IV. TYPE OF CANAL
The controversy over the relative merits of a lock and a sea-level canal at Panama is as old as the question of building the canal itself. Supporters of the lock canal now in process of construction have sought to silence the storm of protest occasioned by its adoption; but in spite of their precautions reports have reached the American public which have created a lack of faith in the present engineers and their methods.
It is, of course, impossible for a layman to decide arbitrarily in favor of the lock or sea-level type. The only reasonable way to arrive at a conclusion is to examine carefully the arguments of both factions and reach a decision therefrom. The writer has found it difficult, if not impossible, to obtain an accurate presentation of the facts. Engineers high in their profession make contradictory statements. Presumably they honestly express their convictions but their failure to agree is strong evidence that there is a large element of uncertainty in the whole proposition. If they, acknowledged authorities, not only cannot arrive at a common decision in this matter, but consider it necessary to ridicule each other’s plans, there is certainly cause to doubt the wisdom of the present project. It is the intention of the writer to state the principal arguments both for and against the two types of canals as presented by their most ardent advocates.
It is generally conceded that a lock canal at Panama would cost less than an efficient sea-level canal. Engineers on the Isthmus make an estimate of over $100,000,000 as the minimum excess of cost of a sea-level canal over the lock canal for construction alone. This estimate does not include the cost of carrying on the work of government and sanitation during the additional years which would be required to build a sea-level canal. Furthermore, it is true that there are many problems in connection with a sea-level canal, in spite of its apparent simplicity, which have never been solved and consequently no engineer can say how many millions would be required for its completion. Experience has shown, however, that the same unsolved problems were also true of the lock type. In their report to the President and to Congress, the minority of the board of consulting engineers pledged their professional reputations that if the lock type of canal were adopted the aggregate cost of completing the canal, exclusive of sanitation and zone government, would not exceed $139,705,200. Not four years have passed since that report was made yet $120,064,468.58 have already been appropriated and the great dams and locks are only fairly begun. In the last session of Congress it was proposed to increase the limit of the cost of construction of the Panama Canal to $500,000,000. Senator Teller in a speech said, “I have said again and again on the floor and I repeat it now — that if we get the canal built for $500,000,000, whether a lock or a sea-level canal, we shall do very well. In my judgment, we will never get that canal, in either form, except at a cost of more than $500,000,000.” These figures are sufficient evidence that the engineers who made the original estimate were dealing with a subject too big for them.
At the time Congress voted to adopt a lock canal the estimated cost of a sea-level canal, excluding the cost of sanitation, civil government, the purchase price and interest on the investment (which seem unnecessary refinement in view of later developments) was given by the Board of Consulting Engineers as $247,021,000. The project on which this estimate was made provided for a waterway 40 feet deep at mean sea-level, 150 feet wide at the bottom in earth and 200 feet wide in rock, with a length of 49.14 miles. On the basis of this estimate advocates of the sea-level canal argue that on grounds of economy alone the lock type should be abandoned in favor of the sea-level type. It stands to reason, however, that some of the causes which have led to an increase in cost over the original estimates for the lock canal, such as the increase in the wage scale and the cost of material, and the adoption of the eight-hour day, would affect equally the sea-level project if it were undertaken.
The total estimated cost by the present canal commission for completing the work, including purchase price is $375,201,000, while the total estimated cost of the sea-level canal made by the same commission is $563,000,000. This latter sum is largely mere conjecture because of the many unknown elements entering into the problem; and there are successful engineers today who do not hesitate to state that a sea-level canal can be constructed for less than the present lock canal.
Very few question the statement that the sea-level canal would take longer for construction than a lock canal. The majority of the Board of Consulting Engineers estimated that from 10 to 13 years would be required. The Isthmian Canal Commission fixed the time at from 18 to 20 years and Lieutenant George W. Goethals, its chairman and chief engineer, states that the lock canal will be completed by January 1, 1915.
A great objection to the narrow sea-level canal is the difficulty of river control. The proposed plan was to construct a huge concrete dam 180 feet high across the Chagres at Gamboa. This of itself is a great undertaking but when done would not solve the question of flood control, for below Gamboa there are many more streams which if unregulated would plunge precipitately into the canal channel thereby not only creating cross-currents extremely unfavorable to navigation, and these would also erode the banks and settle deposits which would necessitate continual dredging for maintenance. If these rivers were not allowed to flow into the canal, the only other solution would be the construction of channels on either side of the canal to take care of this flow. This would be very expensive and decidedly dangerous since the rivers in places would be considerably above the canal. The old Chagres Channel and the old French diversion canal could be utilized for a part of the distance.
It is claimed that even a sea-level canal would require a lock at the Pacific end because of the enormous difference, sometimes 20’ between high and low tides. Even the majority of the Board of Consulting Engineers, the supporters of the sea-level type, considered such a lock necessary. Since they made their report, however, a noted scientist, Dr. C. Lely, formerly minister of waterworks of Holland, has made an extended study of the question and states that the currents in a sea-level canal at Panama would not exceed those now common at Suez, namely, 2½ miles per hour.
On the other hand six huge locks are to be built on the lock canal, and they must be used at every passage of a boat. Their upkeep and operation will be a constant source of expense which would not exist in a sea-level canal. If one pair of locks is destroyed or put out of commission, the whole canal will be disabled and useless. Not only is this so, but they are a constant source of danger. The destruction of the gates of an upper lock, which is by no means an unknown occurrence, would allow the upper lake to empty into the canal channel, and probably destroy everything to the sea, including the dams. That such accidents can occur was demonstrated at the Welland Canal when a small steamer struck one gate and continuing her progress crashed through four other separate gates, the locks being 240 feet long. Again, at the Manchester Canal a vessel collided with a gate and carried it away, allowing the water to escape in such great volumes that it caused the other gates to give way also. Some conception of the force held in leash by the gates at Panama may be gained when it is stated that the “fall from the upper lock at Gatun to the empty second lock is over five times the rate of fall in the Whirlpool Rapids at Niagara and the depth is greater”. It is true that various safety devices are to be installed at the locks but they can serve only to minimize not eliminate a danger which would not exist on a sea-level canal.
The curvature in the proposed sea-level canal is gentle, but for 19 miles of its course a large ship would continually be changing direction in a channel having a width of from one-fourth to one-fifth of her own length and in a current which may be as great as 5 feet per second. On the Manchester Canal all large vessels are aided by two tugs whose duty it is to help in steering. Through the above mentioned 19 miles speed could not exceed 6 miles an hour, and whenever a ship going the opposite direction passed, one or the other would have to stop and tie up to the shore as they do on the Suez Canal.
The courses on the lock canal are straight, giving a clear view ahead, and the vessels can pass without being forced to tie up. The great Gatun Lake will permit of full speed and in all ordinary cases in the passage from ocean to ocean enough time can be saved by reason of the wider and straighter channels of the lock canal to compensate for the time lost in passing through the locks.
While the question of flood control is solved by Gatun Lake the question of water supply is not. This lake must, under the present plans, furnish the water necessary for lockages. Experts have carefully studied this subject, and while most of them agree that there is water sufficient for immediate needs they also recognize the possibility of a scarcity in the future. General L. Abbot, one of the most enthusiastic supporters of the lock plan, states that there will be water for but 26 daily transits during the dry season which would accommodate from 30 to 40 million tons of annual traffic. Other prominent engineers are not so sanguine and some go so far as to say the supply will be totally inadequate even for the first years of canal operation. At any rate there is a considerable element of uncertainty in the matter which actual trial alone will settle. No such trouble, of course, would exist in the operation of the sea-level canal.
Much has been said about the relative vulnerability of the two types. The arguments are decidedly at variance and approach the ridiculous when placed side by side. Common sense dictates that both types are open to injury by earthquakes or the hand of man; neither is invulnerable. It also seems evident that a lock canal with its many artificial devices is more open to serious injury by earthquake than a sea-level canal. In fact it is easy to believe that a shock severe enough to put a lock out of commission would scarcely affect a sea-level canal at all, and all who say otherwise are prejudiced. In fairness be it said that the danger from this source is exaggerated and probably should not occupy as large a place in the discussion of canal problems as has been given to it.
Lock canal advocates say a narrow sea-level canal could easily be obstructed by an obstacle placed in the channel; sea-level advocates say that a bag of dynamite under the lock-gates could put the canal out of service. Both statements are true but the essential element of difference is in degree. The obstruction in the channel would be no real injury to the canal at all: it would necessitate merely a few days work at the most for its removal. An injury to the locks, however, might readily mean draining of the summit lake and the destruction of all between it and the sea not to speak of the indefinite period required for reconstruction. The point is that it is practically impossible for man to seriously injure a sea-level canal; it is easily possible for him to so injure a lock canal. However, lock canals can be more readily defended in time of war because the points of attack are known beforehand.
A very serious objection to the lock type is that it cannot be readily enlarged. The locks are to be 1,000 feet long and 110 feet wide. This is ample for the present but indications are that future needs will be far greater. If they do become greater the Panama Canal will be an inefficient servant and will come far short of fulfilling the purpose which prompted its building. The sea-level canal could be enlarged by dredges without stopping traffic through it, but with a lock canal it is different. When the locks as constructed become inadequate the only way to increase their capacity is to shut down the canal for years while new and larger ones are being built.
It is unquestionably true that the ideal canal is a sea-level canal 500 feet to 600 feet wide. This is of the type known as the “Straits of Panama” proposed by Philippi-Bunau-Varilla to the consulting board in 1905. There is a growing feeling that this plan is the one which will ultimately be adopted for the completion of the canal. It contemplates the construction of a lock canal to be finally converted into a sea-level canal. The locks were to be constructed so that as the levels were deepened by dredging they could be eliminated, navigation continuing during the enlargement. The material removed by the dredges was to be deposited in the lake formed by a dam at Gamboa. The plan was carefully considered and finally rejected because of the excessive time and cost involved. It is interesting to note what the author of the plans states in regard to it. He says in part, “It is easy to see from the records that this rejection was purely based on the false assumption that the transformation of rock into dredgable ground would cost $2.35 (per cubic yard), when it has since been officially demonstrated to cost eleven times less in the Suez Canal and eighteen times less in the Manchester Canal.”
The cost at Panama of that transformation would be certainly inferior to the cost at Manchester not only on account of the saving of expense due to the gratuitous mechanical power given by the falls of the Chagres but also and principally on account of the extremely soft character of the greater part of the isthmian rocks. The electricity generated by the falls of the lake will put in action the rock breakers, the floating dredges, and the scows. The water in the small barge locks will raise the scows from the level of the summit to that of the lake and the depths of the lake will absorb the material of the straits. Thus the Chagres, once harnessed, will offer freely by its waters the way for the excavating and transporting instruments, by its falls the energy to animate everything and by its upper valley the dump to receive the spoils.
If unbiased and free-minded engineer officers of the army, having no anterior connection with the plans under discussion, should be sent to investigate the nature of the rock on the Isthmus and then to study in France, England, and Japan the actual improved methods of dredging soft and hard material the cloud would soon be dissipated. The supposed chimera would become a real tangible thing and the United States, the trustees of humanity in the construction of the great international waterway, would give to the world what it wants, what it is possible now and easy to obtain, the “Straits of Panama.” This sounds very plausible; and it is a significant fact that engineers do not ridicule it. Their respect for it is growing. Today rock-dredging is on trial at Panama. If its feasibility can be there demonstrated the plan will undoubtedly be adopted.
No man can find objections to this type when once constructed. The objections to the narrow sea-level canal first considered do not apply to the “Straits of Panama”, so they will stand as the ideal solution.
A canal designed to carry the world’s commerce, to furnish free communication between the Atlantic and Pacific should be as free from artificial devices as it is possible to make it. It is therefore hoped that some day the present lock canal will be enlarged to an ideal, wide, sea-level channel.