At 11 kps it doesn't take much mass. Even a tin roof will vaporize the leading edge and when it hits anything reasonably dense (concrete, certainly; but at these velocities a flowerbed or duck pond are just as good) and your 200 Kg lawn dart becomes 400 kg of white hot vapor blasting out with the force of 3 tons of TNT.
Planetary bombardment as a terror weapon
- Thread starter batmagoo
- Start date
The explosive energy from 3 tons of TNT can be felt and used in very different ways, depending on how it is deployed. The same goes for the specific type of explosive compound used and how it is packaged. The study of ballistics/armor penetration/explosive characteristics can get extremely esoteric and counter intuitive when you get into the details.
High explosives have the characteristic of brisance; the shock wave of the explosion travels through the explosive filler faster than sound through that explosive. The effect causes mass detonation of the explosive filler and shatters everything nearby and imparts high velocity on the resulting fragments.
Medium explosives have the characteristic of thrusting. The detonation wave travels through the explosive filler at the same rate as the speed of sound. The effect causes a heaving pressure wave to move nearby objects as a whole without breaking them down into tiny bits.
Low explosives are what you see in rocket motors and bullets. There is a burn wave instead of a detonation wave. It may burn at hundreds of miles an hour, but will not detonate on its own. To make it appear to detonate, it may be contained in a vessel designed to hold the mounting pressure until the vessel bursts under tremendous pressure. These are pipe bombs using gun powder or the steam explosions of steam ships.
The materials of penetrators have been studied and ideas changed regularly. Hard penetrators have a tendency to shatter on impact instead of digging in. This was compensated by giving them a soft metal cap. The metal of choice for shape charge penetrators is now copper due to its properties under extreme pressure. Depleted uranium rod penetrators have been discovered to be very hazardous after the battle, poisoning the entire area with radioactive dust.
If you want to actually penetrate an armor thickness, the penetrators must be moving fast enough not to bounce off, be ridged enough not to bend, be tough enough not to shatter, and be long enough not to fully vaporize as it punches through the entire depth of the armor. As a high speed bar penetrator impacts a hard face, the energy of the bar pushes at the interface of the bar and armor. The energy is released by heating the armor and the point of the bar until vaporization happens. The vapor pushes against the incoming penetrator and the armor spreading the vaporization as it goes. The width of the penetrator has little to do with the penetration except to keep the penetrator bar straight. The make or break of the penetration comes if the incoming bar is vaporized, bent, shattered, or bounced off before the armor is burned through. A tiny hole completely through the armor will allow the superheated vapor to blast past the armor as a pressure wave burning all in its path. This will resemble an explosion of a small charge in a confined space.
A bar dropped from orbit will have the energy equivalent of a large stack of bombs. The main determiner of the blast will be the impact characteristics. How near melting/ vaporization point is it on impact? How solid, hard, thick is the impact surface and subsurface? What is the bar made of and what are its characteristics? What angle was the strike? Was the impacting bar still in one piece or did counter fire fragment it or bend it? The aim will be to have the impacting bar hit a hard faced target as close to its vaporization point for maximum blast effect. For penetration, the aim is to hit the target dead on with the penetrator as far under melting point as possible, so freeze the bar before dropping it and hope it doesn’t shatter on a bird while dropping.
BTW, Welcome back to Liam Devlin. The board has missed your inputs.
High explosives have the characteristic of brisance; the shock wave of the explosion travels through the explosive filler faster than sound through that explosive. The effect causes mass detonation of the explosive filler and shatters everything nearby and imparts high velocity on the resulting fragments.
Medium explosives have the characteristic of thrusting. The detonation wave travels through the explosive filler at the same rate as the speed of sound. The effect causes a heaving pressure wave to move nearby objects as a whole without breaking them down into tiny bits.
Low explosives are what you see in rocket motors and bullets. There is a burn wave instead of a detonation wave. It may burn at hundreds of miles an hour, but will not detonate on its own. To make it appear to detonate, it may be contained in a vessel designed to hold the mounting pressure until the vessel bursts under tremendous pressure. These are pipe bombs using gun powder or the steam explosions of steam ships.
The materials of penetrators have been studied and ideas changed regularly. Hard penetrators have a tendency to shatter on impact instead of digging in. This was compensated by giving them a soft metal cap. The metal of choice for shape charge penetrators is now copper due to its properties under extreme pressure. Depleted uranium rod penetrators have been discovered to be very hazardous after the battle, poisoning the entire area with radioactive dust.
If you want to actually penetrate an armor thickness, the penetrators must be moving fast enough not to bounce off, be ridged enough not to bend, be tough enough not to shatter, and be long enough not to fully vaporize as it punches through the entire depth of the armor. As a high speed bar penetrator impacts a hard face, the energy of the bar pushes at the interface of the bar and armor. The energy is released by heating the armor and the point of the bar until vaporization happens. The vapor pushes against the incoming penetrator and the armor spreading the vaporization as it goes. The width of the penetrator has little to do with the penetration except to keep the penetrator bar straight. The make or break of the penetration comes if the incoming bar is vaporized, bent, shattered, or bounced off before the armor is burned through. A tiny hole completely through the armor will allow the superheated vapor to blast past the armor as a pressure wave burning all in its path. This will resemble an explosion of a small charge in a confined space.
A bar dropped from orbit will have the energy equivalent of a large stack of bombs. The main determiner of the blast will be the impact characteristics. How near melting/ vaporization point is it on impact? How solid, hard, thick is the impact surface and subsurface? What is the bar made of and what are its characteristics? What angle was the strike? Was the impacting bar still in one piece or did counter fire fragment it or bend it? The aim will be to have the impacting bar hit a hard faced target as close to its vaporization point for maximum blast effect. For penetration, the aim is to hit the target dead on with the penetrator as far under melting point as possible, so freeze the bar before dropping it and hope it doesn’t shatter on a bird while dropping.
BTW, Welcome back to Liam Devlin. The board has missed your inputs.
Liam,
In the context of the scenario, these would have been dropped off several days/weeks in the orbital path of the target planet, on a time delay for launch. The guidance computer would align on the planet, launch the darts, and quietly await the arrival of the planet to suck them into the gravity well.
A proximity sensor would activate the station keeping thrusters to start an uncontrolled tumble if anyone/thing gets near them.(not many pc's are going to attempt to grab something the size of a minivan thats tumbleing(sp?) out of control)or, I could just make them blow up!
As far as detection prior to activation, you have discovered the one weakness in my evil plan. Poof!
They are now made sensor transparent materials, and launch shortly after deployment.
This whole idea was to have the darts striking the target, as the bombardment fleet arrives in system.
Kind of an elaborate way to about making sure the pc's ship gets pinned to the ground.(Its good to be referee!)
Chuck
In the context of the scenario, these would have been dropped off several days/weeks in the orbital path of the target planet, on a time delay for launch. The guidance computer would align on the planet, launch the darts, and quietly await the arrival of the planet to suck them into the gravity well.
A proximity sensor would activate the station keeping thrusters to start an uncontrolled tumble if anyone/thing gets near them.(not many pc's are going to attempt to grab something the size of a minivan thats tumbleing(sp?) out of control)or, I could just make them blow up!
As far as detection prior to activation, you have discovered the one weakness in my evil plan. Poof!
They are now made sensor transparent materials, and launch shortly after deployment.
This whole idea was to have the darts striking the target, as the bombardment fleet arrives in system.
Kind of an elaborate way to about making sure the pc's ship gets pinned to the ground.(Its good to be referee!)
Chuck