Naval Gun Projects

[RP1]

The base was to be the same as 20mm Phalanx, I believe.

I found I couldn't make it fit on a Phalanx base - assuming the drawing is accurate It would have been wider.

Also I *knew* I'd posted it somewhere, but couldn't find the post, so tried to count the barrels from the drawing

 

[TomS]

The base was to be the same as 20mm Phalanx, I believe.

I found I couldn't make it fit on a Phalanx base - assuming the drawing is accurate It would have been wider.

Also I *knew* I'd posted it somewhere, but couldn't find the post, so tried to count the barrels from the drawing

I've been hunting for the other info I've seen on that. I thought for sure it was in one of the Friedman World Naval Weapons books but I cannot find it.

 

[Firefinder]

The Navy also worked on putting a 60mm revolver cannon on the Phalanx mount in the early 90s.

You can see it here in the video.

Real interesting gun that you cant find much of. Apperantly it was to shot a guided shell and was to have the option for a below decks reloading system like on the Oto Melara 76mm Sovraponte along with a larger built in mag for the production version. Died like many interesting things did in the 90s.

 

[TomS]

The Navy also worked on putting a 60mm revolver cannon on the Phalanx mount in the early 90s.

You can see it here in the video.

Real interesting gun that you cant find much of. Apperantly it was to shot a guided shell and was to have the option for a below decks reloading system like on the Oto Melara 76mm Sovraponte along with a larger built in mag for the production version. Died like many interesting things did in the 90s.

Thanks for digging up that video. The 60mm electrothermal gun embodied a couple of new developments together on one system, which probably didn't help its prospects. It needed guided rounds, and fitting that in 60mm was probably pushing the state of the art at the time. And of course it needed ETC to work, and I'm not sure it really ever lived up to it's promise.

If there had been appetite for a medium caliber guided AA round, fitting it into the 76mm gun would have made more sense to work with the existing guns on the FFGs and then possibly replacing Phalanx on new ships like the DDG-51s. Requiring both a new gun and new ammo at once made for too much risk in one project.

 

[Tzoli]

So the shell would look like something to a fin stabilised / guided shell? Or like a Maverick missile without the rocket motor?

 

[Firefinder]

So the shell would look like something to a fin stabilised / guided shell? Or like a Maverick missile without the rocket motor?

I have seen a picture of a mock up shell and it looked like a maverick without fins and it was to use a similar trick as what the Zeus shell of 1950 vintage was to to use, small retro rockets to kick the shell into posistion to hit the target.

 

[TomS]

So the shell would look like something to a fin stabilised / guided shell? Or like a Maverick missile without the rocket motor?

I have seen a picture of a mock up shell and it looked like a maverick without fins and it was to use a similar trick as what the Zeus shell of 1950 vintage was to to use, small retro rockets to kick the shell into posistion to hit the target.

Interesting. Side thrusters is a tried and true technique (ASTER uses something similar called PIF-PAF).

In looking for a picture of the shell, I came across a really odd study on mining technology (bear with me). Around 2003, Department of Energy was researching the use of gun-fired projectiles for excavation. They apparently got hold of the old 60mm ETC gun for their experiment and reworked it as a conventional powder gun for the test. The interesting thing is that the cases they used for the reworked gun came from IMI. Which suggests the original chamber was similar enough to the IMI 60mm AFV gun for the cases to be usable.

REDUCED ENERGY CONSUMPTION THROUGH PROJECTILE BASED EXCAVATION (Technical Report) | OSTI.GOV

The U.S. Department of Energy's Office of Scientific and Technical Information

www.osti.gov

 

[Firefinder]

So the shell would look like something to a fin stabilised / guided shell? Or like a Maverick missile without the rocket motor?

I have seen a picture of a mock up shell and it looked like a maverick without fins and it was to use a similar trick as what the Zeus shell of 1950 vintage was to to use, small retro rockets to kick the shell into posistion to hit the target.

Interesting. Side thrusters is a tried and true technique (ASTER uses something similar called PIF-PAF).

In looking for a picture of the shell, I came across a really odd study on mining technology (bear with me). Around 2003, Department of Energy was researching the use of gun-fired projectiles for excavation. They apparently got hold of the old 60mm ETC gun for their experiment and reworked it as a conventional powder gun for the test. The interesting thing is that the cases they used for the reworked gun came from IMI. Which suggests the original chamber was similar enough to the IMI 60mm AFV gun for the cases to be usable.

REDUCED ENERGY CONSUMPTION THROUGH PROJECTILE BASED EXCAVATION (Technical Report) | OSTI.GOV

The U.S. Department of Energy's Office of Scientific and Technical Information

www.osti.gov

I do believe I found the PDF where I found it.

Should be in here if I done this right. If I haven't Ill just post a screenshot of the shell.

 

[TomS]

I do believe I found the PDF where I found it.

Should be in here if I done this right. If I haven't Ill just post a screenshot of the shell.

Excellent!

So the projectile is hit to kill and basically consists of a small penetrator on top of a large divert and attitude control system. It's actually similar to the kinetic kill vehicles used for ballistic missile defense. The gas generator produces high volumes of gas, which are vented from probably two valves around the middle of the shell (two rather than four because the projectile is rolling). The shell has no actual seeker; it sends trajectory data via a rearward-looking antenna and receives course update instructions from the launch platform the same way.

It seems to have a sabot, if only to allow that very conical shell to ride the barrel easily, and possibly to protect that aft-facing antenna. There are shallow strakes/fins for some additional stability.

This would have been a pretty expensive projectile, I expect, even with the sophisticated guidance technology offloaded to the launcher.

Edit: I went ahead and pulled out the image of the 60mm shell for ease of reference.

 

[TomS]

Two additional tidbits

A paper on the shell aerodynamics, behind a paywall for me. https://arc.aiaa.org/doi/abs/10.2514/6.1993-3461

And a slide showing the fin configuration (looks like 6 fins) and giving a range of 2750m (probably effective range).

 

[jsport]

Minus the UK Starstreak which has its own uses, the above shows 3 systems which should be in service if it were not for dysfunction.

 

[Grey Havoc]

The 'Peace Dividend' and so-called 'End of History' madness clobbered a lot of good programs & projects.

 

[jsport]

Binary fuels can be safely stored and utilized safely according to the patents as has been repeatedly posted.

Lightweight 155 mm Liquid-Propellant Naval Gun Mount. In 1993, Martin Marietta announced a lightweight 155 mm liquid-propellant naval gun mount for this advanced gun program. It hopes to reach a range of 45 nautical miles with existing ammunition, and to exceed 100 miles with new projectiles, a rate of fire of 11 to 16 rounds per minute, and a velocity accuracy of better than 0.25 percent. It should then be able to fire a 4- to 8-round simultaneous impact mission at 6 to 40 kilometers. Range is increased because there is a capability to precisely inject propellant throughout the combustion process. The system offers soft launch with reduced chamber pressure, and ammunition storage volume is reduced because there are no cartridge cases. Martin Marietta estimates that this 155 mm L52 will weigh 40,000 pounds (compared to 110,000 lb for an 8-inch L55), and will achieve a range of 54,000 yards. Elevation limits are +65 to -15 degrees; rate of fire is 16 to 29 rounds per minute with 60 ready-use rounds. This development has since been at least partly overtaken by the introduction of the L62 barrel on the Mk 45 gun with the capability of firing extended range guided munitions (ERGM). The combination of extended barrel and non-ballistic guided munition will extend the gun’s coverage to about 60 miles (100+ km). Meanwhile, a new 155 mm gun mount is being developed (as a derivative from the USMC 155 mm unit); the DD(X) class will presumably be the first platform to adopt it.

Background. In 1987, FMC (now part of United Defense) announced the development of its combustion-augmented plasma (CAP) technology for advanced gun development. Two major fields of exploitation were envisaged: long-range fire support for shore operations and close-range anti-missile defense. In the 1987 announcement, FMC showed its version of CIWS-2000, which used CAP and carried two rather than six barrels. The first experiments used 10 mm projectiles. Later, 30 mm were used, and FMC expected to fire 90 mm projectiles. All of these experiments used liquid propellants, although a conventional solid propellant might also be used. In 1987, FMC applied its CAP technology to an Air Force funded hypervelocity ammunition technology (HAT) program in which a sideways-pointing anti-tank gun was to be mounted onboard a C-130 or successor gunship that would fly just behind the battle line. CAP was also proposed as part of a hybrid rail gun for anti-missile defense, to be used to inject a projectile into the electric gun. FMC patented its CAP concept in 1985, and in 1990 it began a CAP naval gun project under the US Navy’s Balanced Technology Initiative. The weapon developed under this program is designated the electrothermal gun, and is considered a much nearerterm proposition (e.g., for point defense) than a full electric gun. Compared to alternative exotic guns, CAP can use a conventional barrel and projectiles. FMC claims that CAP offers better reliability and internal ballistics control than a liquid-propellant gun. In late 1990, the US Navy acknowledged the need for a new-generation close-in defense system to combat the latest anti-ship missiles. The use of electrothermal gun technology promised a new weapon that would use the same trunnion that housed the Phalanx system but offer significantly increased performance. Design work commenced in the last quarter of 1990, and was to be completed in the last quarter of 1991. A 31-month design contract valued at US$4.6 million was awarded to FMC for development of the new weapon in November 1990. The FMC 60 mm electrothermal gun and its Martin Marietta (formerly GE) guided round small-caliber smart munition (SCSM) were tested successfully during 1992/93. The SCSM contract was awarded in the autumn of 1991. The 1.75 kilogram rolling-airframe steel shell (illustrated in this report) uses a K-band guidance uplink and an E/F-band telemetry downlink. It carries a thermal battery and a miniature propulsion Electrothermal (ET) Gun, control using a small solid-propellant thruster. Muzzle velocity is 1.4 kilometers per second (4,260 ft/sec); SCSM can maneuver at 40g at Mach 4. Like Phalanx, this weapon kills by impact, not by explosion. Of the seven saboted projectiles successfully fired at Dahlgren Naval Base in the second half of 1992, five carried live gas generators and thermal batteries. The K-band command link was tested over water at Dahlgren in February 1993. Tests against airborne targets were scheduled for late 1994. The gun is an autoloader on a Phalanx mounting. Firing rate is 4 rounds per second/10 round burst); elevation limits are +40/-5 degrees. Following a 30-month design and development program, the first 60 mm ET gun was delivered to the US Navy in July 1993. Following the completion of final NSWC acceptance trials, the gun, autoloader and other program elements – including propellant charges, guided projectiles and the TASD target acquisition system – will be integrated during a series of live firings against airborne targets. In December 1994, the US Navy announced that it expected to make a decision on the feasibility of using electrothermal gun technology for future naval weapons by 1998. The studies, costing some US$107 million, would determine if a 155 mm electrothermal gun would provide a feasible, practical, and affordable solution for the US Navy’s naval surface fire-support requirements. The study program would use a 5-inch L54 Mk 45 mount as a design baseline to evaluate the technology issues involved. The objective is to increase the gun range from its existing 27 kilometers to a maximum of 150 kilometers, and to integrate this improved performance with a new guided round. However, by mid-1996, the whole US Navy side of this program was strongly de-emphasized in favor of the Army-related aspects. No work was being carried out on the naval weapons and no early introduction to service was predicted by company officials. The performance increments gained by the introduction of combustion-augmented plasma technology are evolutionary rather than revolutionary, but, combined with the development of practical guided projectiles, are sufficient to restore a substantial measure of credibility to gun-based CIWS. The application of CAP technology to basic conventional gun designs means that the 60 mm ET-gun technology demonstrator should be adaptable to a service weapon within the forecast period. The timing of such a program will be determined by funding constraints. At present, other priorities are considered more pressing.

 

[Colonial-Marine]

Seems a shame that all of this has apparently gone to waste and not resulted in any new weapon systems at sea (or on land) 20+ years later.

I wonder how the 60mm ETC gun system would compare in effectiveness to the current 57mm Bofors?

 

[ceccherini]

A guy in a Japanese forum wrote that just before Japan entry in WW2 a 53 cm/45 protype gun was planned by IJN. Has any of you ever heard of this? Personally I've many doubts mainly because it seems a far too small improvement over the 51 cm to justify a new design and because a more conservative 50 caliber variant of the 51 cm would give basically the same improvement. Still the idea of a gun over 20 inches at least as a trial gun is not totally fool: the two ocean navy act effectively grounded the Japanese battleship policy by making realistic American battleship larger than Panama locks and already Montanas were believed by the Japanese to be equipped with 8 20". Taking in mind that gun minded officers were still dominant some consideration to a larger gun seems quite logical through a 56 cm or a 61 cm would be a more coherent step. 6 of such guns should be a workable alternative to 8 51 cm on the planned 90-100000 ton post A150 battleships.

 

[Tzoli]

No no no
The Peace Goddess doctrine foreshadowed that the Montanas would be equipped with 18" cannons not 20" hence Yamato upgunning and new construction would be 51cm (510mm not 508 ) armed vessels to provide gunnery superoritiy over them. Yamato being superior over North Carolina, South Dakota and Iowa.

Can you link to this Japanese forum?

A Prototype or Test gun is not impossible as in the late 1910s early 1920s 48cm cannons were constructed to test new large calibre barrel construction methods for the 46cm and possibly for a future 51cm weapon. This 53cm if true would be a logical extension of that idea to test out the 51cm and possible future 56cm weapon though it was stated that the 51cm Type 98 was simply an enlarged 46cm Type 96 (Note that in 1934 there were proposals for a 46cm/50 weapon as the very first Yamato preliminaries were designed with this weapon in mind! )

 

[ceccherini]

No no no
The Peace Goddess doctrine foreshadowed that the Montanas would be equipped with 18" cannons not 20" hence Yamato upgunning and new construction would be 51cm (510mm not 508 ) armed vessels to provide gunnery superoritiy over them. Yamato being superior over North Carolina, South Dakota and Iowa.

Can you link to this Japanese forum?

A Prototype or Test gun is not impossible as in the late 1910s early 1920s 48cm cannons were constructed to test new large calibre barrel construction methods for the 46cm and possibly for a future 51cm weapon. This 53cm if true would be a logical extension of that idea to test out the 51cm and possible future 56cm weapon though it was stated that the 51cm Type 98 was simply an enlarged 46cm Type 96 (Note that in 1934 there were proposals for a 46cm/50 weapon as the very first Yamato preliminaries were designed with this weapon in mind! )

You're confusing 1934 predictions and 1940 intelligence: by 1940 Congressional report on 20" gunned battleships, even if absolutely not grounded in real construction activities or even General Board discussions, were widely circulating and taken very seriously by IJN

 

[Tzoli]

Problem is, the largest calibre ever considered for the Montana was the 18" cannon. The 20" was shown for the 1935/36 Maximum Battleship study only.

 

[CIC-TAO]

First up, a 35mm CIWS proposal presented at the 1991 US Navy League show.

Source: Navy International, November 1991, Vol 96, No 11, Publ: Maritime World Limited

EDIT
Some information from the same source:

• GD proposal to use GE Cased Telescoped ORDALT 35mm weapon system.
• 8 barrels.
• 8000rpm.
• Balanced linkless feed holding 1200 APDS rounds.
• Nearly 6x on target energy per shot compared with 20mm Phalanx.
• Dispersion of less than 1mrad.
• MV greater than 1130m/s.

I tried to find these magazines myself, I looked for <Navy International, November 1991, Vol 96, No 11> and found no CIWS articles as you mentioned.

Can you tell me exactly which page it is on?
Is it the text or the ad?

 

[RP1]

First up, a 35mm CIWS proposal presented at the 1991 US Navy League show.

Source: Navy International, November 1991, Vol 96, No 11, Publ: Maritime World Limited

EDIT
Some information from the same source:

• GD proposal to use GE Cased Telescoped ORDALT 35mm weapon system.
• 8 barrels.
• 8000rpm.
• Balanced linkless feed holding 1200 APDS rounds.
• Nearly 6x on target energy per shot compared with 20mm Phalanx.
• Dispersion of less than 1mrad.
• MV greater than 1130m/s.

I tried to find these magazines myself, I looked for <Navy International, November 1991, Vol 96, No 11> and found no CIWS articles as you mentioned.

Can you tell me exactly which page it is on?
Is it the text or the ad?

There was a typo in the original post. It is the October 1991 issue, in an article entitled "CIWS Anti-Air Defence".

 

[cattalonX]

anyone know something about this 20" gun？？？

Washington Cherry Trees II./ Part 3

The G3

warshipprojects.com

USN 20”/45 Mark 1 * (508mm)

1860

792

583

it has shell weight and muzzle velocity·····

 

[Tzoli]

From Norman Friedman Naval Weapons of WW1:
A Gun design offered late ww1 in around 1917, no actual barrel constructed but it was used for the 1935/36 maximum battleship design (4x2 20")
Shell Weight: 1860kg
Muzzle Velocity: 792m/s