USS Independence (CVA-62) during shakedown cruise 1959

Shakedown cruise is a

nautical term __NOTOC__ M ...

in which the performance of a

ship A ship is a large watercraft that travels the world's oceans and other sufficiently deep waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research, and fishing. Ships are generally distinguished ...

is tested. Generally, shakedown cruises are performed before a ship enters service or after major changes such as a crew change, repair or

overhaul Overhaul may refer to: *The process of overhauling, see ** Maintenance, repair, and overhaul **Refueling and overhaul (eg. nuclear-powered ships) **Time between overhaul * Overhaul (firefighting), the process of searching for hidden fire extensio ...

. The shakedown cruise simulates working conditions for the vessel, for various reasons. For most new ships, the major reasons are to familiarise a crew with a new vessel and to ensure all of the ship's systems are functional.

Overview

If the ship is the first of its class, it will likely also be performing its

sea trial 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 ...

s, a test of its performance. In this context, 'shakedown cruise' and 'sea trials' may be used interchangeably, though each has a slightly different meaning. In such a case, it is likely that the ship's systems will be pushed to redline, or maximum capacity, to demonstrate the class's speed and other important traits. Until bested by another ship of the same class, this shakedown performance will be the standard of the class's capabilities, and its success may determine whether the class is to enter full production. In the travel industry a shakedown cruise is also undertaken to test the ship and service crew. These test cruises are sometimes made with passengers travelling at a discount. It has been suggested that the origin of "shakedown cruise" comes from the need to settle (or literally shake down) the

ballast Ballast is material that is used to provide stability to a vehicle or structure. Ballast, other than cargo, may be placed in a vehicle, often a ship or the gondola of a balloon or airship, to provide stability. A compartment within a boat, ship ...

in the

hold Hold may refer to: Physical spaces * Hold (ship), interior cargo space * Baggage hold, cargo space on an airplane * Stronghold, a castle or other fortified place Arts, entertainment, and media * Hold (musical term), a pause, also called a Ferm ...

of a ship to ensure it is level in the water. However, this would only apply to very granular ballast material such as sand. The term is more likely to have arisen due to the transition from sail to power. The advent of engines within the hull of a ship caused severe vibration. Such vibration would be aggravated by uneven running and different sea conditions. A new ship had many fixtures and fittings throughout its accommodation and work spaces. As the maiden voyage progressed, these would become loose, and in many cases fall to the deck (shaken down). For this reason, it was common for the shipyard to send a 'shake-down' team with the ship on her maiden voyage. These men would be specialists equipped with the proper tools and spares to relocate or replace any displaced fixtures or fittings.

Availability

A vessel is typically not committed to any timetables or tasks until it completes its shakedown cruise. As such, problems detected during the shakedown cruise can be fixed at minimal cost. While the ship is assigned to the industrial activity for this purpose, this period is known as an "availability". In the US Navy, the typical length of an availability is 45 to 120 days, and per regulation, must be completed no more than eleven months after the month the ship was first delivered. This is also known as a "post-shakedown availability".{{cite web, url=https://fas.org/nuke/guide/usa/doctrine/navy/jfmm/vol1/CH_06.htm, title=Postshakedown Availability, publisher=fas.org, access-date=8 February 2018

Famous examples

The USS ''Triton'', a

nuclear-powered Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced b ...

radar picket A radar picket is a radar-equipped station, ship, submarine, aircraft, or vehicle used to increase the radar detection range around a nation or military (including naval) force to protect it from surprise attack, typically air attack, or from cr ...

submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...

, was the first vessel to execute a submerged

circumnavigation Circumnavigation is the complete navigation around an entire island, continent, or astronomical object, astronomical body (e.g. a planet or natural satellite, moon). This article focuses on the circumnavigation of Earth. The first recorded circ ...

of Earth while on its shakedown cruise in early 1960. ''Triton'' is the only

U.S. Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage o ...

ship to receive a Presidential Unit Citation for its shakedown cruise. USS ''Massachusetts'''s shakedown cruise was

Operation Torch Operation Torch (8 November 1942 – Run for Tunis, 16 November 1942) was an Allies of World War II, Allied invasion of French North Africa during the Second World War. Torch was a compromise operation that met the British objective of secu ...

References

Nautical terminology