of Panama. They have no outlet, however, except through the Zone. The United States reserves the right to enforce sanitary ordinances in those two cities, and also to maintain public order in the event that the Republic of Panama is unable to do so. ROUTE OF CANAL. The Canal traverses this Zone from Colon to Panama in a general southeasterly direction, Panama being located 22 miles east of a line running due south from Colon. In passing through the Canal from the Atlantic vessels enter a sea-level channel extending from deep water in the Atlantic to the foot of the locks at Gatun. This channel is 7 miles in length, 500 feet wide and 41 feet deep. At Gatun, vessels are lifted from sea-level to 85 feet above through a flight of three locks, passing directly into the waters of Gatun Lake. Gatun Lake is an artificial body of water with an area of approximately 164 square miles. This lake is formed by impounding the waters of the River Chagres and its tributaries by means of a large dam at Gatun, where there is a break in the range of hills which surround the basin of the Chagres. By building a dam a mile and a half long across this gap, it is possible to back up the waters of the Chagres and form the Gatun Lake. The surface of this lake stands 85 feet above sea- level, the summit level of the Canal, and extends from Gatun clear through the Culebra Cut to the southern end at Pedro Miguel, a distance of 32 miles. From the foregoing, it can be clearly seen that the Culebra Cut is merely a spur of the Gatun Lake, the same water level existing in the Cut as in the balance of the lake. [10] Vessels after entering the lake may go at practically full speed for a distance of 23 miles from Gatun to the mouth of the Cut. The first 16 miles of the channel through the lake is to be 1,000 feet wide and is marked by buoys on the surface of the lake, then for four miles the chan- nel is to be 800 feet wide, narrowing to 500 feet for three miles before entering the Cut. Through the Culebra Cut, which is 9 miles in length, the channel is to be 300 feet in width at the bottom. Passing through this Cut at a re- duced speed vessels arrive at the Pedro Miguel Lock at the south end, through which they are lowered in one step from 85 feet above sea-level to 55 feet above, a drop of 30 feet, passing out into Miraflores Lake, a small artificial lake covering an area of about two square miles. This lake is formed by impounding the waters of the Cocoli, the Rio Grande and the Pedro Miguel Rivers by means of the dam, locks and spillway at Mira- flores. The dam at this point runs practically parallel to the locks on their west side instead of at right angles to them. This is done in order to take in the Cocoli River, which comes in from the west, striking midway of the locks, which makes it necessary either to divert this stream or else to build a dam so as to throw it back into the lake. The latter plan gives additional water for the lake and avoids the silting up of the sea- level portion of the Canal at the point at which the diverted Cocoli would enter it. The spillway is [11] located on the east side of the locks between the side wall and a rocky point, and is of sufficient size to discharge all the water that might flow through one of the twin locks at Pedro Miguel in the event that an accident should establish free communication between Gatun and Mira- flores Lakes. In this way, an accident at Pedro Miguel does not necessarily endanger the locks at Miraflores. Passing through the Miraflores Lake a dis- tance of a mile and a half through a channel 500 feet in width the vessels arrive at the Miraflores Locks and pass down through two locks in flight from 55 feet above sea-level to the sea-level channel on the Pacific side, steaming out through this channel from the foot of the locks at Mira- flores to deep water in the Pacific, a distance of 8 miles. The total length of the Canal is 50' miles and the time for passing through from one ocean to the other will be from ten to twelve hours, ac- cording to the speed a vessel maintains in the lake area. Three hours of this time are taken up in passing through the six locks. Of the total length of the Canal, 40 miles will be of sufficient width to allow vessels to go at practically full speed, there being 15 miles of sea-level channel, 7 on one side and 8 on the other, and 25 miles of open lake navigation in the two lakes, in all of which the minimum channel width is to be 500 feet, and the maximum 1,000 feet. This leaves only 101 miles which is at all narrow, 9 miles being in the Cut where the bottom width is to be 300 feet and through which vessels will go at a reduced rate of speed, and the remainder being through the locks, where the vessel will be towed by means of electric towing engines. Everywhere except through the locks vessels will go under their own power. OCEAN LEVELS. The general conception seems to be that the Pacific Ocean is higher than the Atlantic; this, however, is not the case. Mean sea-level, the point midway between extreme high and low tide, is exactly the same in both the Atlantic and the Pacific. The difference is all in the tides. There is an average tide on the Pacific of 20 feet, while there are approximately but 20 inches of tide on the Atlantic side. This excessively high tide on the Pacific side is apparently due to the shape of the Bay of Panama, which, being shaped like a funnel, tends to exag- gerate the action of the tide. The same thing occurs at several other points throughout the world, the most remarkable case being the Bay of Fundy in Nova Scotia, where the tide sometimes rises and falls 60 feet. FLAT ARCH IN THE CHURCH OF SAN DOMINGO, PANAMA. This arch stands in the ruin of the Old San Domingo Church which was destroyed by fire in 1756. It spans 50 feet, is 35 feet high at the crown and 33 feet at the spring. The question as to whether Panama is subject to severe earthquakes is frequently asked, and the fact that this arch has stood for over 150 years is in itself practically an answer to that question. BREAKWATERS. Breakwaters are being constructed on both the Pacific and the Atlantic sides. The one on the Pacific end is simply an extension of a large dump at East Balboa of material excavated from the Culebra Cut, connecting Naos Island with the mainland and designed to cut off a cross-current which comes in at right angles to the line of the Canal. This current although moving slowly carries an enormous amount of silt and sand, and it was to prevent the filling in of the sea-level portion of the Canal that this breakwater was constructed. The Toro Point breakwater on the Atlantic side extends northeast from Toro Point a distance of 11,000 feet and is designed to protect the Bay of Limon from heavy storms which occur during the winter months and are commonly known as Northers. These storms are of such violence that when one occurs vessels cannot lie at the docks at Cristobal and Colon, but are forced to move out into deep water to seek shelter farther down the coast in the land-locked harbor of Porto Bello. In addition to this breakwater a mole is being built in connection with the dock improve- ment work at Cristobal, behind which the docks will be constructed. If it should be found after this mole is completed that still further protection is required then a second breakwater will be ex- tended from the headland opposite Toro Point. A OLD FRENCH LOCOMOTIVES, NEAR EMPIRE, CANAL ZONE. FRENCH WORK. Active work was started by the French on their Canal in 1881, and this first French Company, which was organized by De Lesseps, failed during the latter part of 1888 after spending $260,000,000.00. For five years the company remained in the hands of a receiver, and in 1894 the New French Com- pany was organized and kept up the work on a very small scale until 1904 when the United States took over the construction. The plan of this last French Company was to build a lock type canal with a total of eight locks and a summit level through the Culebra Cut at 97 feet above sea-level. Starting just behind Cristobal Point, in order to secure the protection of that point against the Northers, and extending for 16 miles inland to Bohio, the Canal was to be a sea-level type. At Bohio a dam and two locks were to be located, forming the Bohio Lake with a surface level of 65 feet above sea-level. Passing through this lake a distance of 14 miles the vessels would arrive at Bas Obispo at the northern end of the Cut, where it was intended to locate two more locks with a combined lift of 32 feet. In order to secure water for the sum- mit level through the Cut it would have been necessary to build an additional reservoir at Alhajuela farther up the valley of the Chagres, bringing a ditch line along the hillsides from this lake down and into the Cut. Passing through [17] ABANDONED FRENCH LADDER DREDGES. :- ^_'*/- * ..1 "s^- + 'ni -.Si ...... , \. ',.B , . the Cut, vessels were to be lowered to the Pacific through four locks, one at Paraiso, two at Pedro Miguel, and one at Miraflores, from which point a sea-level canal 8 miles long led out into deep water in the Pacific. FRENCH PURCHASE. The rights and property of this French Company were purchased by the United States for $40,000,- 000.00; and up to date our country has realized on this purchase, on a very conservative estimate, over forty-two million dollars. Out of 80,000,000 cubic yards of excavation work which the French Company had done only 30,000,000 yards were useful in the construction of the present type of Canal, and in estimating the value of the French purchase an allowance of $25,389,240.00 was made for this excavation work. It had cost approximately one hundred and twenty million dollars. The value of the Panama Railroad was esti- mated at $9,000,000.00. This railroad was ac- quired by the French at a cost of $18,000,000.00. In addition to these two main items the purchase included a great deal of machinery, and the Commission is today using 85 French loco- motives and 7 ladder dredges included in the property purchased. The French also turned over a great many buildings, maps, and scientific data, including records of the flow of the Chagres River through a period of 15 years. On these records it is impossible to place any cash value, as they would not have been available at any price, had not the French kept these records, and with the present type of canal it is a matter of vital importance to be able to estimate ac- curately the volume of the flow of the Chagres, as it is the Chagres that supplies the water to fill the Gatun Lake and make the lockages through the Canal. Now, due to the fact that we have secured these French records, we have a com- plete record of the flow of the Chagres extending through a period of twenty-three years. RELOCATION OF PANAMA RAILROAD. As the construction of the Canal progressed it became necessary from time to time to aban- don small sections of the original Panama Rail- road line, which was built in 1850 by three Americans, Aspinwall, Stephens, and Chauncey. In 1908, the section between Mindi and Tiger Hill was relocated as the old line passed right through the site of the Gatun Dam and Locks. In 1910, the section between Pedro Miguel and Corozal was relocated, establishing the line per- manently at an elevation sufficiently high to be above the level of Miraflores Lake, and on Feb- ruary 15, 1912, the relocated line between Gatun and Matachin was put into service, as the rising [20] water of the Gatun Lake due to the closing up of the Chagres at Gatun on February 9, soon flooded most of the old line between these points. The Gatun Lake now stands 50 feet above sea- level, at which elevation it floods the old railroad right of way to about Tabernilla and covers an area of over 90 square miles. Finally, with the Canal completed, a new rail- road will have been constructed, running from Colon to Panama entirely on the east side of the Canal. The new road after leaving Gatun swings east along the hillsides, and crossing through the lake on high earth fills, follows the borders of the lake to Gamboa, where it crosses the Chagres on a steel girder bridge a quarter of a mile long. From here it swings away from the Cut and, passing around back of Gold Hill, follows the Pedro Miguel valley to Pedro Miguel. Originally it was intended to carry the railroad through the Cut on a bench 10 feet above the water, but the slides in the Cut made that impracticable. GATUN DAM AND LAKE The Gatun Dam is a huge earth structure and is, in fact, more of a mountain than a dam. It is so constructed as to complete the natural range of mountains which, excepting at this one point, entirely surround the low-lying basin of the Chagres. By completing this basin, it is possible to retain the waters of the Chagres and thereby form the Gatun Lake. --, OLD FRENCH EXCAVATION IN CUT NEAR EMPIRE. The dam is constructed of two outer walls of dry fill, a large part of which was excavated from the Culebra Cut. These two walls, or toes, as they are usually called, were constructed so as to be 1,200 feet apart (inside measurement) and this space in between the two walls was filled with a mixture of sand and clay which was sucked up from the river bed of the Chagres, both above and below the dam, by means of large suction dredges and then pumped through long pipe lines into the space between the two walls of dry earth fill. About 20 per cent of the material passing through these pipe lines was solid matter, the bal- ance water. After the solid matter settled the sur- plus water was drained off and in that way the inner portion of the dam was built up. This inner core is usually known as the hydraulic core and forms the watertight portion of the dam. After the hydraulic core had been carried a short way above the water level it was discontinued and the outer walls were then carried higher and closer together until they entirely encased and capped over the inner core. The Gatun Dam at the base is 2,100 feet, or about a half mile thick, 400 feet thick at the water surface, and 100 feet wide across the crest. The crest of the dam stands 105 feet above sea-level and 20 feet above the surface of the water of the lake. The length of the dam measured along the crest is 7,500 feet, but of this length only 500 feet will be subject to the full pressure of 85 feet [23] of water, due to the natural rise of the ground along the inner slopes of the dam. In connection with this dam it is interesting to know that a Frenchman named Lepinay was the first to propose the plan of constructing a dam at Gatun. He proposed this plan in 1879 to the International Scientific Congress which had been convened at Paris to determine upon the general route of the proposed canal, but De Les- seps, who was the leading spirit of this Congress, was so strong an advocate of the sea-level canal that Lepinay's plan was hardly discussed, and is simply a matter of record. SPILLWAY. The spillway, which is located about midway of the dam, is built right into a natural hill, which stood at an elevation of 110 feet above sea-level. This hill was practically solid rock, so it was only necessary to cut a channel 300 feet wide through this hill and line it with concrete, building a dam across the head of this channel to form the spill- way or regulating works for Gatun Lake. This dam forms nearly a semicircle across the head of the spillway channel and will be constructed of solid concrete up to elevation 69. At this level piers rise 45 feet apart on the crest of the solid portion of the dam, and in between these piers come the steel gates nineteen feet high which control the level of the lake. [24] With these gates closed, the crest of the dam would be 88 feet above sea-level, so that it would be possible to store up water in the Gatun Lake up to about 87 feet above sea-level. The normal level of the lake is to be 85 feet and it will be maintained at that level during most of the year; just at the last of the rainy season, however, the lake level will be brought up to 87 in order to supply the water for lockages during the dry season. This will give an additional two feet of water over an area of 164 square miles, which would be sufficient to make 58 lockages a day during the dry season; that is, ten more than could possibly be made with vessels following one another at intervals of one hour. With the lake at 85 the spillway will be capable of discharging 154,000 cubic feet per second, which is more than the greatest momentary discharge on the Chagres River at Gatun. If the Gatun Lake should ever go to elevation 92 the spillway would be capable of discharging over 200,000 cubic feet of water per second, which is very nearly equal to the discharge of the Horse- shoe Falls at Niagara. In addition to the control of the Chagres effected by means of the spillway, there is the great reservoiring effect of the Gatun Lake, it being of such great area that it would take the greatest known flood of the Chagres River nine hours to raise the level of the lake one foot, even though no water was discharging through the spillway at Gatun. WATER SUPPLY. To those who are skeptical as to the supply of water which will be available to fill the Gatun Lake the following figures may be of interest. The rainy season on the Isthmus usually ex- tends through the last eight months of the year and the remaining four months make up the dry season. At Colon the average annual rainfall amounts to 130 inches a year and, as one comes across the Isthmus from Colon to Panama, the rainfall decreases gradually until at Panama the rain- fall averages 70 inches per annum. Now, as one goes east and west from the Zone, one gets into sections that are more mountainous in which it rains almost every day in the year, so that at Porto Bello one finds an annual average rain- fall of 173 inches. In 1909 Porto Bello had 237 inches of rain; during one month of that year it had 58 inches, or more than the average annual rainfall around New York or Boston, which is 40-45 inches. Porto Bello also holds the record for 24 hours' rainfall, which amounted to 10.86 inches. The greatest recorded rainfall for one hour is 5.86 inches at Balboa in June, 1906. The heaviest rainfall of short duration occurred at Porto Bello in December, 1911, amounting to 2.46 inches in three minutes. The area drained by the Chagres and its tribu- taries is 1,320 square miles, and in 1910 the volume [26] of the discharge of that river at Gatun equaled once and a half the volume of water that will be contained in the Gatun Lake. At Gamboa, the river has been known to rise 40 feet in 24 hours and to discharge 100 times the water that it does in the dry season, amounting during one flood to a flow of 170,000 cubic feet per second, which equals two-thirds of the volume of water which passes over the Horseshoe Falls at Niagara. POWER PLANTS. On the east side of the spillway will be located a large hydro-electric plant. This plant will take water from the Gatun Lake, pass it through tur- bines and discharge it through openings in the side wall of the spillway channel, thereby generat- ing all the power necessary to operate the lock machinery throughout the entire length of the Canal. This plant consists of three 2,000 kilowatt generators, one of which is a reserve, producing ordinarily over 5,000 horse power with a reserve of 2,500 horse power. The fall from the level of Gatun Lake to the level of the spillway floor being 75 feet, the supply of water for operating this plant will be ample at all times of the year. As an extra precaution, however, the present 6,000 horse power construction plant at Miraflores, which is an oil-burning steam plant, will be re- tained as an auxiliary to the Gatun plant should it ever be needed. - I-; - a STEAM SHOVEL LOADING ROCK FOR THE TORO POINT BREAKWATER. CULEBRA CUT. The Culebra Cut, from which it was necessary to excavate over 105,000,000 cubic yards of rock and earth, representing nearly half of the excava- tion work on the entire Canal, begins at the point where the Canal leaves the valley of the Chagres near Bas Obispo and follows the winding valley of the Rio Obispo until it reaches the Continental Divide near Culebra. After cutting through the divide it follows the valley of the Rio Grande to Pedro Miguel. The Cut is nine miles long and will be 300 feet wide on the bottom. At all the angles it is widened out sufficiently to allow a vessel 1,000 feet long to make the turn with perfect ease. The average depth to which it was necessary to excavate below the natural surface was approximately 120 feet through the entire length of the Cut. At the point where the Continental Divide was severed between Gold Hill and Contractor's Hill the cutting will average 375 feet. EXCAVATION. On January 1, 1913, there remained to be exca- vated throughout the Cut 5,501,419 cubic yards of material. In the year 1911, 16,600,000 cubic yards were excavated, so that at this time there remains to be taken out less material than was excavated in the past twelve months. The 5,501,419 cubic yards which are still to be excavated lie in the [29] Cut in the shape of a mount 4 miles long at the base and 25 feet high. At the highest point, this summit is located just opposite Culebra, and the mound slopes both ways from that level, so that on either end of the Cut a point is reached where the excavation work has been carried down to the final grade. Thirty-eight steam shovels are at work excavating this material, each one taking out on an average 1,500 cubic yards of rock and earth each day. Records have been made, however, of over 4,000 cubic yards in eight hours. As a matter of fact, the number of hours that a steam shovel is generally employed in loading cars amounts to only about six, as the problem in the Cut is more one of transportation than of excavation, and it is not possible to keep trains standing under the shovels more than six hours out of the eight. All told, there are now about 75 miles of track in the Cut, of which it is necessary to move about a mile each day. At the present time, about 150 loaded trains of earth are passing out of the Cut daily, but at the time when the excavation work was at its maximum 175 trains were leaving each day, which amounted to about one train every two and one-half minutes. The monthly output from the Cut reaches close to 1,500,000 cubic yards. The buckets used on most of the shovels in the Cut load 4 and 5 cubic yards at a time, which by weight means from 6 to 7Y2 tons to the bucketful. DRILLING AND BLASTING. All of the material which is excavated by the shovels is first drilled and then blasted before it can be handled, and in the length of the Cut a great number of drills are constantly working. All of these drills, of which there are two styles, churn and tripod, are operated by compressed air supplied from one long air main which par- allels the line of the Cut. Three compressor plants are pumping into this line, one located near the middle and one near each end of the line. The average depth to which the holes are drilled is 24 feet, and after drilling to this depth a small charge of dynamite is placed in the hole and discharged by means of the magneto battery, enlarging in that way the size of the hole at the bottom. Then, after the hole has cooled off it is ready to receive the large charge of dynamite varying from 75 to 200 pounds to each hole. This charge is exploded by means of the regular electric light current, the ordinary magneto bat- tery having been found too unreliable and its use resulted in too many misfired shots, which had to be subsequently excavated, thereby greatly endangering the lives of the workmen. Each month an average of 75 miles of drill holes are sunk, and if all the drill holes which have been put down since the United States has been at work were placed end to end the hole would pass entirely through the earth, coming [31] STEAM SHOVEL IN CULEBRA CUT, BURIED UNDER SMALL ROCK SLIDE, MAY 31, 1912. STEAM SIHOVEL IN CUTLEIlRA CUT. BURIED UNDER SMALL ROCK SLIDE, MIAY 31, 1912. out in the Indian Ocean south of the Island of Sumatra. Five hundred thousand pounds of dynamite are used each month in the Cut, and on the entire Canal 800,000 pounds are consumed. SLIDES. At the present time, there are in the length of the Cut nineteen slides varying greatly in size, the total area involved amounting to 210 acres. One of the largest is the Cucaracha slide just south of Gold Hill, which started during the French time and now covers an area of 47 acres, and is broken back a distance of 1,800 feet from the center line of the Cut. A great number of smaller slides have occurred throughout the Cut, the worst section for slides being right around the town of Culebra. From time to time small slides have occurred here on both the east and west banks, which have gradually combined, forming two large slides, until they have become more difficult to handle than the Cucaracha slide. Two general characters of slides are found in the Cut. One is the true slide, which is a mass of earth that is sliding from a hard surface that pitches towards the Cut and this slide is glacial in its action. There are no means of overcoming or correcting this character of slide; the only thing that can be done is to take the material out as it slides in and continue to do so until the sliding material reaches an angle flat enough to stand. The other [33] .7 f, h-.-M SLIDE OF 300,000 CUBIC YARDS IN THE EAST BANK OF CULEBRA CUT, AUGUST 21, 1912. ak. is a slide that is caused by the great weight of the banks on either side of the Cut weighting down and squeezing out the soft underlying strata, which in giving away bulge up at the bottom of the Cut, allowing the banks on either side to settle. These banks in settling break loose and begin to move toward the Cut. The first move- ment of the banks in this kind of slide is down- ward and then the lateral motion follows. The slides near Culebra are of this type. In order to correct this character of slide steam shovels are working on top of the banks, taking material off the top, thereby reducing the weight of the banks and to a certain extent preventing further sliding. DIVERSION CHANNELS. As the Cut follows the valleys of the Rio Obispo and Rio Grande, it was necessary to divert these streams and their main tributaries to prevent the Cut from being flooded during the rainy season. So that paralleling the line of the Cut on the west side we have the Rio Grande and Comacho diver- sions, and on the east side the Obispo diversion. These diversion channels parallel the line of the Cut and carry off the water of these small streams as well as a large part of the surface drainage water, thus preventing the flooding of the Cut itself. These channels were all started by the French, but were enlarged after the United States began work on the Canal. [35] GATUN LOCKS IN COURSE OF CONSTRUCTION. LOCKS. There are six locks in the Canal, three in flight at Gatun, one at Pedro Miguel and two in flight at Miraflores. All locks are constructed in pairs, so that vessels can go in opposite directions at the same time. Each Jock or flight of locks is in general to be reserved for ships going in one direction, the twin lock or flight being used for vessels going in the opposite direction. The length of the lock chamber is 1,000 feet, the width 110 feet, and the depth of water over the sills 41'3- feet in fresh water and 40 feet in salt water. The Pedro Miguel Lock is the same in all the essential features as the other locks and as there is only one lift at this point it is the best one to describe. A simple definition of a lock is a walled chamber between two bodies of water of different levels having gates at either end, in which it is possible to confine vessels while they are being raised or lowered from one level to another by allowing water to flow in or out of the lock chamber. The method of raising or lowering the level of the water in the lock chamber varies on different lock canals. The lock chambers on most of the old canals are emptied or filled through sluice gates that slide up and down in the lock gates themselves. This system, however, caused a great deal of surging of the water at that end of the lock at which it was flowing in or out, and the system that has been adopted on the Panama Canal was designed with the idea of avoiding this disturbance of the water in the lock. All the locks on the Panama Canal have two parallel lock chambers separated by a center wall. The water is brought in or out of these chambers through huge tunnels 18 feet in diameter passing lengthwise of the lock through the center and side walls. Branching out from these tunnels at right angles and running out under the lock floor are laterals and these laterals communicate with the lock chamber through openings in the lock floor. The flow of water in or out of the lock is controlled by the gate valves located at both the upper and lower ends of the feed tunnels. In order to raise the water in the lock chamber the valves at the lower end are closed and the ones at the upper end opened. The water then flows from the upper level into the lock, passing down the tunnel in the side wall and out through the laterals under the floor, coming up through the openings in the floor. It continues to flow in this way until the elevation of the water in the lock chamber is the same as that of the water above. To lower the water in the lock the pro- cess is simply reversed. The upper valves are closed and the lower ones opened. The water then flows out from the lock chamber and passing back through the same tunnels that brought it in seeks the level of the water below. So that, in order to raise a vessel from one level to another, the level of the water in the lock chamber is brought to the same level as that at which the vessel stands. The lock gates are then opened, the vessel passes into the chamber and the gates are closed. Water is then allowed to flow into the lock until the vessel is raised to the level of the upper body of water, and with the same level on both sides of the upper gates those gates are thrown open, the vessel passing out at a greater elevation than that at which it entered the lock. The big tunnels passing through the side walls are the main operating tunnels, the one through the center wall being an auxiliary used to assist in filling the lock during the latter part of the opera- tion, thereby increasing the volume of the inflow at the time when the velocity of the water entering the lock from the side wall tunnels is decreasing, keeping up in that way an average rate of filling which would amount to about 2 feet per minute. So that, at Pedro Miguel, where the lift is 30 feet, a vessel would be raised from one level to the other in 15 minutes. The desired rate of filling can be kept up for the 600-foot and 400-foot locks by the side culvert only. It is probable that the center wall tunnel will be used only in case of the 1000-foot lockages. From the center wall tunnel laterals, which alter- nate with laterals from the side walls, lead out under the floors of both lock chambers. They are controlled, independent of the main tunnel, . ,y CROSS-SECTION OF LOCK CHAMBER AND WALLS, GATUN LOCKS. A. Culvert in center wall. E. Culvert in side wall. B. Connections between center and lateral culvert. F. Drainage gallery. C. Lateral culvert. G. Gallery for electric wires. D. Wells opening from lateral culverts into lock chamber. H. Passageway for operators. by cylindrical valves located at the head of each tunnel, so that it is possible to close the laterals all the way down on one side, opening those on the other side, and feed water to one lock chamber; or, by reversing the process, feed water to the other chamber. By opening the valves to the laterals on both sides itis possible to pass water through from one chamber to the other, in that way effecting a saving of water whenever vessels are going in opposite directions at the same time. Another means of economizing water is by using the intermediate lock gate which divides the 1000-foot lock into two sections of 600 and 400 feet, respectively; so that in putting through small vessels it is not necessary to fill or empty the entire chamber. ELECTRIC LOCOMOTIVES. The protective devices are one of the most interesting features of the lock construction, and of these the electric locomotives are the most important. About ninety per cent of all accidents to other locks have been due to misunderstanding in signals between the captain and engineer of the vessel, and all accidents of that kind will be eliminated by requiring vessels to go through the locks in tow of electric locomotives operating on the center and side walls of the locks. A vessel comes in and ties up to the center wall, which is extended beyond the side walls at both the i-.. . . - ; Ti'l . ":a-a.^,'- m.. , li^ ENTRANCE TO UPPER GATUN LOCK FROM THE LAKE. upper and lower ends of the lock simply to act as a wharf or mooring wall. The vessel waits here until the locomotives come down and tow it up to a point where the locomotives on the side walls make fast their lines. The vessel then goes into the lock chamber with two locomotives in front towing, one on either side', and two others behind to retard when she gets into proper position. These towing locomotives operate on tracks close to the edge of the wall and engage in a center cog rail. While running on this cog rail the maximum speed at which they can operate will be two miles per hour. When they have completed a tow, however, they switch over to a track farther back from the edge of the wall and here the cog rail is omitted, so that they can return at a greater speed. PROTECTIVE CHAIN. Should a vessel not obey the order to stop out alongside the center wall but come ahead, it first would encounter a chain stretched across the entrance to the lock chamber. This chain connects on either side with large hydraulic cylinders located in shafts in the lock walls. The pressure from these cylinders causes the chain as it plays out to offer more and more resistance to the motion of the vessel. The chain is capable of stopping in 70 feet a 10,000-ton vessel running four miles per hour. The stock from which it is to be forged is three inches in diameter. - 2~ I N -l ~t.l U H 9, 'I GENERAL VIEW OF THE PEDRO MIGUEL LOCK When not in use the cylinders are forced up and the weight of the chain carries it down into the groove in the bottom of the lock floor and the vessel passes over it. GUARD GATES. If a vessel should break through the fender- chain, it would then ram the lock gate, but with this contingency in view two gates instead of one have been provided at the upper and lower ends of the highest lock in each flight, the upper or guard gate of each pair serving to protect the lower gate from ramming. Both gates would have to be broken down to put the lock out of commis- sion. LOWER GUARD GATE. At the lower end of all the sets of locks a small guard gate has been put in, mitering the other way from the main lock gates, which miter to- wards the high level, and it has been designed to serve two purposes: first, as a coffer gate or dam, if at any time it is necessary to pump the water from the lower lock chamber; second, as a guard gate to the lower lock gate, for, miter- ing as it does, it will stand a heavier blow from the lower side than the lock gate itself. EMERGENCY DAM. If all of these devices should fail and there should be an accident which would establish [45] free communication between the two levels above and below a lock, a most destructive accident would be the result, for the velocity of the water flowing through the lock chamber would be 24 feet per second and the discharge would amount to 90,000 cubic feet per second. In order to shut off this water and prevent it from tearing out the lock floor it is necessary to employ a device known as an emergency dam, of which there are two installed at the upper end of each set of locks, one for either side. These resemble a swing bridge and when put into use they are swung out across the lock and from their lower side a set of open-work wickets are lowered, engaging in a grooved sill on the lock floor. When these wickets are down and in place, small plates resembling little flat cars are allowed to run down, one on each wicket, building up a row of plates across the bottom, one joining the other. When the first complete set has been let down nine feet of the water will be shut off, and then an- other set of plates will be let down, until finally the water rushing through the lock will be entirely shut off. Of course, there will be some seepage through the plates, but the water above this tem- porary dam will be still water and the electric locomotives will go down and take in tow a floating caisson, or hollow steel float, and towing it around seat it against a sill at the upper end of the lock chamber. Then by filling water into the caisson it is sunk, entirely shutting off the water flowing [46] through the lock. The emergency dam is then raised and the necessary repairs made to the locks. LOCK GATES. The construction of the lock gates is also inter- esting. They were built up of big horizontal girders weighing from 12 to 18 tons each, with vertical framework in between and sheathing plate both on the inside and outside of this frame. They are cellular in construction and the lower half of the gate is an air chamber which supports about three-quarters of the weight of the gate when submerged. The upper half of the gate is arranged with openings in the plates on the up- stream side so that water can flow in or out of the upper half of the gate at the same time that it flows in and out of the lock, increasing the weight of the gate as the height of the water on the outside increases, overcoming in that way the lifting effect of the air chamber in the bottom of the gate as it is placed deeper and deeper under water. These gates vary in height from 47 to 82 feet, and in weight from 300 to 700 tons to each half gate. If each half gate were laid flat one on top of the other they would build up a tower contain- ing 58,000 tons of steel standing 32 feet higher than the Singer Building in New York. There are 92 half gates and each is seven feet in thickness Another interesting comparative figure is one pertaining to the excavated material. All of the [47] SANITARY DRIP BARREL. Placed at the headwaters of a stream, these barrels automatically feed crude oil, which spreads out over the surface of the water. excavated material which will have been taken out when the Canal is completed, including the 30,000,000 cubic yards of useful French excava- tion, if loaded on one train of flat cars similar to the wooden cars one sees commonly on the work, would make a train over 110,000 miles long, reaching more than four times around the earth. SANITATION. No one single factor has been more important in making the construction of this Canal a pos- sibility than that of sanitation. One of the worst snags that the French ran against was this very question of sanitation. Unfortunately, there are no accurate figures obtainable on the lives lost during the French time; the only figure available is for the mortality in Ancon Hospital, which for the eight years between 1881 and 1888 amounted to 5,527. But the French were, at this time, doing their work by contract and each con- tractor was charged a dollar per day for each man he had in hospital. It will readily be under- stood, therefore, that if the French contractor were anything like the ordinary contractor, not a very large proportion of the sick would go to this hospital. We hear of many individual instances of heavy loss. The first French director, Mr. Dingler, came to the Isthmus with his wife and three children. At the end of the first six months all had died of yellow fever except him- self. One of the French engineers, who was still on the Isthmus when we first arrived, stated that he came over with a party of seventeen young Frenchmen. In a month they had all died of yellow fever except himself. The super- intendent of the railroad brought to the Isthmus his three sisters; within a month they had all died of yellow fever. The Mother Superior of the sisters nursing in Ancon Hospital told me that she had come out with twenty-four sisters. Within a few years twenty-one had died, the most of yellow fever. Many other instances of this kind could be cited. During the eight years that the Americans have been at work on the Canal the death roll has reached 5,141, of which 995 have been deaths from violence. For the fiscal year 1912 the death rate per thousand on the Isthmus was lower than in almost any large city in the United States, as the following figures will show: Deaths from accidents........... 3.08 Deaths from diseases ....... .... 7.08 Total deaths from all causes....... 10.16 The most important work of the Sanitary Department and the one which has had most to do with the reduction of the death rate is undoubt- edly that which has to do with the control of the breeding of mosquitoes, so that I will speak only of that one feature of its work. [501 I have found it a very prevalent idea among the visitors to the Isthmus that the mosquitoes have been entirely exterminated from the Zone; such, however, is not the case, for, although there are 448 square miles within the Zone, the destruction of the mosquito is carried on over only about 100 square miles. Outside of this area of 100 square miles mosquitoes can be found just as thick as they ever were; but, by constant vigilance and effort, the number of mosquitoes in the sanitated areas has been reduced to such a very few that adult mosquitoes are but seldom seen by the casual observer. For the purpose of sanitation, the Zone is divided into sanitary districts, each district being placed in charge of a sanitary inspector. As a general rule, the sanitary work is carried on to a distance of about 1,000 yards outside the extreme limits of any inhabited district, as this has been found to be about the flying radius of the varieties of mosquitoes which the Sanitary Department has to deal with. The work of controlling the mos- quitoes within these districts falls under three heads: FIRST: Elimination of favorable breeding places by filling, drainage, removal of grass to favor evaporation, clearing of banks of streams and other bodies of water to give access to fish that eat the larvae of the mosquitoes, removal of vegetation and other foreign matter such as algae which gives shelter to the larvae of the mosquitoes, introduction of water supplies to reduce the number of water-holding containers in which the yellow-fever mosquito breeds, and screening of such water containers as cannot be done away with. SECOND: By oiling or larvaciding such bodies of water as cannot be conveniently and economically eliminated, the oil used for this purpose being the ordinary crude oil and the larvacide a mixture of creosote, caustic soda and resin. THIRD: By preventing the access of mos- quitoes to the inhabitants by effectively screening as many dwellings as possible and, in addition, by catching in specially designed traps and by hand such mosquitoes as find their way into dwellings. By the constant application of these methods the malaria rate has been reduced from about 6.83 % of employees admitted each month to the hospital in 1906 to about 1% per month for the current year, and in totally eliminating yellow fever from the cities of Panama and Colon and the Canal Zone, the last case of this disease having occurred in Colon in May, 1906. INTERESTING FACTS AND FIGURES Length of Canal from deep water to deep water (miles) ............... 5012 Length from shore-line to shore-line (m iles) .......... .. . ........... 40 Time of transit through completed Canal (hours)................... 10 to 12 Time of passage through locks (hours) 3 Bottom width of channel, maximum (feet) ........... ..... ......... 1,000 Bottom width of channel, minimum, 9 miles Culebra Cut (feet) .......... 300 Locks, in pairs ..................... 12 Locks, usable length (feet) ........... 1,000 Locks, usable width (feet) ........... 110 Gatun Lake, area (square miles) ...... 164 Gatun Lake, channel depth (feet)... 85 to 45 Culebra Cut, channel depth (feet) ..... 45 Excavation, estimated total (cubic yards) ............ ......... 212,504,138 Excavation, amount accomplished to January 1, 1913 (cubic yards) .....188,280,312 Excavation by the French (cubic yards) 78,146,960 Excavation by French, useful to pres- ent Canal (cubic yards)........... 29,908,000 Excavation by French, estimated value to Canal . . . . . . ........ ........... $25,389,240 Value of all French property ....... . $42,799,826 Concrete, total estimated for Canal (cubic yards) . . . . . . . . . . . . . . . . .... 5,000,000 Weight of one cubic yard of concrete or earth (pounds) ................. 3,000 Relocated Panama Railroad, estimated cost....................... $9,000,000 Relocated Panama Railroad, length (m iles) . ....................... 47.1 Maximum grade on Panama Railroad (per cent) ....................... 1.25 Maximum curve on Panama Railroad (degrees) .......... ............. 7 Gage of Panama Railroad (feet) . . . . . 5 Canal Zone, area (square miles) ...... 448 Canal and Panama Railroad force actually at work (about) ........... 35,000 Canal and Panama Railroad force, Americans (about) ........ . . . 5,000 Cost of Canal, estimated total ....... $375,000,000 Amount spent by French ............ $260,000,000 Work begun by Americans ......... May 4, 1904 Date of official opening ............. Jan. 1, 1915 Population of Colon................ 17,740 Population of Panama City ......... 37,505 Tide on Pacific side (feet) .......... 20 Tide on Atlantic side (inches) ....... 26 Area drained by the Chagres River (square miles) ......... ......... 1,320 Average rainfall at Colon (inches)... 130 Average rainfall at Panama (inches) . 70 Average rainfall at Porto Bello (inches) ....................... 173 Maximum rainfall of record for 3 minutes (inches)......... ... .... 2.46 [54] Maximum rainfall of record for 1 hour (inches) ....................... 5.86 Maximum rainfall of record for 24 hours (inches) .................. 10.86 Maximum temperature of record (de- grees fahr.) .................... 96.6 Minimum temperature of record (de- grees fahr.) .................... 59 Average mean temperature......... 79 Mean relative humidity (per cent) . . 89 Evaporation per annum (inches) ..... 52 Maximum momentary discharge of Chagres at Gamboa (cubic feet per second) . . ....... ............. 170,000 Volume of water passing over the Horseshoe Falls at Niagara (cubic feet per second) . . .. . . . . .. . 250,000 Average amount excavated in 8 hours by each steam shovel in Cut (cubic yards) ............. ... ...... .. 1,500 Record for 8 hours for steam shovels of any class (cubic yards) ......... 5,554 Record for 8 hours for 70-ton shovels, 3-yard bucket (cubic yards) ....... 3,910 Location of Rock Crushers and Sand Pits: Atlantic Side: Rock Quarry, Porto Bello, capa- city, cubic yards per day ..... 3,000 Sand Pits, Nombre de Dios. Pacific Side: Rock Quarry, Ancon Hill, capa- city, cubic yards per day ...... 2,000 Sand Pits, Point Chame. [55] Amount of oil used per month (barrels) 75,000 Cost of same (per barrel) ........... $1.10 Amount of coal used per month (tons) 35,000 Cost of same, delivered in fire-box (per ton) ......... . .......... $6.00 Number of miles of track on Isthmus (about) ............... ....... . 500 Death rate per thousand, 1912: Accidents ...................... 3.08 Disease ....................... 7.08 Total from all causes ...... 10.16 EQUIPMENT. Steam Shovels: 105-ton, 5 cubic yard dippers...... 15 95-ton, 4 and 5 cubic yard dippers. . 32 70-ton, 2Y2 and 3 cubic yard dippers 35 66-ton, 22 cubic yard dippers..... 6 45-ton, 1% cubic yard dippers..... 10 26-ton ........... .. . ....... . 1 Trenching shovel, Y cubic yard dipper.......... ... ...... . 1 T otal ........... ........... . . 100 Cranes: Am erican.......... .......... 60 French .............. ....... . 9 T otal........................ 69 Locomotives: American 106 tons .......... ......... . 100 105tons ................... 40 117 tons........... ........ 20 Total ...................... 160 French 20 tons ....... ... ... ........ 5 28 tons .......... .......... 20 30 tons ........ .. .......... 16 38 tons........ .. .......... 36. Decauville.............. . 8 T otal ...................... 85 Narrow gauge, American, 40 tons. . 10 Narrow gauge, American, 16 tons. . 23 Electric ......... ........ . 12 T otal .......... ........... ... 45 Grand total ..... . . . . . . . 290 Drills: Mechanical churn, or well....... 265 Tripod ..................... 361 Total ........................ 626 [57] Cars: Flat, used with unloading plows .. . 1,800 Steel dumps, large .. . . . . . . . . 600 Steel dumps, small .............. 1,200 Ballast dumps, steel ........... . 12 Ballast dumps, wood ............ . 12 Steel flats.......... ......... 500 Narrow gauge ...... ........... 200 M otor .... ... ...... ....... 6 Pay Car ........ ... ... ...... . 1 Total ....... . . ..... ....... 4,331 Spreaders . ....................... 26 Track shifters .................... 9 U nloaders ....... ...... .... . ..... 26 Pile drivers ....... .... ........... 13 Dredges: American ladder.......... . . . 1 French ladder.......... ....... 7 Dipper .......... ..... ....... 3 Pipe-line .................... 7 Sea-going suction ............ . . 2 Clam shell ..................... 1 T otal ........................ 2 1 Rock breaker, floating ...... . .... 1 T u gs . ........................... 12 T ow boat ....... ........... ...... 1 H house boats...................... 2 [58] C lapets .......................... 11 Pile driver, floating................ 1 Crane boat . .............. ........ 1 Barges, lighters and scows .......... 70 Launches ........................ 14 C utters .......................... 3 D rill boats ...... ......... . .... . 2 Derrick barges................... 2 PANAMA RAILROAD. Locomotives: Road (12 oil burners)............ 36 Switch ............. ......... 34 T otal ........................ 70 Cars: Coaches ........ .... ......... 57 Freight.................... 1,477 T otal ........ .............. 1,534 Locomotive cranes ................ 4 Pile driver, track .................. 1 Pile driver, floating ................ 1 T u g s . . . . . .. . . . . . . . . . . . . . .. . .. . . .. 2 Lighters: Coal, all steel.......... ....... 5 Cargo, steel and iron........ ..... 8 T otal ....... ..... ............ 13 [591 A4 General Map of the Canal Zone and the Panama Canal, printed in three colors and bound in board covers, has just been issued. Size 4� x 13 inches, folded. Published by Wm. M. Baxter, Jr., Official Guide of the Isthmian Canal Commission. * M RAND AVERY SUPPLY CS.. RDSTON. |
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| MILLISECOND | CLASS.METHOD | MESSAGE |
|---|---|---|
| 0 | sobekcm_page_globals.constructor | |
| 0 | sobekcm_page_globals.constructor | Application State validated or built |
| 0 | sobekcm_database.verify_item_lookup_object | |
| 0 | sobekcm_page_globals.constructor | Navigation Object created from URI query string |
| 0 | sobekcm_database.verify_item_lookup_object | |
| 0 | sobekcm_page_globals.display_item | Retrieving item or group information |
| 0 | sobekcm_page_globals.get_entire_collection_hierarchy | Retrieving hierarchy information |
| 0 | sobekcm_assistant.get_entire_collection_hierarchy | |
| 0 | cached_data_manager.retrieve_item_aggregation | |
| 0 | cached_data_manager.retrieve_item_aggregation | Found item aggregation on local cache |
| 0 | item_aggregation_builder.get_item_aggregation | Found 'all' item aggregation in cache |
| 0 | system.web.ui.page.page_load (ufdc.page_load) | |
| 0 | sobekcm_page_globals.constructor.on_page_load | |
| 0 | html_echo_mainwriter.add_style_references | Adding style references to HTML |
| 0 | html_echo_mainwriter.add_text_to_page | Reading the text from the file and echoing back to the output stream |
| 41 | html_echo_mainwriter.add_text_to_page | Finished reading and writing the file |