A question for the naval gunners

[Modeler]

I have a question for you naval gunners types. I've noticed that many naval guns had both inch and caliber designations (3"/50 cal). What does that mean? I understand that the inch is the actual inside diameter of the barrel, right? But where does the "50 cal" part come from?

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[Dungannon]

3"x50cal=150" barrel length

Former soldier, not a sailor but that's how my WWII dad explained it.

 

[oremike]

It's not 3"/50 cal, it's 3"/50, others were 5"/38 and 5"/54 but Dungannon has what it means right.

FT(G)SN Mackie
Haze Gray and under way from '75 to '79

 

[Modeler]

It's not 3"/50 cal, it's 3"/50, others were 5"/38 and 5"/54 but Dungannon has what it means right.

FT(G)SN Mackie
Haze Gray and under way from '75 to '79

Gotcha. So the second number is the barrel length expressed as a multiplier of the caliber? A 3"/50 has a 150" barrel, so a 5"/38 has a 190" barrel and a 5"/54 has a 270" barrel?

 

[oremike]

Yep, the big 16" naval rifles were 16"/45's or 16"/50's. The Oiler I was on only had the 3"/50's

 

[Ura-Ki]

My understanding from Dad ( retired TinCanner Cpt) it that the first number is the diameter of the shell, the second number is the metric number so..........a 16" shell would be called a 16/406 OR in centimeters 16/40 Then the OLD way was "Pounder" referencing the weight of the shell! and the hybrid 9/58 being a 9"58lb shot
Edit to include that the big 16 in naval gun is 50 times the shell diameter!

 

[oremike]

In gun fire control school they used to tell us that the 16"ers could hit a garbage can on a street corner with a projectile that weighted as much as a Volkswagon from 23 miles away. That was never confirmed however because you couldn't find the city block the street corner was on after you hit it with 2700lbs of high explosive.

 

[Ura-Ki]

I had the rare treat of seeing the Iowa fire all 9 rifles in salvo from the air! Even at a distance of about two miles, you could FEEL the heat and the concussion from those guns! I will never forget that experience!!!

 

[captqc]

I had the rare treat of seeing the Iowa fire all 9 rifles in salvo from the air! Even at a distance of about two miles, you could FEEL the heat and the concussion from those guns! I will never forget that experience!!!

I'd give my left nut to experience that!

 

[Brutus57]

Don't forget 5" 50s were pretty fun, too!

Brutus Out

 

[Ura-Ki]

One of the coolest uses of ordnance I have ever seen! They were firing on a gun emplacement on shore, and hit that sucker with all shells fired. A "miss" at 20 miles was measured in meters and if memory serves me, it was less then 5 meters at that range, still a hit as far as they were concerned! The Iowa ( don't know for sure IF it was the big I) was in as close as she could get, there was a serious brown wake behind her from kicking up the bottom

 

[oremike]

Here's a good time waster for ya:
Naval Guns of the United States of America - NavWeaps

 

[Ura-Ki]

 

[Diamondback]

Didn't serve, but as a semi-pro military historian the guys above called it: Diameter of Bore then Length in Calibers.

Trivial aside, the largest naval guns ever put to sea were 460mm (18.1"), carried aboard Yamato and Musashi, though they had designs for a twenty-incher in development. (Which is big enough that if you could protect against shock, you could fire a torpedo as a shell...)

 

[etrain16]

One of the coolest uses of ordnance I have ever seen! They were firing on a gun emplacement on shore, and hit that sucker with all shells fired. A "miss" at 20 miles was measured in meters and if memory serves me, it was less then 5 meters at that range, still a hit as far as they were concerned! The Iowa ( don't know for sure IF it was the big I) was in as close as she could get, there was a serious brown wake behind her from kicking up the bottom

Man I love those big battleships! Got to tour the Missouri in Hawaii a few years ago - what amazing ships they were.

 

[Medic!]

Oh such fond memories.

 

[maddog]

Man I love those big battleships! Got to tour the Missouri in Hawaii a few years ago - what amazing ships they were.

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Dad served on the Indiana during WWII and he was always fond of telling us how the ship would actually move sideways when all nine of those big guns fired. They were shelling Saipan, and Okinawa at a later time.

 

[Certaindeaf]

Neat stuff.
It's just amazing how different the war ships are these days due to technology.. they hardly bother with armor at all. Why bother when you can take out a whole fleet from the next planet over with a push of a button.
Here's a neat pic of old armor girdle with a hole in it.. Yamato holed by a 16".
I don't know how thick it is but it's thick..

 

[Diamondback]

Another fun bit of trivia: One shell from an Iowa is heavier than an old wooden-hulled three-decker ship of the line's entire broadside. (Kinda apt, given that each barrel is about a third of HMS Victory's entire hull length... typical broadside on a standard British 74-gun two-decker was about 800#, a 100+-gun three-decker like Victory threw about a half-ton per full broadside.)

 

[Certaindeaf]

And then the Cole gets almost sunk by a rubber raft (ouch) and a scouting patrol is kidnapped by Iran.. (double ouch).
Come on, navy!
I know, sidetracked but hey