By: kato
- 11th September 2009 at 00:26Permalink- Edited 1st January 1970 at 01:00
The railgun has the advantage of higher rates of fire owing to its unique mechanism.
Compared to a chemical gun of similar caliber and delivered energy? Definitely not. The current railgun designs fire at 6-10 rounds per minute, because the sucker heats up like crazy, and the Navy is demanding 12 rpm. Oh, and of course you still have to mount a fresh track every dozen or so rounds right now.
20+ km/s ? Usable current designs of useful caliber fire at 2.3-2.5 km/s, which is 40-50% higher than current chemical high-pressure guns (albeit with projectiles that weigh only one-third of what a chemical gun would fire, meaning they actually perform at best in the same energy rating). The current target is to bring that up to 5.8 km/s - in the next 10 to 15 years.
By: SpudmanWP
- 11th September 2009 at 01:33Permalink- Edited 1st January 1970 at 01:00
Here are the railgun advantages, once the development is done.
1. Higher rate of fire. A less massive shell can be manipulated faster into a firing position. With all things being equal, this allows for a higher ROF.
2. Lower ammo storage requirements, no powder needed.
3. Better transfer of energy to projectile. In a chemical round, all of the impulse is applied to the round at the start and then drops off till the round leavs the barrel. In a railgun, the acceleration is constant fo the entire barrel.
4. Less duds. With a gentler acceleration, the electronics come under less G stress upon firing.
By: talltower
- 11th September 2009 at 07:06Permalink- Edited 1st January 1970 at 01:00
Here are the railgun advantages, once the development is done.
1. Higher rate of fire. A less massive shell can be manipulated faster into a firing position. With all things being equal, this allows for a higher ROF.
2. Lower ammo storage requirements, no powder needed.
3. Better transfer of energy to projectile. In a chemical round, all of the impulse is applied to the round at the start and then drops off till the round leavs the barrel. In a railgun, the acceleration is constant fo the entire barrel.
4. Less duds. With a gentler acceleration, the electronics come under less G stress upon firing.
By: kato
- 11th September 2009 at 11:08Permalink- Edited 1st January 1970 at 01:00
A less massive shell can be manipulated faster into a firing position. With all things being equal, this allows for a higher ROF.
Except if you fire at higher ROF, your barrel - or in the railgun your track - will melt. And pretty quickly. The Navy is trying to get its railgun design to the point where the track lasts close to 10 seconds (actually more like 8-9) under its current full ROF. A Mk45 or Vulcano could go 400 seconds with a big enough magazine feed, and even high-pressure tank guns would last easily 30-40 seconds at full ROF.
In a chemical round, all of the impulse is applied to the round at the start and then drops off till the round leavs the barrel.
Umm, no? That would be the case if one used explosives to propel the projectile instead of gunpowder, which (relatively) slowly burns while propelling the projectile.
With a gentler acceleration, the electronics come under less G stress upon firing.
... the 64-MJ railgun for the Navy is intended to accelerate at up to 50,000 g. That's twice the g stress encountered in a conventional gun. In any trainable gun, you can't just extend the track to 100 ft.
By: SpudmanWP
- 11th September 2009 at 16:42Permalink- Edited 1st January 1970 at 01:00
Except if you fire at higher ROF, your barrel - or in the railgun your track - will melt. And pretty quickly. The Navy is trying to get its railgun design to the point where the track lasts close to 10 seconds (actually more like 8-9) under its current full ROF. A Mk45 or Vulcano could go 400 seconds with a big enough magazine feed, and even high-pressure tank guns would last easily 30-40 seconds at full ROF.
I did say once the tech matures. A MBT can last a lot longer than a minute at full ROF, I know because I was the loader :)
Umm, no? That would be the case if one used explosives to propel the projectile instead of gunpowder, which (relatively) slowly burns while propelling the projectile.
A chemical round still produces it's greatest G loadings at the first moments of ignition with the G loading falling off until the projectile leaves the barrel.
... the 64-MJ railgun for the Navy is intended to accelerate at up to 50,000 g. That's twice the g stress encountered in a conventional gun. In any trainable gun, you can't just extend the track to 100 ft.
To get a chemical round to those performance levels it would expose the shell to greater than 50k G.
You missed my point. I was not comparing a specific railgun to a specific chemical gun, but the general benefits of railguns once the tech has matured.
By: radar
- 11th September 2009 at 19:20Permalink- Edited 1st January 1970 at 01:00
relating to the topic i think we are talking about railguns as a ciws or as a air defence weapon system. so we are talking about a rof which is much higher than 10 rounds/min. e.g.
single barrel systems mlg27 (27 mm) 1700 rounds/minute
gatling systems 4500, 6000 and more rounds/minute
i want to see a railgun which can top this ;-)
imho we will see direct-energy weapons (most probably lasers) into service years before a aaw-capable railgun will enter service. imho the development today is more focused on replacing higher caliber mainguns with a railgun.
By: sferrin
- 12th September 2009 at 14:18Permalink- Edited 1st January 1970 at 01:00
The projectiles are too small to have guidance systems, and with the extraordinarily high velocity of 20+ km/sec, it can hit any target in less than a few microseconds. The railgun has the advantage of higher rates of fire owing to its unique mechanism.
ROFL!!! 20+ km/sec? ROFLMAO!!! And even at 20 km/sec it's not going to go very far in a "few microseconds". Pull your head out.
The same considerations apply to an anti-ship missile.
Russian missiles are hardened against shrapnel aleady.
And I'm sure the question of targeting in adverse weather can be solved.
Can't build a (primary?) defensive system - any system - that is dependant on nice sunshine.
The same considerations apply to an anti-ship missile.
Russian missiles are hardened against shrapnel aleady.
And I'm sure the question of targeting in adverse weather can be solved.
Can't build a (primary?) defensive system - any system - that is dependant on nice sunshine.
I agree. On the other hand if you hit the missile hard enough even a mile or two will do the trick in most cases.
By: Distiller
- 14th September 2009 at 09:38Permalink- Edited 1st January 1970 at 01:00
That BAE railgun doesn't look realistic. And I bet if you just take that energy needed for the railgun and use it for the shipboard AESA radar to burn the electronics of that incoming missile it might be as effective.
But what is wrong with guns as last defense? Like the 35mm Millennium? Even a missile coming in at 600m/s will be exposed to a cloud of projectiles for 4 or 5 seconds. The missile's maneuvering ability won't amount to much, cause at that phase it's already heading almost straight towards the ship.
By: swerve
- 14th September 2009 at 12:22Permalink- Edited 1st January 1970 at 01:00
But what is wrong with guns as last defense? Like the 35mm Millennium? Even a missile coming in at 600m/s will be exposed to a cloud of projectiles for 4 or 5 seconds. The missile's maneuvering ability won't amount to much, cause at that phase it's already heading almost straight towards the ship.
A large supersonic missile may be severely damaged, but the momentum of the wreck will carry it forward. There's a very good chance it will still hit. Even if the warhead is disabled, the kinetic energy alone will be very damaging to any ship, & any unburnt fuel would start fires.
By: Distiller
- 14th September 2009 at 13:55Permalink- Edited 1st January 1970 at 01:00
A large supersonic missile may be severely damaged, but the momentum of the wreck will carry it forward. There's a very good chance it will still hit. Even if the warhead is disabled, the kinetic energy alone will be very damaging to any ship, & any unburnt fuel would start fires.
I'm aware of such considerations. It's like after WW2 when the Bofors were exchanged for Mark 27.
A Millennium is basically designed to kill a 750-800m/s target with a 1 second burst in the 2250 to 1500 yards belt (everything +/-). The chances that a damaged missile takes a dive over that distance seems pretty high.
Also the system requirements and dependance from central power of a gun seems considerable lower than for a railgun or laser, of importance for survivability in case of more than one hit. Localized emergency hi-power energy supply like some Russian style rocket-generator set would certainly be possible, but much more complex than what a gun needs for emergency supply. Sensors, C2, networking would be identical.
A railgun's low rate of fire (so far) could be a problem. Even with a very fast railgun a missile still flies a multiple of its own length from firing till intercept. Not good for a very-low-rate-of-fire weapon!
And lasers (besides the weather, &c) still need seconds to illuminate a target before it goes boom, and the aspect angle is really not optimal to disable a missile. As long as lasers do not cause instant destruction they are not suitable as CIWS.
New
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By: obligatory
- 14th September 2009 at 15:13Permalink- Edited 1st January 1970 at 01:00
I just think shells has too short range vs super/hyper-sonic missiles, still good point defense vs slower missiles.
By: Jason Simonds
- 15th September 2009 at 02:42Permalink- Edited 1st January 1970 at 01:00
Horses for courses. Helos and aircraft will find it difficult - if not impossible - to handle a Brahmos-class missile, but that doesn't mean such a weapon is useless altogether, other platforms (like large surface ships) will have no issues.
What you're saying is that the PzH2000 artillery piece is irrelevant because Germany also builds the G36 assault rifle :rolleyes:
Not at all. But supersonics are portrayed as instant death for surface combatants and yet REAL Pussers and other Naval warfare officers who train AGAINST these threats are not as concerned by them as the fanboys who like to portray these missiles as invincible simply because they are fast...
Low and slow may not be as "sexy" as something going Mach 4 and lighting up the sky with an enormous thermal bloom, but they sure scare the hell out of people who may be at risk from them...
Posts: 138
By: kato - 11th September 2009 at 00:26 Permalink - Edited 1st January 1970 at 01:00
Compared to a chemical gun of similar caliber and delivered energy? Definitely not. The current railgun designs fire at 6-10 rounds per minute, because the sucker heats up like crazy, and the Navy is demanding 12 rpm. Oh, and of course you still have to mount a fresh track every dozen or so rounds right now.
20+ km/s ? Usable current designs of useful caliber fire at 2.3-2.5 km/s, which is 40-50% higher than current chemical high-pressure guns (albeit with projectiles that weigh only one-third of what a chemical gun would fire, meaning they actually perform at best in the same energy rating). The current target is to bring that up to 5.8 km/s - in the next 10 to 15 years.
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By: SpudmanWP - 11th September 2009 at 01:33 Permalink - Edited 1st January 1970 at 01:00
Here are the railgun advantages, once the development is done.
1. Higher rate of fire. A less massive shell can be manipulated faster into a firing position. With all things being equal, this allows for a higher ROF.
2. Lower ammo storage requirements, no powder needed.
3. Better transfer of energy to projectile. In a chemical round, all of the impulse is applied to the round at the start and then drops off till the round leavs the barrel. In a railgun, the acceleration is constant fo the entire barrel.
4. Less duds. With a gentler acceleration, the electronics come under less G stress upon firing.
5. No muzzle flash (of powder anyways).
6. Safer operations... remember the USS Iowa
Here is the US Navy's FAQ on railguns
http://www.onr.navy.mil/emrg/faqs-electromagnetic-railgun.asp
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By: talltower - 11th September 2009 at 07:06 Permalink - Edited 1st January 1970 at 01:00
About the railgun.
Posts: 138
By: kato - 11th September 2009 at 11:08 Permalink - Edited 1st January 1970 at 01:00
Except if you fire at higher ROF, your barrel - or in the railgun your track - will melt. And pretty quickly. The Navy is trying to get its railgun design to the point where the track lasts close to 10 seconds (actually more like 8-9) under its current full ROF. A Mk45 or Vulcano could go 400 seconds with a big enough magazine feed, and even high-pressure tank guns would last easily 30-40 seconds at full ROF.
Umm, no? That would be the case if one used explosives to propel the projectile instead of gunpowder, which (relatively) slowly burns while propelling the projectile.
... the 64-MJ railgun for the Navy is intended to accelerate at up to 50,000 g. That's twice the g stress encountered in a conventional gun. In any trainable gun, you can't just extend the track to 100 ft.
Posts: 5,197
By: SpudmanWP - 11th September 2009 at 16:42 Permalink - Edited 1st January 1970 at 01:00
I did say once the tech matures. A MBT can last a lot longer than a minute at full ROF, I know because I was the loader :)
A chemical round still produces it's greatest G loadings at the first moments of ignition with the G loading falling off until the projectile leaves the barrel.To get a chemical round to those performance levels it would expose the shell to greater than 50k G.
You missed my point. I was not comparing a specific railgun to a specific chemical gun, but the general benefits of railguns once the tech has matured.
Posts: 210
By: radar - 11th September 2009 at 19:20 Permalink - Edited 1st January 1970 at 01:00
relating to the topic i think we are talking about railguns as a ciws or as a air defence weapon system. so we are talking about a rof which is much higher than 10 rounds/min. e.g.
single barrel systems mlg27 (27 mm) 1700 rounds/minute
gatling systems 4500, 6000 and more rounds/minute
i want to see a railgun which can top this ;-)
imho we will see direct-energy weapons (most probably lasers) into service years before a aaw-capable railgun will enter service. imho the development today is more focused on replacing higher caliber mainguns with a railgun.
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By: Distiller - 12th September 2009 at 11:20 Permalink - Edited 1st January 1970 at 01:00
First the laser has to demonstrate that it works in all weather conditions, like icestorm and tropical squall.
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By: obligatory - 12th September 2009 at 12:27 Permalink - Edited 1st January 1970 at 01:00
An AEGIS on a Tico should be able to focus large ammount of energy on an incoming missile, wonder what the result could be.
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By: sferrin - 12th September 2009 at 14:18 Permalink - Edited 1st January 1970 at 01:00
ROFL!!! 20+ km/sec? ROFLMAO!!! And even at 20 km/sec it's not going to go very far in a "few microseconds". Pull your head out.
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By: sferrin - 12th September 2009 at 14:19 Permalink - Edited 1st January 1970 at 01:00
How well is a supersonic antiship missile going to do flying through an icestorm?
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By: Distiller - 12th September 2009 at 14:53 Permalink - Edited 1st January 1970 at 01:00
Hm. Want to bet the ship on it?
Here
http://www.acq.osd.mil/osbp/sbir/solicitations/sbir093/mda093.htm
slide down to
MDA09-007
they are asking for adverse weather related stuff for BMD.
The same considerations apply to an anti-ship missile.
Russian missiles are hardened against shrapnel aleady.
And I'm sure the question of targeting in adverse weather can be solved.
Can't build a (primary?) defensive system - any system - that is dependant on nice sunshine.
Posts: 9,683
By: sferrin - 12th September 2009 at 15:21 Permalink - Edited 1st January 1970 at 01:00
I agree. On the other hand if you hit the missile hard enough even a mile or two will do the trick in most cases.
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By: talltower - 14th September 2009 at 05:48 Permalink - Edited 1st January 1970 at 01:00
That's why I envisioned the railgun as a CIWS against lethal supersonic AShMs such as Sunburns, BrahMoses and Sizzlers.
SS-N-27 Sizzler
SS-N-22 Sunburn
PJ-10 BrahMos
Rail gun
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By: Distiller - 14th September 2009 at 09:38 Permalink - Edited 1st January 1970 at 01:00
That BAE railgun doesn't look realistic. And I bet if you just take that energy needed for the railgun and use it for the shipboard AESA radar to burn the electronics of that incoming missile it might be as effective.
But what is wrong with guns as last defense? Like the 35mm Millennium? Even a missile coming in at 600m/s will be exposed to a cloud of projectiles for 4 or 5 seconds. The missile's maneuvering ability won't amount to much, cause at that phase it's already heading almost straight towards the ship.
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By: swerve - 14th September 2009 at 12:22 Permalink - Edited 1st January 1970 at 01:00
A large supersonic missile may be severely damaged, but the momentum of the wreck will carry it forward. There's a very good chance it will still hit. Even if the warhead is disabled, the kinetic energy alone will be very damaging to any ship, & any unburnt fuel would start fires.
Posts: 4,674
By: Distiller - 14th September 2009 at 13:55 Permalink - Edited 1st January 1970 at 01:00
I'm aware of such considerations. It's like after WW2 when the Bofors were exchanged for Mark 27.
A Millennium is basically designed to kill a 750-800m/s target with a 1 second burst in the 2250 to 1500 yards belt (everything +/-). The chances that a damaged missile takes a dive over that distance seems pretty high.
Also the system requirements and dependance from central power of a gun seems considerable lower than for a railgun or laser, of importance for survivability in case of more than one hit. Localized emergency hi-power energy supply like some Russian style rocket-generator set would certainly be possible, but much more complex than what a gun needs for emergency supply. Sensors, C2, networking would be identical.
A railgun's low rate of fire (so far) could be a problem. Even with a very fast railgun a missile still flies a multiple of its own length from firing till intercept. Not good for a very-low-rate-of-fire weapon!
And lasers (besides the weather, &c) still need seconds to illuminate a target before it goes boom, and the aspect angle is really not optimal to disable a missile. As long as lasers do not cause instant destruction they are not suitable as CIWS.
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By: obligatory - 14th September 2009 at 15:13 Permalink - Edited 1st January 1970 at 01:00
I just think shells has too short range vs super/hyper-sonic missiles, still good point defense vs slower missiles.
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By: Jason Simonds - 15th September 2009 at 02:42 Permalink - Edited 1st January 1970 at 01:00
Not at all. But supersonics are portrayed as instant death for surface combatants and yet REAL Pussers and other Naval warfare officers who train AGAINST these threats are not as concerned by them as the fanboys who like to portray these missiles as invincible simply because they are fast...
Low and slow may not be as "sexy" as something going Mach 4 and lighting up the sky with an enormous thermal bloom, but they sure scare the hell out of people who may be at risk from them...
Ask the Israelis...