.50 cal not good enough for the Phalanx?

[wacki]

According to wiki
http://en.wikipedia.org/wiki/Phalanx_CIWS

The Phalanx fires 20mm which is .80 call. They also use 3 to 4 inch long depleted uranium and tungsten sabot bullets. That is enough firepower to make swiss cheese out of a stationary Bradley and probably a T-72 tank. Since missiles are traveling toward the Phalanx that only adds to the convergence speed and penetrating ability of the opposing projectile.

In short, my question is "why do they need so much firepower?" I didn't think missiles were that tough.

 

[Outlaws]

I have a feeling that any jet fighters that may approach would have a hell of a time doding/surviving all that. Not to mention that the distance the target would be would require something with great sectional density. You don't want it getting deflected. I have a feeling the distance the target is engauged would require the weapon to be effective at over a mile or more.

 

[FTF]

Well, a missile traveling directly at you is going at an ungodly high rate of speed. Unless you have a super-duper rangefinding system, you pretty much have to throw a wall of lead at it to stop it... or at least have a good chance of doing so. I think they pretty much throw the easiest wall of lead that they think has a big enough impact to stop a target. I don't think it's that missles are "tough"... I think it's that they are "tough to hit" therefore requireing a huge amount of lead in the air.

 

[SoCalShooter]

I believe also the phalanx system is not only for missle defense but can be used for aircraft and surface vessels.

Block 1B Phalanx Surface Mode (PSUM) incorporates a side mounted Forward Looking Infrared Radar (FLIR) which enables CIWS to engage low slow or hovering aircraft and surface craft. Additionally, the FLIR assists the radar in engaging some ASCM’s bringing a greater chance of ship survivability. Block 1B uses a thermal imager Automatic Acquisition Video Tracker (AAVT) and stablilization system that provide surface mode and electro-optic (EO) angle track. These Block 1B enhancements will allow day/night detection capability and enable the CIWS to engage small surface targets, slow-moving air targets, and helicopters.

http://www.fas.org/man/dod-101/sys/ship/weaps/mk-15.htm

 

[wacki]

Unless you have a super-duper rangefinding system, you pretty much have to throw a wall of lead at it to stop it... or at least have a good chance of doing so. I think they pretty much throw the easiest wall of lead that they think has a big enough impact to stop a target. I don't think it's that missles are "tough"... I think it's that they are "tough to hit" therefore requireing a huge amount of lead in the air.

This is an argument for a high rate of fire, not tungsten sabots.

 

[SoCalShooter]

Unless you have a super-duper rangefinding system, you pretty much have to throw a wall of lead at it to stop it...

Is atleast 15 different radars enough of a super duper rangefinding system for you? Cause if you count Aegis cruisers and the carrier radars and awacs then you got a sufficient amount of range finding equipment, but the wall of lead is the general idea. (granted all these radars have to be able to see the target )

 

[Davo]

The .50 is actually puny compared to some of the other rounds employed by out military. Range, and terminal performance are better with the larger rounds.

 

[nyresq]

why do they need so much firepower?

because you're protecting something so valuable...

and the effective range of the 20mm is three to four times that of a .50 cal...

 

[Diamondback6]

Guys, you're confusing two different systems. Phalanx is the radar-guided mounting, the gun that makes it all tick is the good ol' M61A1 Vulcan 6-barrel 20mm Gatling that's served us seemingly forever.

Why 20mm? Bigger slug, bigger HE warhead, bigger heap o' hurt when it hits.

 

[jac714]

The other reason for the M61A1 is that there were a bunch of them around when the system was developed.

 

[SnWnMe]

As a regular ship rider, I think they are NOT using enough firepower. I want 40mm and a force field.

 

[wacki]

As a regular ship rider, I think they are NOT using enough firepower. I want 40mm and a force field.

Self reliant call to authority isn't exactly the most scientific method.

A .50 cal has a range of about 1500 meters.

A 20mm has a range of about ??????
http://www.fas.org/man/dod-101/sys/ac/equip/m61.htm

Not much info. I would think range is a good argument for going big but I'm short on stats. However, range is not an argument for DU or the tungsten sabot round. I really would like to know what missile can't be disarmed by a lead round.

 

[Fosbery]

Phalanx is a pretty poor system to be honest. Won't stop modern anti-ship missiles.

 

[Cromlech]

Try the Goalkeeper:

 

[DRMMR02]

What is the point of this thread again? I'm having a bit of trouble understanding the OP's reasoning. Does he think that Phalanx system is too costly or something?

 

[wacki]

Does he think that Phalanx system is too costly or something?

This thread is about:

1) Do they really need the Tungsten Sabot?
2) Missile toughness
3) How "big" of a bullet do you need to take out a missile

and pretty much nothing else.

 

[DRMMR02]

Well the fact that Phalanx getting more and more out of date just shows that, yes, they do need all the firepower they can get. A lot of those ships cost billions of dollars, not to mention all of the American soldiers on board. And ships like Aegis cruisers coordinate flight operations for aircraft all over. IF one of them were to be taken out by a missile, it would be disastrous. So is .50cal enough? Absolutely not. Is 20mm even enough? That's getting to be no as well. Although, the question about Phalanx has a lot less to do with what projectile it is firing, and a lot more to do with how fast, where, and when. The rate of fire, accuracy, range of radar, how fast the radar can lock on and engage, and the on board computer's ability to predict flight paths are much more important factors. The type of cartridge the weapon uses really only determines range, and destruction on impact. And while range is important, the destruction a projectile will do isn't much of an issue. Missiles are pretty delicate. Like others have said, that happens when you hit the missile isn't really a toss up. It's whether you hit it or not that matters most.

 

[Fred Fuller]

Not because missiles are tough, but because they are so FAST these days. There are several supersonic nuclear antiship missiles out there these days (Google "Sunburn missile" for an example). In reality 20mm isn't enough- they need even more range.

lpl/nc

 

[Sylvan-Forge]

I'll play ..

1) Do they really need the Tungsten Sabot?
Penetrator density and hardness greater than lead and similiar to depleted uranium (with less enviro issues) for greater sectional density and ballistic coefficient yielding greater power at range.
Depleted uranium is also used.

Good old momentum .. especially considering the risk of the projectile glancing off or ricocheting due to the interface angles encountered ..
ie. Bullet cone to missile nose cone.

From the fas.org site :

The gun subsystem employs a gatling gun consisting of a rotating cluster of six barrels. The gatling gun fires a 20mm subcaliber sabot projectile using a heavy-metal (either tungsten or depleted uranium) 15mm penetrator surrounded by a plastic sabot and a light-weight metal pusher. The gatling gun fires 20mm ammunition at either 3,000 or 4,500 rounds-per-minute with a burst length of continuous, 60, or 100 rounds.

2) Missile toughness
I'd guess that anti-ship missiles have hardened nose cones and forward structures to aid in penetration of hull plates.


3) How "big" of a bullet do you need to take out a missile
Good question, but I've always found it easier to poke holes in tough things with small rather than large pointy things..

Biguns ..

Maybe what is needed today is a new gun firing a larger than current caliber sabot for greater velocity and using longer and heavier 15-20mm penetrators ..
Or maybe a whole new system .. MetalStorm to directed energy ..
?

 

[benEzra]

Range, mostly. A .50 (12.7mm) loses velocity WAY quicker than a 20mm, and as a result, even at 1800 yards, the bullets are descending so steeply that you're looking at bullet drop of something like 8 FEET for every 100 yards of forward travel. It would be like trying to shoot a fast-moving target at 300 yards with .22LR subsonics. And remember, your target may be flying at Mach 4 or faster.

The slower (at range) .50 bullets would also greatly increase the lag time involved in aim correction, AND would allow a missile to more easily evade the bullet stream with a bit of pre-programmed erratic jinking on final approach. So, no, 12.7mm probably wouldn't cut it.

 

[SDC]

Having it in 20mm also means you can use the radar proximity fuzes that are available in 20mm, but not available in .50 BMG, which is a BIG asset for anti-aircraft and anti-missile use.

 

[Double Naught Spy]

In short, my question is "why do they need so much firepower?" I didn't think missiles were that tough.

Sorry, but this seems to be a classic example of identifying the exact wrong aspect of the problem as being the critical aspect.

Similarly wrong...

This thread is about:

1) Do they really need the Tungsten Sabot?
2) Missile toughness
3) How "big" of a bullet do you need to take out a missile

and pretty much nothing else.

It isn't that the missiles are that tough. It IS that the missiles can do that much damage. It isn't about putting holes in missiles but about NOT letting missiles put holes in ships.

Put another way, it isn't the component that is so much the problem, but the consequences of the component.

Why do we need that much firepower? I don't know why we aren't using more.

So economics are maybe a problem, then once again the cost of the Plalanx system is the wrong end of the problem to be looking at in this case. It is a very cheap, comparatively, defensive system compared to what it is to do and compared to the cost of the ships it is protecting. It is a LAST LINE of defense AFTER all other systems have failed to successfully neutralize an incoming target.

So when everything else has failed and you are in deep doodoo, do you want the captain to whip out a mouse gun backup or something a little more substantial? After all, this is at the point where things are absolutely critical and any failures after this point mean death to the ship.

 

[dm1333]

CIWS

Close In Weapons System. The Navy named it that because it is the last ditch effort against a missile. The idea behind ship defense is to engage way out beyong one or two miles and stop the missiles before they are launched. CIWS is there to try to take care of any missiles that have made it through a layered defense of aircraft, missiles, chaff, etc. Remember that the missile has a lot of momentum, you can hit it and destroy a lot of the electronics and still get nailed by the missile body with all the explosives and fuel. The CIWS is going to try to shred that whole thing into tiny pieces and having a 20mm sabot round is going to help.

 

[Leatherneck]

It's all about range. At least in the CIWS case, you really want to reach out and touch that ASCM as far away as possible. A "dead" pile O' missile mess hitting your ship is still not a very good deal. .50 cal < 20mm < 30mm < 40mm.

In air-to-ground strafing, again range is important, because the enemy generally takes a dim view of you strafing him, and is allowed to shoot back. Common AAA for point defense is 37mm and 57mm from one, two or four barrels. You do NOT want to get in close and mix it up with your aluminum airplane full of fuel and things that go Boom.

TC

 

[Gifted]

Phalanx is also a "drop in" system. You can bolt it on anywhere with enough deck area and the power leads. This means that a lot of ships that would otherwise be defenseless, are good. Systems like the Goalkeeper need below-deck space that can be hard to find when you're not designing the system into the ship in the first place. That and the price.

Part of the goal is to hopefully detonate the warhead. This requires A LOT of kinetic energy, something that's easy to do with sabot. Someone got velocities available for the rounds in question? The Goalkeeper uses the GAU-8 because the 30mm carries more energy. Makes it more likely that a glancing hit will actually do damage.