Panama Canal

A canal tug making its way down to the Caribbean end of the canal waits to be joined by a ship in the uppermost chamber of the Gatun Locks.

The Panama Canal is a major shipping canal which cuts through the isthmus of Panama in Central America, connecting the Atlantic and Pacific Oceans. The construction of the canal was one of the largest and most difficult engineering projects ever undertaken; it has had an enormous impact on shipping, because it removes the need for ships to travel 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 a distance of 9,500 kilometres (6,000 mi), a saving of almost 13,000 kilometres (8,000 mi) over the 22,500 kilometre (14,000 mi) route around Cape Horn.^[1]

Although the concept of a canal in Panama dates back to the early 1500s, the first attempt to construct a canal began in 1880, under French leadership. This attempt collapsed, and the work was finally completed by the United States; the canal opened in 1914. The building of the 77 kilometer (48 mi) canal was plagued by problems, including disease (particularly malaria and yellow fever) and massive landslides. As many as 27,500 workers are estimated to have died during construction; around 22,000 during the French period (1881&ndash1889),^[2] and 5,609 during the American construction (1904–1914).^[3]

Since opening, the canal has been enormously successful and continues to be a key factor in world shipping. Each year the canal accommodates the passage of over 14,000 ships, carrying over 203 million tonnes of cargo. By 2002, about 800,000 ships had passed through the canal.^[4]

Description

The canal cuts through the Isthmus of Panama from the Pacific at the south-east end to the Atlantic at the north-west end.

The Panama Canal connects the Gulf of Panama, in the Pacific Ocean, with the Caribbean Sea and the Atlantic Ocean. Because of the S-shape of the Isthmus of Panama, the canal runs from south-east, at the Pacific end, to north-west at the Atlantic; to avoid confusion, the canal authorities classify transits of the canal as northbound (Pacific to Atlantic) and southbound (Atlantic to Pacific).

The canal can accommodate vessels from small private yachts up to fairly large commercial ships; the maximum size of vessel which can use the canal is known as Panamax. An increasing number of modern ships exceed this limit, and are known as post-Panamax vessels. A typical passage through the canal by a cargo ship takes around nine hours. 14,011 vessels passed through the canal in 2005, with a total capacity of 278.8 million tons; an average of almost 40 vessels per day.^[5]

Layout

The canal consists of two artificial lakes, several improved and artificial channels, and three sets of locks. An additional artificial lake, Alajuela Lake, acts as a reservoir for the canal. The layout of the canal, as seen by a ship transiting from the Pacific end to the Atlantic, is as follows:^[6]

• from the beginning of the buoyed entrance channel in the Gulf of Panama, ships travel 13.2 kilometres (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 kilometres (1.1 mi) long, with a total lift of 16.5 metres (54 ft) at mid-tide

File:Panama Canal Rough Diagram.png

A schematic of the Panama Canal, illustrating the sequence of locks and passages.

• the artificial Miraflores Lake is the next stage, 1.7 kilometres (1.0 mi) long, and 16.5 metres (54 ft) above sea level

• the single-stage Pedro Miguel lock, which is 1.4 kilometres (0.8 mi) long, is the last part of the ascent, with a lift of 9.5 metres (31 ft), up to the main level of the canal

• the Gaillard (Culebra) Cut slices 12.6 kilometres (7.8 mi) through the continental divide at an altitude of 26 metres (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 kilometres (5.3 mi), merging into Lake Gatun

• Lake Gatún itself, an artificial lake formed by the building of the Gatun Dam, carries vessels 24.2 kilometres (15.0 mi) across the isthmus

• the Gatún locks, a three-stage flight of locks 1.9 kilometres (1.2 mi) long, drops ships back down to sea level

• a 3.2 kilometre (2.0 mi) channel forms the approach to the locks from the Atlantic side

• Limón Bay (Bahia Limón), a huge natural harbour, provides an anchorage for some ships awaiting transit, and runs 8.7 kilometres (5.4 mi) to the outer breakwater

The total transit, from the Pacific entrance channel to the Atlantic breakwater, is 76.9 kilometres (47.8 mi).

The maximum tidal range on the Pacific side is from +3.35 metres (+11.0 ft) to -3.20 metres (-10.5 ft); hence the lift at Miraflores actually varies between 13.1 metres (43 ft) at extreme high tide and 19.7 metres (64.5 ft) at extreme low tide. The tidal range on the Atlantic side does not exceed 60 centimetres (24 in).^[7] Mean sea level at the Pacific end of the canal is on average about 20 centimeters (8 in) higher than at the Atlantic end.^[8]

The locks

Main article: Panama Canal Locks

File:Panama Canal Gatun Lock Chamber.jpeg

The lowest chamber of the east flight of the Gatún locks is seen here from the deck of a small boat about to enter.

The most visually impressive feature of the canal is its locks. The lock chambers are 33.53 metres (110 ft) wide by 320.0 metres (1050 ft) long, with a usable length of 304.8 metres (1000 ft). These dimensions determine the maximum size of ships which can use the canal; this size is known as Panamax. All of the locks on the canal are paired; that is, there are two parallel flights of locks at each of the three lock sites. This, in principle, allows ships to pass in opposite directions simultaneously; however, large ships cannot cross safely at speed in the Gaillard Cut, so in practice ships pass in one direction for a time, then in the other, using both "lanes" of the locks in one direction at a time.

Each lock chamber requires 101,000 cubic metres of water (26.7 million U.S. gallons) to fill; this enters the chamber by gravity via a network of culverts beneath each lock chamber. Ships are hauled through the locks by small railway engines called mulas (mules, named after the animals traditionally used to pull barges), running on tracks on the lock walls; smaller vessels, such as small tour boats and private yachts, are taken as handline transits, where mooring lines to the lock walls are handled manually by line handlers on the vessel.

Lake Gatún

Main article: Lake Gatún

File:Panama Canal Banana Cut Sailboats.jpeg

Southbound sailboats entering the Banana Cut on Lake Gatún have their sails set to get a boost from the trade winds.

Lake Gatún, and the enhanced Chagres River (Río Chagres), are a key component of the canal, carrying ships a significant part of the way across the isthmus. The lake also acts as a reservoir, storing water to allow the locks to continue operation during the dry season. The lake was formed, and the river widened and deepened, by the construction of the Gatun Dam on the Chagres River in 1906–1910. This flooded the originally wooded valley; almost a century later, the stumps of old mahogany trees can still be seen rising from the water, and submerged snags form a hazard for small vessels that wander off the marked channels.

There is a small "shortcut" channel through the lake, the "Banana Cut", providing a slightly shorter route; this is used as a short-cut by canal launches and yachts and to avoid the heavy ship traffic. Several islands are located within the Lake Gatún portion of the Panama Canal, including Barro Colorado Island, home of the world famous Smithsonian Tropical Research Institute (STRI).

Alajuela Lake

The volume of water used by ships passing through the locks, combined with the seasonal nature of the rainfall in Panama, makes it difficult to maintain the level of Lake Gatun, particularly in the dry season. An additional dam, the Madden Dam, was therefore built across the Chagres above Lake Gatun. This created Alajuela Lake — also known as Madden Lake — which provides additional water storage for the canal.

The anchorages

Limón Bay, on the Atlantic side, is an excellent anchorage protected by a huge seawall; this is an impressive structure 5.6 kilometres (3.5 mi) long. However, the space inside the bay is no longer adequate for the number and size of ships using the canal, and many ships wait at anchor in the open sea outside the bay. The bay continues to be a major base of operations for the canal authority, provides an anchorage for small boats, and is home to the Panama Canal Yacht Club.

File:Panama Canal Ship Entering Chamber.jpeg

A cargo ship transiting the Gatún locks northbound is guided carefully between lock chambers by mules on the lock walls to either side.

The anchorage on the Pacific side is open, although it is protected by the enclosed topography of the Gulf of Panama; since the main winds are trade winds blowing from the Atlantic, the isthmus itself provides shelter on the Pacific side.

Crossings

There are several crossings over the canal. At the south (Pacific) end is the Bridge of the Americas, a major road bridge which opened in 1962; for many years, this was the only permanent crossing of the canal. Further north, at the Miraflores locks, there is a swinging road/rail bridge; opened in 1942, it can only carry traffic when no ship is passing, and is now \rarely used.^[9] At the same point, a small swinging road bridge is built in to the Miraflores lock structure; this is also rarely used.^[10]

The newest crossing is the Centennial Bridge, which crosses over the Gaillard Cut just north of the Pedro Miguel locks; this major six-lane road bridge was completed in 2004 (although it opened to traffic in 2005). Finally, another small swinging road bridge is built in to the lock structure at the Gatún Locks; this bridge is only usable when the lock gates are closed, and has a very small capacity.^[11]

In addition to the public crossings, canal workers may walk across the lock gates when they are closed.

Tolls

Car carriers, such as this one at Miraflores locks, are among the largest ships to use the canal.

The toll for the canal is determined by vessel type, size, and the type of cargo carried.^[12]

For container vessels, the toll is assessed per "TEU", which is the size of a container measuring 20 feet by 8 feet by 8.5 feet (6 m by 2.4 m by 2.6 m). Effective May 1, 2005, this toll is $42 per TEU. This is scheduled to rise to $49 on May 1, 2006, and again to $54 on May 1, 2007. (A Panamax container ship may carry over 4,000 TEU.)

Most other types of vessel pay a toll per PC/UMS net ton, in which one "ton" is actually a volume of 100 cubic feet (2.8 m³). (The calculation of tonnage for commercial vessels is quite complex.) As of 2006, this toll is $2.96 per ton for the first 10,000 tons, $2.90 per ton for the next 10,000 tons, and $2.85 per ton thereafter.

Small vessels are assessed tolls based on their length. As of 2006, these are:

Up to 15.240 metres (50 ft)	$500
More than 15.240 metres (50 ft) up to 24.384 metres (80 ft)	$750
More than 24,384 metres (80 ft) up to 30.480 metres (100 ft)	$1,000
More than 30.480 metres (100 ft)	$1,500

The most expensive toll for canal passage to date was charged on September 25, 2003 to the luxurious passenger vessel Coral Princess, which paid $226,194.25 for passage. The least expensive toll was 36 cents and is not credited to a ship, but to athlete Richard Halliburton who swam the canal in 1928.^[13] The average toll is around $54,000.

History

This elevation map of the Panama Canal, prepared in 1923, shows the topography of the region through which the canal was cut.

Main article: History of the Panama Canal

The earliest mention of a canal across the isthmus of Central America dates back to 1524, when Charles V, Holy Roman Emperor and king of Spain, suggested that a canal in Panama would ease the voyage for ships travelling to and from Ecuador and Peru, particularly for ships loaded with gold. Although a survey of the isthmus and a working plan for a canal were drawn up in 1529, the European political situation and relatively limited construction technology of the day made the scheme impossible.

Given the strategic situation of Central America as a narrow land dividing two great oceans, other forms of trade links were attempted over the years. The ill-fated Darien scheme was an attempt launched by Scotland in 1698 to set up an overland trade route, but was defeated by the generally inhospitable conditions, and abandoned in 1700. Finally, the Panama Railway was built across the isthmus, opening in 1855. This overland link greatly facilitated trade and, until the opening of the canal, carried the heaviest volume of freight per unit length of any railroad in the world. This vital piece of infrastructure was a key factor in the selection of the later canal route.

Construction work on the Gaillard Cut is shown in this photograph from 1907.

An all-water route between the oceans was still seen as the ideal solution, and the idea of a canal was revived at various times, and for various routes; a route through Nicaragua was investigated several times (see Nicaragua Canal). Finally, enthused 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 Panama on January 1, 1880. In 1893, after a great deal of work, the French scheme was defeated by disease and the sheer difficulty of building a sea-level canal.

The United States, under Theodore Roosevelt, bought out the French equipment and excavations, and began work in 1904, after helping Panama to declare independence from Colombia in exchange for control of the Canal Zone. A significant investment was made in eliminating disease from the area, particularly yellow fever and malaria, the causes of which had recently been discovered (see 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. The canal was formally opened on August 15, 1914, with the transit of the cargo ship Ancon.

The canal and the zone surrounding it were originally administered by the United States. However, on September 7, 1977, U.S. President Jimmy Carter signed the Torrijos-Carter Treaty, which set in motion the process of handing over the canal to Panamanian control. Although controversial within the U.S., the treaty came into force on December 31, 1999, when control of the canal was handed over to the Panama Canal Authority.

Current issues

There is no question that the Panama Canal continues to be one of the most successful engineering projects of all time. Even though world shipping — and the size and design of ships themselves — have changed beyond recognition since the canal was designed, it continues to be a vital link in world trade, carrying more cargo than ever before, with less overhead. Nevertheless, the canal certainly faces a number of potential problems.

Efficiency and maintenance

File:Admbuilding.jpg

The administration Building of the Panama Canal is in Balboa, Panama.

There were widespread fears that efficiency and maintenance would suffer following the U.S. withdrawal. However, this does not appear to be the case, and the canal's efficiency appears to be improving under Panamanian control.^[14] Canal Waters Time (CWT), the average time it takes a vessel to navigate the canal, including waiting time, is a key measure of efficiency; according to the ACP, CWT is decreasing. At the same time, the rate of accidents is at a record low.^[15]

Increasing volumes of imports from Asia which previously landed in the U.S. west coast ports are now travelling through the canal to the east coast.^[16] The total number of vessel transits in fiscal year 1999 was 14,336; this fell to a low of 13,154 in 2003, due at least in part to global economic factors, but has risen to 14,011 in 2005 (the canal’s fiscal year runs from October to September). However, this has been coupled with a steady rise in average ship size and in the numbers of Panamax vessels transiting, so that the total tonnage carried has risen steadily from 227.9 million PC/UMS tons in fiscal year 1999 to 278.8 million tons in 2005.^[17][2] Given the negative impact of vessel size on the rate of transits (for example, the inability of large vessels to cross in the Gaillard Cut), this represents significant overall growth in canal capacity, despite the reduction in total transits. The canal set a traffic record on March 16, 2004, with 1,005,551 PC/UMS tons of cargo transited in a single day.^[18]

File:Panama Canal Bucket Dredge.jpeg

A bucket dredge works to deepen and widen the canal.

The canal administration has invested nearly $1 billion in widening and modernizing the canal, with the aim of increasing capacity by 20 percent.^[19] The canal authority cites a number of major improvements, including the widening and straightening of the Gaillard Cut to reduce restrictions on crossing vessels, the deepening of the navigational channel in Gatun Lake to reduce draft restrictions and improve water supply, and the deepening of the Atlantic and Pacific Entrances of the Canal. This is supported by new vessels, such as a new drill barge and suction dredger, and an increase of the tugboat fleet by 20 percent. In addition, improvements have been made to the operating machinery of the canal, including an increased and improved tug locomotive fleet, the replacement of more than 16 kilometers of locomotive track, and new lock machinery controls. Improvements have been made to the traffic management system to allow more efficient control over ships in the canal.^[20]

The withdrawal of the U.S. has allowed Panama to sell excess electricity produced by the canal's dams, which was previously prohibited by the U.S. government. Only 25% of the hydroelectric power produced in the canal system is required to run the canal.

Capacity

The canal is presently handling more vessel traffic than had ever been envisioned by its builders; in 2005, 14,011 vessels passed through it (an average of 38.3 vessels/day),and the canal is soon expected to approach its maximum capacity. An additional complication is that the proportion of large (close to Panamax-sized) ships transiting is increasing steadily; this may result in a further reduction in the number of transits, even if cargo tonnage rises. In any case, if the canal is to continue to serve the needs of world shipping, action will be required to increase its capacity.

Gatun Lake, pictured here in 2000, is having difficulty supplying water for the canal's operation.

Competition

Despite having enjoyed a privileged position for many years, the canal is increasingly facing competition from other quarters. Speculation continues over a possible new canal that will be capable of accommodating post-Panamax vessels, through Mexico or Colombia, and there are at least three proposals for the construction of cargo routes across Nicaragua: a major, post-Panamax canal proposed by the government, and two private proposals for a railway linking ports on the two coasts.^[21] (See: Nicaragua Canal)

Critics have also voiced their concerns over the planned increase in canal tolls, suggesting that the Suez Canal may become a viable alternative for cargo en route from Asia to the U.S. East Coast. Nevertheless, demand for the Panama Canal continues to rise.

Water issues

A significant problem is the decreasing average amount of water in Gatún Lake, caused largely by deforestation. 52 million gallons of fresh water from the lake are dumped into the sea by the locks every time a ship transits the canal.^[22] The issue is the seasonal nature of rainfall in Panama; the rainforest plays a role by absorbing this rain, and then releasing it at a steady rate into the lake. With the reduction in vegetation, rain flows quickly down the deforested slopes into the lake, from where the excess is spilled out into the ocean; this results in a shortfall of water during the dry season, when there is comparatively little water flowing to the lake to replenish it. Deforestation also causes silt to be more easily eroded from the area around Gatún Lake and collect at its bottom, reducing its capacity.

The future

With demand rising, it seems certain that the canal will continue to be a significant feature of world shipping for the forseeable future. However, changes in shipping patterns — particularly the increasing numbers of post-Panamax ships — may necessitate changes to the canal. Plans have been floated for a major expansion of the canal; a reincarnation of the 1939 Third Lock Scheme, or something like it, has been proposed,^[23] to allow for a greater number of transits, and the ability to handle larger ships. The current proposals are for a set of locks capable of handling ships of up to 150,000 tons, over twice the Panamax limit.^[24] This would need to be coupled with widening of the Gaillard Cut to handle the larger ships, which would be a major engineering effort.

Any such scheme is likely to be hampered by cost, as well as water supply issues (see above). Current proposals are to address the water issue by expanding the reservoir capacity; however, this has has led to concerns over environmental damage to the watershed area. An alternative proposal is to use water recycling, in which fresh water discharging from the lock chambers is pumped back up into the lake to limit water wastage.^[25]

References

1. ^ The Americans in Panama, by William R. Scott; Statler Publishing Company, New York, NY, 1913
2. ^ The French Failure, from America's Triumph in Panama by Ralph E. Avery; L.W. Walter Company, Chicago, IL, 1913
3. ^ A History of the Panama Canal: French and American Construction Efforts, Panama Canal Authority
4. ^ The Panama Canal, from Global Perspectives
5. ^ Panama Canal Traffic — Fiscal Years 2002–2004, Panama Canal Authority
6. ^ Historical Map & Chart Project from NOAA, including Panama Canal charts
7. ^ The Panama Canal as a Passageway for Fishes, Samuel F. Hildebrand, Zoologica (New York), 1939
8. ^ Sea Level: Frequently Asked Questions and Answers, from Permanent Service for Mean Sea Level
9. ^ Photo: The Opening of the Miraflores Bridge, CZ Brats
10. ^ Costa Rica Tour and Panama Cruise — Photos and text by Jack Yeazel, with detail pictures of the locks
11. ^ Picture of the Gatún locks road bridge, canalmuseum.com
12. ^ Maritime Operations — Tolls, Panama Canal Authority
13. ^ Panama Canal Authority FAQ
14. ^ A Man, A Plan, A Canal: Panama Rises, Smithsonian Magazine, March 2004
15. ^ Tonnage Increases; Canal Waters Time and Accidents Drop, Panama Canal Authority, December 09, 2003
16. ^ New York Port Hums Again, With Asian Trade, Eric Lipton, New York Times, November 22, 2004
17. ^ Annual Reports of the Panama Canal Authority
18. ^ Panama Canal Sets Historic Record in Tons of Cargo, Panama Canal Authority, March 18, 2004
19. ^ Transfer heavy on symbolism, light on change, Steve Nettleton, CNN Interactive
20. ^ Modernization & Improvements, Panama Canal Authority
21. ^ NICARAGUA: Plan for Inter-Ocean Canal Reborn, an analysis of several proposed land and water routes for cargo across Nicaragua, from Inter Press Service
22. ^ Panama Canal Authority FAQ
23. ^ The Panama Canal, Business in Panama (an article on proposed future development of the canal)
24. ^ Enlarging Panama Canal is engineers' chance of lifetime, Pittsburgh Tribune-Review, September 18, 2005
25. ^ Pumping Up the Panama Canal, Mechanical Engineering Magazine (an article on recycling lock water)

External links

• Official website of the Panama Canal Authority — Has a simulation that shows how the canal works
• Canal Zone Brats — Comprehensive information on the canal and the zone
• History of the Canal Zone — including much canal information, from CZ Brats
• Panama Canal Webcams
• Time Lapse Video of the Canal (created using one week of webcam footage).
• Template:Es icon Dr. Alonso Roy's short essays on Panama Canal History
• Judicial Watch, Inc. v. Panama Canal Commission case (archived)
• Structurae: Panama Canal
• Satellite view in Google Maps
• Map of Panama Canal
• General information regarding Panama Canal
• Information on early history
• Current Issues since the return to Panama
• Panama Canal Yacht Club