The Secretary of the Army ( Royall ) to the Secretary of State

Dear Mr. Secretary: I am enclosing for your information a copy of a letter of this date which I have addressed to The President, submitting my observations on various interoceanic canal routes and alternative methods of transit, made during my trip of inspection in Mexico and Central America in February 1948.

I shall be pleased to communicate further with you when I have received from the Governor of the Panama Canal his report on the additional investigations in the Republic of Colombia which are discussed in my letter to The President.

Sincerely yours,

Kenneth C. Royall
[Page 484]

The Secretary of the Army ( Royall ) to the President of the United States

Dear Mr. President: I respectfully submit my observations on various interoceanic canal routes and alternative methods of transit, made during my trip of inspection in Mexico and Central America in February, 1948. In addition to inspecting the present Panama Canal and discussing with the Governor and his assistants the conversion of the existing lock canal into a sea level canal, I looked into the matters covered in the following paragraphs.

Isthmus of Tehuantepec: From my aerial reconnaissance, flying at low level over the Isthmus of Tehuantepec, it seemed apparent that it would be impracticable to construct a lock or sea-level canal on this route at reasonable cost. This observation is in accord with the report of the Governor of the Panama Canal which shows that a lock canal at Tehuantepec would be three times as long as the Panama Canal, would cross a divide which is twice as high, and would cost over 13 billion dollars. The report makes no estimate of cost for a sea-level canal at Tehuantepec, but shows that such a canal would involve about six times as much excavation as would be required to convert the present Panama Canal to a sea-level project.

The Tehuantepec route has been considered repeatedly since 1880 as the location for a ship railway, but all engineering studies have shown that a railway capable of transporting modern shipping across the isthmus would be impractical and very expensive. A project of this kind would involve such unprecedented problems of design and construction for foundations, road-bed, bridging, and rolling stock, that its capacity would undoubtedly be limited to small ships. It would be extremely vulnerable to destruction by sabotage and aerial bombing.

The existing single-track railway across the Isthmus of Tehuantepec has heavy grades, numerous curves, light rail (60 pounds), and inadequate terminals on the Gulf of Mexico and Pacific Ocean, and is totally inadequate as a modern means for trans-shipment of cargo. Reconstruction to provide adequate facilities would be very expensive, and even an improved rail line with adequate terminals could not compete with the existing Panama Canal for commercial traffic since any savings of time due to shortening of the ship route would be more than offset by the time required for unloading, handling and reloading of cargo. Furthermore, the use of pallets or standardized shipping cases would not eliminate the necessary delays of trans-shipment, and would [Page 485] not be practicable for general and miscellaneous cargo, and would in addition probably require ships with especially constructed holds and cargo hatches. The value of such a railway in time of war would be limited, as it would serve only as an emergency means for passage of cargo across the isthmus in the event of blocking of a canal, and like a ship railway, it would be vulnerable to attack and destruction.

Nicaraguan Route: This proposed canal route lies in part along the boundary between Nicaragua and Costa Rica. It is a feasible route for a lock canal, although the cost involved would be about one billion dollars more than conversion of the Panama Canal to sea level. A sea level canal along this route would necessarily pass close to Lake Nicaragua, which lies about 110 feet above sea level. Separation of the lake from the canal would involve serious problems of see page, and stability of embankments and channels. Such a project would have an extremely heavy cost, even if all engineering difficulties could be overcome. Both Nicaragua and Costa Rica would be involved in a canal along this route and political difficulties would be increased by the necessity for dealing with two countries.

Panama Parallel Route: One of the routes which has been studied provides for construction of a new sea level canal parallel and closely adjacent to the present Panama lock canal. This proposal would cost about 900 million dollars more than conversion of the present Panama lock canal to a sea-level project. While it is of interest, as it could be built and operated so as to provide the continued use of both the lock and sea-level canals, the advantages are not as real as they appear at first glance. Both canals would have the same harbor and terminal facilities, damage to which would affect both canals at the same time. Further, the continued existence of Gatun Lake required by the lock canal would constitute an additional hazard to the sea-level canal. A breaching of the dikes and dams separating the two canals, by either sabotage or bombing, would flood out the sea-level canal and choke it with large quantities of earth. A sea-level canal thus damaged would probably require a longer time for repair and reestablishment of a navigable channel than would the proposed sea-level conversion canal, not subject to this additional hazard. In addition, during the years of peace, there would be the continued cost of maintenance and operation of a lock canal which would not be needed by commercial traffic.

Atrato–Truandó Route: The valleys of the Atrato and Truandó Rivers in Colombia have been studied as a possible route for a ship canal during the present investigation and in a number of previous explorations. This route is 95 miles long as compared with the 51-mile length of the present Panama Canal. Data on the elevation of the divide on the Atrato–Truandó Route, determined by previous reconnaissance [Page 486] surveys, is not as reliable as that available for some of the other routes, but is sufficiently accurate to indicate an elevation of about 930 feet above sea level. The route appears feasible for either a lock or sea-level canal; although present estimates prepared by the Governor of the Panama Canal indicate that the cost of a sea-level canal along the Atrato and Truandó would be about two billion dollars greater than the cost of converting the Panama Canal to sea level.

Aerial reconnaissance of the Atrato–Truandó Route indicates, however, that terrain on the Atlantic side is particularly suitable for canal construction as excavation through the alluvial valley of the Atrato should be relatively inexpensive. Problems involving control of floods and handling of alluvial deposits might be met by constructing a canal paralleling the lower river to a terminus separate from the mouth of the Atrato and its delta. Further reconnaissance would determine the exact height of divide and the best alignment for a canal. Low excavation cost in the lower reaches on the Atlantic side might offset costs involved in greater length and greater height of divide. In view of these considerations, it would be desirable to make some further field investigations to obtain more specific data on alignment, elevations and geologic formations. The expense of such investigations can be kept to a minimum by use of available small craft and planes of the Army and Navy; and it is understood that the Governor of the Panama Canal has sufficient funds for such a reconnaissance.

The additional investigation described above would, of course, require the approval of the Republic of Colombia. I have communicated with the Secretary of State with a view to presenting the matter to the government of the Republic of Colombia.

Sincerely yours,

Kenneth C. Royall