[skeetldoo]

I've always wondered about the science involved in firing a large caliber weapon, such as a cannon or a ship mounted gun. Just outside South Harbor in San Pedro and next to the U.S.S. Los Angeles Monument resides one of the 16 inch guns from the U.S.S. New Jersey. The gun barrel rests atop concrete support anchorages. Here are the projectile and gun stats:

16 INCH ARMOR PIERCING PROJECTILE

LENGTH: 72 INCHES WEIGHT 2700 LBS.

600 LBS. OF POWDER CREATES 17.5 TONS OF PRESSURE PER SQUARE INCH IN THE POWDER CHAMBER, FORCING THE PROJECTILE THROUGH THE 68 FT. GUN BARREL TOWARDS ITS TARGET - TRAVELING AT 1653 MILES PER HOUR/ SPINNING AT 4000 R.P.M.

MAXIMUM RANGE: 22.8 MILES RATE OF FIRE: 2 ROUNDS PER MINUTE

My question for anyone who might know is:
Depending on variable conditions and the correction factors involved how much does wind speed, angle of gun barrel, coriolis force, shell time of flight, etc., figure into firing the shell on target.? .. Is the correction measured in inches, feet, yards, etc.? ...

How about firing a field artillery piece such as a howitzer or cannon.? .. What has to be done to land a shell on target.? .. With the exception of close range targets at what point, distance wise, do the correction factors need to be considered for accurate shell placement.?

Someone figured this stuff out a long, long, time ago.
Just wondering ..

 

[TexasTon]

you need to catch the segments run on the history channel--preferably ''battleships'' and ''tanks''. you can probably find a schedule on the net.

as far as that is concerned now, computers control it, gyro aided. what gets me is the speed the projectiles are fired at :shock: :shock:

as far as in the day---correct the shot by glass or radio

 

[aimless]

My grandfather did some of his midshipman cruises on the USS Missouri over his summers at the USNA. He had the privilege of seeing the Missouri "kick Cadillacs over the side" on more than one occasion. (They called it that because each shell cost the same as a new Cadillac.) According to him, there was very little computing done to shell a target. For instance, when firing upon the shore the ship would turn parallel to the target so it could point all its guns at it. Distance to the target was judged visually, and using simple physics the guns were pitched up at an angle that would hopefully land them on target. The trigger was pulled. A lookout above the conn would then call back a damage report of "short, on target, or long." Short meant increase angle, long meant decrease angle, and on target meant just that. If I remember right, the guns are on gyroscopes - they move independently from the ship, meaning they always stay on target regardless of heavy seas.

 

[pumpgun]

Wonder how many shots those barrels will last.

 

[artz]

short story...
I was off the coast of Lebanon during the bombings in 1984 on the USS John F. Kennedy. One day the cap'n came on the 1MC and announced that whoever could...go up to the flight deck and look a certain direction and you will see the USS New Jersey firing upon Lebanon. We were a good 50 plus miles of shore, and the New Jersey had to have been within' about 20 miles to hit anything. We waited a few minutes and the shoe began. The sky was cloudy and you couldn't tell sky from water from a distance, but you could see the heavens light up in fireball with a flashing glow. Better than a incoming storm... 8)

 

[qwert]

For the old M60A3 Tanks and the M1 series tanks the calculations are done by a computer with an external sensor for wind speed etc. depending on the type of round being fired (Fin Stabilized Discarding Sabot or High Explosive Anti Tank).

For artillery to my understanding (I am not a cannon cocker) it is still mostly done by a forward observer and calls for adjustment for fire (which is why they usually fire one round at a time and observe the splash point before making a final adjustment and calling in a fire for effect). With artillery the other thing you have to worry about is calling for fire to close to your position (referred to as danger close). Different artillery pieces have different danger close parameters depending on what is being fired. MLRS has a larger danger close area than standard tubed artillery unless you start getting into the naval artillery to my understanding. The two reasons for this are the "footprint" of the rounds and the accuracy of the artillery piece being fired.

Like I said before I am not an expert but this is the way we were trained. Thankfully I never had to put it in practice but I just thought you may like to know.

Have a good day.

 

[Swamp Yankee]

I remember reading about the German's Paris gun from WW1. It's range was about 76 miles, shell time in flight was about 5 minutes (once the french figured out where the shells were coming from an observer would call Paris after seeing the gun being fired so people could get under cover), and the fire control people had to figure rotation of the earth to drop shells on target.

 

[Paul F.]

We had New Jersey fire support for us in Vietnam. Very scarey experience as "short" rounds were not uncommon and danger close to one of those shells was listed as 500 yards, I believe. They were effective rounds, though... OMG the damage they could do! :shock:

 

[tools8288]

My granfather was stationed on the USS New Jersey BB-62 durin WWII in the Jap. area mostly bombing small islands. He has some gret stories including one where an officer was rendered unconcous due to the fact that he was accidently on the deck while the 16 in. guns went off. Also, one of his duties included loading the powder bags into the main guns.

 

[EyeMissum]

If I remember right, the guns are on gyroscopes - they move independently from the ship, meaning they always stay on target regardless of heavy seas.

I oftened wondered how they kept the barrels on target on rolling seas.

My wifes Dad was in WW2 overseas an he would tell about how the Germans would open up with their "88's" on the American lines. He said they would walk those rounds in on their positions. By that he meant the first round might hit a mile away, the second might be 8-900 yards an the third would be very close. When they figured out they were on target, then all hell would break loose. They would open up with everything they had, an this would go on for hours on end.

 

[Red-Leg]

For artillery to my understanding (I am not a cannon cocker) it is still mostly done by a forward observer and calls for adjustment for fire (which is why they usually fire one round at a time and observe the splash point before making a final adjustment and calling in a fire for effect). With artillery the other thing you have to worry about is calling for fire to close to your position (referred to as danger close). Different artillery pieces have different danger close parameters depending on what is being fired. MLRS has a larger danger close area than standard tubed artillery unless you start getting into the naval artillery to my understanding. The two reasons for this are the "footprint" of the rounds and the accuracy of the artillery piece being fired.

Like I said before I am not an expert but this is the way we were trained. Thankfully I never had to put it in practice but I just thought you may like to know.

Have a good day.

As an Artillery FO for twelve years (including the first Gulf War) this sums it up fairly well.

I will add that there are a number of non-traditional artillery rounds out there now. The "Copperhead" round is laser guided by an FO illuminating the target with a ground or vehicle mounted laser. It's pretty impressive to light up a tank, call for fire, and see it killed with a single round.

 

[qwert]

Red-Leg

Hey now be nice to tankers. We don't like the Copperhead brought up and are not to crazy about FASCAM either .

Thanks for making sure I had my facts straight. It has been a while.

Have a good day (Steel Tigers)

 

[Donnie]

Ive never shot a cannon , but i am a long distance rifle precision shooter and im sure the same geometry applies. The shells ballistics have been recorded to an art , they know range , trajectory drop and how wind affects the round by 1 MPHer increments. Once you know the range in YDS or meters and how fast the wind is blowing and in what direction ...... ITS ALL OVER WITH!!!

 

[skeetldoo]

It's been said that the German 88mm was right up there with the best of guns used during WWII. Versatile too in that this piece was also used as AAA.