Panama Canal Locks
From Wikipedia, the free encyclopedia
There are three sets of locks in the canal. A two step flight at Miraflores, and a single flight at Pedro Miguel, lift ships from the Pacific up to Lake Gatun; then a triple flight at Gatun lowers them to the Atlantic side. All three sets of locks 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.
The lock chambers are 33.53 meters (110 ft) wide by 320.0 meters (1050 feet) long, with a usable length of 304.8 metres (1000 feet). These dimensions determine the maximum size of ships which can use the canal; this size is known as Panamax. The total lift (the amount by which a ship is raised or lowered) in the three steps of the Gatun locks is 25.9 m (85 ft); the lift of the two step Miraflores locks is 16.5 m (54 feet). The single step Pedro Miguel lock has a lift of 9.5 m (31 feet). The lift at Miraflores actually varies due to the extreme tides on the Pacific side, between 13.1 m (43 feet) at extreme high tide and 19.7 m (64.5 feet) at extreme low tide; the tides on the Atlantic side, however, are very small.
The lock chambers are massive concrete structures. The side walls are from 13.7 to 15.2 metres (45 to 55 feet) thick at the bases; towards the top, where less strength is required, they taper down in steps to 2.4 m (8 feet). The centre wall between the chambers is 18.3 m (60 ft) thick, and houses three long galleries which run the full length of the centre wall. The lowest of these is a drainage tunnel; above this is a gallery for electrical cabling; and towards the top is a passageway which allows operators to gain access to the lock machinery.
The project of building the locks began with the first concrete laid at Gatun, on August 24, 1909. The locks at Gatun are built into a cutting made in a hill bordering the lake, which required the excavation of 3,800,000 m (5,000,000 cubic yards) of material, mostly rock. The locks themselves were made of 1,564,400 m (2,046,100 cubic yards) of concrete. The quantity of material needed to construct the locks required extensive measures to be put in place to handle the stone and cement. Stone was brought from Portobelo to the Gatun locks; the work on the Pacific side used stone quarried from Ancon Hill.
Huge overhead cableways were constructed to transport concrete into the construction at Gatun. 26 metre (85 feet) high towers were built on the banks of the canal, and cables of 6 cm (2.5 inch) steel wire were strung between them to span the locks. Buckets running on these cables carried up to six tons of concrete at a time into the locks. Electric railways were constructed to take stone, sand and cement from the docks to the concrete mixing machines, from where another electric railway carried two 6 ton buckets at a time to the cableways. The smaller constructions at Pedro Miguel and Miraflores used cranes and steam locomotives in a similar manner. Concrete is normally moulded in formwork, temporary structures which give shape to the concrete as it sets. For a simple construction, these would normally be made quite simply of wood, but the scale of the locks demanded extraordinary forms.
The forms for the walls consisted of towers, fronted with braced vertical sheets, 19 cm (7 inches) thick, mounted on rails to allow the locks to be constructed in sections; a section of lock would be poured behind the form, and when it was set, the form would be moved to do the next section. Each of the twelve towers was 23.8 m (78 feet) high by 11.0 m (36 feet) wide. The forms for the culverts were made of steel, and were collapsible so they could be removed and moved along after each section of culvert had set. There were, in all, 33 forms for the centre and side wall culverts, each 3.7 m (12 feet) long; and 100 smaller forms for the lateral culverts.
The ships name Pennsylvania can be clearly read on both sides of the bow in the photograph. Below here, for reference, is some found information on the S.S. Pennsylvania:
Panama Pacific Line
From Wikipedia, the free encyclopedia
The Panama Pacific Line was a subsidiary line of International Mercantile Marine (IMM) established to carry passengers and freight between the United States East and West Coasts via the Panama Canal. Although IMM had begun preparations for this intercoastal service as far back as 1911. Service began in May 1915 with the former Red Star Line (another IMM subsidiary line) ships Kroonland and Finland. When landslides in September 1915 closed the canal for an extended time, Kroonland and Finland were reassigned to the IMM's American Line. The outbreak of World War I and its strain on international shipping caused the intercoastal route to be abandoned. In 1923, Kroonland and Finland were returned to the resurrected intercoastal route along with the American Line passenger steamer S.S.ÊManchuria. Manchuria's sister ship Mongolia supplanted Kroonland on the route in 1925.
Three ships featuring steam turbines and electric drive: S. S. California, S. S. Pennsylvania, and S. S. Virginia came into service beginning in 1928, replacing all of the other ships on the intercoastal service. These three newest ships featured a drive on service for passengers' automobiles, which allowed passengers to disembark with their car at ports of call, like Havana, a stop added in the early 1930s. In 1936, California, docked at San Pedro, California, was the setting for the S.S. California strike, which contributed to the demise of the International Seamen's Union and the creation of the National Maritime Union. By 1938, the intercoastal service had ended and the three electric ships, S.S. California, S.S. Pennsylvania, and S.S. Virginia were sold for use on South American routes.
Later the S. S. Pennsylvania was changed to the U.S.A.T. Argentina.
USAT Argentina sometimes called the SS Argentina is a ship that was built in 1929 by the Newport News Shipbuilding and Drydock Company. The ship was originally named SS Pennsylvania as a luxury liner and launched 10 July 1929.
Early in 1942 the ship was taken over by the United States War Shipping Administration and refitted as a United States Army Transport (troop transport) Ship. On July 1, 1942 the ship left the New York Port of Embarkation for Greenock, Scotland, entering into troop transport service for the first time. After World War II was over, the USAT Argentina resumed liner service. The ship was sold for scrap in 1964.