Introduction to How the Panama Canal Works
When the conquistador Vasco Núñez de Balboa summited a peak in the region Dariên, his eyes beheld a tantalizing sight. Behind him, the Atlantic Ocean that he had crossed from Spain; before him, the Pacific -- the two bodies of water separated by an impossibly narrow isthmus. However, Balboa was simply the first in a long line of outsiders to underestimate the difficulty of connecting the two oceans. It took more than 400 years from his 1513 discovery to create the canal that revolutionized world trade.
Today, more than 943,042 vessels have passed through the Panama Canal since its opening [source: Panama Canal Authority]. It acts as benchmark to the world's economic health -- bustling with freighters carrying grain, petroleum and coal during high times and slowing down when global markets lag. The canal shortened the trip between the East and West coasts of the United States by 8,000 nautical miles (15,000 km), allowing ships to avoid the dangerous, expensive trip around South America's Cape Horn [source: Britannica].
The canal also occupies a strange place in geopolitics. Until 1979, it was under the exclusive control of the United States. The U.S.-run Canal Zone slashed through the Republic of Panama just as the canal cut through the American continents. It also served as a symbol of injustice for many Panamanians. But after a 20-year period of joint agency between the U.S. and the Republic of Panama, complete control passed to Panama. Since then, the Panama Canal Authority (an agency responsible to the Panamanian government) has managed the canal and maintained the waterway's safety record and efficiency.
That's a fairly impressive feat considering the volume of the canal's traffic -- and the age of the canal itself. Ships are raised and lowered over the continental divide by a series of locks, which are built with two chambers to accommodate two-way traffic. It's a trade artery, operating almost beyond capacity, and it was built in challenging terrain.
So what did it take to rend two continents? And why did an estimated 22,000 people die in a failed attempt to make it happen? We'll find out.
The French Attempt to Build a Canal at Panama
As soon as the Spanish realized how narrow the Panamanian isthmus really was, they began exploring ways to cross it. They surveyed the area in 1534 (ironically choosing a course very much like that of today's waterway), but it wasn't until the 1820s that European efforts to dig a canal really took off. Steam technology had eliminated the need for towpaths -- the narrow, level paths that flank a river or canal and allow horses, mules and even men to tow craft along. Canal construction had subsequently exploded, and entrepreneurs were eager to open up the next great waterway.
But a Panamanian canal wasn't yet a given. Two isthmian routes -- one through Panama, the other through Nicaragua -- were considered right up into the 20th century. That the French (and ultimately the Americans) chose a route through Panama was due partly to the 1855 opening of a Panamanian railway -- the first to connect the coasts of a continent. In its incomplete form, the railway even played a part in the gold rush, carrying eager '49ers embarking from the U.S. East coast and headed to California.
But the French also chose Panama over Nicaragua because they believed it could support a sea-level canal, or canal without locks. Locks are used to carry a waterway over uneven terrain by raising and lowering the water level in a series of steplike chambers. A canal without locks simply carves through the terrain -- maintaining the same water level from start to finish. Although the French eventually realized it's extremely difficult to cut through the Continental Divide, they abandoned the plan too late to save the effort from failure.
French construction was financed by private investors and run by the Compagnie Universelle du Canal Interocéanique, which had been given permission to build by the Colombian government that controlled the area. The famous hero of the Suez Canal in Egypt, Ferdinand de Lesseps, managed the company and was responsible for persisting in the sea-level plan. His triumphant experience at Suez made him blasé about Panama's geographical challenges. In reality, the 40-mile (64-km) isthmus was studded with a mountain range, choked with jungle, plagued by mosquitoes and subject to the powerful fluctuations of the Chagres River.
Also, the construction plan of the Compagnie Universelle was hazy and poorly planned. The machinery was often too light for the massive task of mountain-moving. And worst of all, thousands of people were unable to withstand the harsh climate and tropical fevers. It's impossible to say how many people died over the course of the French effort, as the hospitals didn't keep records, but it's estimated that 22,000 lost their lives [source: Panama Canal Authority].
Although de Lesseps eventually accepted the impossibility of a sea-level canal and commissioned Gustav Eiffel (of Eiffel Tower fame) to construct a series of locks, it was too late for the inefficient French effort. By 1888, the Compagnie Universelle crashed, leaving its principals slapped with lawsuits and a nation of disappointed investors.
So how did the United States gain control of the isthmus, and why was the takeover so controversial?
The Disaster at DariénThe French weren't the only ones to sink money into the isthmus with no return. In the early 1700s, a Scottish settlement set up camp at Darién, intending to trade. But since both English and Spanish merchants placed an embargo on the settlers, business was decidedly bad. Two thousand people died from fever or starved to death, and on a wider scale, private investments depleted Scotland's savings and hurried the country's eventual merging with Great Britain.
Americans Take the Panamanian Isthmus
While a fear of "entangling alliances" dominated the early history of the United States, that mindset was disintegrating by the late 19th century [source: Jefferson]. As the U.S. began to acquire territories like the Philippines, Puerto Rico and Hawaii, its leaders became less scrupulous about using gunboat diplomacy to get exactly what they wanted.
In 1902, Congress authorized the purchase of the failed French company's assets, setting the stage for the construction of a canal. However, there was one stipulation to the act. It required that the U.S. first form a treaty with Colombia (which at the time controlled Panama) for the use and control of a canal zone. When negotiations with Colombia failed, the U.S. government supported Panamanian independence -- freeing up the desirable territory from Colombia.
The United States and the fledgling Panama then drafted the Hay-Bunau-Varilla Treaty, with Panama signing over the rights to the Canal Zone without the benefit of a Spanish translation. Many senators were disturbed by the deal and felt that the United States had simply stolen the Canal Zone from Colombia [source: Parker]. But they passed the treaty anyway, believing what was done was done and a canal would be nice. In 1904, the United States paid $40 million for the assets of the Compagnie Universelle and offered Panama alimony of sorts totaling $10 million [source: Parker].
The U.S.-led project got up and running fast. There were some salvageable remnants of the French effort, including buildings, supplies, dredged sea passages and 11 miles of canal. But before work could begin in earnest, two things had to be dealt with: the type of canal that would be built and the fever that made work practically impossible.
The old debate over lock-type vs. sea-level construction ended when President Theodore Roosevelt chose to back Chief Engineer John Frank Stevens' lock-based model in 1906. Stevens' plan called for a dam at the notoriously hard-to-control Chagres River. Damming the river would create Gatún Lake and make up a large part of the canal route. Ships traveling toward the Pacific would enter the canal at Limon Bay in the Caribbean, pass through a series of locks that carried them upward in steplike increments, navigate though Gatún Lake and descend toward Panama City through another series of locks. The lock plan would carry the waterway over the mountains instead of driving it through them.
By 1906, the Canal Zone was also cleared of yellow fever. The fever, a viral disease, plagued people who hadn't become immune as children. It could appear suddenly and often ended in agonizing death. The at first unbelievable discovery that mosquitoes spread yellow fever and malaria led to a mass sanitary campaign to clean up Panama, Colon and other canal sites. Col. William Gorgas headed sanitation squads that fumigated houses, searched for the stagnant water that could support mosquito larvae and checked screens for signs of rust. The efforts worked; the fever that had been attributed to everything from poor morals to bad dirt was finally eradicated. Work could begin.
Next, we'll learn about canal construction, the locks and find out why the one section of the canal earned the nickname "Hell's Gorge."
Northwest PassageThe Panama Canal was a welcome solution to a centuries-old problem: how to trade around the obnoxiously large American continents. For many years, explorers sought a fabled Northwest Passage, or shortcut arching over North America between Europe and Asia. The icy conditions of the Arctic, however, made such a passage impossible -- until now. Satellite images released by the European Space Agency (ESA) show that rising global temperatures have thawed much of the passage. While it's a disturbing sign of our planet's rising temperature, a Northwest Passage might soon be open for business [source: BBC News].
Panama Canal Construction
With the lock-type plan in place for the Panama Canal, the United States needed an expert to execute it. Lt. Col. George Washington Goethals, an army engineer with lock expertise, became the new chief engineer. He divvied up the work into thirds: The Atlantic Division would work from Limón Bay to Gatún; the Central Division would run from Gatún to Pedro Miguel (and tackle the most challenging part of the project: the Gaillard (Culebra) Cut); and the Pacific Division would work from Pedro Miguel to the Panama Bay's deep waters.
The U.S. made good use of the Panamanian railroad that ran near the work, and the crews employed steam shovels, rock drills and dynamite to increase the efficiency of excavation. The work at the Gaillard (Culebra) Cut through the Continental Divide would have been impossible without such technology; men moved 96 million cubic yards (73 million cubic meters) of earth and rock and coped with huge dirt slides [source: Britannica]. Extreme heat and grisly accidents in the Cut gave it the name "Hell's Gorge."
On Jan. 7, 1914, the crane Alexander La Valley made the first canal transit. The canal didn't open officially, however, for another eight months. Celebrations to mark the event were scaled back as news reached Panama of Germany's declaration of war on France, the effective start of World War I.
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Goethals' three-part division can be used to understand the canal as it is today. Ships approaching from the Atlantic first pass through the Gatún Locks -- a series of three lock sets that lift vessels 85 feet (26 m) to Gatún Lake. Once there, ships wind through the lake's channel for about 23 miles (37 km) before entering the Gaillard (Culebra) Cut. After about 8 miles (13 km) spent crossing through the Cut, ships reach the Pedro Miguel Locks. These locks lower ships 30 feet (9 m) to the Miraflores Lake, where they pass through a mile-long (2 km) channel. Ships then approach the two-stepped Miraflores Locks that return them to sea level. A 7-mile (11-km) passage takes them out to the Pacific. From deep water to deep water, the canal is 50 miles (80 km) long.
Each of the locks is built in pairs to allow for two-way traffic. With a total transit time of eight to 10 hours, it just wouldn't make sense to run a one-way street [source: Panama Canal Authority]. To raise a ship, water is released from a lake (Gatún, Alajuela or Miraflores) or from a higher lock through valves that open on the upper end of the lock. To lower a ship, water drains to a lower lock or to the ocean through valves that open at the lower end of the lock. The locks are powered by electricity.
Because so much hinges on the locks' integrity, safety precautions prevent large ships from sailing through on their own steam. An out-of-control large ship could plunge through a lock. Large craft are instead escorted by electric towing locomotives.
So how is the Panama Canal run today? And what new additions are in store for the nearly century-old waterway? Find out in the next section.
A 36-cent SwimTolls help finance canal maintenance and improvements, but actual profit was a long time coming. Although the U.S. spent $400 million on the canal between 1904 and 1914, it didn't make up that cost until the 1950s [source: Parker]. Today's tolls can reach into the hundreds of thousands of dollars, but brave swimmers got a pretty good deal in 1928. When Richard Halliburton swam the length of the Panama Canal, he paid only a 36-cent toll [source: Panama Canal Authority].
The Panama Canal Today
Today, the Panama Canal is still a roaring thoroughfare (although an increasingly outdated one). After more than 60 years under the near-exclusive control of the United States, Gen. Omar Torrijos Herrera of Panama and President Jimmy Carter negotiated a path to full Panamanian sovereignty. Their Panama Canal Treaty, which went into effect in 1979, granted full control of the canal to Panama after a transition period of 20 years. On Dec. 31, 1999, the Panama Canal Authority assumed full control of the waterway.
And although the Panama Canal Authority has managed the canal successfully since then, the waterway's age and its volume of traffic are starting to catch up to it. It's become somewhat of an international trade traffic jam, with fleets of ships waiting offshore to go through. Many vessels are also no longer built as Panamax ships, the maximum size the canal can accommodate. The owners of post-Panamax supertankers and naval ships find it more efficient to increase their loads and take alternate routes than wait in line at Panama.
Panamanians who depend on the canal for their country's livelihood can't afford to see it become obsolete. With Nicaragua planning its own canal and threatening the old monopoly, Panamanians enthusiastically voted in favor of a 2006 referendum to modernize the canal. An additional larger set of locks -- a third lane -- will double the waterway's capacity [source: Lacey].
Some environmentalists, however, aren't too happy about the expansion plan. The canal's traffic, as well as the populations of Panama City and Colón, already take a tremendous toll on the area's watershed -- an area filled with diverse wildlife and important to intercontinental migrations. But planners say that the new set of locks will use water-saving basins to conserve 60 percent of the water used on each transit [source: Matalon]. Reforestation of surrounding areas should also help keep the reservoirs flowing and traffic bustling.
To learn more about the Panama Canal and international trade, traverse the links on the next page.
My Fellow Americans?The U.S. Constitution requires that a president be a "natural-born citizen," that is, born on American soil. This stipulation caused a slight bump for 2008 presidential candidate John McCain. The Republican nominee was born in 1936 while his military father was stationed in the Panama Canal Zone. Although a 1937 law granted retroactive citizenship to American children born in the Canal Zone after 1904, one analysis suggested this law came a year too late to make McCain "natural-born." However, such technicalities didn't cause any real issues for McCain's run. The Senate approved his eligibility in April 2008 [source: Liptak].