Ordnance BL Tk. L11A5 (120 mm) - Revision history

U28580205: /* Pros and cons */

2024-07-28T21:50:37Z

‎Pros and cons

U8209876: /* History */

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‎History

U8209876: /* History */

2024-07-23T14:59:05Z

‎History

U8209876: /* Pros and cons */

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‎Pros and cons

U8209876: /* General info */

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‎General info

U8209876: /* History */

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‎History

U8209876: /* History */

2024-07-23T14:25:56Z

‎History

U8209876: /* Pros and cons */

2024-07-23T13:17:02Z

‎Pros and cons

U38088265: U38088265 moved page Ordnance BL Tk. L11 (120 mm) to Ordnance BL Tk. L11A5 (120 mm): Renamed in-game

2023-12-14T15:35:52Z

U38088265 moved page Ordnance BL Tk. L11 (120 mm) to Ordnance BL Tk. L11A5 (120 mm): Renamed in-game

U9202753: Thumbnail added

2023-02-13T21:18:34Z

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 * The L15A3 APDS round has high penetrating power for its BR, able to defeat all but the most heavily armoured MBTs it encounters.
-* L23 and L26 family APFSDS ammunition at higher tiers on Chieftain Mk 10 and Challenger 1 can comfortably defeat common MBT-type enemies at usual combat ranges.
+* L23 and L26 family APFSDS ammunition at higher ranks on Chieftain Mk 10 and Challenger 1 can comfortably defeat common MBT-type enemies at usual combat ranges.
 * Has access to HESH ammunition, being capable of overpressuring and destroying lightly armoured vehicles in a single shot.
 * The L21A1 12.7 mm Heavy Machine Gun can be used alongside with the main gun to accurately rangefind targets for the HESH due to the similar ballistic performance of both rounds.

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 == History ==
-During the development stage of the main armament of the future FV4201 Main Battle Tank, several novel propellant systems were considered. One of those was most notably a liquid propellant compound which would have allowed the crew to vary the propellant amount for each shot and thus the ballistics of the projectile. However, this system was quickly found to be unfeasible after trials in 1953, and thus a bag-charge system became the favoured method. A 105mm gun using bag-charges was specified in 1954. At this time, the turret design of FV4201 allowed a limited amount of space, leading engineers to limit the length of ammunition components to 27 inches (68,58cm) as the maximum. This ruled out conventional one-piece ammunition such as usually found on contemporary tank guns like the [[20pdr OQF Mk.I (84 mm)]] or the Soviet [[D-10T (100 mm)]]. Separate bag-charge ammunition was chosen, dividing the ammunition up into three pieces: Projectile, Bagged propellant charge, and ignition primer in the form of a small magazine containing essentially blank rifle caliber rounds to ignite the propellant. From Chieftain to Challenger 2, this system was retained. Curiously, an attempt was made to achieve a proper seal in the gun breech using brass stub cases (as later used on the [[Rh120 L/44 (120 mm)]] and its US American derivative, the [[M256 (120 mm)|M256]]<nowiki/>m which are ejected after every shot automatically as the rest of the casing is combustible. However, this could not be made reliable or safe at the time. The British solution designed 100% of the propellant charge to be combustible, so that as soon as the breech opens, a new shell can be loaded. It was claimed that this system reduces loader fatigue, as each individual component the loader has to handle weighs much less than  the equivalent one-piece 105mm round.
+During the development stage of the main armament of the future FV4201 Main Battle Tank, several novel propellant systems were considered. One of those was most notably a liquid propellant compound which would have allowed the crew to vary the propellant amount for each shot and thus the ballistics of the projectile. However, this system was quickly found to be unfeasible after trials in 1953, and thus a bag-charge system became the favoured method. A 105mm gun using bag-charges was specified in 1954. At this time, the turret design of FV4201 allowed a limited amount of space, leading engineers to limit the length of ammunition components to 27 inches (68,58cm) as the maximum. This ruled out conventional one-piece ammunition such as usually found on contemporary tank guns like the [[20pdr OQF Mk.I (84 mm)]] or the Soviet [[D-10T (100 mm)]]. Separate bag-charge ammunition was chosen, dividing the ammunition up into three pieces: Projectile, Bagged propellant charge, and ignition primer in the form of a small magazine containing essentially blank rifle caliber rounds to ignite the propellant. From Chieftain to Challenger 2, this system was retained. Curiously, an attempt was made to achieve a proper seal in the gun breech using brass stub cases (as later used on the [[Rh120 L/44 (120 mm)]] and its US American derivative, the [[M256 (120 mm)|M256]]<nowiki/> which are ejected after every shot automatically as the rest of the casing is combustible. However, this could not be made reliable or safe at the time. The British solution designed 100% of the propellant charge to be combustible, so that as soon as the breech opens, a new shell can be loaded. It was claimed that this system reduces loader fatigue, as each individual component the loader has to handle weighs much less than  the equivalent one-piece 105mm round.
 The 120mm calibre was not set in stone from the start either. Twelve guns in calibres between 105 and 130mm were considered before 120mm was recommended for further development in December of 1955. This experimental gun, designated as 120mm X23E2/3 was estimated to be able to defeat 120mm of RHA at 60° at 2000 yards (The same layout as the glacis plate of the [[T-54 (1947)|T-54 Mod. 1947]] and 20mm thicker than on subsequent variants of the [[T-54/55 (Family)|T-54]] and T-55, all of which was yet unknown to the British before a T-54 could be gathered after the Hungarian uprisings in 1956). Using the HESH round, about 150mm of RHA could be defeated  at any combat range. By comparison, the NATO standard 105mm L7 derivative guns used on [[Leopard 1 (Family)|Leopard 1]] and [[M60]] could only defeat the NATO standard medium target ( a T-54) at 1.250 yards, and could not reliably defeat the NATO standard heavy target ( a T-10) at any range. Notably, whilst never entering British service, a range of export ammunition types destined for Iranian use was developed, including a sharp-nosed HESH shell and even a HEAT-FS round.

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 During the development stage of the main armament of the future FV4201 Main Battle Tank, several novel propellant systems were considered. One of those was most notably a liquid propellant compound which would have allowed the crew to vary the propellant amount for each shot and thus the ballistics of the projectile. However, this system was quickly found to be unfeasible after trials in 1953, and thus a bag-charge system became the favoured method. A 105mm gun using bag-charges was specified in 1954. At this time, the turret design of FV4201 allowed a limited amount of space, leading engineers to limit the length of ammunition components to 27 inches (68,58cm) as the maximum. This ruled out conventional one-piece ammunition such as usually found on contemporary tank guns like the [[20pdr OQF Mk.I (84 mm)]] or the Soviet [[D-10T (100 mm)]]. Separate bag-charge ammunition was chosen, dividing the ammunition up into three pieces: Projectile, Bagged propellant charge, and ignition primer in the form of a small magazine containing essentially blank rifle caliber rounds to ignite the propellant. From Chieftain to Challenger 2, this system was retained. Curiously, an attempt was made to achieve a proper seal in the gun breech using brass stub cases (as later used on the [[Rh120 L/44 (120 mm)]] and its US American derivative, the [[M256 (120 mm)|M256]]<nowiki/>m which are ejected after every shot automatically as the rest of the casing is combustible. However, this could not be made reliable or safe at the time. The British solution designed 100% of the propellant charge to be combustible, so that as soon as the breech opens, a new shell can be loaded. It was claimed that this system reduces loader fatigue, as each individual component the loader has to handle weighs much less than  the equivalent one-piece 105mm round.
-The 120mm calibre was not set in stone from the start either. Twelve guns in calibres between 105 and 130mm were considered before 120mm was recommended for further development in December of 1955. This experimental gun, designated as 120mm X23E2/3 was estimated to be able to defeat 120mm of RHA at 60° at 2000 yards (The same layout as the glacis plate of the [[T-54 (1947)|T-54 Mod. 1947]] and 20mm thicker than on subsequent variants of the [[T-54/55 (Family)|T-54]] and T-55, all of which was yet unknown to the British before a T-54 could be gathered after the Hungarian uprisings in 1956). Using the HESH round, about 150mm of RHA could be defeated  at any combat range. By comparison, the NATO standard 105mm L7 derivative guns used on [[Leopard 1 (Family)|Leopard 1]] and [[M60]] could only defeat the NATO standard medium target ( a T-54) at 1.250 yards, and could not reliably defeat the NATO standard heavy target ( a T-10) at any range.
+The 120mm calibre was not set in stone from the start either. Twelve guns in calibres between 105 and 130mm were considered before 120mm was recommended for further development in December of 1955. This experimental gun, designated as 120mm X23E2/3 was estimated to be able to defeat 120mm of RHA at 60° at 2000 yards (The same layout as the glacis plate of the [[T-54 (1947)|T-54 Mod. 1947]] and 20mm thicker than on subsequent variants of the [[T-54/55 (Family)|T-54]] and T-55, all of which was yet unknown to the British before a T-54 could be gathered after the Hungarian uprisings in 1956). Using the HESH round, about 150mm of RHA could be defeated  at any combat range. By comparison, the NATO standard 105mm L7 derivative guns used on [[Leopard 1 (Family)|Leopard 1]] and [[M60]] could only defeat the NATO standard medium target ( a T-54) at 1.250 yards, and could not reliably defeat the NATO standard heavy target ( a T-10) at any range. Notably, whilst never entering British service, a range of export ammunition types destined for Iranian use was developed, including a sharp-nosed HESH shell and even a HEAT-FS round.
 The design of the X23 which in service became the [[L11A5 (120 mm)|L11]] offers a fascinating insight into tank design procedures: It was found that most loaders were right handed and preferred to load using their dominant arm. This meant they are best positioned on the left of the turret so gunner and commander would have to be on the right. This in turn meant that the sights would be offset to the right of the barrel's bore, and therefore the rifling of the barrel had to have a clockwise twist in order to compensate. A mechanised ramming system was also experimented with, however it was unreliable and added even more weight to an already [[Chieftain Mk 3#History|dangerously overweight vehicle]]. British Army loaders therefore resorted to "charge-ramming", using the bagged propellant charge to push the projectile all the way into the breech. Gunnery trials in July of 1962 impressed: At targets out to 2000m, the crews managed an 81% first round hit probability using APDS, proving the L11's accuracy. <ref>Taylor, Dick. ''Chieftain, Main Battle Tank, Owners' Workshop Manual 1966 to present.'' Haynes Publishing Inc., 2016</ref>

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 '''Pros:'''
-* The APDS round has high penetrating power, able to defeat all but the most heavily armoured MBTs it encounters.
+* The L15A3 APDS round has high penetrating power for its BR, able to defeat all but the most heavily armoured MBTs it encounters.
 * Has access to HESH ammunition, being capable of overpressuring and destroying lightly armoured vehicles in a single shot.
 * The L21A1 12.7 mm Heavy Machine Gun can be used alongside with the main gun to accurately rangefind targets for the HESH due to the similar ballistic performance of both rounds.
 '''Cons:'''
-* Slightly less accurate than smoothbore counterparts
+* HESH shells produce little spalling, making them impracticable to fight heavy vehicles and vehicles with spaced and/or composite armour.
-* HESH shells produce little spalling, making them impracticable to fight heavy vehicles
+* No access to conventional HE or HEAT shells.
 == History ==

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 === Comparison with analogues ===
-''Give a comparative description of cannons/machine guns that have firepower equal to this weapon.''
 == Usage in battles ==

← Older revision		Revision as of 14:26, 23 July 2024
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	== History ==		== History ==
−	''Examine the history of the creation and combat usage of the weapon in more detail than in the introduction. If the historical reference turns out to be too long, take it to a separate article, taking a link to the article about the weapon and adding a block "/History" (example: <nowiki>https://wiki.warthunder.com/(Weapon-name)/History</nowiki>) and add a link to it here using the <code>main</code> template. Be sure to reference text and sources by using <code><nowiki><ref></ref></nowiki></code>, as well as adding them at the end of the article with <code><nowiki><references /></nowiki></code>.''
−
	During the development stage of the main armament of the future FV4201 Main Battle Tank, several novel propellant systems were considered. One of those was most notably a liquid propellant compound which would have allowed the crew to vary the propellant amount for each shot and thus the ballistics of the projectile. However, this system was quickly found to be unfeasible after trials in 1953, and thus a bag-charge system became the favoured method. A 105mm gun using bag-charges was specified in 1954. At this time, the turret design of FV4201 allowed a limited amount of space, leading engineers to limit the length of ammunition components to 27 inches (68,58cm) as the maximum. This ruled out conventional one-piece ammunition such as usually found on contemporary tank guns like the [[20pdr OQF Mk.I (84 mm)]] or the Soviet [[D-10T (100 mm)]]. Separate bag-charge ammunition was chosen, dividing the ammunition up into three pieces: Projectile, Bagged propellant charge, and ignition primer in the form of a small magazine containing essentially blank rifle caliber rounds to ignite the propellant. From Chieftain to Challenger 2, this system was retained. Curiously, an attempt was made to achieve a proper seal in the gun breech using brass stub cases (as later used on the [[Rh120 L/44 (120 mm)]] and its US American derivative, the [[M256 (120 mm)\|M256]]<nowiki/>m which are ejected after every shot automatically as the rest of the casing is combustible. However, this could not be made reliable or safe at the time. The British solution designed 100% of the propellant charge to be combustible, so that as soon as the breech opens, a new shell can be loaded. It was claimed that this system reduces loader fatigue, as each individual component the loader has to handle weighs much less than the equivalent one-piece 105mm round.		During the development stage of the main armament of the future FV4201 Main Battle Tank, several novel propellant systems were considered. One of those was most notably a liquid propellant compound which would have allowed the crew to vary the propellant amount for each shot and thus the ballistics of the projectile. However, this system was quickly found to be unfeasible after trials in 1953, and thus a bag-charge system became the favoured method. A 105mm gun using bag-charges was specified in 1954. At this time, the turret design of FV4201 allowed a limited amount of space, leading engineers to limit the length of ammunition components to 27 inches (68,58cm) as the maximum. This ruled out conventional one-piece ammunition such as usually found on contemporary tank guns like the [[20pdr OQF Mk.I (84 mm)]] or the Soviet [[D-10T (100 mm)]]. Separate bag-charge ammunition was chosen, dividing the ammunition up into three pieces: Projectile, Bagged propellant charge, and ignition primer in the form of a small magazine containing essentially blank rifle caliber rounds to ignite the propellant. From Chieftain to Challenger 2, this system was retained. Curiously, an attempt was made to achieve a proper seal in the gun breech using brass stub cases (as later used on the [[Rh120 L/44 (120 mm)]] and its US American derivative, the [[M256 (120 mm)\|M256]]<nowiki/>m which are ejected after every shot automatically as the rest of the casing is combustible. However, this could not be made reliable or safe at the time. The British solution designed 100% of the propellant charge to be combustible, so that as soon as the breech opens, a new shell can be loaded. It was claimed that this system reduces loader fatigue, as each individual component the loader has to handle weighs much less than the equivalent one-piece 105mm round.

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 === Available ammunition ===
 {{:{{PAGENAME}}/Ammunition|Shot L15A3, Shell L31A7, Shot L23, L34}}
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 == History ==
 ''Examine the history of the creation and combat usage of the weapon in more detail than in the introduction. If the historical reference turns out to be too long, take it to a separate article, taking a link to the article about the weapon and adding a block "/History" (example: <nowiki>https://wiki.warthunder.com/(Weapon-name)/History</nowiki>) and add a link to it here using the <code>main</code> template. Be sure to reference text and sources by using <code><nowiki><ref></ref></nowiki></code>, as well as adding them at the end of the article with <code><nowiki><references /></nowiki></code>.''
 == Media ==
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 == External links ==
-''Paste links to sources and external resources, such as:''
+[[Category:Tank cannons]]
-[[Category:Tank cannons]]
+=== References: ===

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 '''Pros:'''
-* APDS round has high penetrating power, able to defeat all but the most heavily armoured MBTs it encounters.
+* The APDS round has high penetrating power, able to defeat all but the most heavily armoured MBTs it encounters.
-* Has access to HESH ammunition, being capable to hull-break lightly armoured vehicles
+* Has access to HESH ammunition, being capable of overpressuring and destroying lightly armoured vehicles in a single shot.
-* The L21A1 12.7 mm Heavy Machine Gun can be used alongside with the main gun to accurately rangefind targets due to the similar ballistic performance of both rounds.
+* The L21A1 12.7 mm Heavy Machine Gun can be used alongside with the main gun to accurately rangefind targets for the HESH due to the similar ballistic performance of both rounds.
 * Late vehicles (namely the Chieftain Mk 10) have access to APFSDS ammunition
@@ Line 56: / Line 56: @@
 == See also ==
 ''Links to the articles on the War Thunder Wiki that you think will be useful for the reader, for example:''
 * ''reference to the article about the variant of the cannon/machine gun;''
 * ''references to approximate analogues by other nations and research trees.''
@@ Line 61: / Line 62: @@
 == External links ==
 ''Paste links to sources and external resources, such as:''
 * ''topic on the official game forum;''
 * ''other literature.''

← Older revision	Revision as of 15:35, 14 December 2023
(No difference)

← Older revision		Revision as of 21:18, 13 February 2023
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		+	[[File:Weapon Ordnance BL Tk. L11 (120 mm).png\|thumb\|right\|x250px\|The Ordnance BL Tk. L11 (120 mm) on the Chieftain Mk 10 gun mantlet.]]
		+
	== Description ==		== Description ==
	<!-- ''Write an introduction to the article in 2-3 small paragraphs. Briefly tell us about the history of the development and combat using the weaponry and also about its features. Compile a list of air, ground, or naval vehicles that feature this weapon system in the game.'' -->		<!-- ''Write an introduction to the article in 2-3 small paragraphs. Briefly tell us about the history of the development and combat using the weaponry and also about its features. Compile a list of air, ground, or naval vehicles that feature this weapon system in the game.'' -->