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Diving planes, also known as hydroplanes, are control surfaces found on a submarine which allow the vessel to pitch its bow and stern up or down to assist in the process of submerging or surfacing the boat, as well as controlling depth when submerged. [1]
Diving planes are usually fitted in two pairs, the bow planes at the front of the submarine and the stern planes at the rear. The stern planes function in much the same way as an aircraft's elevator. As the planes are a long distance fore-and-aft from the hull's centre of buoyancy, they introduce a pitching moment. Ballast tanks within the submarine adjust buoyancy to be neutral, making the boat controllable. The position of the planes controls the pitch of the boat and, with the forward motion of the boat, this controls depth. If not carefully controlled, this could lead to a 'porpoising' motion whereby the planesman continually hunts for a stable combination of depth and pitch. [2]
For easier berthing close alongside a jetty, submarines have used folding bow planes that retracted alongside the hull. Earlier submarines (to World War II) used vertical folding planes perpendicular to their surface. US submarines referred to this stowage as 'rigging' the planes, and 'tilting' for their control movement. [3] Later Soviet submarines have tended to fold backwards, into recesses in the casing.
Simon Lake of the Lake Torpedo Boat Company [2] was the first to develop planes that could control depth without introducing a pitching moment. Stern planes and rudder were mounted below the stern akin to a conventional ship. The depth control planes were mounted on the beam, so that they acted vertically, without the lever arm to introduce the usual pitch. [2]
Diving planes located on the sail (conning tower) are called fairwater planes on US Navy submarines. [4] Fairwater planes do not pitch the ship up or down; they cause the boat to rise or sink on a level plane as they are operated.
When operating beneath polar ice, a submarine with planes on the sail must break them through the ice when surfacing. From the Sturgeon class they were arranged to be able to be pointed vertically upwards, rather than being rigged or folded in. [4]
Newer boats, starting with the third-flight Los Angeles class subs (or 688is) have eliminated the sail planes, and operate instead with bow planes.
From the outset, diving planes were controlled remotely by telemotors, early servomechanisms operated electrically or by hydraulics.
Maintaining depth in a submarine is a sophisticated task. The planesman was provided with a prominent depth gauge to monitor this, usually a circular Bourdon gauge. For precise maintenance at periscope depth an additional shallow-depth manometer, a transparent vertical pipe, would be provided too. With the development of active sonar, depth control became even more complex. Rather than maintaining a simple depth, the planesman must now keep the boat beneath a thermocline in order to hide from sonar. To this end, the helm position may also show external water thermometers and salinometers.
Early submarines had separate controls for each pair of planes, bow and stern. Together with the helmsman, this required three ratings in the already-crowded control room. By the 1960s, combined controls were introduced. These incorporated all planes onto a single aircraft-style control wheel.
In automotive terms, dive planes (which physically resemble submarine diving planes) are aerodynamic devices fitted on cars just ahead of the front wheels. They are most commonly found on racing cars such as the Le Mans Prototype Series and are used to create additional downforce and channel airflow to help balance the car. The 2012 Mercedes-Benz C63 AMG Black Series is one of the first road cars to feature these devices. [5]
A submarine 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 operated vehicles and robots, as well as medium-sized or smaller vessels, such as the midget submarine and the wet sub. Submarines are referred to as boats rather than ships irrespective of their size.
The Gato class of submarines were built for the United States Navy and launched in 1941–1943. Named after the lead ship of the class, USS Gato, they were the first mass-production U.S. submarine class of World War II.
Buoyancy, or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the pressure at the bottom of a column of fluid is greater than at the top of the column. Similarly, the pressure at the bottom of an object submerged in a fluid is greater than at the top of the object. The pressure difference results in a net upward force on the object. The magnitude of the force is proportional to the pressure difference, and is equivalent to the weight of the fluid that would otherwise occupy the submerged volume of the object, i.e. the displaced fluid.
USS Albacore (AGSS-569) is a unique research submarine that pioneered the American version of the teardrop hull form of modern submarines. The revolutionary design was derived from extensive hydrodynamic and wind tunnel testing, with an emphasis on underwater speed and maneuverability. She was the third vessel of the United States Navy to be named for the albacore.
The Skipjack class was a class of United States Navy nuclear submarines (SSNs) that entered service in 1959-61. This class was named after its lead boat, USS Skipjack. The new class introduced the teardrop hull and the S5W reactor to U.S. nuclear submarines. The Skipjacks were the fastest U.S. nuclear submarines until the Los Angeles-class submarines, the first of which entered service in 1974.
A submersible is an underwater craft which needs to be transported and supported by a surface vessel or platform. This distinguishes submersibles from submarines, which are self-supporting and capable of independent operation.
A diver propulsion vehicle (DPV), also known as an underwater propulsion vehicle, sea scooter, underwater scooter, or swimmer delivery vehicle (SDV) by armed forces, is an item of diving equipment used by scuba divers to increase range underwater. Range is restricted by the amount of breathing gas that can be carried, the rate at which that breathing gas is consumed, and the battery power of the DPV. Time limits imposed on the diver by decompression requirements may also limit safe range in practice. DPVs have recreational, scientific and military applications.
The Plunger class was an early class of United States Navy submarines. In the first years of their service, they were used primarily as training and experimental vessels for the newly formed "silent service" to familiarize naval personnel with the performance and operations of such craft. They were known as the "A class" after being renamed to A-type designations on 17 November 1911. All except Plunger ended up being stationed in the Philippines, an American possession, prior to the outbreak of World War I. They were shipped there on colliers and formed an integral part of the harbor defense system for Manila. In some instances, this class of submarines is referred to as the Adder class, as USS Adder was the first boat of the class to be completed.
USS Barbel (SS-580) was the lead ship of her class of submarines in the United States Navy. She was the second Navy ship named for the barbel, a cyprinoid fish, commonly called a minnow or carp.
A crash dive is a maneuver by a submarine in which the vessel submerges as quickly as possible to avoid attack. Crash diving from the surface to avoid attack has been largely rendered obsolete with the advent of nuclear-powered submarines, as they normally operate submerged. However, the crash dive is also a standard maneuver to avoid a collision.
The United States' S-class submarines, often simply called S-boats, were the first class of submarines with a significant number built to United States Navy designs. They made up the bulk of the USN submarine service in the interwar years and could be found in every theater of operations. While not considered "Fleet Submarines" in the traditional sense of that term, they were the first submarines in the USN designed for open ocean, blue water operations. All previous submarines had been intended for harbor or coastal defense. These boats were intended to have greater speed and range than previous classes, with improved habitability and greater armament.
The K-class submarines were a class of steam-propelled submarines of the Royal Navy designed in 1913. Intended as large, fast vessels with the endurance and speed to operate with the battle fleet, they gained notoriety and the nickname of "Kalamity class" for being involved in many accidents. Of the 18 built, none were lost through enemy action, but six sank, with significant loss of life, in accidents. Only one ever engaged an enemy vessel, K-7 hitting a U-boat amidships, though the torpedo failed to explode with what has been described as typical "K" luck; K-7 escaped retaliation by steaming away at speed.
A ballast tank is a compartment within a boat, ship or other floating structure that holds water, which is used as ballast to provide hydrostatic stability for a vessel, to reduce or control buoyancy, as in a submarine, to correct trim or list, to provide a more even load distribution along the hull to reduce structural hogging or sagging stresses, or to increase draft, as in a semi-submersible vessel or platform, or a SWATH, to improve seakeeping. Using water in a tank provides easier weight adjustment than the stone or iron ballast used in older vessels, and makes it easy for the crew to reduce a vessel's draft when it enters shallower water, by temporarily pumping out ballast. Airships use ballast tanks mainly to control buoyancy and correct trim.
A radio-controlled submarine is a scale model of a submarine that can be steered via radio control. The most common form are those operated by hobbyists. These can range from inexpensive toys to complex projects involving sophisticated electronics. Oceanographers and military units also operate radio-controlled submarines.
A submarine hull has two major components, the light hull and the pressure hull. The light hull of a submarine is the outer non-watertight hull which provides a hydrodynamically efficient shape. The pressure hull is the inner hull of a submarine that maintains structural integrity with the difference between outside and inside pressure at depth.
The British U-class submarines were a class of 49 small submarines built just before and during the Second World War. The class is sometimes known as the Undine class, after the first submarine built. A further development was the British V-class submarine of 1942.
German submarine U-521 was a Type IXC U-boat of Nazi Germany's Kriegsmarine during World War II.
German submarine U-353 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 30 March 1940 at the Flensburger Schiffbau-Gesellschaft yard at Flensburg, launched on 11 November 1941, and commissioned on 31 March 1942 under the command of Oberleutnant zur See Wolfgang Römer. After training with the 5th U-boat Flotilla based at Kiel, U-353 was transferred to the 1st U-boat Flotilla at Brest in France for front-line service from 1 October 1942.
A teardrop hull is a submarine hull design which emphasizes submerged performance over surfaced performance. It was somewhat commonly used in the early stages of submarine development, but was gradually abandoned in the early 20th century in favour of designs optimized for high performance on the surface as a result of changes in operational doctrine. Although naval doctrine changed, design practices remained until the later parts of World War II when the German Kriegsmarine suffered ever-growing losses of submarines in the Battle of the Atlantic.
The Sjöormen class was a class of submarines built for the Swedish Navy in the late 1960s. They had a teardrop hull shape and were capable of diving to 150 metres (490 ft). At the time of their deployment they were regarded as one of the most advanced non-nuclear submarine-classes in the world, incorporating many new features including x-rudder and anechoic tiles. Both speed and underwater endurance was at this time very high for a conventional submarine. The submarines were retired by Sweden in the early 1990s. In the late 1990s, four submarines were acquired by the Republic of Singapore Navy (RSN) and relaunched as the Challenger class following modernisation and tropicalisation.
