Panama Canal - Geography. I INTRODUCTION Panama Canal, canal across the Isthmus of Panama, in Central America, that allows vessels to travel between the Pacific and Atlantic oceans. The waterway measures 64 km (40 mi), including dredged approach channels at each end. The Panama Canal handles a large volume of world shipping and enables vessels to avoid traveling around South America, reducing their voyages by thousands of miles and many days. The canal consists of artificially created lakes, channels, and a series of locks, or water-filled chambers, that raise and lower ships through the mountainous terrain of central Panama. Built by the United States from 1904 to 1914, the Panama Canal posed major engineering challenges, such as damming a major river and digging a channel through a mountain ridge. It was the largest and most complex project of this kind ever undertaken at that time, employing tens of thousands of workers and costing $350 million. The canal cuts through the central and most populated region of Panama, and it has been a point of dispute between the governments of Panama and the United States through most of its existence. Under a 1903 treaty, the United States controlled both the waterway and a large section of the surrounding land, known as the Panama Canal Zone, as if they were U.S. territory. Panamanians resented this arrangement and argued that their country was unfairly denied benefits from the canal. Eventually, riots and international pressure led the United States to negotiate two new treaties, which were signed in 1977 and took effect in 1979. The treaties recognized Panama's ultimate ownership of the canal and all the surrounding lands. More than half of the former Canal Zone came under Panamanian control shortly after the treaties were ratified. Control of the canal was turned over to Panama on December 31, 1999. II TRAVELING THROUGH THE CANAL The canal consists of dredged approaches and three sets of locks at each end; Gatún Lake, one of the largest artificially created bodies of water in the world; and the excavated portion of the crossing, called Gaillard Cut. At Gatún, on the Atlantic side, the locks form continuous steps; on the Pacific side, a small lake (Miraflores) separates the middle and upper locks. Because the Isthmus of Panama extends east-west, a ship sailing from the Atlantic to the Pacific through the canal actually travels from northwest to southeast. To travel from the Atlantic to the Pacific, a ship enters Limón Bay from the north and anchors behind a breakwater to await scheduling of its passage. When ready, the canal authorities send out a canal pilot to take the vessel through the locks. The canal employs about 240 highly trained and experienced pilots to handle the complex job of steering ships through the waterway. As soon as the pilot takes over, the ship is under canal jurisdiction. Very large or hard-to-maneuver ships may require two or more pilots and assistance from tugboats. The ship travels south-southeast about 11 km (7 mi) and enters the first lock at Gatún. Line handlers at the lock attach steel mooring cables that are controlled by powerful electric locomotives, called mules. The mules guide the ship through the locks and steady it while the chambers are filled with water. In three steps the ship is raised to the level of Gatún Lake, 26 m (85 ft) above the sea. The canal's 12 locks (3 sets of double locks at each end) have the same dimensions: 33.5 m (110 ft) wide by 305 m (1,000 ft) long. The gates at each end are 2.1 m (7 ft) thick. Water enters and leaves each lock through a system of main culverts or pipes, which connect to 100 holes in the floor of each chamber. For each ship traveling through the canal, 197 million liters (52 million gallons) of fresh water are used, fed by gravity flow from Gatún Lake. To conserve water, smaller ships often go through the locks together. At the top of the Gatún locks, the ship drops the mooring lines and proceeds under its own power for 37 km (23 mi) through the lake, following the former channel of the Chagres River. Gatún Dam, built adjoining the locks, flooded the river basin and formed the lake, which covers 430 sq km (166 sq mi). The flooding created a number of islands, as the water covered all but the tops of hills. One of these islands, Barro Colorado, is a wildlife refuge operated by the Smithsonian Tropical Research Institute. The waterway gradually narrows until the river turns to the east at Gamboa, flowing under a bridge of the Panama Railroad. The canal's marine division, with cranes, dredges, tugs, and barges, is located at Gamboa. South from Gamboa, the canal follows a channel dug through the mountains, which was the most difficult part of the construction project. Called Gaillard Cut, this section measures 14 km (9 mi) and traverses the Continental Divide, a ridge made of rock and shale. Numerous landslides occurred both during and after construction, requiring frequent dredging to keep the canal open. The channel through the cut is 150 m (500 ft) wide, the narrowest part of the canal. Originally only 91.5 m (300 ft), the cut was widened in phases beginning in the 1930s to allow two-way traffic. In the 1990s it was enlarged even more to accommodate larger ships. At the southern end of Gaillard Cut, the ship slows and enters Pedro Miguel locks. Again, cables and mules guide and steady the ship before it is lowered 9.4 m (31 ft) to Miraflores Lake. The cables are released and the ship crosses the lake, which is 2.1 km (1.3 mi) long and lies 16 m (54 ft) above sea level. The ship then enters the last two locks, also named Miraflores, and is lowered to the level of the Pacific Ocean. The final stretch of the canal carries the ship to the harbor of Balboa, where the canal pilot leaves the vessel. The ship sails under the Bridge of the Americas (formerly known as the Thatcher Ferry Bridge) and into the Bay of Panama, an arm of the Pacific Ocean. Northbound ships anchor in the Bay of Panama while waiting for their turn to travel through the canal to the Atlantic. The entire trip through the canal takes between 8 and 10 hours plus waiting time. The canal operates 24 hours a day year-round. Each ship that travels through the canal pays a toll based on its capacity. III TRAFFIC VOLUME A large volume of the world's ships, cargo, and passengers travel through the canal every year. In 1996 more than 15,000 ships, about 42 per day, made the crossing. From 1985 to 1995 the number of ships, their tonnage, and the amount of tolls collected all increased. Tolls rose to $460 million in 1995, a 50 percent increase over 1985 figures. About 14,000 ships, 400,000 crew members, and 300,000 passengers traveled through the canal in 1995. A wide variety of general cargo vessels and specialized ships pass through the canal. The most common are bulk carriers for ore, grain, and liquids; automobile carriers; container ships; refrigerated ships; tankers; liquid-gas carriers; and passenger liners. Many naval vessels, fishing boats, barges, dredges, floating drydocks, and oceangoing tugs also use the canal. The principal commodities shipped through the canal in 1993 were canned and refrigerated foods, chemicals, coal and coke, grains, lumber and wood products, machinery and equipment (including automobiles), iron and steel products, minerals, ores and metals, agricultural commodities, and petroleum and by-products. The single largest commodity was grain, mostly being shipped from the U.S. Gulf Coast region to Asia. Another important group was automobiles: About half of the cars shipped from Asia to the United States went through the canal in the mid-1990s. The size of ships using the Panama Canal has steadily increased. About 27 percent of the vessels that use the canal are built to the maximum dimensions that can pass through it (a category called "Panamax"). This has prompted further widening of Gaillard Cut, so that the larger Panamax vessels may transit safely. However, some of the world's commercial and military ships are too large for the canal. Since the 1940s, new U.S. battleships and aircraft carriers have been built exceeding the canal's dimensions; so have some petroleum supertankers, huge container ships, and ore carriers. Despite this trend, planners anticipate steadily increasing demand for use of the canal for the next 20 years. The Panama Canal was built in part for military reasons, to give the U.S. Navy rapid access to both the Atlantic and Pacific oceans. Many U.S. Army, Navy, and Air Force bases were built in the canal zone to defend the vital channel. However, since World War II (1939-1945) the canal has been considered vulnerable to attack. A single bomb or a scuttled ship could disrupt canal traffic for a long period, and the jungles along the canal could be used by guerrilla forces. Therefore, the canal was considered less valuable as a military asset. The nearby bases, while continuing to guard the canal, became a center for U.S. military operations throughout Central America and the Caribbean. The headquarters for the U.S. military's Southern Command was relocated from bases in Panama to Florida in 1997. All U.S. military bases in Panama were closed before the end of 1999. IV CANAL ADMINISTRATION The canal is operated by the Panama Canal Authority, a public Panamanian corporation. Before Panama took control of the canal in 1999, the canal was managed by the Panama Canal Commission, a U.S. government agency under the Department of Defense. The commission was established in 1979 to operate the canal during the 20year transition from U.S. to Panamanian control, and it gave Panamanians a role in governing the canal for the first time. The commission was supervised by a ninemember board composed of five U.S. citizens and four Panamanians. After 1990 the canal's administrator was a Panamanian. The commission provided Panamanian employees with specialized training, and Panamanians formed more than 90 percent of the canal's workforce by 1996. Until 1979 the canal and adjoining lands had been run solely by the U.S. government as if they were U.S. territory. The Panama Canal Authority manages and maintains the canal and all its related functions and equipment. Tolls and other canal fees generally pay all the costs of running and maintaining the waterway. Treaties between the United States and Panama guarantee the permanent neutrality of the Panama Canal, allowing ships of all nations to use it even in time of war. Panama and the United States share responsibility for the defense of the canal. V A HISTORY Early Efforts As early as the 16th century, Europeans dreamed of building a ship canal across the Isthmus of Panama. Spanish kings considered building a canal to carry treasure from their South American colonies back to Spain, but no attempt was made. Such a project became possible only in the 19th century, with the machinery and knowledge produced during the Industrial Revolution, the transition from an agricultural to a mechanized economy. In the 1830s and 1840s, while Panama was a province of Colombia, a number of European and U.S. studies were conducted to determine where and how such a crossing could be built. In 1850 the United States and Britain signed the Clayton-Bulwer Treaty, in which they pledged to cooperate if either one undertook such a project. That same year, a New York company began construction of the Panama Railroad, along the same general route as the present-day canal. It opened to traffic five years later, carrying many gold seekers to California during the gold rush. During the rest of the 1800s, the U.S. government frequently sent in troops to protect the railroad from bandits and military threats, under the authority of a treaty signed with Colombia in 1846. In the late 1870s a private French company won a concession from Colombia to build a sea-level canal in Panama and soon raised enough money to begin construction. The company was directed by Ferdinand de Lesseps, a French engineer and diplomat who had overseen construction of the Suez Canal in Egypt. Excavation in Panama began in 1882, but the company quickly ran into problems caused by the difficult terrain, climate, tropical diseases, labor shortages, and a flawed design. In 1888 it ceased work and went into bankruptcy. Reorganized a few years later as the New Panama Canal Company, it barely managed to keep the concession and prevent the equipment from deteriorating. At that stage, the French company sought another sponsor for the project. B U.S. Involvement The United States had long been interested in a Central American canal, to link its east and west coasts and expand trade. However, it did not have the money or the will to build one before 1900. During the 1890s Congress appropriated money to begin work on a canal in Nicaragua, but the project was soon cancelled. The Spanish-American War in 1898 heightened military interest in a canal. After defeating Spain, the United States acquired the Philippines and Puerto Rico and wanted better access for its navy to both the Atlantic and Pacific oceans. American officials negotiated the Hay-Pauncefote Treaty with Britain in 1901, in which the two countries agreed that the United States alone could build and regulate a canal. The canal issue reached a critical point in 1902 and 1903. In a complex series of events, Congress and President Theodore Roosevelt decided on Panama over Nicaragua and negotiated a treaty with Colombia. Under the agreement, the United States would obtain a strip of land across the isthmus and build a canal. But Colombia's senate rejected the treaty. Panamanians feared the United States would build a canal in Nicaragua instead, so they took matters into their own hands. A group of Panamanians conspired with agents of the French company and the Panama Railroad to rebel against Colombian rule and declared Panama independent on November 3, 1903. The United States supported the revolt and used its navy to prevent Colombia from defeating the rebels. Two weeks later Panama signed a treaty with the United States giving permission for the canal project. The Panamanians had authorized Philippe Bunau-Varilla, a French citizen and longtime official of the French canal company, to negotiate the terms and sign the agreement. Bunau-Varilla gave the United States even more than it had asked for: a perpetual lease on a section of central Panama 16 km (10 mi) wide, where the canal would be built; the right to take over more Panamanian land if needed; and the right to use troops to intervene in Panama. The United States agreed to guarantee Panama's independence and pay $10 million, plus an annual fee of $250,000. In exchange for their independence, then, Panamanians were forced to accept the treaty, which no Panamanian ever signed, that virtually gave away the canal zone to the United States (see Panama: History). C Construction Canal construction began in 1904, directed by an Inter-Oceanic Canal Commission. Most of the excavation and construction was done by private contractors. The U.S. Army Corps of Engineers supplied the technical guidance, and Colonel George W. Goethals served as chief engineer from 1907 to 1916. After initial plans for a sea-level canal, the commission decided on a canal with locks. The canal commission recruited more than 50,000 laborers, mostly from nearby Caribbean islands, to work on the canal. In all, another 100,000 people migrated to Panama during the construction era, adding to the diversity of Panama's population. An important breakthrough during construction was the successful effort to control mosquito-borne diseases. Malaria and yellow fever had killed thousands of workers during the French canal attempt. But a U.S. campaign, directed by Army medical officer William Gorgas, drained or sprayed mosquito breeding grounds and built sewage and water systems. Within two years the diseases were brought under control. The overall cost of the canal was about $350 million, the largest and costliest work ever undertaken by the U.S. government. It became one of the world's premier feats of engineering. The concrete lock chambers and mechanical lock gates were the largest ever built. At the time, Gatún Dam was the largest earthen dam ever built, forming the world's largest artificial lake. More than 190 million cubic meters (250 million cubic yards) of earth and rock were excavated from the canal route. Frequent landslides caused problems and delays as workers dug through the ridge of the Continental Divide to form Gaillard Cut. Despite the challenges and difficulties, the Panama Canal was completed sooner than expected. The first ship traveled through it from the Atlantic to the Pacific on August 15, 1914. However, further landslides caused closures in 1915, and the canal's formal opening was postponed until 1920 because of World War I (1914-1918). D Canal Since Completion Since it opened, the canal has served as a U.S. shipping facility for vessels of all countries. Most ships and cargo traveling through the canal belong to U.S. companies, although a majority of the ships are registered in Panama or Liberia, countries that have low fees and less restrictive regulations. Starting in the 1930s Gaillard Cut was widened to improve navigation, and in the 1990s it was expanded again. Madden Dam was built in the 1930s to control the flow of water into Gatún Lake and generate electricity. In 1962 a high-level bridge was built over the Pacific entrance to the canal. Known as the Bridge of the Americas or Thatcher Ferry Bridge, this structure carries the Pan-American Highway into Panama City. For much of its history, the canal and the surrounding Panama Canal Zone were run as a colony of the United States. The U.S. Department of the Army administered the canal, the Panama Railroad, and many businesses run by the railroad company. It also built 14 military bases in the area. The governor of the canal region was appointed by the secretary of the Army and was usually a retired general from the Corps of Engineers who had served in Panama. U.S. civilian employees supervised canal operations, while Panamanians and West Indians formed the labor force. In 1950 the U.S. government reorganized management of the area into two agencies: the Panama Canal Company, which ran the canal's commercial operations and the railroad, and the Canal Zone government, which handled courts, police, and other functions. The governor headed both agencies. A separate military structure controlled the military bases in the Canal Zone and operated independently of the civilian authorities. The U.S. control of the area caused decades of conflict with Panamanians, who felt excluded from the economic benefits of the canal and from territory they regarded as rightfully belonging to Panama. Before negotiating the 1977 treaties, the United States and Panama modified the 1903 treaty twice. In 1936 they signed an agreement by which the United States raised Panama's annual payment from the canal and prevented shipments of untaxed goods from the canal zone into Panama, which Panamanian merchants regarded as unfair competition. The United States also gave up the rights to intervene militarily in Panama and to take over more land for canal operations. In 1955 another treaty raised the annuity again, made Panamanians who worked in the canal zone subject to Panamanian taxes, and promised to end a wage system that paid American employees at a higher rate than Panamanians. But these concessions did not end tensions between the United States and Panamanians, who staged demonstrations and protests in the late 1950s and 1960s. AntiAmerican riots in 1964 caused the two countries to suspend diplomatic relations briefly. After they were restored, the United States and Panama began negotiating new treaties, a process that lasted more than 12 years. In 1977 U.S. president Jimmy Carter and the Panamanian leader, General Omar Torrijos Herrera, signed treaties that gave control of the canal and all its operations to Panama in 1999. The agreements were ratified by Panama immediately and by the United States the following year. The treaties went into effect in 1979. More than 60 percent of the U.S.-held Panama Canal Zone was returned to Panama. The Panama Canal Commission was established to run the canal during the transition to Panamanian control, and Panama took over operation of ship repairs, piers, and railroad operations. In 1994 the government of Panama created an agency, the Interoceanic Regional Authority, to administer the non-canal facilities of the former zone. The Panama Canal Authority, a public corporation, took possession of the canal from the Panama Canal Commission on December 14, 1999. That day the United States transferred the canal to Panama at a ceremony attended by Panamanian president Mireya Moscoso de Gruber and former U.S. president Jimmy Carter. In 2006 Panamanian voters approved a referendum calling for a major expansion of the canal. The planned $5.2-billion expansion will involve the creation of a new channel and new locks. The current canal cannot accommodate many of the modern container ships, and traffic has become so heavy that many ships experience costly delays waiting to enter the locks. The expansion project was set to begin in 2008 and expected to be completed in 2014. Contributed By: Michael L. Conniff Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. 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