Panama Canal is a waterway that cuts across the Isthmus of Panama and links the Atlantic Ocean and the Pacific Ocean . It ranks as one of the greatest engineering achievements in the world. Upon its completion in 1914, the canal shortened a ship’s voyage between New York City and San Francisco to less than 5,200 miles (8,370 kilometers). Previously, ships making this trip had to travel around South America —a distance of more than 13,000 miles (20,900 kilometers).
The United States built the Panama Canal at a cost of about $380 million. Thousands of laborers worked on it for about 10 years, using steam shovels and dredges to cut through jungles, hills, and swamps. They had to conquer such tropical diseases as malaria and yellow fever.
The Panama Canal extends about 51 miles (82 kilometers) from Limón Bay on the Atlantic Ocean to the Bay of Panama on the Pacific Ocean. A ship traveling through the canal from the Atlantic to the Pacific sails from northwest to southeast. The ship actually leaves the canal 27 miles (43 kilometers) east of where it entered.
Originally, the canal had two lanes of locks—that is, rectangular chambers that enable ships to move from one water level to another. The locks raise and lower ships in stages between sea level and Gatun Lake , 85 feet (26 meters) above sea level . The locks were built in pairs at three locations to allow ships to travel in the same direction or in opposite directions at the same time. They are 1,000 feet (300 meters) long and 110 feet (34 meters) wide and have a minimum water depth of about 42 feet (13 meters). This depth allows for ship drafts of up to 39.5 feet (12 meters). Draft is the distance from the water’s surface to a ship’s bottom. The largest ships that can fit in these locks are known as “Panamax” ships.
A third lane with locks at two locations was built alongside the original locks from 2007 to 2016 to accommodate larger ships. The new locks are 1,400 feet (427 meters) long and 180 feet (55 meters) wide and have a minimum water depth of 60 feet (18 meters). As a result, ships with drafts of up to 50 feet (15 meters) can now travel through the canal. The largest ships that can use the new locks are called “NeoPanamax” ships.
A 1903 treaty between the United States and Panama gave the United States the right to build and operate the waterway. The United States also received the right to govern an area of land called the Panama Canal Zone on both sides of the canal. For many years, Panama tried to gain control of the canal and the zone. In 1977, Panama and the United States signed a new treaty. As a result of this treaty, Panama received territorial jurisdiction over the zone in 1979. The United States kept administrative control of some military installations and areas necessary to operate and defend the canal. Also as a result of the treaty, Panama took control of the operations of the canal and its associated military installations on Dec. 31, 1999. A second treaty gave the United States the right to defend the neutrality of the canal.
A trip through the canal
Entering the canal.
A ship sailing from the Atlantic Ocean enters the canal by way of Limón Bay, the harbor of the town of Cristóbal, near the city of Colón . While the ship is still in deep water, a canal pilot comes on board from a small boat. The pilot has complete charge of the ship during its trip through the canal. After passing through the breakwater at the entrance to the bay, the ship heads south along an approach channel, about 7 miles (11 kilometers) long, leading to the older, smaller Gatun Locks or the newer, larger Agua Clara Locks. The shipyards, docks , and fueling stations of Cristóbal line the eastern shore of the bay.
The Gatun Locks
look like giant steps. They consist of three pairs of concrete chambers that lift ships about 85 feet (26 meters) from sea level to Gatun << guh TOON >> Lake. Small electric locomotives called mules run on tracks along both sides of the locks. They help to position and stabilize ships in the locks. They also pull and guide small ships through the locks. Large ships go through the locks chiefly under their own power. But locomotives help pull them, and also guide them.
As a small Pacific-bound ship approaches the first chamber, its engines are shut off. A large ship approaching the chamber keeps its engines on. Canal workers fasten the ends of the locomotives’ towing cables to the vessel. The locomotives then pull a small ship, or help pull a large ship, into the first chamber. Huge steel gates swing shut behind the vessel. Workers open valves that allow water from Gatun Lake to flow into the chamber through openings in the bottom of the lock. During the next 8 to 15 minutes, the rising water slowly raises the ship. When the level of the water is the same as the level of the water in the second chamber, the gates in front of the ship swing outward. The locomotives pull, or help pull, the vessel into the second chamber. Again the water level is raised. This process is repeated until the third chamber raises the ship to the level of Gatun Lake.
The Agua Clara Locks
look like even larger steps than the Gatun Locks. They consist of three chambers that raise ships from sea level to Gatun Lake. Tugboats rather than locomotives help ships move through the locks and into the lake. The locks have rolling gates supported by tracks on the ocean floor, rather than hinged swinging gates like those in the Gatun Locks. Unlike the original locks, the Agua Clara Locks include water-saving basins that reduce the use of fresh water from Gatun Lake. They use slightly less water than the original locks.
Gatun Lake.
After passing through the Gatun or Agua Clara locks, the ship heads south across the quiet water of Gatun Lake. The huge Gatun Dam lies west of the locks. This 23-million-cubic-yard (18-million-cubic-meter) earth dam is one of the largest in the world. Gatun Dam created 163-square-mile (422-square-kilometer) Gatun Lake by holding back the waters of the Chagres River . The ship travels across the lake from the locks to Gamboa, following the 22-mile (35-kilometer) channel that was once the Chagres River Valley.
The tops of trees and hills jut above the water. Many were completely submerged when engineers flooded the valley to create Gatun Lake. The violet flowers and green leaves of water hyacinths float on the lake. Their long, coarse stems can become tangled in ship propellers and endanger navigation. A special hyacinth patrol destroys the plants to keep the channel clear.
The Gaillard Cut.
When the ship reaches the southeastern end of Gatun Lake it enters the Gaillard << gihl yahrd >> Cut, 8 miles (13 kilometers) long, about 55 feet (17 meters) deep, and a minimum of 715 feet (218 meters) wide. This part of the canal crosses the Continental Divide . Cut is an engineering term for an artificially created passageway or channel. The highest part of the Gaillard Cut runs between Gold Hill on the east and Contractor’s Hill on the west. Gold Hill is nearly 600 feet (180 meters) tall. Dredgers work constantly to keep the channel clear of landslides . In some years, they have removed as much as 10 million cubic yards (7.6 million cubic meters) of earth. The Gaillard Cut originally was called the Culebra Cut. It was 300 feet (90 meters) wide at the bottom, about 42 feet (13 meters) deep, and accommodated one-way traffic. In 1913, the cut was renamed for David DuBose Gaillard, the engineer in charge of excavating the cut. Today, both names are used. Since 1955, the cut has been widened several times and deepened to accommodate larger ships and two-way traffic. The Centennial Bridge, completed in 2004, crosses the Gaillard Cut. After a Pacific-bound ship leaves the Gaillard Cut, it approaches the original Pedro Miguel Locks or the newer, larger Cocolí Locks.
The Pedro Miguel and Miraflores locks.
Electric locomotives pull, or help pull, a ship into the Pedro Miguel Locks. These locks lower the vessel 31 feet (9 meters) in one step to Miraflores Lake. The ship sails 11/2 miles (2.4 kilometers) across the lake to the Miraflores Locks. Here, two chambers lower it to the level of the Pacific Ocean. The distances these chambers must lower the ship depend on the height of the tide in the Pacific. Tides at the Pacific end of the canal rise and fall up to nearly 12 feet (3.7 meters) a day. Tides on the Atlantic side change only about 2 feet (60 centimeters) daily.
The Cocolí Locks
have the same dimensions as the Agua Clara Locks. They also use tugboats to help position and move ships and have rolling, rather than swinging, gates. Ships using the Cocolí Locks do not cross Miraflores Lake. The locks’ three chambers are positioned closer together than those of the Pedro and Miraflores locks.
Out of either the Miraflores or Cocolí locks, a ship heads down a channel several miles long to the end of the canal. It passes the towns of Balboa, Balboa Heights, and La Boca. The ship also passes under the Bridge of the Americas. After the canal pilot leaves, the vessel enters the Bay of Panama and heads toward the open sea. It has traveled a little over 50 miles (80 kilometers) from the Atlantic to the Pacific.
Importance of the canal
The Panama Canal is an important commercial and military waterway. Thousands of oceangoing vessels travel through it yearly. The ships carry hundreds of millions of tons of cargo annually, measured as special “Panama canal tons.” More than half of the cargo is being carried to or from U.S. ports. Other frequent users of the canal include Chile, China, Japan, and South Korea.
Until 1999, the United States maintained several military bases to defend the canal. Huge quantities of war materials and thousands of troops passed through the canal during World War II (1939-1945), the Korean War (1950-1953), and the Vietnam War (1957-1975).
Administration and defense
Administration.
Panama took over control of the canal on Dec. 31, 1999, under terms of a treaty that had been signed by the United States and Panama in 1977. Prior to the canal’s transfer to Panama, a U.S. government agency called the Panama Canal Commission operated and maintained the waterway. In addition, the commission operated public utilities and provided community, sanitation, security, and transportation services. By the time of the transfer, the Panama Canal Commission had more than 7,000 employees, about 95 percent of whom were Panamanian. The commission’s board of directors consisted of five Americans and four Panamanians.
After the transfer of the canal to Panama, the Panamanian government placed it under the control of a new agency created specifically to operate and maintain the waterway. Unlike the old U.S. Panama Canal Commission, the Panama Canal Authority is controlled by a Panamanian board of directors appointed by the president of Panama and approved by the country’s legislature. The authority is an extremely powerful agency with the right to manage all its own financial affairs, control its labor force, and make its own laws.
The Panama Canal Authority collects tolls from ships that use the canal. The amount of the toll paid by a merchant ship is generally determined by the ship’s cargo space. The toll for certain smaller vessels is based on the length of the vessels. Military ships pay a toll based on their weight.
Defense.
International law requires that commercial and military vessels of all nations be allowed to pass through the canal in peacetime. A treaty signed by the United States and Panama in 1977 guarantees that the canal will remain open to all nations even in time of war. The agreement gives the United States the right to use military force if necessary to protect the neutrality of the canal.
History
Early efforts.
Hundreds of years before the Panama Canal was completed, many people dreamed of building a canal across Central America . As early as 1517, Vasco Núñez de Balboa , the first European to reach the Pacific, saw the possibility of a canal connecting the Atlantic and Pacific oceans.
Throughout most of the 1800’s, Nicaragua was the chief center of efforts to build a canal. Both the United States and the United Kingdom considered a canal across Nicaragua. During the 1840’s, the two nations almost went to war because of disputes over which one would control the proposed canal. In 1850, in the Clayton-Bulwer Treaty , they agreed to protect the neutrality of a canal to be built somewhere across the Central American isthmus.
During that period, present-day Panama was a province of Colombia . Colombia feared that the United Kingdom would try to seize Panama for use as a canal site. Colombia signed a treaty with the United States in 1846. The United States agreed to guard all trade routes across Panama and to preserve Panama’s neutrality.
The Panama Railroad.
During the California gold rush that began in 1849, the Isthmus of Panama became an important route between the Eastern United States and California. Many prospectors sailed from Atlantic Coast ports to Panama, crossed the isthmus by boat, on mules, and on foot, and then took another ship for California. In 1850, Colombia permitted a group of business executives from New York City to build a railroad across the isthmus. The line was completed in 1855 at a cost of $8 million. It linked Colón on the Atlantic side and Panama City on the Pacific side.
The French failure.
In 1878, Colombia granted a French adventurer named Lucien Napoleon Bonaparte Wyse the right to build a canal across Panama. He sold the right to a French company headed by Ferdinand Marie De Lesseps , who had directed the construction of the Suez Canal . The French also bought control of the Panama Railroad for $20 million. The company began digging in 1882. The French planned a canal that would run at sea level between the Atlantic and Pacific, and so would need no locks. In 1886, the problems of building a sea-level canal forced the French to decide to build a canal similar to the present one. De Lesseps and his assistants planned most of the project carefully and carried out some of it efficiently. However, the French wasted great quantities of material and effort. A group of dishonest politicians who supported De Lesseps stole large amounts of money from the canal company. The French engineers lacked the proper tools to complete such a huge digging job. In addition, scientists did not know how to fight the epidemics of tropical diseases that hit the workers.
De Lesseps’s company went bankrupt in 1889, after digging out some 76 million cubic yards (58 million cubic meters) of earth. A second French firm, the New Panama Canal Company, took over the property and franchise in 1894. But the new company made only half-hearted efforts to continue digging, in order to keep the franchise until a buyer could be found.
The United States and the canal.
A group of United States business executives began working on a canal across Nicaragua in 1889. But the group ran out of money soon after beginning the Nicaraguan project. Both the American and French groups tried to sell their rights and property to the United States government. However, American railroad executives opposed construction of any Central American canal because they feared competition from shipping lines that would use the canal. As a result, the United States government took no action on either project.
During the Spanish-American War in 1898, the United States Navy sent the battleship Oregon from San Francisco to Cuba to reinforce the Atlantic Fleet. The Oregon had to sail nearly 13,000 miles (20,900 kilometers) around the tip of South America. The trip would have been only about 4,600 miles (7,400 kilometers) long through a canal. This fact helped convince the United States Congress that a canal was essential for national defense.
In 1899, Congress authorized a commission to survey possible canal routes. The commission favored Nicaragua, because a canal there would require less digging than one across Panama. But the French company offered to sell its Panama rights and property and the Panama Railroad for $40 million. Philippe Bunau-Varilla, of the French company, convinced leading Americans that Nicaragua’s volcanoes presented the danger of earthquakes and that Panama was safer. In 1902, Congress gave President Theodore Roosevelt permission to accept the French offer if Colombia would give the United States permanent use of a canal zone. Congress acted after the United States and the United Kingdom had replaced the Clayton-Bulwer Treaty with the Hay-Pauncefote Treaty . This treaty gave the United States sole right to build and operate a canal across Central America.
In 1903, U.S. Secretary of State John Hay signed a canal treaty with a Colombian representative, Tomás Herrán. The treaty provided that the United States would give Colombia an initial payment of $10 million and pay $250,000 annual rent for the use of the zone. But the Colombian legislature refused to approve the treaty because it felt that this was not enough money.
A group of Panamanians feared that Panama would lose the commercial benefits of a canal across the isthmus. The French company worried about losing the sale of its property to the United States. The Panamanians, with the help of the French and some encouragement from the United States, revolted against Colombia on Nov. 3, 1903, and declared Panama independent. In accordance with its 1846 treaty with Colombia, the United States sent ships to Panama to protect the Panama Railroad. Marines landed in Colón and prevented Colombian troops from marching to Panama City, the center of the revolution. On Nov. 6, 1903, the United States recognized the Republic of Panama. Less than two weeks later, Panama and the United States signed the Hay-Bunau-Varilla Treaty. It gave the United States permanent, exclusive use and control of a canal zone 10 miles (16 kilometers) wide. In return, the United States gave Panama an initial payment of $10 million, plus $250,000 a year, beginning in 1913. The United States also guaranteed Panama’s independence. The United States took over the French property in May 1904.
Victory over disease.
The greatest obstacle to building the Panama Canal was disease. The Isthmus of Panama was one of the most disease-ridden areas in the world. In 1904, Colonel William C. Gorgas took charge of improving sanitary conditions in the Canal Zone. Gorgas, an American physician, had become famous for wiping out yellow fever in Havana , Cuba, after the Spanish-American War.
Gorgas began a campaign to destroy the types of mosquitoes that carried malaria and yellow fever. The first two years of canal building were devoted largely to clearing brush, draining swamps, and cutting out large areas of grass where the mosquitoes swarmed.
By 1906, Gorgas had wiped out yellow fever and eliminated the rats that carried bubonic plague in the Canal Zone. By 1913, he had also reduced the rate of deaths caused by malaria.
Cutting through the isthmus.
Roosevelt appointed a civilian commission to lead the canal project. In 1906, Congress decided to build a canal with locks, rather than the sea-level canal that the French had originally planned. Engineers believed a canal with locks would be cheaper and faster to build. They also felt a canal with locks would control the Chagres River’s floodwaters better than a sea-level canal would. The work progressed slowly, chiefly because of disagreements among the commission members. In 1907, Roosevelt put Colonel George W. Goethals , an Army engineer, in charge of the project and the Canal Zone.
The construction task involved three major engineering jobs. The builders had to excavate the Gaillard Cut, build a dam across the Chagres River to create Gatun Lake, and build the canal’s locks. The biggest job was digging the Gaillard Cut. The hills through which the cut runs consist of a soft volcanic material, and digging into them was like digging into a pile of grain. As soon as workers dug a hole, more rock and earth would slide into the space, or push up from below. The engineers had expected to remove about 95 million cubic yards (73 million cubic meters) of earth and rock to build the canal. They actually dug out about 211 million cubic yards (161 million cubic meters). Some of this was used later in the construction of Gatun Dam.
At the height of the work in 1913, more than 43,400 people worked on the Panama Canal. Three-fourths were blacks from the British West Indies . The British West Indies were a group of islands in the Caribbean, including the Bahamas and Jamaica, that were part of the British Empire . Other workers came from Italy and Spain. Most of the clerical and skilled workers came from the United States.
The oceans united.
The main work of building the Panama Canal was completed in 1914. On August 15, 1914, a passenger-cargo ship owned by the Panama Railroad Company, the S.S. Ancon, made the first complete trip through the canal. The ship sailed from the Atlantic to the Pacific and made a reality of the canal slogan—”The Land Divided, the World United.” A giant landslide in the Gaillard Cut closed the canal for several months in 1915 and 1916. It was the last major interruption in the operation of the Panama Canal. President Woodrow Wilson proclaimed the official opening of the Panama Canal on July 12, 1920.
The canal cost the United States about $380 million. This included the $40 million paid to the French company, the $10 million paid to Panama, and $20 million for sanitation. The remaining $310 million was spent for the actual construction work.
The canal under U.S. control.
The Madden Dam, completed in 1935, was the first major improvement on the canal. The dam lies across the Chagres River, east of the canal. It created 22-square-mile (57-square-kilometer) Madden Lake, which stores water for use in Gatun Lake. The dam also holds back the floodwaters of the Chagres River during the rainy season.
In 1936, the United States agreed to raise its annual payments to Panama to $430,000, which made up for a devaluation of the dollar. In 1955, the payments were increased to about $2 million a year.
During the 1950’s, engineers began to widen the Gaillard Cut from 300 to 500 feet (90 to 150 meters). This project was completed in 1970.
From the 1920’s to the 1970’s, the United States and Panama had many disputes concerning U.S. control over the Panama Canal Zone. The Panamanians regarded the zone as part of their country. They believed the 1903 treaty, which established the zone, was unfairly favorable to the United States. Some Panamanians also resented the large number of U.S. military bases in the zone. See Panama Canal Zone .
In 1971, Panama and the United States began negotiations for a new treaty to replace the 1903 pact. In 1977, the two nations signed two new treaties. One of the treaties provided for the transfer of territorial jurisdiction over the Panama Canal Zone to Panama in 1979. This treaty also provided for Panama to take control of canal operations in 1999. The other agreement gave the United States the right to defend the neutrality of the canal beyond 1999.
Many Americans opposed giving up control of the canal and the zone, which they regarded as United States property. Other Americans favored the treaties. They believed continued United States control would harm relations with Latin American nations. The two agreements were approved by Panama’s voters in 1977 and by the U.S. Senate in 1978. The treaties took effect in 1979.
The canal under Panamanian control.
Panama formally took control of the canal on Dec. 31, 1999. Former President Jimmy Carter represented the United States at ceremonies held earlier that month to mark the transfer of the canal. Carter had played a leading role in negotiating the canal treaties.
In 2006, Panamanians voted in a national referendum to expand the Panama Canal. Construction lasted from 2007 to 2016, with a budget of more than $5 billion. The expansion enabled the canal to handle more cargo and traffic and to accommodate the larger ships increasingly being used in the shipping industry.
