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Author Topic: MK 71 Lightweight 8" gun.  (Read 23539 times)

Online sferrin

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MK 71 Lightweight 8" gun.
« on: November 22, 2006, 02:56:49 pm »
Not sure if this is entirely appropriate.  It's a naval weapon but it's a gun.  Maybe we should add a gun section?   ???

At one point it was intended that the forward Mk45 on the Spruance class would be swapped out for these.
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Offline TinWing

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Re: MK 71 Lightweight 8" gun.
« Reply #1 on: November 22, 2006, 03:05:54 pm »
Not sure if this is entirely appropriate.  It's a naval weapon but it's a gun.  Maybe we should add a gun section?   ???

At one point it was intended that the forward Mk45 on the Spruance class would be swapped out for these.

There was a revival of this proposal in the early 1990s, leading to the upcoming 155mm AGS.

Oddly, a 175mm design preceded the 8 inch MCLWG.  Don't ask me how and why the U.S. Army ever adopted a 175mm and 203 mm guns, and I still don't have a clue whether the MCLWG was related to Army's M110 203mm howitzer?

Offline snurg

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Re: MK 71 Lightweight 8" gun.
« Reply #2 on: June 04, 2007, 12:54:24 pm »
Not sure if this is entirely appropriate.  It's a naval weapon but it's a gun.  Maybe we should add a gun section?   ???

At one point it was intended that the forward Mk45 on the Spruance class would be swapped out for these.

There was a revival of this proposal in the early 1990s, leading to the upcoming 155mm AGS.

Oddly, a 175mm design preceded the 8 inch MCLWG.  Don't ask me how and why the U.S. Army ever adopted a 175mm and 203 mm guns, and I still don't have a clue whether the MCLWG was related to Army's M110 203mm howitzer?

I doubt whether the MCGLW was related to the army's 8in howitzer.  It is possible, but the USN has a long tradition of 8in guns, and had quite a few in service into the 60's or 70's.

I also remember reading that the 8in design was preceded by 175mm designs, which were terminated as the army was dropping the 175mm.  Apparently, the USN had quite large stocks of 8in shells, which also made the 8in design more attractive.

Offline smurf

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Re: MK 71 Lightweight 8" gun.
« Reply #3 on: June 05, 2007, 01:37:01 am »
Original 8" howitzer muzzle velocity a bit low for naval use, though a longer barrelled version replaced the long range partner gun of 175mm on the M110, but I don't know how the dates stack up.

Offline Jemiba

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Re: MK 71 Lightweight 8" gun.
« Reply #4 on: June 05, 2007, 11:03:41 am »
For the fans of cut aways :
(from : Norman Friedman "Modern Warship")
It takes a long time, before all mistakes are made ...

Offline Trident

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Re: MK 71 Lightweight 8" gun.
« Reply #5 on: June 05, 2007, 11:58:40 am »
Nice! It's size is quite apparent in those pictures, one of the few modern naval guns that actually look dangerous ;)

Offline uk 75

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Re: MK 71 Lightweight 8" gun.
« Reply #6 on: June 12, 2007, 04:32:21 am »
Have finally got my paws on the Norman Friedman US Amphibious ships as recommended to me from this site.  If you are interested in the saga of the USN's heavy gunnery efforts in the 60s to the present and the fascinating twin version of the standard automatic 5" US gun and some nice drawings of fire support ships I recommend this book.
On a lateral subject Friedman notes that the automatic guns were supposed to be able to fire fast enough to replace heavier types, but in reality they could not. I think the same thing happened to the RN in the Falklands were the earlier turrets performed better than their replacements, but I may be wrong on that.
The saga of the US Army 175mm gun being replaced by 203mm is well covered in Friedman but also applied NATOwide, including the Rhine Army.
UK 75

Offline RyanC

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Re: MK 71 Lightweight 8" gun.
« Reply #7 on: January 13, 2010, 06:54:48 pm »
Photos of the Mk 71 as installed on DD-945 HULL from NARA:

Offline Abraham Gubler

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Re: MK 71 Lightweight 8" gun.
« Reply #8 on: January 13, 2010, 10:12:00 pm »
Have finally got my paws on the Norman Friedman US Amphibious ships as recommended to me from this site.  If you are interested in the saga of the USN's heavy gunnery efforts in the 60s to the present and the fascinating twin version of the standard automatic 5" US gun and some nice drawings of fire support ships I recommend this book.

The Mk 45 was the "lightweight" version of the new 127mm L54 guns. The rival and much heavier Mk 65 was to have a rate of fire of 48 rpm compared to 16-20 rpm of the Mk 45. It was to use pre loaded drums feeding a central carousel.

The Mk 66 was a specialist twin barrel 127mm L54 gun firing from a 100 round drum for the new fire support ships (LFS). ROF would have been 96 rpm and it would have rivaled the exsisting 127mm rocket launchers for area bombardment.

http://www.navweaps.com/Weapons/WNUS_5-54_mk65.htm

On a lateral subject Friedman notes that the automatic guns were supposed to be able to fire fast enough to replace heavier types, but in reality they could not. I think the same thing happened to the RN in the Falklands were the earlier turrets performed better than their replacements, but I may be wrong on that.

The new automatic turrets like the Mk 42, Mk 45 and the British Mk 8 113mm could fire at roughly the same rate as the wartime twin turrets. They also had improved ballistics (range and shell weight) despite the calibre staying the same. The 113mm ammunition of the RN’s Mk 8 is not interchangeable with the twin turret Mk 6.

In the Falklands there were cases of the Mk 8 suffering more frequent mechanical failures than the Mk 6. However you could shoot further with the Mk 8 and no doubt these failures were identified and fixed. In VietNam the RAN stunned the USN (and the RAN) with the effectiveness of the old Daring class destroyer HMAS Vendetta which had to deploy because none of the RAN’s Chalres F. Adams class were available. With three Mk 6 turrets the Vendetta achieved great accuracy, weight of fire and reliability. However to keep this up the CO was often shooting from only two turrets keeping the third down for maintenance. The Vendetta’s heavy 40mm armament was also very useful for maritime interdiction; the shooting up of NVA/VC Junks used to run supplies to the south.

But you can’t really replace a heavier gun like the 203mm with a lighter calibre despite increases in rate of fire. What the heavy shell brings to the NGS mission is increased range, accuracy and shell power to defeat fortifications (including improvised bunkers) and the like. Even heavier shells like the 406mm can also be used to clear beach zone minefields and offer further improvements in accuracy and destruction of fortifications. What is interesting is how these dynamics will be changed by guided rounds like the 127mm BTERM and 155mm LRLAP.
« Last Edit: January 18, 2010, 07:56:26 pm by Abraham Gubler »
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Offline Pioneer

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Re: MK 71 Lightweight 8" gun.
« Reply #9 on: January 14, 2010, 03:42:57 am »
I find the information on the Mk 66 barrel 127mm L54 gun very interesting
Thanks for bring it up!
I think the drive for lightweight may have gone to far in Western Navy at some time - hence why I agree and understand the statement
 
Quote
In the Falklands there were cases of the Mk 8 suffering more frequent mechanical failures than the Mk 6. However you could shoot further with the Mk 8 and no doubt these failures were identified and fixed. In VietNam the RAN stunned the USN (and the RAN) with the effectiveness of the old Daring class destroyer HMAS Vendetta which had to deploy because none of the RAN’s Chalres F. Adams class were available. With three Mk 6 turrets the Vendetta achieved great accuracy, weight of fire and reliability. However to keep this up the CO was often shooting from only two turrets keeping the third down for maintenance.

Isn't it some what ironic just how much the West had to relearn after the Falkland Islands War of 1982. And yet in someways we still have not implemented these lesson's or think we know better once again!

Where the West went through a period of discarding the purpose built gun mount on their modern warships, it appears that the Soviet's knew something or just didn't forget when they developed and fielded the 130 mm/70 AK-130 twin DP mount.
Saying this maybe a Mk 66 twin 127mm or 114mm type mount has a lot of merit!
But then again we in the West would probably over-engineer it, make it way to costly and if the U.S Navy is behind its development - cancel the whole program at the time it has been proven and perfected!

P.S. I think in the West the reverting back to the likes and the capability of the warrented 203mm Mk 71 is and will always run up against the likes of the missile lobby in our navies - Pity!!!!

Regards
Pioneer  
« Last Edit: January 14, 2010, 03:45:13 am by Pioneer »
And remember…remember the glory is not the exhortation of war, but the exhortation of man.
Mans nobility, made transcendent in the fiery crucible of war.
Faithfulness and fortitude.
Gentleness and compassion.
I am honored to be your brother.”

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Offline Pioneer

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Re: MK 71 Lightweight 8" gun.
« Reply #10 on: January 14, 2010, 03:49:40 am »
Quote
The Mk 66 was a specialist twin barrel 127mm L54 gun firing from a 100 round drum for the new fire support ships (LFS).

Sorry a little of topic - but does anyone have anything on this proposed Fire Support Ship (LFS)
and what time period was the Mk 66 twin 127mm mount program?

Regards
Pioneer
And remember…remember the glory is not the exhortation of war, but the exhortation of man.
Mans nobility, made transcendent in the fiery crucible of war.
Faithfulness and fortitude.
Gentleness and compassion.
I am honored to be your brother.”

— Lt Col Ralph Honner DSO M

Offline Sea Skimmer

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Re: MK 71 Lightweight 8" gun.
« Reply #11 on: January 16, 2010, 01:22:39 pm »

There was a revival of this proposal in the early 1990s, leading to the upcoming 155mm AGS.

Oddly, a 175mm design preceded the 8 inch MCLWG.  Don't ask me how and why the U.S. Army ever adopted a 175mm and 203 mm guns, and I still don't have a clue whether the MCLWG was related to Army's M110 203mm howitzer?

The US Army adapted a 175mm gun because with the technology of the time this caliber was necessary to achieve significantly greater ranges then the M1 155mm gun was capable of for the counter battery mission. The specific caliber choice was driven by the success of the German 17cm K 18 in WW2, and older work involving the French 194mm GPF. The Soviet adoption of the 180mm S-23 long range gun in the mid 1950s was further driver, though at the time the US actually thought this was an 8in weapon since we only had photos to scale from. It wasn't until 1973 that Israel captured a few and the truth was learned.

The US Army only ever had an proper 8in gun during WW2 (we had railroad pieces in WW1), which had to transported in two pieces and shared a carriage with the 240mm howitzer. A 20 ton truck crane assembled them in position, though winches and A-frames could also be used. Both were tested on self propelled mountings using the Pershing Tank, but the war ended before either was mass produced.  Both weapons were retired in the mid 1950s when we ran out of ammunition for them. The 240mm howitzer saw action in Korea, but not the 8 inch gun. A single prototype of a 240mm gun was produced, which is on display in Virginia. It formed the basis for the postwar 280mm atomic cannon.

All postwar US 8in weapons are howitzers with significantly shorter range and much less weight. The Navy 175mm and then 8in program would have shared ammo with the Army, but not any piece of the gun itself.


Offline Abraham Gubler

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Re: MK 71 Lightweight 8" gun.
« Reply #12 on: January 18, 2010, 08:12:10 pm »
Sorry a little of topic - but does anyone have anything on this proposed Fire Support Ship (LFS)
and what time period was the Mk 66 twin 127mm mount program?

Friedman's "U.S. Amphibious Ships and Craft" has a whole chapter on the development of LFS in the late 60s and then later in the mid 80s. None of these ships were built and they included several purpose built designs and conversion of the Spurance class design. A quick summary of the designs is:

1967 high end LFS: 8,000 tons, 2x 203mm, 2x Mk 45 127mm, 8x Mk 105 127mm rocket launchers, one landing force fire support weapon (LFSW) a Lance type missile launcher
1967 monitor LFS: 9,000 tons, 3x 406mm, 1x 175mm, 2x Mk 42 127mm
1968 LFSR: 7,825 tons, 2x 175mm, 4 x Mk 45 127mm, BPDMS, 12x Mk 105 launchers
1969 inshore LFS: 2x 175mm, >4x Mk 105 launchers
1970 Spruance LFS: 7,461 tons, 2x MCLWG, 1x Mk 45 127mm, BPDMS, ASROC
1970 LFS: 7,856 tons, 3x Mk 71 203mm, 2x Mk 66 twin 127mm, BPDMS
1986 LFS v3: 1x Mk 71 203mm (500 rounds), 1 x MLRS (900 rockets), 2x Phalanx
1986 LFS v4: 2x Mk 71 203mm, 2x Phalanx
1986 LFS v7: 2x Mk 71 203mm, 2 x MLRS, 2x Phalanx
"There is a tendency in our planning to confuse the unfamiliar with the improbable." Thomas Schelling

Offline Pioneer

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Re: MK 71 Lightweight 8" gun.
« Reply #13 on: January 19, 2010, 01:54:36 am »
Thanks heaps for this info Abraham Gubler
These look very impressive proposals/programs
Are there any drawings/artist impressions to go with these ? ??? :o ;D

One thing that I have never completely understood is the US Navy's apparent reluctance to consider, let alone field a navalized variant of the army's MLRS system!
Ok some people would say that to use them would bring US Amphibious units into harms way!
Some would say that the loading/reloading process is unacceptable on a ship!
Its strange - but as far as multiple rockets launchers on Western/NATO ships go in the amphibious support fire role, I think only the Italian navy utilize them aboard there ships(??)

Regards
Pioneer
And remember…remember the glory is not the exhortation of war, but the exhortation of man.
Mans nobility, made transcendent in the fiery crucible of war.
Faithfulness and fortitude.
Gentleness and compassion.
I am honored to be your brother.”

— Lt Col Ralph Honner DSO M

Offline Abraham Gubler

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Re: MK 71 Lightweight 8" gun.
« Reply #14 on: January 19, 2010, 02:19:00 am »
These look very impressive proposals/programs
Are there any drawings/artist impressions to go with these ? ??? :o ;D

Yeah there are a bunch of SCB drawings. But bear in mind that this is a freely available book and its not the policy of this web forum to copy stuff from books… If you have access to a university or state library they should have a copy of Friedman’s books.

Also parts of this book are available online at Google Books:

http://books.google.com/books?id=oWX-x0b4pw4C&printsec=frontcover&dq=u.s.+amphibious+ships+and+craft&cd=1#v=onepage&q=&f=false

Including much of the chapter on the LFS options (Fire Support Revisited).

One thing that I have never completely understood is the US Navy's apparent reluctance to consider, let alone field a navalized variant of the army's MLRS system!
Ok some people would say that to use them would bring US Amphibious units into harms way!
Some would say that the loading/reloading process is unacceptable on a ship!

Well that’s not true. The US Navy has extensively considered, trailed and designed naval MLRS and ATCAMS in both trainable launcher and vertical launcher options for their ships. Its just they haven’t had the money or got sidetracked into 155mm artillery options, which is a great shame because MLRS is ideal for NGS. It can do all the missions required with a single system (albeit with three different rocket types).

Its strange - but as far as multiple rockets launchers on Western/NATO ships go in the amphibious support fire role, I think only the Italian navy utilize them aboard there ships(??)

The Italians like the Israelis have rocket launchers on their ships mostly for launching decoys. The US Navy on the other hand has fired more rockets from their ships than the rest of the world combined. The LSM(R) and IFS types perfected the mass bombardment area rocket capability. This enabled a single ship to shoot up to 400 127mm rockets per minute for 30 minutes. Was to be replaced by the Mk 66 twin barrelled 127mm L54 gun which in a four turret, 750 rpg ship would provide the same capability but with better range, accuracy and far more compact ammunition storage.
"There is a tendency in our planning to confuse the unfamiliar with the improbable." Thomas Schelling