Historia

LayoutUThe 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:[23]From the buoyed entrance channel in the Gulf ofPanama (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. Thesingle-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 LakeGatún, 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 (BahíaLimón), a huge natural harbour, provides an anchorage for some ships awaiting passage, and runs 8.7 km (5.4 mi) to the outer breakwater.
Lock sizelock gate at MirafloresThe size of the locks determines the maximum size of ships allowed passage. Because of the importance of the canal to international trade, many ships are built to the maximum size allowed. These are known as Panamax vessels.Initially thelocks at Gatun had been designed to be 28.5 meters (94 ft) wide. In 1908 the United States Navy requested that width be increased to at least 36 meters (118 ft) which would allow the passage of US naval ships. Eventually a compromise was made and the locks were built 33.53 meters (110.0 ft) wide. Each lock is 320 meters (1,050 ft) long with the walls ranging in thickness from 15 meters (49 ft) atthe base to 3 meters (9.8 ft) at the top. The central wall between the parallel locks at Gatún is 18 meters (59 ft) thick and stands in excess of 24 meters (79 ft) high. The steel lock gates measure an average of 2 meters (6.6 ft) thick, 19.5 meters (64 ft) wide and 20 meters (66 ft) high.[24] It is the size of the locks, specifically the Pedro Miguel Locks, along with the height of the Bridge ofthe Americas at Balboa, that determine the Panamax metric and limit the size of ships that may use the Canal.The 2006 Third lock lane project will create larger locks, and deeper and wider channels, allowing bigger ships to transit. The allowed dimensions of ships will increase by 25% in length, 51% in beam, and 26% in draft, as defined by New Panamax.[25]
CapacityThe canal is presently handlingmore vessel traffic than had ever been envisioned by its builders. In 1934 it was estimated that the maximum capacity of the canal would be around 80 million tons per year;[43] as noted above, canal traffic in 2009 consisted of 299.1 million tons of shipping.The water that is used to raise and lower vessels in the Canal is fed by gravity from Gatun Lake (pictured above) into each set of locks.Toimprove capacity a number of improvements have been imposed on the current canal system. These improvements aim to maximise the possible use of current locking system:[44]Implementation of an enhanced locks lighting system; Construction of two tie-up stations in Gaillard Cut; Gaillard Cut widening from 192 to 218 metres (630 to 715 ft); Improvements to the tugboat fleet; Implementation of the...