INS Betwa (F139) - Revision history

CleanupBot: /* Development and design */clean up

2022-01-01T18:30:07Z

Development and design: clean up

← Older revision		Revision as of 00:00, 2 January 2022
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	==Development and design==		==Development and design==
	These ships were designed to provide anti-aircraft escorts to convoys and light fleet [[~~Aircraft~~ carrier~~\|aircraft carriers~~]] of the ''Sydney'' and ''Virkant'' classes and act as light destroyers on detached duties; as a result they were not built for fleet carrier task force speed —28 knots for the ''Victorious'' and ''Audacious'' classes and made only {{convert\|24\|kn\|km/h}}. They were envisioned in late World War II and immediately after as part of the 1944 project for a common hull [[anti-submarine warfare]] (A/S), [[anti-air warfare]] (A/A), and A/D frigate, and the design of the Type 41 was completed by December 1947.<ref>D.K. Brown & G. Moore. Rebuidling the Royal Navy. Naval Design since 1945. Seaforth. Barnssley (2013) p 74</ref>		These ships were designed to provide anti-aircraft escorts to convoys and light fleet [[aircraft carrier]]s of the ''Sydney'' and ''Virkant'' classes and act as light destroyers on detached duties; as a result they were not built for fleet carrier task force speed —28 knots for the ''Victorious'' and ''Audacious'' classes and made only {{convert\|24\|kn\|km/h}}. They were envisioned in late World War II and immediately after as part of the 1944 project for a common hull [[anti-submarine warfare]] (A/S), [[anti-air warfare]] (A/A), and A/D frigate, and the design of the Type 41 was completed by December 1947.<ref>D.K. Brown & G. Moore. Rebuidling the Royal Navy. Naval Design since 1945. Seaforth. Barnssley (2013) p 74</ref>

	Through their diesel-electric propulsion the Type 41s achieved long range through their low fuel use. The ''Leopard'' class was also fitted with an early type of hydraulic stabiliser system consisting of two fins that could be extended outside the main hull, to port and starboard, from a compartment between the two engine rooms. Gyro controlled with a relatively simple control system, they proved very effective in use. During testing every three months at sea, the ship could be easily driven into a 20°+ roll from the manual control on the bridge. Prior warning had to be given over the ship's tannoy system before testing was carried out, to allow stowage of loose items. Slight reduction in top speed was also noticed when in use.		Through their diesel-electric propulsion the Type 41s achieved long range through their low fuel use. The ''Leopard'' class was also fitted with an early type of hydraulic stabiliser system consisting of two fins that could be extended outside the main hull, to port and starboard, from a compartment between the two engine rooms. Gyro controlled with a relatively simple control system, they proved very effective in use. During testing every three months at sea, the ship could be easily driven into a 20°+ roll from the manual control on the bridge. Prior warning had to be given over the ship's tannoy system before testing was carried out, to allow stowage of loose items. Slight reduction in top speed was also noticed when in use.
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	However, by 1955 success had been achieved, with difficulty and limitations, in developing new steam turbines giving 30-knot speed and the range to take convoys across the Atlantic, embodied in the [[Whitby-class frigate\|''Whitby''-class Type 12 frigates]]. As a result, the orders for the new diesel-electric frigates were cancelled, changed to orders for Type 12, or sold to India.		However, by 1955 success had been achieved, with difficulty and limitations, in developing new steam turbines giving 30-knot speed and the range to take convoys across the Atlantic, embodied in the [[Whitby-class frigate\|''Whitby''-class Type 12 frigates]]. As a result, the orders for the new diesel-electric frigates were cancelled, changed to orders for Type 12, or sold to India.

	Within a few years of the Type 41's introduction in the late 1950s they were regarded as obsolete for their intended function as anti-aircraft convoy escorts. This was emphasized when the planned replacement of the 4.5" guns with 3"/70 AA guns was abandoned (in January 1955) due to cost and the view that AA guns were obsolete against jets and missiles. <ref>Brown & Moore. Rebilding the RN (2012) p 73-74 & N, Friedman. British Destroyers and Frigates after WW2. Seaforth. Barnsley (2012) p 208-211</ref> Adding power-ramming for the twin 4.5" guns, intended to boost the rate of fire from 14rpm to 24rpm, failed. Innovative additions of [[Whitby class frigate#Armament\|STAAG]] ("Stabilised Tachymetric Anti-Aircraft Gun"), [[CIWS]] mount, and replacement of the experimental version of the fast rotating 992 target indicators with the slower standard 993 were all abandoned. Only a short range 262 radar MRS1 provided secondary AA fire control for the main armament.		Within a few years of the Type 41's introduction in the late 1950s they were regarded as obsolete for their intended function as anti-aircraft convoy escorts. This was emphasized when the planned replacement of the 4.5" guns with 3"/70 AA guns was abandoned (in January 1955) due to cost and the view that AA guns were obsolete against jets and missiles.<ref>Brown & Moore. Rebilding the RN (2012) p 73-74 & N, Friedman. British Destroyers and Frigates after WW2. Seaforth. Barnsley (2012) p 208-211</ref> Adding power-ramming for the twin 4.5" guns, intended to boost the rate of fire from 14rpm to 24rpm, failed. Innovative additions of [[Whitby class frigate#Armament\|STAAG]] ("Stabilised Tachymetric Anti-Aircraft Gun"), [[CIWS]] mount, and replacement of the experimental version of the fast rotating 992 target indicators with the slower standard 993 were all abandoned. Only a short range 262 radar MRS1 provided secondary AA fire control for the main armament.

	==Construction and career==		==Construction and career==

>Derekbridges: fix sclass

2021-09-28T14:09:47Z

fix sclass

New page

{{Other ships|INS Betwa}}
{{Use dmy dates|date=November 2020}}
{|{{Infobox ship begin}}
{{Infobox ship image
| Ship image =
| Ship caption =
}}
{{Infobox ship career
| Hide header =
| Ship country = India
| Ship flag = {{Shipboxflag|India|naval}}
| Ship name = ''Betwa''
| Ship owner = Government of India
| Ship namesake = [[Betwa River|Betwa]]
| Ship ordered = 1954
| Ship builder = [[Vickers-Armstrongs]] Shipbuilders Limited, Newcastle upon Tyne
| Ship laid down = 29 May 1957
| Ship launched = 15 September 1959
| Ship acquired =
| Ship commissioned= 8 December 1960
| Ship decommissioned = 31 December 1991
| Ship identification = [[Pennant number]]: F139
| Ship in service =
| Ship out of service =
| Ship struck =
| Ship reinstated =
| Ship honours =
| Ship fate = Broken up, 1998
| Ship status =
}}
{{Infobox ship characteristics
| Hide header =
| Header caption =
| Ship class = {{sclass|Leopard|frigate}}
| Ship displacement =
| Ship length = {{convert|101|m|ft}}
| Ship beam = {{convert|10.6|m|ft}}
| Ship draught = {{convert|3|m|ft}}
| Ship draft =
| Ship propulsion = 8 × Admiralty Standard Range ASR1 diesels, 14,400 shp (10,738 kW), 2 shafts
| Ship speed = {{convert|22|kn}}
| Ship range = {{convert|7400 |mi|km}} at 18 kn
| Ship complement = 200 (22 officers)
| Ship sensors =
*[[Radar]] System:
**Surface/Air search: Type 960
**Air search: Type 965 ''AKE-1''
**Type 293/993 target indication radar
**Navigation: Type 974 /978
**Fire control: Type 275 on director Mark 6M
*Sonar system:
**Type 174 search sonar
**Type 164 attack sonar
| Ship EW =
| Ship armament =
*2 × twin [[QF 4.5-inch Mk I – V naval gun|4.5 in guns Mark 6]]
*1 × twin [[Bofors 40 mm gun#Naval versions|40 mm Bofors gun]] STAAG Mark 2
*1 × single 40 mm Bofors gun Mark 9
*1 × [[Squid (weapon)|Squid A/S mortar]]
| Ship armour =
| Ship armor =
| Ship aircraft =
| Ship aircraft facilities =
| Ship notes=
}}
|}
'''INS ''Betwa'' (F139)''' was a [[Leopard class frigate|''Leopard''-class]] Type 41 [[anti-aircraft warfare|anti aircraft]] [[frigate]] of the [[Indian Navy]], named after the [[Betwa River|Betwa river]].

==Development and design==
These ships were designed to provide anti-aircraft escorts to convoys and light fleet [[Aircraft carrier|aircraft carriers]] of the ''Sydney'' and ''Virkant'' classes and act as light destroyers on detached duties; as a result they were not built for fleet carrier task force speed —28 knots for the ''Victorious'' and ''Audacious'' classes and made only {{convert|24|kn|km/h}}. They were envisioned in late World War II and immediately after as part of the 1944 project for a common hull [[anti-submarine warfare]] (A/S), [[anti-air warfare]] (A/A), and A/D frigate, and the design of the Type 41 was completed by December 1947.<ref>D.K. Brown & G. Moore. Rebuidling the Royal Navy. Naval Design since 1945. Seaforth. Barnssley (2013) p 74</ref>

Through their diesel-electric propulsion the Type 41s achieved long range through their low fuel use. The ''Leopard'' class was also fitted with an early type of hydraulic stabiliser system consisting of two fins that could be extended outside the main hull, to port and starboard, from a compartment between the two engine rooms. Gyro controlled with a relatively simple control system, they proved very effective in use. During testing every three months at sea, the ship could be easily driven into a 20°+ roll from the manual control on the bridge. Prior warning had to be given over the ship's tannoy system before testing was carried out, to allow stowage of loose items. Slight reduction in top speed was also noticed when in use.

However, by 1955 success had been achieved, with difficulty and limitations, in developing new steam turbines giving 30-knot speed and the range to take convoys across the Atlantic, embodied in the [[Whitby-class frigate|''Whitby''-class Type 12 frigates]]. As a result, the orders for the new diesel-electric frigates were cancelled, changed to orders for Type 12, or sold to India.

Within a few years of the Type 41's introduction in the late 1950s they were regarded as obsolete for their intended function as anti-aircraft convoy escorts. This was emphasized when the planned replacement of the 4.5" guns with 3"/70 AA guns was abandoned (in January 1955) due to cost and the view that AA guns were obsolete against jets and missiles. <ref>Brown & Moore. Rebilding the RN (2012) p 73-74 & N, Friedman. British Destroyers and Frigates after WW2. Seaforth. Barnsley (2012) p 208-211</ref> Adding power-ramming for the twin 4.5" guns, intended to boost the rate of fire from 14rpm to 24rpm, failed. Innovative additions of [[Whitby class frigate#Armament|STAAG]] ("Stabilised Tachymetric Anti-Aircraft Gun"), [[CIWS]] mount, and replacement of the experimental version of the fast rotating 992 target indicators with the slower standard 993 were all abandoned. Only a short range 262 radar MRS1 provided secondary AA fire control for the main armament.

==Construction and career==
''Betwa'' was [[Keel laying|laid down]] on 29 May 1957 by [[Vickers-Armstrongs|Vickers-Armstrong]] and [[Ceremonial ship launching|launched]] on 15 September 1959. [[Commissioned (ship)|Commissioned]] on 8 December 1960. She was [[Decommissioned (ship)|decommissioned]] on 31 December 1991.<ref name=Conwaysp174>Gardiner, Robert ''Conway's All the World's Fighting Ships 1947–1995'', pub Conway Maritime Press, 1995, {{ISBN|0-85177-605-1}} page 174.</ref>

She was [[Ship breaking|broken up]] in 1998.

==References==
{{reflist}}

{{Leopard class frigate}}

{{DEFAULTSORT:Betwa (1959)}}
[[Category:1959 ships]]
[[Category:Leopard-class frigates]]