These three photos are of the battleship USS Iowa (BB-61) in Dry dock Number 4 at Norfolk Naval Shipyard-Portsmouth, April and May 1985. The Navy had placed the battleship in the dry dock for four months of what the Navy calls "post shakedown availability" (PSA) repairs. PSA repairs are conducted on ships to fix problems found during a ship's first cruise after being launched or overhauled.
Number 4 was one of the few places the Navy could place a ship the size of Iowa. Growing pains led the Navy to build the dry dock in the early 1900s. The Fleet's newest battleship designs were longer than the U.S. Government's current docks and the Navy wanted to keep the ability to repair its own ships and its own facilities. Contractors finished work on the facility in 1919.
Harrison S. Taft,an 1896 naval architect graduate of MIT, designed and oversaw construction of the dry dock. The school's alumni magazine proudly produced this description of Taft's work: "Dry dock No. 4 is said to have been the most complicated reinforced concrete structure ever built for the Navy Department. The dock is of the largest size, being 1,000 feet in length and 144 feet in width; its depth is 51 feet. In its construction 625,000 cubic yards of earth were excavated and 185.000 cubic yards of concrete were poured and reinforced. The dock is capable of handling the largest ships now afloat and will probably be able to handle any which may be designed in the future unless radical changes take place in the world's harbors and ship channels. Work was begun in January, 1917, and the entire job was completed two years and three months later, a feat which is said to constitute a record in the United States."
No comments:
Post a Comment