Timerover51
SOC-14 5K
I was looking at the weapon effects in the Cepheus Engine and then started to think about how conventional explosives cause damage, and how that can be modified by the atmosphere that they are in.
An explosive device causes damage in two ways. Either by blast effect, i.e. shock or pressure wave, or fragmentation, or both. Generally, one or the other is emphasized, although in aerial bombs, the aim is to get a reasonable medium for effects.
Now, when an explosion occurs in a Vacuum, say a demolition charge is set off against an object, something interesting happens. That portion of the explosive charge next to the object generates a shock wave in the material of the object. However, there is no atmosphere to support a shock ware elsewhere around the charge. All you have is a rapidly expanding ball of initially hot gases. Anyone standing a few feet away will not be effected by either the shock wave or the gaseous ball, and unless there is some form of fragmentation cover over the explosive, no fragment damage either. A Trace atmosphere would have a very similar effect, but you would get a minor shock wave that will dissipate very quickly, without a whole lot of effect.
Now, if you are dealing with say a fragmentation grenade or an artillery shell, then things get a bit more interesting. In a Vacuum, there is no atmosphere to slow the fragments down, so they retain their initial velocity and ability to cause damage. However, the effective radius of burst for casualties is not going to increase that much, as that radius is based on the probability of being hit by an effective fragment, and that will not change a lot. The problem is that those fragments are going to travel a lot farther then they would in a standard atmosphere, so the danger areas, that radius within which the possibility of being hit by a fragment is going to increase a lot. As artillery shells typically hit at an angle to the ground, some of those fragments are going to be given trajectories of 30 degrees of more, which means that they may travel several hundred meters to several kilometers, depending on the gravity of the planet. A combination of a vacuum and a low-gravity planet might make it a bit hazardous to use a lot of either hand grenades or artillery fire because of unwanted collateral damage.
Note, this would also hold true for bullets being fired. No atmosphere means no bullet is slowed down as it heads down range. If firing with any kind of a upward inclination, such as you would have if your weapon was sighted for a standard atmosphere, you are going to be firing high at targets a couple of hundred meters away, and your rounds are going to travel a LONG way. Your artillery and mortar ranges are going to increase as well, simply because of no atmospheric resistance. Oh, and fin-stabilized projectiles are not going to work too well either. With no atmosphere, the fins have noting to work on in stabilizing the round, so no Armor-Piercing Fin-Stabilized Discarding Sabot rounds. They may travel a long way, but they might be doing cartwheels while so doing, along with heading in directions that you might now want them to go. The discarded sabots are also going to be traveling a ways. Again, nothing to slow them down. If you are on a small, low-gravity planet, your tank guns might be firing a couple of thousand kilometers if the muzzle velocity is say 1500 meters per second.
Hmm, maybe the Zero-G combat skill implies a lot more than you think when combined with a Vacuum.
An explosive device causes damage in two ways. Either by blast effect, i.e. shock or pressure wave, or fragmentation, or both. Generally, one or the other is emphasized, although in aerial bombs, the aim is to get a reasonable medium for effects.
Now, when an explosion occurs in a Vacuum, say a demolition charge is set off against an object, something interesting happens. That portion of the explosive charge next to the object generates a shock wave in the material of the object. However, there is no atmosphere to support a shock ware elsewhere around the charge. All you have is a rapidly expanding ball of initially hot gases. Anyone standing a few feet away will not be effected by either the shock wave or the gaseous ball, and unless there is some form of fragmentation cover over the explosive, no fragment damage either. A Trace atmosphere would have a very similar effect, but you would get a minor shock wave that will dissipate very quickly, without a whole lot of effect.
Now, if you are dealing with say a fragmentation grenade or an artillery shell, then things get a bit more interesting. In a Vacuum, there is no atmosphere to slow the fragments down, so they retain their initial velocity and ability to cause damage. However, the effective radius of burst for casualties is not going to increase that much, as that radius is based on the probability of being hit by an effective fragment, and that will not change a lot. The problem is that those fragments are going to travel a lot farther then they would in a standard atmosphere, so the danger areas, that radius within which the possibility of being hit by a fragment is going to increase a lot. As artillery shells typically hit at an angle to the ground, some of those fragments are going to be given trajectories of 30 degrees of more, which means that they may travel several hundred meters to several kilometers, depending on the gravity of the planet. A combination of a vacuum and a low-gravity planet might make it a bit hazardous to use a lot of either hand grenades or artillery fire because of unwanted collateral damage.
Note, this would also hold true for bullets being fired. No atmosphere means no bullet is slowed down as it heads down range. If firing with any kind of a upward inclination, such as you would have if your weapon was sighted for a standard atmosphere, you are going to be firing high at targets a couple of hundred meters away, and your rounds are going to travel a LONG way. Your artillery and mortar ranges are going to increase as well, simply because of no atmospheric resistance. Oh, and fin-stabilized projectiles are not going to work too well either. With no atmosphere, the fins have noting to work on in stabilizing the round, so no Armor-Piercing Fin-Stabilized Discarding Sabot rounds. They may travel a long way, but they might be doing cartwheels while so doing, along with heading in directions that you might now want them to go. The discarded sabots are also going to be traveling a ways. Again, nothing to slow them down. If you are on a small, low-gravity planet, your tank guns might be firing a couple of thousand kilometers if the muzzle velocity is say 1500 meters per second.
Hmm, maybe the Zero-G combat skill implies a lot more than you think when combined with a Vacuum.