MOA of a 16" artillery / naval gun

T

TXAZ

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We were discussing the MOA of long range shots, that 1 MOA at a mile is about 18", and once you get sighted in, the wind isn't too wonky and you know how your rifle acts on non-cold bore shots, these shots aren't heroic, but do take significant skill and some luck.

Fast forward to guns that shoot the equivalent mass of a Volkswagen 20 miles. What kind of MOA do these guns have, anything close to an MOA, which would be about 30'?
 
I can't tell you about 16" guns but i can tell you what I saw with our 5" gun. We had a max range somewhere around 5NM. While at shorter ranges, the gun would be aimed visually at longer ranges it was strictly by radar and observer direction. You couple that with the fact that the gun itself is always moving (either because the ship is moving forward or if anchored simple wave action) and trying to measure actual MOA becomes an impossibility. Perhaps in a test environment on land the engineers could make that kind of measurement but never on a ship.

We spent the better part of a week in Chesapeak Bay shooting at an island doing NGFS practice (Naval Gun Fire Support) for the Army. Even though we were anchored and could actually see the targets on shore it was very tough for our gun to hit them. This was using technolgy in effect as of the mid 80's (mainly designed in the 70's). The 16" guns you asked about used technology much older than that.
 
From what I've read, the 16" ship mounted guns had the same problems that Doyle's 5 inchers had. The ship was moving a little even when it was dead calm. A "tight" group would be on the order of one or two football fields. If the MOA at 20 miles is 30 feet (I'll trust your math on that), then the best a 16" gun could do is roughly 15 MOA. Don't forget though that the target was generally also huge.

16" coastal guns (mounted on land) I'm sure could do a lot better than that.
 
I would point out a couple of things, first, say you're right and MOA is about 30' at 20 miles, the shells have enough of a blast radius that 30 feet is pinpoint on target.

Also, in addition to the 1940s tech of our battelships, they have been upgraded with radar and computers. I've read the standard procedure is for the flight path to be computed, and ONE shot is fired, tracked by some kind of "millimeter" radar, and the actual flight path is compared to the calculated one, and adjustments made (if needed) then the rest of the guns volley fire.

And they usually don't fire just one broadside. SO, I think even if impact area is 300yds in size, the effect of multiple 9 gun salvos of 16" shells would be considerable.

Yes, the ship is always moving, and in fact the big guns firing actually moves the ship as well. I expect the "big boys" take that into account, as well.
 
I have a BIL and some friends who served in the USMC as part of an artillery battery up until they all retired just a few years ago. They served in both Gulf wars.

They claimed pretty good accuracy with computer assisted aiming. If I understood right they could track incoming fire by radar, and calculate exactly where it came from. Then return fire taking out the enemy artillery. They would send out patrols to draw enemy fire in order to locate the other artillery.
 
Considering the "standard" projectile of a 16 inch high explosive weighed 2,700 lbs, the blast area is larger than even a 2,000 lb aerial "blockbuster." With nine of them coming at you, there's no place to hide..
 
The great advance in conventional naval gunnery was the "all big gun" ship.
A salvo of large and uniform shells was going to fall in a fairly tight group. You adjusted until you got a "straddle" with some under and some over, then "fire for effect".
 
Here's data on Iowa class battleship 16 inch gun accuracy:

http://www.navweaps.com/Weapons/WNUS_16-50_mk7.php

Use math to calculate MOA size of shot dispersion at target ranges. One MOA subtends 1/3600th of range.

44AMP mentions
Yes, the ship is always moving, and in fact the big guns firing actually moves the ship as well. I expect the "big boys" take that into account, as well."
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Yes, those battleship 16" guns move the ship sideways. A 9 gun broadside moves the ship about 1 millimeter in the water. Read this:

http://www.navweaps.com/index_tech/tech-022.php

It's often stated battleships move 4 feet from a broadside. That is a misunderstanding of the 4 foot recoil each barrel has sliding back in its carriage burning over 600 pounds of powder to shoot a projectile weighing a ton or more.
 
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Considering the "standard" projectile of a 16 inch high explosive weighed 2,700 lbs, the blast area is larger than even a 2,000 lb aerial "blockbuster."
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Gonna have to do some checking on that. You're probably right, but it may be a close thing.

On a weight per weight basis, conventional artillery shells, and that includes the 16" naval rifles are the least efficient/effective explosive rounds.

This is because artillery shells have a thicker casing than bombs or mortar rounds. The thicker casing is needed to survive the stress of being fired, so on a pound for pound basis, the artillery shell has less explosive than a bomb.

Not a LOT less, but enough less to be measurable, and have a slightly smaller blast radius. On the plus side, the velocity and construction of artillery shells generally allows them to penetrate better than bombs or mortar rounds, which may be an important consideration.
 
My father worked with a WWII Navy vet…he told him a story about a church they targeted as the Germans were using it as an artillery observation post. Long story short the locals didn’t want the church destroyed but were OK with just the bell tower being hit. First shot they went long, second shot the tower was gone…ship was 7-10 miles off coast when shot was taken…either the Missouri or Wisconsin.
 
Also, in addition to the 1940s tech of our battelships, they have been upgraded with radar and computers.
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The Dakotas and Iowas came standard with the Ford Mk1 computer and Radars. The WW1 era Standards were upgraded in the 30's and 40's. When the Iowas were upgraded in the 80's they got newer radars but still had the same old Ford Mk1's because those old tanks were really that good in the first place.

Use math to calculate MOA size of shot dispersion at target ranges.
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You have to look at shot dispertion in the PoV of three groups of rifle men firing at a target from three different positions. IOW it is more of a shot gun pattern because not all three barrels in a turret are fully aligned with each other let alone the three turrets firing at three distinct andgles in X,Y and possible minor differences in Z.

The ship was moving a little even when it was dead calm.
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Put David Tubb on an 80 foot boat with his favorite rifle and watch his groups open WAY up. I'll bet a paycheck he couldn't put three into under an inch at 100 yards in an ocean harbor. Not only would his boat be moving but so would his target.
 
My father worked with a WWII Navy vet…he told him a story about a church they targeted as the Germans were using it as an artillery observation post. Long story short the locals didn’t want the church destroyed but were OK with just the bell tower being hit. First shot they went long, second shot the tower was gone…ship was 7-10 miles off coast when shot was taken…either the Missouri or Wisconsin.
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If that actually happened, it was a purely luck shot. Our guns weren't even that good in the '80s.
 
FWIW at the Battle of the Surigao Straight USS West Virginia (a WW1 Standard) opened fire on the IJN Yamashiro at 0353 hrs. at a range of 22,800 yards and scored a hit. That 16" 2240 lb shell was in the air for over 32 seconds before finding its mark.
 
I don’t think they were fighting the Germans, I think it was in the Mediterranean and the call went out. As mentioned, I heard second hand from my father.
 
I operated the MK1A Ford Instrument computer and MK 6 stable element below decks, the MK 25 radar and the optical rangefinder in the MK 37 director on two destroyers from mid 1957 to early 1960
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One of my friends performed the same duty on the only DD that packed an 8" 71 Caliber.

I tip my hat to you for your duty Shellback.
 
I have no idea as to the answer, I’ve called in artillery and they got really close to where I thought the target was initially. After that, it’s fine tuning until the impacts bracket the target.
Also I served in a support role in an artillery battery for 3 yrs... 155 paladins, being in close proximity to one of those While firing is awe inspiring, real bad for your sleep.
 
HMS Warspite hit the Italian battleship Guilio Cesare in July 1940 at a range of about 26,000 yds. HMS Warspite had 15" guns.


In June 1940 DKM Scharnhorst sank HMS Glorious at even greater range.
Scharnhorst was 28,600 yds. distant at 1632 when she opened fire
Her third salvo hit Glorious at 1638.

DKM Scharnhorst's main armament was 11" guns.

these were daylight engagements with visual spotting only, unlike Suriago Straight which was a night engagement, where American fire control radar played a significant role.

First shot they went long, second shot the tower was gone…ship was 7-10 miles off coast when shot was taken…either the Missouri or Wisconsin.
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If they were shooting at Germans, then it wasn't the Missouri.

Also I served in a support role in an artillery battery for 3 yrs... 155 paladins, being in close proximity to one of those While firing is awe inspiring, real bad for your sleep.
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What's really impressive is seeing the M109A1 in direct fire. Recoil of the gun firing "level" lifts the track off the ground all the way back to the 3rd roadwheel!!

Interesting tidbit, we put the .50 cal M2 on top of ours. The Canadians, had .50 cal M2s but the gun on top of their M109A1s was the Browning 1919, converted to fire 7.62 NATO.

If you want to look at REAL long range gunnery, look up the German "Paris Gun" in WW I. More than 3 times longer range than any naval gun, but easier in a way, as cities don't move much, unlike enemy ships. ;)
 
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