Recently, I made my fourth trip to Panama. Each trip, a short visit to the Canal in one form or another, gets included in the itinerary. To understate the importance of the Canal to Panama and the World from an economic point of view is not possible. The Canal gives Panama money to do things many other countries in Latin America – especially in Central America – can only dream about. Large freeways, light rail, subways, and a seemingly burgeoning economy from a casual tourist outlook reflect success in the heat, humidity, and constant drip – or sudden deluge – from the skies here in Panama. One factor hiding from plain sight today are the former huge efforts made in defense of the Canal.
CANAL OVERVIEW
In visiting the Canal, one needs to first visit both Visitor Centers the Canal Authority runs – Miraflores on the Pacific side and Agua Clara on the Caribbean. The Center at Miraflores lets one observe ships passing through the double locks of the original Canal. Agua Clara, set above a hill on the east side of where the new Canal enters Gatun Lake, allows one to observe how the megaships – larger than the Panamax ships of the original Canal – pass through with a very different procedure.
Ships transiting the Canal pay for the privilege. Since taking over the Canal, Panama has made the concern a moneymaking effort charging about a half million dollars to transit the original version while the super-sized ships pay a million or more. To say the economy of Panama lies tied to the two Canals is only part of the story. The shortcut from West-to-East and vice versa is worth much more to constant flow of freight on its way from one continent to another.
DEFENSE BEGINNINGS
Recognizing the vital economic importance of the Canal, almost from the beginning of the project when the United States became involved, efforts developed on how to defend the Canal. Even before the Canal, US Marines arrived on the scene in 1903 to protect the Panama Railroad, the important transshipment mode before the Canal. Another mission included protecting an ongoing revolution by Panamanians against the Colombian government. The presence of the Marine battalion at Colon along with several naval vessels just offshore prevented any landing of Colombian troops from the Caribbean side. By January 1904, there were four Marine battalions on site.
With Colombia accepting the situation in place – though not legally until a 1921 treaty gave them $25 million – the Marines did not face action in the time of their stationing in Colòn – no action in Panama, at least. The Marines left with the stationing of Army troops to the Canal Zone which began in 1913-1914. A Joint Army-Navy Fortification Board was appointed on 10 October 1909. They came up with a defense plan a year later which included strong fortifications at each entrance to the Canal with fieldworks set up in the vicinity of the Canal locks and other vital installations. A minimum of 7,000 troops were to provide a mobile force capable of providing close-in defense to any invader happening to land troops nearby the Canal.
DEFENDING AGAINST MAHANIAN STRATEGIES
The guns used in the fortifications planned to outrange or at least equal any known naval weapon of the time – the primary reason for the defense posture of the Canal directed itself at enemy battleships, the major strategic weapon of the time. Three forts were planned for the Atlantic side – Forts de Lesseps, Randolph, and Sherman -with four 13-inch rifles, six 4-inch rifles and sixteen 12-inch mortars placed within.
Fort Grant was the main artillery installation on the Pacific side. Using the “Fortified Islands” – three small islands just off the east side of the entrance linked to the shoreline by a rail causeway created with dredging spoils from building of the Canal – six 14-inch rifles, six 6-inch rifles, one 16-inch rifle and twelve 12-inch mortars mounted in gun batteries.
The 14-inch guns mounted on disappearing carriages with a maximum range of 13.64 miles. These designed to directly take on enemy battleships. The 6-inch guns sat on barbette carriages or disappearing carriages with a range of just over 8 miles. The smaller guns designed to attack smaller enemy vessels like cruisers or destroyers. The 12-inch mortars ranged out to just over 10 miles. Mortars fired plunging projectiles aimed for the decks of ships getting past the 14-inch guns.
GUN SUPPORT APPARTUS
To mount the heavy guns, massive concrete emplacements were constructed behind a thick concrete-earthen parapet. Hardened concrete bunkers were built to house ammunition magazines along with range plotting, fire control and communication rooms. Smaller observation points to better correct fire from also developed at some distance from the gun sites.
Submarine mine fields were readied for use in case of attack. Fifteen groups of 19 controlled submarine mines controlled the Caribbean entrance with another sixteen groups of 19 mines planned for the entrance on the Pacific side. Two minelaying boats became assigned on each side. For night action, 60-inch searchlights were installed, some permanently and others maneuvered on rail push cars. Ten lights emplaced on the Caribbean side and another fourteen on the Pacific.
cANAL ZONE MOBILE FORCE
Between the end of 1913 until 1917, nine companies of coast artillery troops came stationed on each side of the Isthmus. The first elements of the Mobile Force arrived at the end of 1911 with the 10th Infantry Regiment establishing Camp Otis near the settlement of Empire located at the Culebra Cut. November 1914 saw the 5th Infantry coming to the Zone with the 29th Infantry in the following March. The last regiment encamped in old French Canal Company buildings at Culebra renaming their new post, Camp Gaillard. The 1st Squadron 12th Cavalry, Signal and Engineer units arrived in 1915, also. The 2nd Battalion 4th Field Artillery arrived in March 1916 to round out the complement of the Mobile Force. Headquarters for all Army units in the Zone developed at Ancon Hill.
WORLD WAR 1
World War 1 came and went without much impact upon the Canal. The Canal was geographically isolated from the events of the war. A few German ships with their crews became interned. The Canal operated only during daylight hours with navigation aids turned off at night.
Surplus guns became available after the war’s end with 75mm and 155mm guns assigned for beach defense. The new guns became placed near the main Canal batteries and other key sites. For rapid fire adjustment for the 155mm guns, the Panama Mount was devised. Rail tracks encircling the gun made it possible with small, flanged wheels to swing the gun in a 360-degree traverse.
LESSONS FROM THE WAR
Apparent by the end of World War 1, newer developments in naval ordinance outpaced the older guns in the Zone. Most of the guns still mounted on disappearing carriages. These carriages allowed guns crews to work from behind the parapet, rising only to fire. The carriages could not adapt to give higher angles of fire needed to increase the ranges of the guns. Flat trajectories limited the ranges and lethality of defenders’ shells.
Naval guns capable of firing from higher angles of fire became capable of dropping high explosive shells inside the concrete emplacements to reach the vulnerable magazines beneath the big guns. Just such an event occurred on Corregidor Island in the Philippines. There, in defenses mirroring those in the Canal Zone, Japanese artillery blasted away at the island around the clock knocking out many of the artillery batteries on the island before it finally succumbed to invaders 6 May 1942.
Four 12-inch rifles on barbette carriages went to Fort Sherman on the Caribbean side in the early 1920’s. Four 16-inch rifles went to Bruja Point – Fort Kobbe – in the late 1920’s with a range double that of the earlier 16-inch gun on Perico Island. Barbette mounts allowed a 360-degree traverse covering all approaches to the Canal for 25 miles. Two more 14-inch guns placed on railway carriages arrived for use on the Isthmus in 1928. Firing emplacements developed at Fort Randolph and Culebra Island – Fort Grant by each Canal entrance. The rail connection allowed these guns to go to either side wherever needed. These rail guns also had double the range over the older 14-inch guns mounted on disappearing carriages.
QUIET BEFORE THE STORM
Between the wars, like many guns in the Coast Artillery repertoire around the US, many of the big guns shifted to reserve. All were rehabilitated, tested, and placed back in service in the years immediately before World War 2. Future plans for four more 16-inch guns to go to the Zone along with four 16-inch mortars. The war ended before anymore big guns reached the scene.
Pearl Harbor became the first demonstration of carrier-based aerial attacks mounted far beyond the reach of the coast artillery guns. The usefulness of the massive guns became overtaken by changes in the techniques of modern warfare. Many of the guns returned back into caretaker status before the end of the war.
Defense for the Canal Zone went far beyond the main gun emplacements. Two regiments played roles in providing guards for the various locks. Other troops became assigned to other installations critical for maintaining the Canal: dams at Gatun and Madden, water filtration plants, ordnance dumps, power stations among others including the Mechanical Division yards at both Balboa – Pacific – and Cristobal – Caribbean, as well as fuel tank farms. Transit guards placed on circumspect vessels had the role of preventing possible sabotage efforts carried out by vessels moving through the Canal.
AIRPOWER CHANGING THE EQUATION
The biggest changes in the Canal Zone, especially in the last few years before World War 2, were in creating airfields and air defense. With the carrier-based air attacks, most of the major defensive structure of the Zone became outdated and superfluous. On the Caribbean side, the Navy built Coco Solo Naval Air Station for their patrol planes ranging out into the Caribbean. The Army built a France Field, the site of today’s Enrique Adolfo Jiménez International Airport serving Colòn. On the Pacific side, Albrook Field – today, Marcus Gelabert Airport – and Howard Field – today, Panama Pacific International Airport – served American needs out of the Canal Zone.
Further west, the airfield at Rio Hato developed in the late 1930’s giving an expanded coverage for airplanes working out from both sides of the Canal Zone plus providing an area for bombing ranges. With the war, several other airfields outside of the Canal Zone became created around Panama allowing dispersal of aircraft so as not to replicate events in the Philippines at the beginning of the war – Clark Airfield.
Defense in the Canal Zone reflected those in America, Hawaii and the Philippines. Created to contest enemy battleships, enormous guns with like-minded concrete fortifications built in state-of-the-art manner. Like the battleship, the fortifications quickly fell by the wayside as airpower superseded both in a very short time. Fortifications, themselves, underwent a fast cycle of change during the late 19th and early 20th centuries. American fortifications certainly did not represent the latest development in fortress technology – there, one needed to look more to French developments such as the Maginot Line. Still, the American defenses were enough for enemy fleets to take pause.
INDIRECT THREATS AND SOME WHICH NEVER TOOK PLACE
During both World Wars, sabotage to the locks, dams or other important utilities within the Zone was more of an immediate problem than an actual attack. The problem of sabotage carried out from transiting ships, especially so.
A Japanese plan fostered by Admiral Inoue Yamamoto aimed at sending seaplane bombers launched off of large-scale submarines never came about due to Yamamoto’s death and delays in building submarines large enough to carry the planes. By the time the submarines became ready, the war already was lost. The Germans also had a plan in which a couple of Ju-87 Stuka bombers would ship in parts by submarine to uninhabited Colombian islands in the Caribbean. Reassembled, they were to launch at the Canal, as well. If either attack had come off, a successful strike on the Canal would have had serious repercussions.
FORTS GIVE WAY TO THE NEXT WAVE IN DEFENSE SPENDING
While the attacks did not come off, they pointed the way for the future. Big guns drifted out with the new dimensions added to warfare. Air warfare came to new climax during the American “Just Cause” operation 20 December 1989. Some 10,000 troops flew into augment an already 13,000 troops stationed in the Canal Zone. Troops flew from US bases directly into combat in the case of Rio Hato, as well as Canal Zone-based troops inserted by air directly to important sites around Panama to enable the capture of Manuel Noriega.
Monies spent developing, creating and manning the defense of the Canal became monies thrown after outdated technologies. Defense spending over the last two centuries never seemed to keep up with the times. Battleships and forts being prime examples as newer technologies, both with artillery and ordinance improvements and the development of the aerial element,s cases in point.
Another factor in the defense of the Canal post World War 2 was the dawn of atomic warfare. The Canal was considered a primary target in any potential nuclear exchange. Times had changed dramatically from the era of the disappearing carriages of the Zonian defense batteries.