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Quoted: Quoted: Quoted: Because at zero degrees you would NOT compensate for range, rather you would compensate deflection.(I believe that is the term) Please, for the love of all that is holy and pure, do not argue with RON on the subject of artillery. The baby Jesus just curb stomped an angel for crying out loud, and RON, I believe, isn't even Christian (my apologies if I am wrong on that) I'm not arguing with RON. I'm honestly trying to understand why the facts and figures agree with me, yet I'm being told I'm wrong. Maybe I'm forgetting about the effects of air resistance. (TBF, I haven't looked at the Shuszengrupfinneaglin effect quoted a few pages back... ![]() Also, the title of this thread is: Will artillery fly farther when fired into or away from the direction of Earth's rotation? you brought it up, not me. I brought what up? |
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yep we once had a other unit firing on the same GT line of our observers. Round lands 100m off due deflection error, result round lands on the 40m from the foxes on the hill lucky they were in tracks at the time, needless to say after that they were always very concerned with GT and Angle T as well as where and what other units were shooting that day. View Quote View All Quotes View All Quotes Quoted:
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This has turned into an interesting thread. More people still think it does not matter than think it does. Arty guys are saying both it does and doesn't. When you are firing 98lbs of Comp B in your direction it most certainly matters.. It's all good in the hood if you're the gun bunny or in the FDC, but when you're the guy on the other end of the radio, 50 meters can be a big deal. I remember when a gunner once transposed a couple of digits because he was tired. Rather than land in the impact area, the round flew right over the Humvee in which I was sitting, went through the trees directly over the area where my former FIST team was playing spades, and landed 82 meters away from them, sending shrapnel over their heads. Minor things can definitely mean the difference between life and death with field artillery. yep we once had a other unit firing on the same GT line of our observers. Round lands 100m off due deflection error, result round lands on the 40m from the foxes on the hill lucky they were in tracks at the time, needless to say after that they were always very concerned with GT and Angle T as well as where and what other units were shooting that day. I lost the front end of my jeep at NTC once. The Battalion FDC input me for the registration point. Fortunately I was in a bit if a rise and the round impacted below us. As my driver and I were getting off the ground, two four-deuce rounds impacted. Good thing it was a registration. It would have been nice to know I was doing the Task Force mortars. |
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It's not the Coriolis effect. Coriolis affects n-s ballistics (or the n-s component of the ballistics). E-w ballistics is, as pointed out earlier by other folks, affected by the eotvos effect. Artillery tables should account for it because it does matter. View Quote View All Quotes View All Quotes Quoted:
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It's the coriolis effect, and the question isn't "how much further does it fly" the question is more along the lines of "is the target rising or falling relative to my initial assuming point based on the rotation of the earth" Shooting against the rotation the target actual rises in Ralston to where it was at ignition, and falls if shooting with rotation. Long range shooters with flight times of several seconds have to account for this It's not the Coriolis effect. Coriolis affects n-s ballistics (or the n-s component of the ballistics). E-w ballistics is, as pointed out earlier by other folks, affected by the eotvos effect. Artillery tables should account for it because it does matter. I stand corrected, I had forgotten the E/W name, I was lumping any rotational adjustment for earth rotation under coriolis, incorrectly. I'll remember the eotvos term for about another hour before I forget it again.... ![]() |
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Quoted: Which is the practical application of ballistics so that the desired effects are obtained by fire. You are correct in that the position of the gun doesn't matter after firing. You are not considering the location of the target before or after firing. The Army calculates firing data based on the distance between the gun and the target. Further, the standard conditions the Army assumes include the earth not rotating. So say the target is 2000 m from the gun. We could pull an elevation from the TFT that would let the gun fire 2000 m under standard conditions. Since the earth is spinning, the achieved range would be more or less than 2000 m; depending on which direction the gun was fired. That brings us to the question posed by the OP. If fired in the direction of the rotation of the earth, the achieved range will be less than the firing data under standard conditions. If fired against the direction of the rotation of the earth, the achieved range will be further than predicted under standard conditions. The OP is poorly phrased. The projectile does not fly shorter or further relative to the gun's position when fired. But it does impact shorter or further relative to the target, which is what we really care about. View Quote View All Quotes View All Quotes Quoted: Quoted: Quoted: Quoted: Christ you people could fuck up a free lunch. What happened here? Physics. Gunnery. Which is the practical application of ballistics so that the desired effects are obtained by fire. Quoted: OK, educate me. If the gun is moving 660 mph relative to Earth's center, and the shell is fired east or west at the equator, the shell does not travel any further than if the Earth wasn't rotating at all. Doesn't matter if the gun's position moves towards the target or away from the target relative to the shell, since the shell's velocity has been increased or decreased the exact same amount relative to the Earth's center. Right? You are correct in that the position of the gun doesn't matter after firing. You are not considering the location of the target before or after firing. The Army calculates firing data based on the distance between the gun and the target. Further, the standard conditions the Army assumes include the earth not rotating. So say the target is 2000 m from the gun. We could pull an elevation from the TFT that would let the gun fire 2000 m under standard conditions. Since the earth is spinning, the achieved range would be more or less than 2000 m; depending on which direction the gun was fired. That brings us to the question posed by the OP. If fired in the direction of the rotation of the earth, the achieved range will be less than the firing data under standard conditions. If fired against the direction of the rotation of the earth, the achieved range will be further than predicted under standard conditions. The OP is poorly phrased. The projectile does not fly shorter or further relative to the gun's position when fired. But it does impact shorter or further relative to the target, which is what we really care about. That's because of air resistance, right? Because if the shell were fired to the east or west at the equator, in a vacuum, then the time-to-distance relative to the gun would be exactly the same. It's simple physics. Fired to the east, the velocity of the shell in the chamber relative to the center of the Earth is around 1000 fps. When fired (again, in a vacuum) it leaves the muzzle at 1000 fps plus 2400 fps. Since the gun is still traveling at 1000 fps, the distance the bullet travels is ONLY related the the muzzle velocity and the elevation of the barrel. It's simple physics. Similarly, when fired to the west, the velocity of the shell in the chamber relative to the center of the Earth is around -1000 fps. When fired (again, in a vacuum) it leaves the muzzle at 2400 fps minus 1000 fps (relative.) Since the gun is still traveling at -1000 fps, the distance the bullet travels is again ONLY related the the muzzle velocity and the elevation of the barrel. |
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I brought what up? View Quote You brought up the amount of range increase or decrease at zero deflection. You are the one who originally quoted that part of the chart. And you also edited out the post above mine so it would be very clear. zero mils would obviously have no increase or decrease in range because its perpendicular to the rotation of the earth. |
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I lost the front end of my jeep at NTC once. The Battalion FDC input me for the registration point. Fortunately I was on a bit if a rise and the round impacted below us. As my driver and I were getting off the ground, two four-deuce rounds impacted. Good thing it was a registration. It would have been nice to know I was doing the Task Force mortars. View Quote View All Quotes View All Quotes Quoted:
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This has turned into an interesting thread. More people still think it does not matter than think it does. Arty guys are saying both it does and doesn't. When you are firing 98lbs of Comp B in your direction it most certainly matters.. It's all good in the hood if you're the gun bunny or in the FDC, but when you're the guy on the other end of the radio, 50 meters can be a big deal. I remember when a gunner once transposed a couple of digits because he was tired. Rather than land in the impact area, the round flew right over the Humvee in which I was sitting, went through the trees directly over the area where my former FIST team was playing spades, and landed 82 meters away from them, sending shrapnel over their heads. Minor things can definitely mean the difference between life and death with field artillery. yep we once had a other unit firing on the same GT line of our observers. Round lands 100m off due deflection error, result round lands on the 40m from the foxes on the hill lucky they were in tracks at the time, needless to say after that they were always very concerned with GT and Angle T as well as where and what other units were shooting that day. I lost the front end of my jeep at NTC once. The Battalion FDC input me for the registration point. Fortunately I was on a bit if a rise and the round impacted below us. As my driver and I were getting off the ground, two four-deuce rounds impacted. Good thing it was a registration. It would have been nice to know I was doing the Task Force mortars. |
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Quoted: You brought up the amount of range increase or decrease at zero deflection. You are the one who originally quoted that part of the chart. And you also edited out the post above mine so it would be very clear. zero mils would obviously have no increase or decrease in range because its perpendicular to the rotation of the earth. View Quote View All Quotes View All Quotes Quoted: Quoted: I brought what up? You brought up the amount of range increase or decrease at zero deflection. You are the one who originally quoted that part of the chart. And you also edited out the post above mine so it would be very clear. zero mils would obviously have no increase or decrease in range because its perpendicular to the rotation of the earth. Quoting the OP's first post. "It seems like artillery rounds would travel further if fired in the opposite direction the world is turning at 1000 miles per hour. When it comes to artillery with ranges of dozens of miles, does the round fly the same distance if fired exactly into the rotation and exactly away from the rotation of the planet?" Granted, he didn't ask about the shot being taken at different latitudes (which I acknowledged would alter the range of the shell.) What I'm arguing is a direct analysis of a thought experiment, as suggested by the OP. You seem to have a strange need to prove me either wrong (I'm not,) or arrogant (I'm not that either.) Is it because I've never served in the military? Does that bother you? |
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Quoting the OP's first post. "It seems like artillery rounds would travel further if fired in the opposite direction the world is turning at 1000 miles per hour. When it comes to artillery with ranges of dozens of miles, does the round fly the same distance if fired exactly into the rotation and exactly away from the rotation of the planet?" Granted, he didn't ask about the shot being taken at different latitudes (which I acknowledged would alter the range of the shell.) What I'm arguing is a direct analysis of a thought experiment, as suggested by the OP. You seem to have a strange need to prove me either wrong (I'm not,) or arrogant (I'm not that either.) Is it because I've never served in the military? Does that bother you? View Quote View All Quotes View All Quotes Quoted:
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I brought what up? You brought up the amount of range increase or decrease at zero deflection. You are the one who originally quoted that part of the chart. And you also edited out the post above mine so it would be very clear. zero mils would obviously have no increase or decrease in range because its perpendicular to the rotation of the earth. Quoting the OP's first post. "It seems like artillery rounds would travel further if fired in the opposite direction the world is turning at 1000 miles per hour. When it comes to artillery with ranges of dozens of miles, does the round fly the same distance if fired exactly into the rotation and exactly away from the rotation of the planet?" Granted, he didn't ask about the shot being taken at different latitudes (which I acknowledged would alter the range of the shell.) What I'm arguing is a direct analysis of a thought experiment, as suggested by the OP. You seem to have a strange need to prove me either wrong (I'm not,) or arrogant (I'm not that either.) Is it because I've never served in the military? Does that bother you? huh ![]() I'd leave the "rocket science" to the experts. |
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Quoting the OP's first post. "It seems like artillery rounds would travel further if fired in the opposite direction the world is turning at 1000 miles per hour. When it comes to artillery with ranges of dozens of miles, does the round fly the same distance if fired exactly into the rotation and exactly away from the rotation of the planet?" Granted, he didn't ask about the shot being taken at different latitudes (which I acknowledged would alter the range of the shell.) What I'm arguing is a direct analysis of a thought experiment, as suggested by the OP. You seem to have a strange need to prove me either wrong (I'm not,) or arrogant (I'm not that either.) Is it because I've never served in the military? Does that bother you? View Quote View All Quotes View All Quotes Quoted:
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I brought what up? You brought up the amount of range increase or decrease at zero deflection. You are the one who originally quoted that part of the chart. And you also edited out the post above mine so it would be very clear. zero mils would obviously have no increase or decrease in range because its perpendicular to the rotation of the earth. Quoting the OP's first post. "It seems like artillery rounds would travel further if fired in the opposite direction the world is turning at 1000 miles per hour. When it comes to artillery with ranges of dozens of miles, does the round fly the same distance if fired exactly into the rotation and exactly away from the rotation of the planet?" Granted, he didn't ask about the shot being taken at different latitudes (which I acknowledged would alter the range of the shell.) What I'm arguing is a direct analysis of a thought experiment, as suggested by the OP. You seem to have a strange need to prove me either wrong (I'm not,) or arrogant (I'm not that either.) Is it because I've never served in the military? Does that bother you? I don't care if you have served or not. But you injected yourself into a conversation you have no idea about and tried to argue with no shit subject mattter experts on the subject. and you still refuse to admit you are wrong on this subject. |
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Because if the shell were fired to the east or west at the equator, in a vacuum, then the time-to-distance relative to the gun would be exactly the same. It's simple physics. Fired to the east, the velocity of the shell in the chamber relative to the center of the Earth is around 1000 fps. When fired (again, in a vacuum) it leaves the muzzle at 1000 fps plus 2400 fps. Since the gun is still traveling at 1000 fps, the distance the bullet travels is ONLY related the the muzzle velocity and the elevation of the barrel. It's simple physics. Similarly, when fired to the west, the velocity of the shell in the chamber relative to the center of the Earth is around -1000 fps. When fired (again, in a vacuum) it leaves the muzzle at 2400 fps minus 1000 fps (relative.) Since the gun is still traveling at -1000 fps, the distance the bullet travels is again ONLY related the the muzzle velocity and the elevation of the barrel. View Quote No, actually. I learned something out of all this as well. The problem is that the earth is spinning. So you have to take rotational physics and centripetal forces into account as well. The projectile behaves differently traveling with the rotation than it does traveling against the rotation of the earth. You can look it up - it's called the Eötvös effect, and it is physics, it's just not linear physics. |
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I lost the front end of my jeep at NTC once. The Battalion FDC input me for the registration point. Fortunately I was in a bit if a rise and the round impacted below us. As my driver and I were getting off the ground, two four-deuce rounds impacted. Good thing it was a registration. It would have been nice to know I was doing the Task Force mortars. View Quote View All Quotes View All Quotes Quoted:
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This has turned into an interesting thread. More people still think it does not matter than think it does. Arty guys are saying both it does and doesn't. When you are firing 98lbs of Comp B in your direction it most certainly matters.. It's all good in the hood if you're the gun bunny or in the FDC, but when you're the guy on the other end of the radio, 50 meters can be a big deal. I remember when a gunner once transposed a couple of digits because he was tired. Rather than land in the impact area, the round flew right over the Humvee in which I was sitting, went through the trees directly over the area where my former FIST team was playing spades, and landed 82 meters away from them, sending shrapnel over their heads. Minor things can definitely mean the difference between life and death with field artillery. yep we once had a other unit firing on the same GT line of our observers. Round lands 100m off due deflection error, result round lands on the 40m from the foxes on the hill lucky they were in tracks at the time, needless to say after that they were always very concerned with GT and Angle T as well as where and what other units were shooting that day. I lost the front end of my jeep at NTC once. The Battalion FDC input me for the registration point. Fortunately I was in a bit if a rise and the round impacted below us. As my driver and I were getting off the ground, two four-deuce rounds impacted. Good thing it was a registration. It would have been nice to know I was doing the Task Force mortars. They just wanted to see if you were paying attention. ![]() I think I would have buried him somewhere in the desert, after they surgically removed my foot from his ass. |
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Tell me what I don't understand when I say that an artillery shell fired at the equator in either a due east or due west direction will go the same distance. I've learned about your deflection tables, thanks to this thread. The table shows that there is no range correction in those two scenarios. How am I wrong? http://www.globalsecurity.org/military/library/policy/army/fm/6-40/fig7-17.gif View Quote View All Quotes View All Quotes Quoted:
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I brought what up? You brought up the amount of range increase or decrease at zero deflection. You are the one who originally quoted that part of the chart. And you also edited out the post above mine so it would be very clear. zero mils would obviously have no increase or decrease in range because its perpendicular to the rotation of the earth. Quoting the OP's first post. "It seems like artillery rounds would travel further if fired in the opposite direction the world is turning at 1000 miles per hour. When it comes to artillery with ranges of dozens of miles, does the round fly the same distance if fired exactly into the rotation and exactly away from the rotation of the planet?" Granted, he didn't ask about the shot being taken at different latitudes (which I acknowledged would alter the range of the shell.) What I'm arguing is a direct analysis of a thought experiment, as suggested by the OP. You seem to have a strange need to prove me either wrong (I'm not,) or arrogant (I'm not that either.) Is it because I've never served in the military? Does that bother you? huh ![]() I'd leave the "rocket science" to the experts. Tell me what I don't understand when I say that an artillery shell fired at the equator in either a due east or due west direction will go the same distance. I've learned about your deflection tables, thanks to this thread. The table shows that there is no range correction in those two scenarios. How am I wrong? http://www.globalsecurity.org/military/library/policy/army/fm/6-40/fig7-17.gif Due east-west causes the greatest change in range, north-south causes no charge. Table I to correct for the Coriolis effect, at lower ranges because of low times of flight you don't see a correction however you start seeing a correction because of time of flight in any direction of fire. |
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Quoted: Due east-west causes the greatest change in range, north-south causes no charge. Table I to correct for the Coriolis effect, at lower ranges because of low times of flight you don't see a correction however you start seeing a correction because of time of flight in any direction of fire. View Quote It looks like my definition of azimuth was wrong. Thanks for for rationally setting me straight. |
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There is a another set of ranges after the 8000m under the line of ***. Those ranges have different corrections. What is the difference between the two sets of 8000m data?
Just trying to understand the tables. A comprehensive set of equations would be fun to dig through, I might have to do some research. (The engineer in me is curious) |
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There is a another set of ranges after the 8000m under the line of ***. Those ranges have different corrections. What is the difference between the two sets of 8000m data? Just trying to understand the tables. A comprehensive set of equations would be fun to dig through, I might have to do some research. (The engineer in me is curious) View Quote High angle fire, fires above 800 mils |
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High angle fire, fires above 800 mils View Quote Thanks, It makes sense because there is less horizontal velocity for the Eotvos effect (which is new to me). I was assuming it was for a different powder load producing different velocity and requiring a different angle to reach the target; as in the multiple rounds hitting simultaneously technique. But it seemed to me that there would be way more than 2 sets needed if that was the case. I can see why a computer would do this way faster. |
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Thanks, It makes sense because there is less horizontal velocity for the Eotvos effect (which is new to me). I was assuming it was for a different powder load producing different velocity and requiring a different angle to reach the target; as in the multiple rounds hitting simultaneously technique. But it seemed to me that there would be way more than 2 sets needed if that was the case. I can see why a computer would do this way faster. View Quote View All Quotes View All Quotes Quoted:
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High angle fire, fires above 800 mils Thanks, It makes sense because there is less horizontal velocity for the Eotvos effect (which is new to me). I was assuming it was for a different powder load producing different velocity and requiring a different angle to reach the target; as in the multiple rounds hitting simultaneously technique. But it seemed to me that there would be way more than 2 sets needed if that was the case. I can see why a computer would do this way faster. A computer is faster and easier to use for a wider variety of conditions, but there are ways of creating and applying a general correction to your manual firing data. Anywhere from correcting for muzzle velocity outside of standard, weather conditions, target elevation above/below gun, the two corrections being discussed in this thread, and a couple others. Good people with manual can be pretty fast and accurate, but it takes prep work to come up with the corrections beforehand. |
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A computer is faster and easier to use for a wider variety of conditions, but there are ways of creating and applying a general correction to your manual firing data. Anywhere from correcting for muzzle velocity outside of standard, weather conditions, target elevation above/below gun, the two corrections being discussed in this thread, and a couple others. Good people with manual can be pretty fast and accurate, but it takes prep work to come up with the corrections beforehand. View Quote View All Quotes View All Quotes Quoted:
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High angle fire, fires above 800 mils Thanks, It makes sense because there is less horizontal velocity for the Eotvos effect (which is new to me). I was assuming it was for a different powder load producing different velocity and requiring a different angle to reach the target; as in the multiple rounds hitting simultaneously technique. But it seemed to me that there would be way more than 2 sets needed if that was the case. I can see why a computer would do this way faster. A computer is faster and easier to use for a wider variety of conditions, but there are ways of creating and applying a general correction to your manual firing data. Anywhere from correcting for muzzle velocity outside of standard, weather conditions, target elevation above/below gun, the two corrections being discussed in this thread, and a couple others. Good people with manual can be pretty fast and accurate, but it takes prep work to come up with the corrections beforehand. A good FDC crew with sticks can get a solution as fast as computer. |
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Thanks, It makes sense because there is less horizontal velocity for the Eotvos effect (which is new to me). I was assuming it was for a different powder load producing different velocity and requiring a different angle to reach the target; as in the multiple rounds hitting simultaneously technique. But it seemed to me that there would be way more than 2 sets needed if that was the case. I can see why a computer would do this way faster. View Quote View All Quotes View All Quotes Quoted:
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High angle fire, fires above 800 mils Thanks, It makes sense because there is less horizontal velocity for the Eotvos effect (which is new to me). I was assuming it was for a different powder load producing different velocity and requiring a different angle to reach the target; as in the multiple rounds hitting simultaneously technique. But it seemed to me that there would be way more than 2 sets needed if that was the case. I can see why a computer would do this way faster. 155 use to have green bag (charge 1-5), white bag (charge 3-7), red bag (Charge 8 or 7R) and Charge 8 Super Now we have the modular artillery charge system with M231 Green (charge 1-2) n and M232 brown (charge 1-5, but normally 3-5) |
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