Posted on 03/24/2017 8:23:12 AM PDT by C19fan
4500 mph? That’s only Mach 6. I once worked on missiles that were faster than that. I think someone got the wrong information.
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That is the “un-classified” speed. Research papers say 7000 MPH.
Yes at 125 miles the slug will be less speed than it left but not much. It will go through a “Lot” of concrete and kill a lot of people inside a concrete building. It will tear right through most armor because of the speed which is a force multiplier. There is no armored vehicle that can be protected from that kind of speed.
The speed is something like a hundred miles a minute. I would not want to be on the receiving end.
Naw. I’ve seen this before. The gov’t has apparently concluded that a giant slag of metal is cheaper than a missile.
You’re right that there are missiles way faster than this; this is WAY slower than orbital velocity. But I guess a hundred $10,000 slabs of metal can do way more damage at 4,500 MPH than one million-dollar missile. (I have no real idea how big the projectile is, I’m just throwing out numbers for example.)
I think that’s considered a feature, not a bug in this case. If you spot ISIS operating out of a school, you can completely obliterate the fortified principal’s office, and leave the secretary’s office undamaged.
They need to be able to send out a swarm of these projectiles like buck shot out of a 12 gauge shotgun.
I think the idea would be to put the railgun slug through the Target restroom while the perverts are in there causing trouble ...
The projectile is a 25 pound piece of aluminum.
4500 mph is more than enough to do a lot of damage, but I’d more likely believe that the velocity is classified and not available to the public or reporters.
I worked on the control surfaces (fins) design of a missile that went about 2.5X faster than that. My biggest problem was creating a design where the stainless steel fins didn’t melt from air friction before the missile got to the target.
Good Old 1/2 MV^2 to the rescue. That squaring of the velocity is a real “killer”.
If it is already Mach 6 when it leaves the barrel, air resistance is not going to much of an issue for quite a while. After you get past about Mach 1.2, drag is reduced substantially, so the inertia of the projectile could carry it pretty far.
Aluminum? That’s so much more expensive per pound than iron, I’m surprised there is no OTHER metal that’s also cheaper (but not magnetic?).
... I guess not... looks like Aluminum is the cheapest stuff per pound out there,... only thing that comes close in zinc.
Well, it’ll be better than that. Depending on the trajectory, it would go miles in the air. And physics tells us (as do meteorite strikes) that whatever energy it had in the vertical direction going up, it will reclaim coming down (discounting air resistance). Depending on the shape and size of the projectile, the terminal velocity could be quite great - BIG impact.
WWII battleships did it with great accuracy at 20 miles or better.
Yeah - this is a whole lot farther, but ballistic trajectories (parabolic) are still described by the same equations - just using bigger numbers, and I’m sure adjusting for the special considerations for the super-fast launch.
Bottom line? Hitting the target will not be a problem. Artillery men have been doing it for ages.
Aluminum makes sense, 1/3rd the density of steel.
It’s light so that it can achieve higher velocity for the same energy. And the delivered impact energy is equal to the mass times the velocity squared.
Do da name "development" ring a familiar note?
>> It’s light so that it can achieve higher velocity for the same energy. And the delivered impact energy is equal to the mass times the velocity squared. <<
A pound of feathers weights the same as a pound of bricks. If it has one third the weight when launched, so it goes three times faster, than it impacts with one third the mass. IOW, 3 * 1/3 = 1. But the pound of bricks hurts your foot more, because the denser object creates less wind resistance.
Agreed! 4500 mph initial velocity and 15 degrees elevation yields about 125 mile range. That parabola is about 8.5 miles high.
Not much air resistance at that altitude... The troposphere only goes up 7 miles. That’s 90% of the air.
(Alan Shepard went up 116 miles - he was basically riding a ballistic missle.)
One of the big issues with railgun technology is that the rails wore out quickly. How many shots will this one deliver before the gun rails need replacing?
What weighs more? 25 pounds of aluminum or 25 pounds of feathers.
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