...[ed]...
Initially the locks at Gatun had been designed as 28.5 metres wide. In 1908 the United States Navy requested that the locks should be increased to have a width of at least 36 metres which would allow for the passage of US naval ships. Eventually a compromise was made and the locks were to be constructed to a width of 33 meters. Each lock is 300 metres long with the walls ranging in thickness from 15 metres at the base to 3 metres at the top. The central wall between the parallel locks at Gatun has a thickness of 18 metres and stands in excess of 24 metres in height. The lock gates are made from steel and measures an average of 2 metres thick, 19.5 metres in length and stand 20 metres in height
Tolls for the canal are decided by the Panama Canal Authority and are based on vessel type, size, and the type of cargo carried.[19]
For container ships, the toll is assessed per the ship's capacity expressed in twenty-foot equivalent units or TEUs. One TEU is the size of a container measuring 20 feet (6 m) by 8 feet (2 m) by 8.5 feet (6 m by 2.4 m by 2.6 m). Effective May 1, 2007, this toll is US$54 per TEU. A Panamax container ship may carry up to 4,400 TEU. A reduced toll is charged for container ships carrying no cargo or passengers.
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 2007, this toll is US$3.26 per ton for the first 10,000 tons, US$3.19 per ton for the next 10,000 tons, and US$3.14 per ton thereafter. As with container ships, a reduced toll is charged for freight ships "in ballast".
Small vessels are assessed tolls based on their length. As of 2007, these are:
Length of vessel Toll
Up to 15.240 metres (50 ft) US$500
More than 15.240 metres (50 ft) up to 24.384 metres (80 ft) US$750
More than 24.384 metres (80 ft) up to 30.480 metres (100 ft) US$1,000
More than 30.480 metres (100 ft) US$1,500
The most expensive regular toll for canal passage to date was charged on February 24, 2008 to the Norwegian Jade cruise liner, which paid just over US$313,000.[20] The least expensive toll was 36 cents to American adventurer Richard Halliburton who swam the canal in 1928.[21] The average toll is around US$54,000. The highest fee for priority passage charged through the Transit Slot Auction System was US$220,300, paid on August 24, 2006 by the Panamax tanker Erikoussa,[22] bypassing a 90-ship queue waiting for the end of maintenance works on the Gatun locks, thus avoiding a 7-day delay. The normal fee would have been just US$13,430.[23]