OVERWHELMING ENDORSEMENT BY NEW ORLEANS.
When the Canal was about half finished it received the most tremendous endorsement by every interest of New Orleans in its history. The question was put squarely before the people: "Do you think it is a good thing, and you are willing to be taxed to put it across, and, if so, how much?" And the answer came without hesitation: "It is absolutely necessary to the industrial progress of the city. We must have the Canal at all costs, and are willing to be taxed any amount for it."
On September 24, 1919, George M. Wells, consulting engineer, made a report to the Dock Board, showing that the last bond issue of $6,000,000 had been exhausted, and about $5,000,000 more was needed to finish the Canal.
This was in the last days of the Thompson Board, and it took no action. The Hudson board entered upon its duties October 2. It comprised William O. Hudson, president; William A. Kernaghan, René F. Clerc, Albert Mackie, Thomas H. Roberts. Later, Mr. Roberts resigned and Hugh McCloskey took his place. All are sound business men, with the interests of the port at heart.
They found, in the bank, only $2,067,845.37 to the Industrial Canal Account. After deducting the obligations already made there was left only $112,064.43 to continue the work. Without a public expression from New Orleans they were unwilling to incur the responsibility of issuing $5,000,000 more bonds.
President Hudson called a series of meetings of the representative interests of the city to decide what was to be done. As the people of New Orleans had decided to begin the Canal in the first place, it was only right that they should determine whether the undertaking, costing five times as much as the original plan, should be carried through.
The governor, the mayor, presidents of banks, committees of commercial exchanges, the president of the Public Belt Railroad, the president of the Levee Board, newspaper publishers, labor leaders and prominent business men were invited. Likewise, a general call was made to the community at large to express an opinion as to finishing the Canal.
At the meeting of October 17 the city made its answer.
President Hudson outlined the attitude of the Dock Board as follows:
"The board has no feeling of prejudice against the completion of the Canal. We are in favor of it. We are anxious to complete it. It was fostered by the citizens of New Orleans.
"The floating of the bond issue is a simple matter, if you men think we ought to do it; but where is the money for meeting the interest to come from? The $600,000 interest on bonds now outstanding is being paid, $550,000 by the Levee Board, and $50,000 by the Public Belt Railroad. The Public Belt's share is paid from its earnings; but the Levee Board's share is being paid by direct taxation on the citizens of New Orleans. Must we increase that tax? I personally won't object to any taxation as a citizen to pay my part towards financing the Canal."
"I want to see the canal completed," said Governor Pleasant. "But it is up to the people of New Orleans to say whether they are willing to assume the added obligation."
R. S. Hecht, president of the Hibernia Bank, and a recognized financial leader in New Orleans, then arose.
"I feel," he said, "that all who have the future of New Orleans at heart must agree that we are here to discuss notwhetherthe Canal is to be finished, buthow.
"Finished it must be, or our commercial future will be doomed for many years. If the Dock Board were to stop the work, it would forever kill its credit for any other bond issue that might be proposed for wharf development, new warehouses, or anything else.
"The cost of the canal is a surprise to everybody. I was present when the cost was originally estimated at $3,500,000 with a leeway of $1,000,000. I said then, and I repeat now, that the canal could be financed if the people of New Orleans stood squarely behind it.
"The cotton warehouse and the grain elevator cost a great deal more than the original estimates. So the Industrial Canal, though it is costing more than anticipated, because of the increased cost of material and labor and the increased size in the Canal, will, I feel sure, be justified by the development of the future.
"Are we to be taxed for fifty years for our investment of $12,000,000 and get no return, or are we willing to pay a little bit more and get something worth while?"
That expressed the sentiment of the meeting.
BUILDING THE LOCKBUILDING THE LOCK
"The people of New Orleans," said Hugh McCloskey, financier and dean of all Dock Board presidents, "have never failed to meet a crisis. It is the duty of the Dock Board to finish the Canal, no matter what the doubting Thomases may say."
Similar expressions were made by Thomas Killeen, president of the Levee Board; Thomas Cunningham, of the Public Belt Railroad; D. D. Moore, editor of the Times-Picayune; James M. Thompson, publisher of the Item; B. C. Casanas, president of the Association of Commerce; L. M. Pool, president of the Marine Bank; J. E. Bouden, president of the Whitney-Central Bank; Bernard McCloskey, attorney; Frank B. Hayne, of the Cotton Exchange; Jefferson D. Hardin, of the Board of Trade; William V. Seeber, representative of the Ninth Ward; Marshall Ballard, editor of The Item. Others present, assenting by their silence, included John F. Clark, president, and E. S. Butler, member of the Cotton Exchange; W. Horace Williams, of Doullut & Williams Shipbuilding Company; E. M. Stafford, state senator; C. G. Rives of the Interstate Bank; S. T. DeMilt, president of the New Orleans Steamship Association; R. W. Dietrich of the Bienville Warehouse Corporation; Edgar B. Stern, Milton Boylan, W. H. Byrnes, J. C. Hamilton, and about thirty other representative business and professional men. Mayor Behrman, John T. Banville, president of the Brewery Workers' Union, and George W. Moore, president of the Building Trades Council, at a subsequent meeting, gave their endorsement.
With only one dissenting voice, these meetings were unanimous that the Industrial Canal must be completed at all costs; that without it, the growth of the city would be seriously interrupted. The one protest was by the Southern Realty and Securities Company. It was made October 23 against the Levee Board's underwriting the interest on the new bond issue.
On that date the Levee Board unanimously voted to guarantee these interest charges, amounting to $375,000 a year. This brings the total being paid by that body out of direct taxation to $925,000.00 a year. The other $50,000 is paid by the Public Belt Railroad.
To provide a leeway against the engineer's estimates, the Dock Board made provision for a bond issue of $7,500,000, but actually issued only $5,000,000 worth. This was taken by the same syndicate of bankers that had taken the previous issues, but this time they paid par. That was a point on which President Hudson had insisted. The contract was accepted December 10, 1919.
And the work went on, with every effort concentrated on economical construction.
SIPHON AND BRIDGES.
As an incident in the work of building the Industrial Canal, it was necessary to create a disappearing river.
This is the famous siphon—the quadruple passage of concrete that will carry the city's drainage underneath the shipway. It is one of the largest structures of its kind in the country.
A word about New Orleans' drainage problem. The city is the bowl of a dish, of which the levees against river and lake are the rim. There is no natural drainage. The rainfall is nearly five feet a year, concentrated at times, upon the thousand miles of streets, into cloudbursts of four inches an hour and ten inches in a day. In the boyhood of men now in their early thirties it was a regular thing for the city to be flooded after a heavy rain.
To meet the situation, New Orleans has constructed the greatest drainage system in the world. There are six pumping stations on the east side of the river, connected with each other by canals, and with a discharge capacity of more than 10,000 cubic feet a second. The seven billion gallons of water that these pumps can move a day would fill a lake one mile square and thirty-five feet deep.
Three of the canals empty into Lake Pontchartrain, the fourth, the Florida Walk Canal, into Bayou Bienvenu, which leads into Lake Borgne, an arm of Pontchartrain.
Because of this drainage contamination, the lake shore front of New Orleans has been held back in its development. Yet it is an ideal site for a suburb—on a beautiful body of water, and just half a dozen miles from the business district.
So the Sewerage and Water Board has been planning ultimately to turn the city's entire drainage into Bayou Bienvenu, a stream with swamps on both sides, running into a lake surrounded by marsh.
The Industrial Canal crosses the Florida Walk drainage canal. This made it necessary to build the inverted siphon.
A siphon, in the ordinary sense, is a bent tube, one section of which is longer than the other, through which a liquid flows by its own weight over an elevation to a lower level. But siphon here is an engineering term to describe a channel that goes under an obstruction—the canal—and returns the water to its former level.
Like the famous rivers that drop into the earth and appear again miles further on, the Florida drainage canal approaches to within a hundred or so feet of the Industrial Canal, then dives forty feet underground, passes beneath the shipway, and comes to the surface on the other side, in front of the pumping station, which lifts it into Bayou Bienvenu.
At first it was planned to build a comparatively small siphon, but while the plans were being drawn, New Orleans entered upon its tremendous development. The engineers threw away their blueprints and began over again. They designed one that is capable of handling the entire drainage of the city. And in April, 1920, it was finished—a work of steel and concrete and machinery, costing nearly three-quarters of a million dollars, and with a capacity of 2,000 cubic feet of water a second, 7,200,000 an hour, 172,800,000 a day.
It was a work that presented many difficulties. First the Florida Walk canal had to be closed by two cofferdams. The space between was pumped out, the excavation was made, and the driving of foundation piling begun. Quicksands gave much trouble. They flowed into the cut, until they were stopped with sheet piling. The piles were from 30 to 60 feet in length and from three to five feet apart on centers.
Forty-six feet below the ground surface (-26 Cairo datum) was laid the concrete floor of the siphon.
The siphon is divided into four compartments. There are two storm chambers, measuring 10 by 13 feet each, one normal weather chamber measuring 4 by 10 feet, and one public utilities duct, measuring 6 by 10 feet. These are inside dimensions. The floor of the siphon is two feet thick; the roof, one foot nine inches. The whole structure is a solid piece of concrete and capable of standing a pressure of more than 2,000 pounds to the square foot. Its total length is 378 feet; the shipway passing over it is 105 feet wide and 30 feet deep.
In the public utilities duct are carried the city's water pipes, cables, telephone and telegraph wires, and gas mains.
The storm chambers will handle the rainfall of cloudbursts. In ordinary weather the water will be concentrated through the smaller chamber, in order to produce a strong flow and reduce the settlement of sediment to a minimum.
Eight sluice gates, each 6 by 10 feet, open or close the water chambers. They are operated by hydraulic cylinders of the most approved type.
For sending workmen inside the siphon to make repairs or clearing away an obstruction there are eight manholes. Four measure 6 by 13 feet, two 6 by 6 feet, and two 6 by 4 feet.
As soon as the Florida Walk canal can be deepened and a few link-ups in the drainage system can be made, the entire drainage of New Orleans, in normal weather and during light storms, will, according to announcement by the Sewerage and Water Board, be sent through this outlet. During the occasional cloudbursts it will be necessary to send some of the drainage into the lake, but this will be rapidly flowing water and will sweep offshore. It means a great deal to the suburban development of the city.
A year and a half the siphon was in the making. Preparations for the structure cost more than $250,000—excavation foundation, etc. The concrete alone cost $170,000. Machinery and the work of housing and installing it cost $60,000 more.
Four bascule steel bridges now cross the Industrial Canal. They are the largest in the city. Three of them—at Florida Walk, for the Southern and Public Belt Railways; Gentilly, for the Louisville & Nashville; and on the lake front, for the Southern, weigh 1,600,000 pounds each—superstructure only. The fourth—at the lock—weighs 1,000,000 pounds. They are balanced by 800-ton concrete blocks and concrete adjustment blocks. Their extreme length is 160 feet; the moving leaf has a span of 117 feet.
With a 30-foot right of way for railroad tracks, 11 feet for vehicles and trolley cars and four feet for pedestrians, they are designed to meet traffic conditions of a great and growing city. They will support 50-ton street cars or 15-ton road rollers—New Orleans has nothing as heavy as that now—and trains a great deal heavier than are now coming to the city. No bridge in the South will support as heavy loads.
The tensile strength of the steel of which the bridges are constructed is from 55,000 to 85,000 pounds to the square inch, and they will bear a wind load of 20 pounds to the square inch of exposed surface.
They are operated by two 75-horse power electric motors, 440 volts, 60-cycle, 3-phase current, which is stepped down from 2,200 volts by means of transformers. In addition, there is a 36-horse power gasoline engine, to be used if the electrical equipment is out of order. To open or close the bridges will require a minute and a half.
THE REMARKABLE LOCK.
Not only is the lock of the Industrial Canal one of the largest in the United States, but its construction solved a soil problem that was thought impossible. That of the Panama Canal is simple in comparison. The design is unique in many respects. The lock is a monument to the power of Man over the forces of Nature, and to the progress of a community that will not say die.
Because of the great variation in the level of the river at low and high water—a matter of twenty feet—it was necessary to make the excavation, for building the lock, about fifty feet deep. In solid soil this would be a simple matter. But this ground has been made by the gradual deposit of Mississippi River silt upon what was originally the sandy bed of the ocean, and through these deposits run strata of water-bearing sand, or quicksand. This flows into a cut and causes the banks to cave and slide into the excavation. Underneath there is a pressure of marsh gas, which, with the pressure of the collapsing banks, squeezes the deeper layers of quicksand upwards, creating boils and blowing up the bottom.
New Orleans has had plenty of experiences with these flowing sands in its shallow sewerage excavations. How, then, expect to make an excavation fifty feet deep? asked the doubting Thomases. It couldn't be done. The quicksands would flow in too fast. The dredges would drain the surrounding subsoil, but that wouldn't get beyond a certain depth. Furthermore, what assurance was there that the soil that far down would supply sufficient friction to hold the piles necessary to sustain the enormous weight of the lock and the ships passing through it?
Undaunted by these croakings, the engineers, from test borings, calculated the sliding and flowing character of the soil, and estimated the various pressures that would have to be counteracted, balanced this with the holding power of pine and steel and concrete, evolved a plan, and began an excavation of a hole 350 feet wide by 1,500 feet long, gradually sloping the cut (1 to 4 ratio) to a center where the lock, 1,020 by 150 feet, outside dimensions, was to be built.
INNER HARBOR—NAVIGATION CANALINNER HARBOR—NAVIGATION CANALLock and Vicinity
The gentle slope of the cut was to prevent slides.
It had been ascertained that the first stratum of quicksand began twenty-eight feet below the ground surface (-3 Cairo datum) and was three feet thick; the second stratum, forty-eight feet below the surface (-23 Cairo datum) and ten feet thick. Coarser sand extended eleven feet below this, from -33 Cairo datum. The second stratum of flowing sand began just below where the lock floor had to be laid. The third layer was 80 feet below the surface (-55 Cairo datum); the tips of the piling would just miss it.
Excavation began in November, 1918. While the dredges were at work a wooden sheet piling cofferdam was driven completely around the lock, and about 125 feet from the edge of the bank, to cut off the first quicksand stratum. About 150 feet further in, when the excavation was well advanced, a second ring of sheet piling was driven, to cut off the second stratum, which carried a static pressure of 55 feet and was just a foot or so below where the floor of the lock would be. It was not thought necessary to cut off the third stratum.
The excavation was made in the wet. When it was finished the dredges moved back into the Canal, the entrance closed, and the work of unwatering the lock site began. This was in April, 1919.
There had never been such a deep cut made in this section. Consequently, the character of the soil, while it could be estimated, could not be known absolutely. And the exact pressure of the gas could not be known.
The sands proved to be more liquid and the gas pressure stronger than anticipated. Quicksands ran through the sheet piling as through a sieve. The walls of the excavation began to slough and cave. The gas pressure became alarming when the weight of earth and water was taken off; sand boils began to develop at the bottom; the floor of the cut was blowing up.
The fate of the Industrial Canal hung in the scale.
To meet the situation the engineers pumped a great volume of water into the excavation. Its weight counterbalanced the earth pressure of the side and the gas pressure of the bottom.
Then another ring of sheet piling was driven inside the other two. This one was of steel, and the walls were braced apart by wooden beams ten inches square and fifteen feet apart in both directions. This is one of the largest cofferdams of steel ever driven. As an added precaution against the danger of a blowout by the third stratum of quicksand, which had a static head of 75 feet, 130 ten-inch artesian wells were driven inside the steel cofferdam. Fifty-six similar wells were driven between the steel and the wooden cofferdams to dry out the second stratum of quicksand, as much as possible, and lessen its flowing character.
In November, 1919, the work of unwatering the lock site again began. Only one foot every other day was taken off. Engineers watched every timber. It was not until January 4, 1920, that the unwatering was complete. The plan had worked. Only in one place had there been any movement—a section of the wooden sheet piling about 300 feet long bulged forward a maximum distance of three inches, when the bracing caught and stopped it.
Then began the work of driving the 24,000 piles on which the lock was to be floated. They are 60 feet long and their tips are 100 feet below the surface of the ground.
In March, 1920, the work of laying the concrete began. The work was done in 15-foot sections, for only a few of the braces could be moved at one time. When it was finished in April, 1921, the lock was in one piece, a solid mass of steel and stone, 1,020 feet long, 150 feet wide, and 68 feet high, weighing, with its gates and machinery, 225,000 tons, and filled with water, 350,000 tons.
The concrete floor of the lock is 9 to 12 feet thick, the walls 13 feet wide at the bottom, decreasing to a two foot width at the top. Six thousand tons of reinforcing steel were used in the construction, and 125,000 barrels of cement. There are 90,000 cubic yards of concrete in the structure. Two and a half million feet of lumber were used in building the forms.
Usable dimensions of the lock are 640 feet long, 75 feet wide, and 30 feet (at minimum low water of the river) deep.
The top of the lock is 20 feet above the natural ground surface and 6 feet above the highest stage of the Mississippi River on record. To the top the ground will be sloped on a 150-foot series of terraces. This will brace the walls against the pressure of water within the monolith. It will be developed to a beautiful park. Heavy anchor-columns of concrete will hold the walls against the pressure of these artificial hills when the lock is empty.
Traffic crosses the canal here by a steel bascule bridge 65 feet wide, with two railroad and two street car tracks, two vehicle roadways, and two ways for pedestrians. Concrete viaducts lead to the bridge.
Gas and water mains, sewer pipes and telephone, telegraph and electric wires pass under the lock in conduits cast in the living concrete.
Water is admitted into and drained from the lock by culverts cast in the base. These are 8 by 10 feet, narrowing at the opening to 8 by 8 feet, and closed by 8 sluice gates, each operated by a 52-horsepower electric motor. It will be possible to fill or empty the lock in ten minutes.
There are five sets of gates to the lock. They are built of steel plates and rolled shapes, four and a half feet thick and weighing 200 tons each. And there is an emergency dam weighing 720 tons, which in case of necessity can be used as a gate.
Four pairs of the gates are of 55-foot size; one of 42-foot. Each gate is operated by a 52-horsepower electric motor. When open, the gates fit flush into the walls of the locks.
In the emergency dam is the refinement of precaution—designed as it was to save the city from overflow in the remote event of the lock gates failing to work during high water, and to insure the uninterrupted operation of the lock in normal times, if the gates should be sprung by a ship, or otherwise put out of commission.
This dam consists of eight girders or sections, 80 feet long, 3 feet wide and 6 feet high. They weigh 90 tons each. They are kept on a platform near the river end of the lock. Nearby is the crane with a 300-horsepower motor, that picks up these girders and drops them into the slots in the walls of the lock. To set this emergency dam is the work of an hour.
A ship passing through the lock will not proceed under her own power. There are six capstans, two at each end of the lock and two at the middle, each operated by a 52-horsepower electric motor, and capable of developing a pull of 35,000 pounds, which will work the vessels through.
The lock complete, counting the bridge and approaches, cost $7,500,000. One and a half million of this is for machinery, and $56,000 for the approaches.
Henry Goldmark, the New York engineer who designed the gates of the Panama Canal and the New Orleans Industrial Canal, in a letter of March 24, 1921, to the engineering department of the Dock Board, comments as follows on the remarkable lock:
"I was much impressed by the uniformly high grade of construction of the lock, the systematic and energetic way in which the work was being carried on, and especially by the admirable spirit of team work, shown by the employees of the Dock Board, of different grades, as well as the contractors, superintendents and foremen.
"The desire to get the best possible results in all the details, at the least cost, was manifest throughout.
"The unique method used for carrying on the very difficult and risky work of excavation has attracted much professional attention in all parts of the country. Its successful completion is very creditable to all concerned, in the inception and carrying out of the method used.
"The concrete work gives the impression of lightness, as well as strength, as though every yard of concrete was doing its special share of the work without overstraining, which is, of course, the characteristic of well-designed reinforced masonry.
"The outer surfaces are particularly smooth and well finished, more so than in any work I have recently seen.
"The erection of the gates, valves, operating machinery and the protective dam, has kept up closely with the concrete work, so that no delays need be apprehended at the close of the construction period.
"The shop and field work in the lock gates is excellent. The rivet holes match well and the rivet heads appear to be tight and well formed. The gate leaves seem very straight and true."
The lock was designed by George M. Wells of the George W. Goethals Company, assisted by R. O. Comer, designing engineer of the Dock Board, and approved by General Goethals. The methods employed to unwater the lock were devised by Mr. Wells. J. Devereux O'Reilly, chief engineer of the Dock Board, to November, 1919, had charge of the details of installing the unwatering and safety devices. He was succeeded by General Arséne Perrilliat, who supervised the final unwatering process. Upon his death in October, 1920, he was succeeded by J. F. Coleman & Company, in charge of the engineering department, and H. M. Gallagher, chief engineer, under whom work is being brought to a conclusion.
From first to last, Tiley S. McChesney, assistant secretary and treasurer of the Dock Board, rendered intelligent and invaluable service, gathering together and holding the threads of the enterprise, and attending promptly to the multitude of details connected with the prosecution of the work.
The lock was formally dedicated May 2, 1921—a ceremony that was the feature of the Mississippi Valley Association's convention in New Orleans.
With the dredging of the channel between the river and the lock, a work that should be finished before January, 1922, ships will be able to pass from the Mississippi into Lake Pontchartrain. Then New Orleans can plan its next great development.
CROSS SECTION OF LOCKCROSS SECTION OF LOCK
CROSS SECTION OF SIPHONCROSS SECTION OF SIPHON
NEW CHANNEL TO THE GULF.
George M. Wells, George R. Goethals, son of the General, Colonel E. J. Dent, U.S. district engineer at New Orleans, and other engineers who have studied the problem, say that the dredging of a channel from the Industrial Canal to the gulf through Lake Pontchartrain, or the marshes, is feasible, comparatively cheap, and maintenance would be simple. This would shorten the distance from New Orleans to the sea by about 50 miles, and would be a vast saving for ships. It is one of the objects towards which the Hudson Dock Board is working.
It is Uncle Sam's recognized duty to develop and maintain harbors and channels to the sea. Distance is obviously an important factor; furthermore, the proposed new outlet would be an important link in the Intracoastal Canal, connecting with the Warrior River section of Alabama, which the government is developing between the Atlantic and Gulf Coasts. A bill was introduced in the Senate in 1920 by Senator Ransdell of Louisiana, providing for the development of the proposed channel; it was not pressed because the canal was far from completed. However, every effort will be made by the Dock Board from now on to have Uncle Sam take hold.
Colonel Dent has for a number of months been studying the feasible routes. He, by the way, is thoroughly convinced of the value of the Industrial Canal to the development of New Orleans, and the commerce of the nation, and has so expressed himself in public.
The Pontchartrain route has been laid off, by engineers, beginning at the Canal, paralleling the south shore of the Lake Pontchartrain to the south draw of the Southern Railway bridge, thence to the Rigolets to Cat Island Pass, from there to Cat Island Channel and so to the deep water of the Gulf, a total distance of 75 miles.
Soundings and surface probings have been taken at frequent intervals over the entire route. These have shown the engineers the following:
Three-quarters of a mile from the south shore of the lake, and as far as the railroad drawbridge, a hard bottom is found. The material is principally packed sand, rather fine, with a small amount of clay, and occasionally some broken shells. Beyond this distance from the shore, the bottom is softer, consisting of mud mixed with sand. From the bridge over the remainder of the route, the bottom, with the exception of a few sand pockets, is soft—a blue mud with a large percentage of sand. This soft material has so much tenacity, however, that current and wave wash, which tend to fill up artificially dredged channels, would affect only the surface.
The government is conducting large dredging operations in Mobile Bay, Gulfport Channel, Atchafalaya Bay and the Houston Ship Channel. An outline of the results there will show how feasible the dredging of the Pontchartrain Channel would be, and how much cheaper in comparison.
The channel connecting Mobile Bay with the Gulf of Mexico has a bottom very soft for the most part, and with a small percentage of sand. Towards the outer end, the material is black mud, about equal in consistency to the softest material found in the Pontchartrain route. A sounding pole with a 4-inch disc on the end can be easily pushed three or four feet into the mud and pulled out again. Wave and current action cause the channel to shoal at the rate of 78,000 to 132,000 cubic yards per mile per year, depending on the softness of the bottom and the depth. Where the highest rate obtains, the surrounding material consists of soft mud, without a trace of sand. Experience shows that where there is a fair percentage of sand in the material adjacent to the channel bed, the shoaling is lessened. In general, the material along the Pontchartrain route contains a greater percentage of sand and is far more tenacious than that along the Mobile Bay Channel. Furthermore, the Pontchartrain route is not exposed to such strong cross currents.
The Gulfport Channel is dredged through very soft material, a grayish-blue mud of oozy consistency, into which the sounding pole penetrates six feet with very little exertion. On top, a small amount of sand is found, but practically none in the lower stratum. The material is considerably softer than any encountered on the Pontchartrain route, except for one small stretch. Yet the shoaling is not great. Where the shoaling is heaviest, between the end of the pier and Beacon 10, only about 700,000 cubic yards a mile has to be dredged out every year to maintain the channel. From Beacon 10 out, the average annual maintenance is less than 200,000 cubic yards a mile. Except for the four-mile stretch west of the inner entrance to the Cat Island Channel, the bottom, on the Pontchartrain route, is harder than that of the Gulfport Channel. Therefore, it is reasonable to conclude that the maintenance of the Pontchartrain Channel would not average as high as the outer portion of the Gulfport Channel.
The Atchafalaya Bay Ship Channel, extending from the mouth of the Atchafalaya River across the shoal waters of Atchafalaya Bay, to about the 20-foot contour of the Gulf, a distance of fifteen miles, is through a material of slushy mud, with occasional thin pockets of sand. The shoaling runs from 540,000 to 1,680,000 cubic yards a mile a year. The highest rate is obtained in shallow water. Except in the stretch mentioned, the material on the Pontchartrain route is not as soft as on the Atchafalaya, nor are the depths as shoal, nor is there the exposure to cross currents.
In the Houston Ship Channel, the material is composed of soft mud with a small amount of sand. A two-mile stretch through Red Fish Reef is practically self-maintaining. For the remainder of the channel, during the six years from 1915 to 1920, a total excavation of 13,574,000 cubic yards was necessary to maintain the depth. This is equivalent to 100,000 cubic yards a mile a year.
In summary, then:
1. The Lake Pontchartrain route is practically unexposed to cross currents, as is the case with the Mobile Bay, Gulfport, Atchafalaya, and, to a certain extent, the outer portion of the Houston Ship Channels.
2. The material along and on the sides of the Pontchartrain route is, with the exception of a small stretch, more tenacious, and contains, in general, a greater proportion of sand than in the case of the neighboring channels mentioned.
The channel could therefore be more easily maintained.
Engineers estimate that a channel with a 300-foot bottom would be needed. On the south shore of the lake, the side slopes should be on the 1 to 3 ratio, with provision for a 1 to 5 ratio at the end of five years. Dumped on shore, the material would reclaim considerable frontage, and eliminate the re-deposit of this material in the channel.
Through the remainder of the route, the original excavation should be made with side slopes on the 1 to 5 ratio, with provision made for a 1 to 10 ratio in five years.
The dredging of the 75 miles of the Pontchartrain Channel would amount to 97,200,000 cubic yards, it is estimated by engineers. The cost would be around $10,000,000. The annual maintenance, during the first five years, would amount to 8,880,000 cubic yards—an estimate based on a comparison with the other channels into the Gulf, and the character of the material to be excavated. This estimate is considered large—but even at that, it is only 118,400 cubic yards a mile a year, and the cost would be about $750,000, according to Colonel Dent. After five years, it would be less.
Another proposed route, investigated by Colonel Dent, is through Lake Borgne. A canal some miles in length, through the marsh, would connect the lake with the Industrial Canal. This route has considerable maintenance advantages over the Pontchartrain route. The character of the bottom in Borgne is more or less the same as in Pontchartrain.
Sooner or later, one of these channels will be built by the government. That it has not already been begun is due to the fact that the Canal has not yet been completed, and the expected development has not taken place. But there is no doubt that it will.
TYPICAL BRIDGE ON CANALTYPICAL BRIDGE ON CANAL
EMERGENCY DAM CRANEEMERGENCY DAM CRANE
WHY GOVERNMENT SHOULD OPERATE CANAL.
It is the function of the state to provide port facilities in the form of docks, piers, warehouses, grain elevators, mechanical equipment, etc. But it is the duty of the national government to improve harbors, dredge streams, dig canals for navigation and irrigation, erect levees to protect the back country, and build locks and dams when needed.
These are the premises from which the Hudson Dock Board reasons that the cost of construction and maintenance of the New Orleans Navigation Canal and Inner Harbor should be assumed by Uncle Sam. It will leave no stone unturned to have him assume the obligation.
The Navigation Canal is essentially a harbor improvement. It enables practically unlimited industrial development and commercial interchange. It is an important link in the Intracoastal Canal system which the government is developing to provide an inland waterway from Boston, Mass. to Brownsville, Tex., and, with the dredging of a channel through Lake Pontchartrain to the Gulf, a problem which U.S. engineers have been studying for some time and an undertaking which they have found feasible, it will put the nation's second port about fifty miles closer to the sea. It has considerable military value. Its purpose is, therefore, national; the local interests are secondary.
It is no new principle, this obligation of the government. That duty has been recognized by Congress since the United States was.
Any rivers and harbors bill will show great and useful expenditure for waterways improvement.
The Panama Canal, built by the government, is the greatest example.
Coming closer home, there is south pass at the mouth of the Mississippi. A bar, with a nine-foot depth of water, blocked the commerce of New Orleans. Under the rivers and harbors act of 1875, Captain James B. Eads was paid $8,000,000 for building the famous jetties to provide a 26-foot channel. Since then, the channel has been deepened to 33 feet.
In more recent years, the government began to improve southwest pass, the westernmost mouth of the Mississippi. A nine-foot bar was there, too. To increase the depth to 35 feet, the government spent, up to 1919, about $15,000,000, and is still spending.
"Just as the purpose of the improvements of these channels was to bridge the distance from deep water to deep water" says Arthur McGuirk, special counsel of the Dock Board, in a report of February 23, 1921, to the Board, "so is the purpose of the Navigation Canal to bridge the distance from the deep water of the river to the proposed deep water channel of the lake."
In the annual report of the chief of engineers, U.S.A., for the fiscal year ending June 30, 1919, are listed the following waterways improvements and canal developments being made by the Government:
"Operating and care of canals, $3,596,566.20.
"Cape Cod canal, purchase authorized, river and harbors act, August 8, 1917, cost not exceeding $10,000,000, and enlargement $5,000,000.
"Jamaica Bay channel, 500 feet width, 10 feet depth, to be further increased to 1,500 feet width entrance channel and 1,000 feet interior channel, maximum depth of 30 feet, length of channel 12 miles. Approved estimate of cost to United States not to exceed $7,430,000. River and harbors act of June 25, 1910. House document No. 1488, 60th Congress.
"Ambrose channel, New York harbor, appropriation new work and maintenance, $4,924,530.88, year ending June 30, 1919.
"Bay Ridge and Red Hook channels, $4,471,100.
"Locks and dams on Coosa River, Alabama-Georgia, $1,700,918.21.
"Channel connecting Mobile Bay and Mississippi Sound, act of June 13, 1902, original project, for construction and maintenance total cost $7,809,812.42.
"Black Warrior river, 17 locks, Mobile to Sanders' Ferry, 443 miles. Total to date, $10,101,295.54. Indefinite appropriation.
"Sabine Pass, act of June 19, 1906 and prior, channels, turning basins and jetties, March 2, 1907, and previously, total appropriations, $1,875,506.78.
"Trinity River, Galveston, north, 37 miles locks and dams. Act of June 13, 1902, house document 409, 56th congress. Estimate cost complete canalization of river, revised 1916, in addition to amounts expended prior to rivers and harbors act of July, 1916, in round numbers $13,500,000. Estimated annual cost of maintenance, $280,000.
"Houston to Galveston ship canal, act of July 25, 1912, and July 27, 1916. Cost, $3,850,000. Annual maintenance, $325,000.
"Rock Island Rapids (Ill.) and LeClaire canal, rock excavations, etc., act of March 2, 1907, dams, 3 locks, etc., to June 30, $31,180,085.62 and $130,158.03 for 1 year maintenance.
"Keokuk, Iowa (formerly Des Moines Rapids canal), old project (act of June 23, 1866), $4,574,950.00.
"Muscle Shoals Canal (Tennessee River), 36.6 miles, depth 5 feet, $4,743,484.50. Exclusive of cost of nitrate plant.
"Locks and dams on Ohio River, act of March 3, 1879, to act of March 2, 1907, including purchase of Louisville and Portland canal, $17,657,273.78.
"Estimated cost of new work, widening Louisville and Portland canal and changes in dams, $63,731,488. Annual maintenance covering only lock forces and cost of repairs and renewals, $810,000. Act of June 25, 1920, house document 492, 65th congress, first session. Also act of March 4, 1915, house document 1695, 64th congress, second session.
"Ship channel connecting waters of great lakes, including St. Mary's river (Sault Sainte Marie locks), St. Clair and Detroit rivers, locks and dams, total appropriations to June 30, 1919, $26,020,369.68. Estimate new work, $24,085.
"St. Clair river, connecting Lakes St. Clair and Erie, shoalest part was 12-1/2 to 15 feet. Improved at expense of $13,252,254.00. Estimated cost of completion, $2,720,000.
"Niagara river, $15,785,713.07.
"Los Angeles and Long Beach harbor, $4,492,809.80.
"Seattle, Lake Washington ship canal, in city of Seattle, from Puget Sound to lake; original project, act of August 18, 1894. Double lock and fixed dam. Length about 8 miles. Total appropriation to date, $3,345,500.00."
These are only some of the larger projects. Of course there are a great number of such works, all over the country, constructed and maintained by the United States, sometimes alone, and again by co-operation with local authorities.
New Orleans was founded because of the strategic value of the location, both from a commercial and a military standpoint. The power that holds New Orleans commands the Mississippi Valley—a fact which the British recognized in 1812 when they tried to capture it. Likewise, when Farragut captured New Orleans, he broke the backbone of the Confederacy.
Mr. McGuirk, in the report to which reference has already been made, discusses the military importance of the Industrial Canal as follows:
"A ship canal, connecting the river and the lake at New Orleans will be a Panama or a Kiel canal, in miniature, and double in effectiveness the naval forces defending the valley, as they may be moved to and fro in the canal from the river to the lake. On this line of defense heavy artillery on mobile mounts can be utilized, in addition to heavy ships of the line. That is to say, just as light-draft monitors, and even floats carrying high-powered rifles were used effectively on the Belgian coast; on the Piave river in Italy, and on the Tigris in Mesopotamia, so may they be used in the defense of the valley, on any canal connecting the Mississippi river and Lake Pontchartrain. Changes are constantly occurring in the details of work of defense due to development of armament, munitions and transport. The never-ending development of range and caliber has assumed vast importance, particularly with reference to the effect on the protection of cities from bombardment. Naval guns are now capable of hurling projectiles to distances of over 50,000 yards, 28 to 30 miles. For the protection of the valley we should have at New Orleans armament mounted on floating platforms which will hold the enemy beyond the point where his shells may not reach their objective, and in this operation the canal, affording means of rapid transport, will render invaluable and essential service."
A country's ports are its watergates. Their local importance is comparatively small. They are important or not according to whether they are on trade routes, and easily accessible. An infinitesimal part of the trade that flows through New Orleans originates or terminates there. The back country gets the bulk of the business. The development of the harbor is for the service of the interior. It is essentially national.
From every point of view, therefore, it is the duty of the national government to take over the Navigation Canal and release the monies of the state so they may be devoted to the improvement of the waterway with wharves and other works in aid of the nation's commerce.