Kamis, 09 Desember 2010

The Panama Canal

The Panama Canal is a 77 km (48 mi) ship canal in Panama that joins the Atlantic Ocean and the Pacific Ocean and is a key conduit for international maritime trade. Built from 1904 to 1914, annual traffic has risen from about 1,000 ships in the canal's early days to 14,702 vessels in 2008, measuring a total 309.6 million Panama Canal/Universal Measurement System (PC/UMS) tons.

One of the largest and most difficult engineering projects ever undertaken, the canal had an enormous impact on shipping between the two oceans, replacing the long and treacherous route via the Drake Passage and Cape Horn at the southernmost tip of South America. A ship sailing from New York to San Francisco via the canal travels 9,500 km (5,900 mi), well under half the 22,500 km (14,000 mi) route around Cape Horn.

The concept of a canal near Panama dates to the early 16th century. The first attempt to construct a canal began in 1880 under French leadership, but was abandoned after 21,900 workers died, largely from disease (particularly malaria and yellow fever) and landslides. The United States launched a second effort, incurring a further 5,600 deaths but succeeding in opening the canal in 1914. The U.S. controlled the canal and the Canal Zone surrounding it until the 1977 Torrijos–Carter Treaties provided for the transition of control to Panama. From 1979 to 1999 the canal was under joint U.S.–Panamanian administration, and from 31 December 1999 command of the waterway was assumed by the Panama Canal Authority, an agency of the Panamanian government.

While the Pacific Ocean is west of the isthmus and the Atlantic to the east, the 8- to 10-hour journey through the canal from the Pacific to the Atlantic is one from southeast to northwest. This is a result of the isthmus's "curving back on itself" in the region of the canal. The Bridge of the Americas at the Pacific end is about a third of a degree of longitude east of the end near Colon on the Atlantic.

The maximum size of vessel that can use the canal is known as Panamax. A Panamax cargo ship will typically have a DWT of 65,000-80,000 tonnes, but its actual cargo will be restricted to about 52,500 tonnes because of draft restrictions in the canal. The longest ship ever to transit was the San Juan Prospector, now Marcona Prospector, an ore-bulk-oil carrier that is 973 ft (296.57 m) long, with a beam of 106 ft (32.31 m).

History

Early proposal

The earliest mention of a canal across the Isthmus of Panama dates to 1534, when Charles V, Holy Roman Emperor and King of Spain ordered a survey for a route through Panama that would ease the voyage for ships traveling to and from Spain and Peru, as well as give the Spanish a tactical military edge over the Portuguese. During his expedition of 1788–1793, Alessandro Malaspina demonstrated the feasibility of a canal and outlined plans for its construction. Given the strategic situation of Panama and its narrow isthmus separating two great oceans, other forms of trade links were attempted over the years. The ill-fated Darien scheme was an attempt launched by the Kingdom of Scotland in 1698 to set up an overland trade route, but was defeated by the generally inhospitable conditions, and abandoned in July of 1699. Finally, the Panama Railway was built across the isthmus, opening in 1855. This overland link became a vital piece of infrastructure, greatly facilitating trade and largely determining the later canal route.

Also in 1855, William Kennish, a Manx-born engineer in the employ of the United States government, surveyed and issued a report on a route for a proposed Panama Canal. His report was published in a book entitled The Practicality and Importance of a Ship Canal to Connect the Atlantic and Pacific Oceans.
French construction attempt

An all-water route between the oceans was still seen as the ideal solution, and the idea of a canal was enhanced by the success of the Suez Canal. The French, under Ferdinand de Lesseps, began construction on a sea-level canal (i.e., without locks) through what was then Colombia's province of Panama, on January 1, 1880. The French began work in a rush, with insufficient prior study of the geology and hydrology of the region. Excavation was conducted at such a steep angle that, in some years, rain-induced landslides poured nearly as much material into the canal as had been removed. In addition, disease, particularly malaria and yellow fever, sickened and killed vast numbers of employees, ranging from laborers to top directors of the French company. Public health measures were ineffective because the role of the mosquito as a disease vector was then unknown. These conditions made it impossible to maintain an experienced work force as fearful technical employees quickly returned to France. Even the hospitals contributed to the problem, unwittingly providing breeding places for mosquitoes inside the unscreened wards. Actual conditions were hushed up in France to avoid recruitment problems. In 1893, after a great deal of work, the French scheme was abandoned due to disease and the sheer difficulty of building a sea-level canal, as well as lack of French field experience, such as with downpours that caused steel equipment to rust. The high toll from disease was one of the major factors in the failure; as many as 22,000 workers were estimated to have died during the main period of French construction (1881–1889).

Beyond the hygienic and technical difficulties, financial mismanagement and political corruption also contributed to the French failure.

U.S. construction

At this time, various interests in the United States were also expressing interest in building a canal across the isthmus, with some favouring a route across Nicaragua (see Nicaragua Canal and Ecocanal) and others advocating the purchase of the French interests in Panama. Eventually, in June 1902, the U.S. Senate voted in favor of pursuing the Panamanian option, provided the necessary rights could be obtained. (It is claimed that the vote was swayed by William Nelson Cromwell.)

On January 22, 1903, the Hay-Herran Treaty was signed by United States Secretary of State John M. Hay and Dr. Tomás Herrán of Colombia. It would have granted the United States a renewable lease in perpetuity from Colombia on the land proposed for the canal. This is often misinterpreted as the "99-year lease" due to misleading wording included in article 22 of the agreement that refers to property within the land but does not pertain to the control of the canal and the right for the United States to renew the lease indefinitely. It was ratified by the United States Senate on March 14, 1903, but the Senate of Colombia did not ratify the treaty. Philippe Bunau-Varilla, chief engineer of the French canal company, told Roosevelt and Hay of a possible revolt and hoped that the U.S. would support it with troops and money. President of the United States Theodore Roosevelt changed tactics, promising support for Panama's intermittent separatist movement. On November 2, 1903, U.S. warships blocked sealanes for Colombian troops from coming to put down the revolt, while dense jungles blocked land routes. Panama achieved independence on November 3, 1903 when the United States sent naval forces to encourage Colombia's surrender of the region. The United States quickly recognized them. Also, on November 6, 1903, Phillipe Bunau-Varilla, Panama's ambassador to the United States, signed the Hay-Bunau Varilla Treaty, granting rights to the United States to build and indefinitely administer the Panama Canal. Although Bunau-Varilla was serving as Panama's ambassador, he was a French citizen and was not authorized to sign treaties on behalf of Panama without Panamanian review.[citation needed] This treaty would later become a contentious diplomatic issue between the two countries.

The United States, under President Theodore Roosevelt, bought out the French equipment and excavations for US$40 million and began work on May 4, 1904. The United States paid Colombia $25,000,000 in 1921, seven years after completion of the canal, for redress of President Roosevelt's role in the creation of Panama, and Colombia recognized Panama under the terms of the Thomson-Urrutia Treaty.

John Frank Stevens, Chief Engineer from 1905 to 1907, argued the case against a sea-level canal like the French had tried to build and convinced Theodore Roosevelt of the necessity of a canal built with dams and locks. Stevens' primary achievement in Panama was in building the infrastructure necessary to complete the canal. He rebuilt the Panama Railway and devised a system for disposing of soil from the excavations by rail. He also built proper housing for canal workers and oversaw investment in extensive sanitation and mosquito-control programmes that eliminated disease from the area — particularly malaria and yellow fever, the vector of which had been identified as the mosquito by Cuban physician and scientist Dr. Carlos Finlay in 1881. Finlay's theory and investigative work had recently been confirmed by Dr. Walter Reed while in Cuba with U.S. Army motivation during the Spanish-American War (see also Health measures during the construction of the Panama Canal).

With the diseases under control, and after significant work on preparing the infrastructure, construction of an elevated canal with locks began in earnest and was finally possible. The Americans also gradually replaced the old French equipment with machinery designed for a larger scale of work (such as the giant hydraulic crushers supplied by the Joshua Hendy Iron Works) to quicken the pace of construction. President Roosevelt had the former French machinery minted into medals for all workers who spent at least two years on the construction to commemorate their contribution to the building of the canal. These medals featured Roosevelt's likeness on the front, the name of the recipient on one side, and the worker's years of service, as well as a picture of the Culebra Cut on the back.

In 1907 Roosevelt appointed George Washington Goethals as Chief Engineer of the Panama Canal. Ellicott Dredges, a Baltimore, MD, USA company formerly known as the Ellicott Machine Company, built the cutter dredges used in construction of the Panama Canal. The first machine delivered was a steam-driven, 900 hp (670 kW), 20-inch dredge. In 1941, Ellicott Dredges also built the dredge MINDI, a 10,000 hp (7,500 kW), 28-inch cutter suction dredge still operating in the Panama Canal.

The building of the canal was completed in 1914, two years ahead of the target date of June 1, 1916. The canal was formally opened on August 15, 1914 with the passage of the cargo ship SS Ancon. Coincidentally, this was also the same month that fighting in World War I (the Great War) began in Europe. The advances in hygiene resulted in a relatively low death toll during the American construction; still, 5,609 workers died during this period (1904–1914). This brought the total death toll for the construction of the canal to around 27,500.

Later developments

By the 1930s it was seen that water supply would be an issue for the canal; this prompted the building of the Madden Dam across the Chagres River above Gatun Lake. The dam, completed in 1935, created Madden Lake (later Alajuela Lake), which acts as additional water storage for the canal. In 1939, construction began on a further major improvement: a new set of locks for the canal, large enough to carry the larger warships which the United States was building at the time and had planned to continue building. The work proceeded for several years, and significant excavation was carried out on the new approach channels, but the project was canceled after World War II.

After the war, U.S. control of the canal and the Canal Zone surrounding it became contentious as relations between Panama and the U.S. became increasingly tense. Many Panamanians felt that the Canal Zone rightfully belonged to Panama; student protests were met by the fencing in of the zone and an increased military presence. The unrest culminated in riots in which approximately 20 Panamanians and 3–5 U.S. soldiers were killed on Martyr's Day, January 9, 1964. Negotiations toward a new settlement began in 1974, and resulted in the Torrijos-Carter Treaties. Signed by President of the United States Jimmy Carter and Omar Torrijos of Panama on September 7, 1977, this mobilized the process of granting the Panamanians free control of the canal so long as Panama signed a treaty guaranteeing the permanent neutrality of the canal. The treaty led to full Panamanian control effective at noon on December 31, 1999, and the Panama Canal Authority (ACP) assumed command of the waterway.

Before this handover, the government of Panama held an international bid to negotiate a 25-year contract for operation of the container shipping ports located at the canal’s Atlantic and Pacific outlets. The contract was not affiliated with the ACP or Panama Canal operations and was won by the firm Hutchison Whampoa, a Hong Kong-based shipping concern whose owner is Li Ka Shing.

Layout

The canal consists of artificial lakes, several improved and artificial channels, and three sets of locks. An additional artificial lake, Alajuela Lake (known during the American era as Madden Lake), acts as a reservoir for the canal. The layout of the canal as seen by a ship passing from the Pacific end to the Atlantic is as follows:

* From the buoyed entrance channel in the Gulf of Panama (Pacific side), ships travel 13.2 km (8.2 mi) up the channel to the Miraflores locks, passing under the Bridge of the Americas.
* The two-stage Miraflores lock system, including the approach wall, is 1.7 km (1.1 mi) long, with a total lift of 16.5 meters (54 ft) at mid-tide.
* The artificial Miraflores Lake is the next stage, 1.7 km (1.0 mi) long, and 16.5 meters (54 ft) above sea level.
* The single-stage Pedro Miguel lock, which is 1.4 km (0.8 mi) long, is the last part of the ascent with a lift of 9.5 meters (31 ft) up to the main level of the canal.
* The Gaillard (Culebra) Cut slices 12.6 km (7.8 mi) through the continental divide at an altitude of 26 meters (85 ft), and passes under the Centennial Bridge.
* The Chagres River (Río Chagres), a natural waterway enhanced by the damming of Lake Gatún, runs west about 8.5 km (5.3 mi), merging into Lake Gatun.
* Gatun Lake, an artificial lake formed by the building of the Gatun Dam, carries vessels 24.2 km (15.0 mi) across the isthmus.
* The Gatún locks, a three-stage flight of locks 1.9 km (1.2 mi) long, drop ships back down to sea level.
* A 3.2 km (2.0 mi) channel forms the approach to the locks from the Atlantic side.
* Limón Bay (Bahía Limón), a huge natural harbour, provides an anchorage for some ships awaiting passage, and runs 8.7 km (5.4 mi) to the outer breakwater.

Thus, the total length of the canal is 80 km (50 mi).

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