Saddam's super gun

[Calin]

The automatic 75mm cannon found on many small warships (Otto Melara I think) has a small powder charge at the "tail" of the shell that is intended to fill the low pressure area that is formed behind the shell. It seems that while the range of the projectile in somewhat increased, the accuracy is increased (especially at long range) by a very good amount

edited... guess what

 

[Siddy]

ROFL, stupid americans "we are all under attack"

 

[scottish144]

Originally posted by: Calin

Originally posted by: Farmer
Calin:

I think the correct term is sabot, or FSDS (Fin Stabilized Discarding Sabot). AFAIK, subcalibre refers to pistol cartridges.

Originally posted by: maluckey
krcat1

Makes you wonder about thie possibility of nukes, when you consider that the gun would have to be disassembled/reassembled to aim it at different targets. A nuke wouldn't need to be pinpoint accurate to stop an oncoming advance. Within a couple of miles in the desert is close enough.

Didnt the US army try that idea out?:

http://www.globalsecurity.org/military/systems/ground/m65.htm

Maybe with a railgun, or some sort of maglev launched space vehicle. Dont think chemical weapons can take you that far that precisely. Of course, I'm just assuming; I know very little about this.

An maglev or railgun won't be a bit more precise. However, the big guns have a rather short lifespan of their barrels until reworking/replacing is needed (the rifling inside the barrel is eaten away by the shells).
However, for very long range ballistics (like over 20 miles or even more), self-guiding projectiles are a must. Especially considering that self-guiding projectiles (high speed gliding ones, let's call them) can greatly increase the range a payload can be delivered (double the range I think for non-powered projectiles). Using small rockets the payload delivered to the target is smaller, but the range can be increased even more.

Not really. According to Popular Science The military is currently developing nuclear powered rail guns that would be mounted on destroyers. These guns lauch dumb, non explosive tungsten rods at their targets at distances of 50 miles. Also according to Popular Science, NASA is working with DARPA to develope a system where satallites in orbit simply drop dumb tungsten rods from orbit. This rods would vaporize anything on impact.

 

[Calin]

I heard about that - a crowbar dropped from orbital height will create a very localized hit capable to destroy everything (its speed on ground hit would be several times hypersonic, for a low earth orbit of 200 km, speed at ground would be 1400m/s or 3000 miles/hour). Descent time would be 300 seconds since launch (drop).
However, one thing not everyone consider (I didn't until I heard of it) is that at low earth orbit that rod is flying with 7 km/s or 4 miles per second, and to "drop" it you need to stop it first. Also, as there is no air at that height, you can't really use wings to stop the rod. So, you will wase 7km/s of kinetic energy to obtain 1.4 km/s kinetic energy.

A rod will have a better shape than an artillery shell - however, take into account that even penetrating rounds (having 1.4 metric tons, or 2500+ pounds) are not accurate enough at their first hit (anti bunker fire missions fired first some shells to "calibrate" the hit. So even a tungsten rod will need help to hit small things at 50 miles (assuming the rod is propelled at 3000 miles per hour, it will fly for a minute and a half. They won't have such a great accuracy

 

[grant2]

Originally posted by: Emultra
Not if you're using neutron bombs.

I think for this discussion we'd like to remain within the realm of reality.

 

[Intelia]

Originally posted by: maluckey
Gerald Bull, the creator of the Babylon Gun, was successful at most all of his ventures in large-bore guns. He devised a formula (I can't find it at the moment) that was simple, to calculate the optimal length/bore for any gun.

the HARP project in Barbados was one of his early attempts to show that high altitude research could be done with a gun. his record of 180 Km altitude set in 1966 stood for 25 years.

As far as the barrel withstanding the blast...not an issue. The force on the satellite itself is quite another story. The G forces are high to say the least.

He was murdered shortly before the Gulf War. Canadian reporters claimed it was the Israelis, but it was a messy murder with plenty of witnesses, which is VERY unlike the Mossad. More likely to have been Iraqi agents silencing Bull forever about his work on the Babylon gun, of which only one was completed before the war. It was never fired.

Very nice post well done I was surprized to see it but again well done. Bulls biggest problem with this weapon was the barrel length and how to mount it. I don't believe he ever solved this problem before the traitor was assinated. This weapon was never designed to attain low earth orbit.

 

[Intelia]

Originally posted by: Calin
I heard about that - a crowbar dropped from orbital height will create a very localized hit capable to destroy everything (its speed on ground hit would be several times hypersonic, for a low earth orbit of 200 km, speed at ground would be 1400m/s or 3000 miles/hour). Descent time would be 300 seconds since launch (drop).
However, one thing not everyone consider (I didn't until I heard of it) is that at low earth orbit that rod is flying with 7 km/s or 4 miles per second, and to "drop" it you need to stop it first. Also, as there is no air at that height, you can't really use wings to stop the rod. So, you will wase 7km/s of kinetic energy to obtain 1.4 km/s kinetic energy.

A rod will have a better shape than an artillery shell - however, take into account that even penetrating rounds (having 1.4 metric tons, or 2500+ pounds) are not accurate enough at their first hit (anti bunker fire missions fired first some shells to "calibrate" the hit. So even a tungsten rod will need help to hit small things at 50 miles (assuming the rod is propelled at 3000 miles per hour, it will fly for a minute and a half. They won't have such a great accuracy

Been awhile since I have read anything on this but if the object is simply dropped from orbit I don't believe it can attain the speed required to do what your saying. A falling object can only fall at a speed equal to the pull on it. Since the gravitational pull of the earth is a constant there is set value that the speed of an object can fall and you would not need orbit height to get this speed. I can't remember what that speed is its been so long but 32 feet per second pops into my head. than you have to figure in air density ect. ect. ect.
Do you remember the feather and the penny dropped on the moon ? How about that Newton was right. Imagine that!

 

[aka1nas]

Gravitational acceleration is 9.8 m/s^2. So, discounting air friction, the projectile would increase it's speed by ~10m/s every second it fell. If the above math was correct and it would take 300 seconds to fall, then a 3000 m/s velocity at impact is not a bad estimation. It's too early for calculus for me so I won't try to work out the rest of his math right now.

 

[Intelia]

Originally posted by: aka1nas
Gravitational acceleration is 9.8 m/s^2. So, discounting air friction, the projectile would increase it's speed by ~10m/s every second it fell. If the above math was correct and it would take 300 seconds to fall, then a 3000 m/s velocity at impact is not a bad estimation. It's too early for calculus for me so I won't try to work out the rest of his math right now.

So are you saying in a vacuum that if it could fall for ever it would continue to gain speed infinitly or am I misunderstanding you?

 

[scottish144]

In a pure vacuum, yes, as long as it was under the influence of gravity, or some other constant force. However, the only scenario where the rod could fall forever would be a black hole, where time is slowed down exponentially.

 

[Intelia]

Originally posted by: scottish144
In a pure vacuum, yes, as long as it was under the influence of gravity, or some other constant force. However, the only scenario where the rod could fall forever would be a black hole, where time is slowed down exponentially.[/q

*************************************************************************

Ya I see

 

[BitByBit]

Gravitational acceleration is 9.8 m/s^2. So, discounting air friction, the projectile would increase it's speed by ~10m/s every second it fell. If the above math was correct and it would take 300 seconds to fall, then a 3000 m/s velocity at impact is not a bad estimation.

If we're dealing with an object falling from 200km, then I'm afraid that estimation is a little off.
Keeping things simple, the velocity at impact can be calculated using energy:

Loss in PE = Gain in KE.
mgh = (1/2)mv^2 (/m)
gh = (1/2)v^2 =>
v = (2gh)^0.5
v = (2 X 9.81 X 2 X 10^5)^0.5
v = 1980 m/s.

The real velocity would be lower, due to air resistance.

So are you saying in a vacuum that if it could fall for ever it would continue to gain speed infinitly or am I misunderstanding you?

An unbalanced force will accelerate an object until its velocity approaches that of light.

 

[Gamingphreek]

An unbalanced force will accelerate an object until its velocity approaches that of light.

Yes, but in the instance of an object falling to earth, it would max out because of friction. In other words it would reach its terminal velocity.

-Kevin

 

[BitByBit]

The question was talking about a vacuum.

 

[tmiranda]

I'm not a physicist but I believe the impact speed can not be calculated simply by looking at the speed attained by a verticle drop. Obects in orbit have a "horizontal" speed of several thousand miles per hour. Some of that will be bled off due to friction but I doubt that the speed will drop to 0.

In any case, if a crowbard dropped from orbit hit me on the head I'm sure it would hurt

 

[hardwareuser]

Originally posted by: tmiranda
I'm not a physicist but I believe the impact speed can not be calculated simply by looking at the speed attained by a verticle drop. Obects in orbit have a "horizontal" speed of several thousand miles per hour. Some of that will be bled off due to friction but I doubt that the speed will drop to 0.

In any case, if a crowbard dropped from orbit hit me on the head I'm sure it would hurt

Actually, it probably wouldn't even hurt a bit since you'd be dead before you know it

 

[MrDudeMan]

Originally posted by: hardwareuser

Originally posted by: tmiranda
I'm not a physicist but I believe the impact speed can not be calculated simply by looking at the speed attained by a verticle drop. Obects in orbit have a "horizontal" speed of several thousand miles per hour. Some of that will be bled off due to friction but I doubt that the speed will drop to 0.

In any case, if a crowbard dropped from orbit hit me on the head I'm sure it would hurt

Actually, it probably wouldn't even hurt a bit since you'd be dead before you know it

exactly. im pretty sure it would utterly destroy your body.

 

[Snakexor]

::grumbles quietly over the codec:: "...metal gear...."

 

[Intelia]

In 1913 Einstein developed a theory that stated it is not always possiable to tell the effects of gravitational from the effects of acceleration. This has to do with the wave theory. Weber was said to be the first to detect these waves. In a vacuum speed can increase at a rate of 32 feet persecond. In earth atmosphere all objcts will reach a terminal velocity which of course is dependant on the size and shape of that object . So to ask my question one more time take a height of 100 miles and use one of these tungsten rods of your size and shape and tell me its terminal velocity. in earths atmosphere . and than i can tell you the effect of the impact. Keep it simple here we were talking about tungsten rods . use 5 pounds based on the weight at the equator please

 

[Mokmo418]

the remains of one of the prototypes of that gun can be found somewhere near Sherbrooke, Quebec (just north of NH). It is known as fact that many test-fires occured there in the years before this scientist defected.

 

[TRUMPHENT]

There is another Bull gun on Barbados. It was made by glueing two 16inch naval rifles end to end. It fired a projectile called the MARTLET.

The Martlet 2 was supposed to achieve a muzzle velocity of 2100 meters per second. It used a discarding sabot.

"Martlet" is also what the Royal Navy called the F4F Grumman they used on their convoy escort carriers during WW2. The US Navy called it the "Wildcat". Don't ask me why, I just think it important that you know this.