A sea trial is the testing phase of a watercraft (including boats, ships, and submarines). It is also referred to as a "shakedown cruise" by many naval personnel. It is usually the last phase of construction and takes place on open water, and it can last from a few hours to many days.
Sea trials are conducted to measure a vessel's performance and general seaworthiness. Testing of a vessel's speed, maneuverability, equipment and safety features are usually conducted. Usually in attendance are technical representatives from the builder (and from builders of major systems), governing and certification officials, and representatives of the owners. Successful sea trials subsequently lead to a vessel's certification for commissioning and acceptance by its owner.
Although sea trials are commonly thought to be conducted only on new-built vessels (referred by shipbuilders as 'builders trials'), they are regularly conducted on commissioned vessels as well. In new vessels, they are used to determine conformance to construction specifications. On commissioned vessels, they are generally used to confirm the impact of any modifications.
Sea trials can also refer to a short test trip undertaken by a prospective buyer of a new or used vessel as one determining factor in whether to purchase the vessel.
Sea trials are fairly standardized using technical bulletins published by ITTC, SNAME, BMT, regulatory agencies or the owners. They involve demonstrations and tests of the ship's systems and performance.
In a speed trial the vessel is ballasted or loaded to a predetermined draft and the propulsion machinery is set to the contracted maximum service setting, usually some percentage of the machinery's maximum continuous rating (ex: 90% MCR). The ship's heading is adjusted to have the wind and tide as close to bow-on as possible. The vessel is allowed to come to speed and the speed is continuously recorded using differential GPS. The trial will be executed with different speeds including service (design) and maximum speed. The ship is then turned through 180° and the procedure is followed again. This reduces the impact of wind and tide. The final "Trials Speed" is determined by averaging all of the measured speeds during each of the runs. This process may be repeated in various sea states.
To test a crash stop, the vessel is ballasted or loaded to a predetermined draft and the propulsion machinery is set to the contracted maximum service setting, usually some percentage of the machinery's maximum continuous rating. The trial begins once the order to "Execute Crash Stop" is given. At this point the propulsion machinery is set to full-astern and the helm is put hard-over to either port or starboard. The speed, position and heading are continuously recorded using differential GPS. The final time to stop (i.e.: ship speed is 0 knots) track line, drift (distance traveled perpendicular to the original course) and advance (distance traveled along the original course line) are all calculated. The trial may be repeated at various starting speeds.
During endurance trials the vessel is ballasted or loaded to a predetermined draft and the propulsion machinery is set to the contracted maximum service setting, usually some percentage of the machinery's maximum continuous rating. The fuel flow, exhaust and cooling water temperatures and ship's speed are all recorded.
Maneuvering trials involve a number of trials to determine the maneuverability and directional stability of the ship may be conducted. These include a direct and reverse spiral manoeuvres, zig-zag, and lateral thruster use.
Seakeeping trials were used exclusively for passenger ships, but are now used in a variety of vessels. They involve measurements of ship motions in various sea states, followed by a series of analyses to determine comfort levels, likelihood of sea sickness and hull damage. Trials are usually protracted in nature due to the unpredictability of finding the correct sea state, and the need to conduct the trials at various headings and speeds.
Queen Elizabeth 2, often referred to simply as QE2, is a retired British ocean liner converted into a floating hotel. Originally built for the Cunard Line, Queen Elizabeth 2 was operated by Cunard as both a transatlantic liner and a cruise ship from 1969 to 2008. She was then laid up until converted and since 18 April 2018 has been operating as a floating hotel in Dubai.
Cunard Line is a British cruise line based at Carnival House at Southampton, England, operated by Carnival UK and owned by Carnival Corporation & plc. Since 2011, Cunard and its three ships have been registered in Hamilton, Bermuda.
The RMS Queen Elizabeth was an ocean liner operated by Cunard Line. With Queen Mary she provided weekly luxury liner service between Southampton in the United Kingdom and New York City in the United States, via Cherbourg in France.
The RMS Queen Mary is a retired British ocean liner that sailed primarily on the North Atlantic Ocean from 1936 to 1967 for the Cunard-White Star Line and was built by John Brown & Company in Clydebank, Scotland. Queen Mary, along with RMS Queen Elizabeth, were built as part of Cunard's planned two-ship weekly express service between Southampton, Cherbourg and New York. The two ships were a British response to the express superliners built by German, Italian and French companies in the late 1920s and early 1930s.
The Blue Riband is an unofficial accolade given to the passenger liner crossing the Atlantic Ocean in regular service with the record highest average speed. The term was borrowed from horse racing and was not widely used until after 1910. The record is based on average speed rather than passage time because ships follow different routes. Also, eastbound and westbound speed records are reckoned separately, as the more difficult westbound record voyage, against the Gulf Stream and the prevailing weather systems, typically results in lower average speeds.
An ocean liner is a passenger ship primarily used as a form of transportation across seas or oceans. Liners may also carry cargo or mail, and may sometimes be used for other purposes.
RMS Aquitania was a British ocean liner of the Cunard Line in service from 1914 to 1950. She was designed by Leonard Peskett and built by John Brown & Company in Clydebank, Scotland. She was launched on 21 April 1913 and sailed on her maiden voyage from Liverpool to New York on 30 May 1914. Aquitania was the third in Cunard Line's grand trio of express liners, preceded by RMS Mauretania and RMS Lusitania, and was the last surviving four-funnelled ocean liner. Shortly after Aquitania entered service, World War I broke out, during which she was first converted into an auxiliary cruiser before being used as a troop transport and a hospital ship, notably as part of the Dardanelles Campaign.
RMS Mauretania was an ocean liner designed by Leonard Peskett and built by Wigham Richardson and Swan Hunter for the British Cunard Line, launched on the afternoon of 20 September 1906. She was the world's largest ship until the launch of RMS Olympic in 1910. Mauretania became a favourite among her passengers. She captured the eastbound Blue Riband on her maiden return voyage in December 1907, then claimed the westbound Blue Riband for the fastest transatlantic crossing during her 1909 season. She held both speed records for 20 years.
The SS Normandie was a French ocean liner built in Saint-Nazaire, France, for the French Line Compagnie Générale Transatlantique (CGT). She entered service in 1935 as the largest and fastest passenger ship afloat, crossing the Atlantic in a record 4.14 days, and remains the most powerful steam turbo-electric-propelled passenger ship ever built.
The second RMS Mauretania was an ocean liner that was launched on 28 July 1938 at the Cammell Laird yard in Birkenhead, England, and was completed in May 1939. She was one of the first ships built for the newly formed Cunard-White Star company following the merger in April 1934 of the Cunard and White Star Line. On the withdrawal of the first Mauretania in 1935, to prevent a rival company using the name and to keep it available for the new liner, arrangements were made for the Red Funnel paddle steamer Queen to be renamed Mauretania in the interim.
RMS Majestic was a White Star ocean liner working on the North Atlantic run, originally launched in 1914 as the Hamburg America Line liner SS Bismarck. At 56,551 gross register tons, she was the largest ship in the world until completion of SS Normandie in 1935.
MS Queen Victoria (QV) is a Vista-class cruise ship operated by the Cunard Line and is named after the former British monarch Queen Victoria. The vessel is of the same basic design as other Vista-class cruise ships including Queen Elizabeth. At 90,049 gross tonnage (GT) she is the smallest of Cunard's ships in operation. Her facilities include seven restaurants, thirteen bars, three swimming pools, a ballroom, and a theatre.
Parsons Marine Steam Turbine Company was a British engineering company based on the River Tyne at Wallsend, North East England.
MS Queen Elizabeth (QE) is a cruise ship of the Vista class operated by the Cunard Line. The design is modified from that of previous ships of that class, and slightly larger than Queen Victoria, at 92,000 GT, largely due to a more vertical stern. The ship is able to carry up to 2,092 passengers.
RMS Ivernia was a Saxonia class ocean liner, built in 1955 by John Brown & Company in Clydebank, Scotland for Cunard Line, for their transatlantic passenger service between the UK and Canada. In 1963 she was rebuilt as a cruise ship and renamed RMS Franconia, after the famous pre-war liner RMS Franconia. She continued to sail for Cunard until being withdrawn from service and laid up in 1971. In 1973 she was sold to the Soviet Union's Far Eastern Shipping Company and, renamed SS Fedor Shalyapin, cruised around Australia and the far East. In 1980 she was transferred to the Black Sea Shipping Company fleet, and for a time returned to cruising in the Mediterranean and around Europe. In 1989 she was transferred again, to the Odessa Cruise Company, and continued her career as a cruise ship until 1994. She was then laid up at Illichivsk, a Black Sea port 40 km southwest of Odessa, until 2004 when, as the Salona, she sailed to Alang, India, where she was scrapped.
RMS Carinthia was an ocean liner built in 1956 as one of the four Saxonia class ships. She sailed for Cunard Line from her completion until 1968 when she was sold to Sitmar Line, rebuilt into a full-time cruise ship and renamed SS Fairsea. She sailed with Sitmar until 1988, when Sitmar was sold to P&O. She was renamed SS Fair Princess and sailed for Princess Cruises and P&O Cruises until 2000. She was then sold to China Sea Cruises and renamed SS China Sea Discovery. In 2005 or 2006 she was scrapped in Alang, India.
SS Archimedes was a steamship built in Britain in 1839. She was the world's first steamship to be driven by a screw propeller.
Persia was a British passenger liner operated by the Cunard Line that won the Blue Riband in 1856 for the fastest westbound transatlantic voyage. She was the first Atlantic record breaker constructed of iron and was the largest ship in the world at the time of her launch. However, the inefficiencies of paddle wheel propulsion rendered Persia obsolete and she was taken out of service in 1868 after only twelve years. Attempts to convert Persia to sail were unsuccessful and the former pride of the British merchant marine was scrapped in 1872.
RMS Queen Mary 2 is a British transatlantic ocean liner. She has served as the flagship of Cunard Line since succeeding Queen Elizabeth 2 in 2004. As of 2017, Queen Mary 2 was the only ocean liner still in service.
Captain John Treasure Jones was a British sea officer who became a well-known media figure in the mid-1960s following his appointment as the last master of the Cunard liner, RMS Queen Mary. He has been described as one of the 20th century's most distinguished mariners, in war and in peacetime. His forebears were men of the sea, who had captained sailing ships, and he elected to follow in their tradition.