Editing Torpedo (section)

===Radio and wire guidance===
{{See also|Command guidance}}
Though Luppis' original design had been rope-guided, and numerous early examples of torpedoes possessed [[Manual command to line of sight|MCLOS]] wire guidance and radio guidance, wire-guided torpedoes did not become common until the 1960s.

[[File:PSM V56 D0325 Launching of patrick torpedo from the ways.png|thumb|A Patrick wire-guided torpedo in launch configuration, circa 1899.]]

[[File:PSM V56 D0325 Patrick torpedo moving at 23 knots per hour.png|thumb|A Patrick wire-guided torpedo moving at 23 knots. The flags were used for line-of-sight control.]]

One of the earliest examples of an electrical wire-guided torpedo was the Lay torpedo, designed by [[John Louis Lay]] between 1867 and 1872.<ref>{{cite web|last = Rigby|first = Rebecca|title = The Lay Torpedoes|url = https://www.torp.esrc.unimelb.edu.au/biogs/E000124b.htm|website = 19th Century Torpedoes, An Annotated Bibliography|access-date = 8 May 2025}}</ref> It would eventually be developed into the Patrick torpedo circa 1899, which was capable of speeds up to {{cvt|23|kn|kph}}.<ref>{{cite web|last = Rigby|first = Rebecca|title = The Patrick Torpedo|url = https://www.torp.esrc.unimelb.edu.au/biogs/E000113b.htm|website = 19th Century Torpedoes, An Annotated Bibliography|access-date = 8 May 2025}}</ref>

The [[Brennan torpedo]] of 1877 was a wire-guided weapon which had an all-mechanical control scheme, and also utilized the control wires as a source of propulsive energy. By selectively putting more or less tension on the control wires as they were payed out, the weapon could be steered left and right. Line-of-sight control was accomplished by observing a tracking mast which projected above the water from the weapon's body.<ref>{{cite web|last = Rigby|first = Rebecca|title = The Brennan Torpedo|url = https://www.torp.esrc.unimelb.edu.au/biogs/E000123b.htm|website = 19th Century Torpedoes, An Annotated Bibliography|access-date = 8 May 2025}}</ref>

One of the most sophisticated early examples of a radio-controlled torpedo was the Sims-Edison torpedo (circa 1890), later known as the Sims-Shoemaker torpedo (after 1902). The weapon carried a {{cvt|500|lb|kg}} [[Gelignite|nitrogelatin]] warhead and was capable of a speed of {{cvt|20|kn|kph}}.<ref>{{cite web|author = Scientific American|title = The Sims-Edison Electric Torpedo - The Torpedo at Full Speed - Sectional View of the Torpedo|url = https://web.archive.org/web/20130527115531/http://www.scientificamericanpast.com/Scientific%20American%201890%20to%201899/1/lg/sci7261890.htm|website = scientificamericanpast.com|date = 26 July 1890|access-date = 8 May 2025}}</ref><ref>{{cite web|last = Rigby|first = Rebecca|title = The Sims-Edison Torpedo|url = https://www.torp.esrc.unimelb.edu.au/biogs/E000115b.htm|website = 19th Century Torpedoes, An Annotated Bibliography|access-date = 8 May 2025}}</ref> Control signals utilized code sequences transmitted via radio, in a manner similar to a [[Teleprinter|teletype]]; aside from steering, the weapon could also be remotely armed and detonated, sped up or slowed down, and halted entirely at the operator's discretion. The weapon was effectively impossible to hijack even if an identical command console were possessed by the adversary, and the brevity of command signals would have also enormously complicated radio signal detection and jamming.<ref>{{cite book|first = H. R.|last = Everett|title = Unmanned Systems of World Wars I and II|publisher = [[Massachusetts Institute of Technology]]|date = 2015|isbn = 978-0-262-02922-3|pages=205-211}}</ref>

[[File:330-ps-9119 15540094799 o.jpg|thumb|Artist's impression of a USN Mark 39 wire-guided torpedo approaching a hostile submarine.]]

During the First World War, the U.S. Navy evaluated a radio controlled torpedo launched from a surface ship, called the Hammond torpedo.<ref>{{cite news| url=https://www.nytimes.com/1916/08/29/archives/to-test-hammond-torpedo-general-wood-named-as-head-of-board-to-pass.html | work=The New York Times | title=TO TEST HAMMOND TORPEDO; General Wood Named as Head of Board to Pass Judgment on Invention | date=29 August 1916}}</ref> A later version tested in the 1930s was claimed to have an effective range of {{convert|6|mi}}.<ref>{{cite magazine |url=https://books.google.com/books?id=p-IDAAAAMBAJ&pg=PA262 |title=Torpedo Controlled By Radio After Striking Water|magazine=Popular Mechanics |date=February 1930 |publisher=Hearst Magazines}}</ref>

The first major example of a wire-guided torpedo which was used against live targets in warfare was the German [[List of World War II torpedoes of Germany|G7ef ''"Spinne"'']], introduced in 1944, which was a [[G7e torpedo|G7e]] variant equipped with an electronic guidance wire, controlled by means of [[Beam riding|acoustic beam riding]] by the launching entity. Originally intended for use by land emplacements for strait defense, later examples were deployed by submarines.

Another example of a guided torpedo during the Second World War was the [[Helmover torpedo]], which was a colossal aerial torpedo with an overall mass of {{cvt|11500|lbs|kg}}, carrying a warhead filled with {{cvt|2204|lb|kg}} of [[RDX]] explosive. The Helmover torpedo possessed a vertical mast which projected above the water and shone infrared lights towards the guiding aircraft to indicate its location and orientation, in a manner similar to a [[Precision approach path indicator|PAPI array]]. Guidance signals to the torpedo were transmitted via radio.

The first truly modern electronically wire-guided torpedo was the [[USN]] [[Mark 39 torpedo|Mark 39]], introduced in 1946. It possessed three-dimensional acoustic homing and used a control wire for mid-course guidance. In 1956, the Mark 39 would be superseded by the [[Mark 37 torpedo|Mark 37]], which served as a mainstay [[Anti-submarine warfare|ASW]] weapon during the 1960s.

Another advancement in the field of teleoperated torpedoes was the [[Royal Navy]] [[British 21-inch torpedo#Mark 23 Grog|Mark 23 Grog]], first available in 1959, an ASW weapon which established a direct audio signal link between the hydrophones of the weapon's seeker head and the command console onboard the launching submarine. A human operator would directly listen to the sounds heard by the torpedo, allowing for sophisticated discrimination of acoustic decoys and target recognition.

Modern torpedoes use an [[Umbilical cable|umbilical wire]], which nowadays allows the computer processing power of the submarine or ship to be used. Torpedoes such as the USN [[Mark 48 torpedo|Mark 48]] can operate in a variety of modes, increasing tactical flexibility.