Naval gun rifling cutter photo's

[JoeMcNeill]

Lots of information available on the Mark 7 naval guns:
Shells weight from 2900 lbs. for HC to 1900 lbs for the HE.
Charge weight from 660 lbs. to 305 lbs.
Muzzle velocity from 2500 fps to 1800 fps.
Barrel life 180 to 250 rounds.
Accuracy @ 34,000 yards was 150 yds to 250 yds from target

In Vietnam the New Jersey would fire 1 round to clear a helicopter landing zone, 200 yds wide!
They also made a M23 nuclear round but none were ever fired.

JDM

 

[Dusty Stevens]

 

[sandwarrior]

View attachment 1216115

Here's a good example. The waves are caused by the blast. But, if you look at the white at the bow and the light colored water right behind that, that is the force of the guns moving the ship away from the blast of the guns. YES, the guns recoil moves the ship.

 

[Cecil S.]

Very cool photos.

 

[snakepit]

How about 18 inch guns on the Iowa Class Battleships. They were tested with a 3,848 lb projectile at a velocity of 2,508 FPS but they decided on the 16 inch guns with one of the reasons being barrel life.

Here is some information on the 18 inch guns.

18-inch/48-caliber Mark 1 gun - Wikipedia

en.wikipedia.org

The Japanese had two battleships in WWII with 18" guns, the Yamato and the Musashi.

 

[snakepit]

Here is a picture of the battleship USS Iowa firing it's guns. Look to the left of the fireball and you can see three shells in the air.View attachment 1216194[/ATTACH]

 

[Gun Smith]

How about 18 inch guns on the Iowa Class Battleships. They were tested with a 3,848 lb projectile at a velocity of 2,508 FPS but they decided on the 16 inch guns with one of the reasons being barrel life.

Here is some information on the 18 inch guns.

18-inch/48-caliber Mark 1 gun - Wikipedia

en.wikipedia.org

The Japanese had two battleships in WWII with 18" guns, the Yamato and the Musashi.

Might have to stretch my Rock Chucker a bit to reload them puppies!

 

[ND shooter]

Link did not work for me??

Worked for me. And yes you can see the shells in air! Wow

 

[sandwarrior]

How about 18 inch guns on the Iowa Class Battleships. They were tested with a 3,848 lb projectile at a velocity of 2,508 FPS but they decided on the 16 inch guns with one of the reasons being barrel life.

Here is some information on the 18 inch guns.

18-inch/48-caliber Mark 1 gun - Wikipedia

en.wikipedia.org

The Japanese had two battleships in WWII with 18" guns, the Yamato and the Musashi.

Iowa and Iowa class all had 16" guns. Yamamato and Musashi had 18" guns.

 

[riflewoman]

Assuming that the ship has to move, the ship also has to move the water out of the way. So taking the draft to the waterline and the length times the beam (the assumed amount of water impacted) we get a total mass of the ship and water to be about 150000 tons. The projectiles weigh 1.2 ton and exit at 2000 fps. So 9 times (1.2x2000)/150000 ~= .14 ft/sec. or about 2 inches per second. Considering it’s probably steaming at 7-10 knots...pretty meaningless

 

[Dusty Stevens]

Assuming that the ship has to move, the ship also has to move the water out of the way. So taking the draft to the waterline and the length times the beam (the assumed amount of water impacted) we get a total mass of the ship and water to be about 150000 tons. The projectiles weigh 1.2 ton and exit at 2000 fps. So 9 times (1.2x2000)/150000 ~= .14 ft/sec. or about 2 inches per second. Considering it’s probably steaming at 7-10 knots...pretty meaningless

Do they have to slow down that much? I hear top speed may be 40+

 

[snakepit]

Iowa and Iowa class all had 16" guns. Yamamato and Musashi had 18" guns.

You are correct but in the early design phase of the Iowa Class Battleships they looked at using the 18" guns but decided against it in favor of the 16" guns.

"Ultimately, the General Board decided that a 16"/50 cal gun offered the best combination of performance and weight, and the new 16"/50 caliber Mark 7 gun was used by the Iowa-class battleship design."

 

[jackieschmidt]

You are correct but in the early design phase of the Iowa Class Battleships they looked at using the 18" guns but decided against it in favor of the 16" guns.

"Ultimately, the General Board decided that a 16"/50 cal gun offered the best combination of performance and weight, and the new 16"/50 caliber Mark 7 gun was used by the Iowa-class battleship design."

Also, one huge consideration of the 16 inch gun was with the 18 inch of equal number, everything had to grow. The Japanese Yamato Class actually had around 20,000 more tons of displacement than the Iowas's.
The big caveat was the US ships had to still get through the Panama Canal. The additional displacement in order to mount the 18 inch gun would probably render the hull too large to make that pass.

There has always been a big discussion centering around a battle between the Yamato and the Iowa. The general consensus has always been that the Iowas were such superior ships in many critic levels areas, such as speed and fire control etc, that they would probably win such a slugfest.
That is, unless the Yamato did score a hit with one of the 18 inchers. That would hurt.

 

[jelenko]

I've always found it interesting that the Japanese went with high speed, high agility with their fighter planes, but went with heavy hitting with the Yamato and the Musashi.

 

[snakepit]

I seen somewhere that the ship moves sideways 7’ when they go off

I have heard the same thing. A sailor who had been on one of the Iowa Class battleships said they would sometimes take the middle 16 inch turret and fire it in the opposite direction to help stabilize the ship. You can see this in the 2nd picture of post #73.

 

[riflewoman]

Do they have to slow down that much? I hear top speed may be 40+

I dunno... I don’t think so even with WW2 fire control systems. But the point was that the sideways velocity isn’t very high and less so compared to a slow steaming rate.

 

[spclark]

Here is a picture of the battleship USS Iowa firing it's guns. Look to the left of the fireball and you can see three shells in the air.View attachment 1216194[/ATTACH]View attachment 1216198

Can't do that with a .308 now can yah?

 

[sandwarrior]

I dunno... I don’t think so even with WW2 fire control systems. But the point was that the sideways velocity isn’t very high and less so compared to a slow steaming rate.

I want people to go out and take a 200 gr. bullet and launch it out of a 30-06 @ 2700 fps and tell me the recoil has no effect. That's basically what a 2700 pound shell does out of a 16" gun at 2700 fps.

Now, line up nine of them and shoot at the same time! I'm sure that wouldn't move you.

Can't do that with a .308 now can yah?

Put nine of them together and I bet it will move you...to a place you don't want to end up in...

 

[sandwarrior]

I've always found it interesting that the Japanese went with high speed, high agility with their fighter planes, but went with heavy hitting with the Yamato and the Musashi.

They didn't go with high speed. They went with "light and maneuverable". Japanese fighters were lighter, but didn't have as much horsepower and were therefore slower. P-40B/C's were 20-25 mph faster than A6M2/KI-43 fighters (Zeros/land based zeros). P-40's also had self-sealing fuel tanks which meant they didn't catch fire and explode when hit with a few rounds. We also had superior pilot armor. P-40's also had a faster roll rate and higher manueverability at high speeds (lower maneuverability at low speeds). U.S. fighter planes were way more 'tough' as the P-40 could dive at speeds of over 600 mph and absorb damage. Surprisingly, they didn't suffer from the 'compression' that many other U.S. fighters did. The Japanese aircraft could go just over 400 mph in a dive before they began to tear apart. They were light so the p-factor also kept them from turning right as fast as our aircraft.

The concept of early Japanese fighters was a very advanced WWI fighter. Manueverability was the #1 goal. What the U.S. fielded (P-40) was a very primitive WWII fighter. Fast and tough, but could not turn at LOW SPEED with Japanese aircraft.

With ships it was the opposite. Heavier and heavier battleships. But, the carrier concept was embraced by the Japanese, who delved into it deeply. And, had it not been for the "luck" of the U.S. at Midway we would have faced much more formidable odds against Japanese carriers/aircraft. For, even though we had fielded aircraft superior in speed, armor and armament, we still taught WWI tactics to our pilots. Not a trait where we had advantages.

 

[riflewoman]

I want people to go out and take a 200 gr. bullet and launch it out of a 30-06 @ 2700 fps and tell me the recoil has no effect. That's basically what a 2700 pound shell does out of a 16" gun at 2700 fps.

Now, line up nine of them and shoot at the same time! I'm sure that wouldn't move you.

Put nine of them together and I bet it will move you...to a place you don't want to end up in...

So then why didn’t the big German railway cannons drive themselves all the way back to Berlin?