Keel laying in the context of "German battleship Bismarck"

The keel is the bottom-most longitudinal structural element of a watercraft, important for stability. On some sailboats, it may have a hydrodynamic and counterbalancing purpose as well. The laying of the keel is often the initial step in constructing a ship. In the British and American shipbuilding traditions, this event marks the beginning date of a ship's construction.

INS Vikrant is an aircraft carrier in service with the Indian Navy. The carrier is India's fourth carrier and the first to be built domestically. It was constructed by the Cochin Shipyard Limited (CSL). The name Vikrant is a tribute to India's first aircraft carrier INS Vikrant (1961). Vikrant means "courageous" in Sanskrit. The motto of the ship, "जयेम सम् युधिस्पृधः" (Sanskrit), means "I defeat those who dare to challenge me" (English). It is currently one of two active aircraft carriers in the Indian Navy, the other being the flagship INS Vikramaditya.

Work on the ship's design began in 1999. The keel was laid in 2009. The carrier was floated out of dry dock in December 2011 and launched in August 2013. Basin trials were completed in December 2020, and sea trials started in August 2021. Its commissioning ceremony was held on 2 September 2022. Aircraft flight trials have been completed in 2023. The total cost of the project is approximately ₹23,000 crore (equivalent to ₹260 billion or US$3.1 billion in 2023) at the time of first sea trials.

HMS Sheffield was the third of ten Town-class light cruisers of the Royal Navy. The ship was laid down in January 1935, launched in July 1936, and commissioned in August 1937. She was active in all major naval European theatres of the Second World War, in the Atlantic Ocean, the Mediterranean Sea and the Arctic Ocean.

Her career started with service in the Home Fleet, which took her on patrols against German blockade runners and on actions during the Norwegian Campaign. In August 1940, Sheffield was transferred to Force H stationed in Gibraltar. During her service with Force H, most of the operations involved either ferrying aircraft or escorting convoys to Malta. Sheffield also operated against German surface raiders in the Atlantic, and took part in the chase for the German battleship Bismarck. On 26 May 1941, she directed torpedo bombers from the aircraft carrier Ark Royal to Bismarck, but took no part in the sinking of Bismarck one day later.

German submarine U-995 is a Type VIIC/41 U-boat of Germany's Kriegsmarine. She was laid down on 25 November 1942 by Blohm & Voss in Hamburg, Germany, and commissioned on 16 September 1943 with Oberleutnant zur See Walter Köhntopp in command. She is preserved at Laboe Naval Memorial near Kiel, Germany.

The Iowa class was a class of six fast battleships ordered by the United States Navy in 1939 and 1940. They were initially intended to intercept fast capital ships such as the Japanese Kongō-class battlecruisers and serve as the "fast wing" of the U.S. battle line. The Iowa class was designed to meet the Second London Naval Treaty's "escalator clause" limit of 45,000-long-ton (45,700 t) standard displacement. Beginning in August 1942, four vessels, Iowa, New Jersey, Missouri, and Wisconsin, were completed; two more, Illinois and Kentucky, were laid down but canceled in 1945 and 1958, respectively, before completion, and both hulls were scrapped in 1958–1959.

The four Iowa-class ships were the last battleships commissioned in the U.S. Navy. All older U.S. battleships were decommissioned by 1947 and stricken from the Naval Vessel Register (NVR) by 1963. Between the mid-1940s and the early 1990s, the Iowa-class battleships fought in four major U.S. wars. In the Pacific Theater of World War II, they served primarily as fast escorts for Essex-class aircraft carriers of the Fast Carrier Task Force and also shelled Japanese positions. During the Korean War, the battleships provided naval gunfire support (NGFS) for United Nations forces, and in 1968, New Jersey shelled Viet Cong and Vietnam People's Army forces in the Vietnam War. All four were reactivated and modernized at the direction of the United States Congress in 1981, and armed with missiles during the 1980s, as part of the 600-ship Navy initiative. During Operation Desert Storm in 1991, Missouri and Wisconsin fired missiles and 16-inch (406 mm) guns at Iraqi targets.

USS Concord (Gunboat No. 3/PG-3) was a member of the Yorktown class of steel-hulled, twin-screw gunboats in the United States Navy in the late 19th and early 20th centuries. She was the second U.S. Navy ship named in honor of the town of Concord, Massachusetts, site of the Battle of Concord in the American Revolutionary War.

The contract to build Concord was awarded to N. F. Palmer & Co. of Philadelphia in the 1888 fiscal year. Her hull was subcontracted to the Delaware River Iron Shipbuilding & Engine Works which laid down her keel in May 1888. Concord was launched in March 1890. She was just over 244 feet (74 m) long and 36 feet (11 m) abeam and displaced 1,710 long tons (1,740 t). She was equipped with two steam engines which were supplemented with three schooner-rigged masts. The ship had a main battery of six 6-inch (15.2 cm) guns, and several smaller caliber guns.