Not to take anything away from the other battleships but FWIW only the Iowa, New Jersey, Wisconsin and Missouri had 16" 50 Caliber Guns.

The Alabama and North Carolina which were also mentioned had 16" 45 Caliber guns.

I would love to see the video of the receiving end of that.

What size are the guns on the Massachusetts, 16"/45 Caliber or some other 16" combination?  I know she's a different class from the North Carolina, and possibly different from Alabama as well and I don't know how that might affect the main guns.

Updated the OP to add a few videos.





Many people see many things when they see these pictures. As a reloader, one additional thing thing I see - questionable powder choice!  Look at all that muzzle blast and smoke.  Signs of using too slow a powder!    I also see a bit of a half-hazard house-keeping with the shells in the proof house testing.  

It isn't a Japanese video but Chinese.

If anyone is curious this is what the narrator said.

"In 1989, on the Iowa during a training mission, a terrible incident happen as they were preparing to fire the 16inch gun in 2nd turret. This terrible accident which there was no reason for, 47 crew members lost their lives."

Well, someone on an earlier page posted the barrel length:bore diameter ratio for the 16"/50 as well as .223, .308, etc. and it turns out to be fairly short. IIRC the same 50-calibers-long bore in a .223 (.224 dia.) is 11.2", so that's part of it. It's actually a pretty short barrel, as are most naval guns--the WW2 standard gun for DE, DD's, and some CL's was 5"/38, which is analogous to a .223 with an 8.5" barrel.

It takes a lot to accelerate a 1,800 lb mass to 2,700 fps in the span of a millisecond.  My wild ass guess would say that faster powder would push pressures to catastrophic levels before it could get the shell out of the bore, but I honestly have no idea why they use what they use.

The Washington class (Washington and NC) and the South Dakota class (South Dakota, Alabama, Massachusetts and several others) all used the 16" 45 cal.  Only the Iowas used the 16" 50 cal. though some projectiles were used in both (and also some older 16" guns on older BBs)

The key was that the fire control was about the same on all of the newer ships and it was advanced for the time.

My father was a gun captain in the #3 turret of the U.S.S. Washington.  His duty station was right next to the breech of one of the guns in the turret.  He supervised the loading, insured that the breech was clear of any embers before loading and sent the signal that the gun was ready for firing again.   He did this for almost 6 years.   In 1980 I took him down to see the USS North Carolina.   Other than being 40 years younger again he gave us one heck of a tour.  Since the North Carolina and Washington were sister ships they had the exact same layouts.  

When a friend of his who was a career naval officer showed him photos of the damage after the explosion on the Iowa my father looked for a few seconds and simply said over ram.  To him it was the only logical explanation.  It was also the greatest fear of the turret crew.  It later proved to be the cause.  Whoever was running the ram simply pushed it too far into the breech when he was loading the powder bags.  Heat generated as the powder was compressed ignited it.  

There are three ramming cycles during loading a 16" turret.  First the shell is loaded, then three 110 pound bags of powder then a second group of three more bags.  All the ramming was done by feel.  There are no stops on the lever that controls the ram.  Training is crucial.  Luckily the Washington started her career with 200 of the best chiefs in the Navy.  On top of that her first sea captain was old school and a training fanatic.  The Washington may have been he best run battleship in the Navy in WWII.   In fact their fastest time to reload a 16" gun and get it back to ready was 14 seconds.  

A full broadside was nothing more than a photo op.  In practice the jolt to the ship is quite severe causing circuit breakers to trip, things to jar loose, people get knocked around etc.  Each gun in a turret had it's own trigger (looks like a pistol grip) and could be individually fired.  An individual turret always operated against a single target.   In a battle each of the five 5" turrets could target individual targets.   The same for the 16" turrets.  

The USS Mississippi actually suffered two turret explosions during it's career.  One was in 1924 and other in 1943.  

16" 45 Cal.

This was the key.  The Kaigun used optical tracking and fire control, even using colored marking shells to range and adjust on targets.  We used gyroscopic computers driven by some of the most advanced radar in the world on a mobile platform at that time.  In the right atmospheric conditions, we had over-the-horizon detection, tracking, gunlaying, and (nearly) first-round-hit capability... in the dark.

Whereas when we faced Japanese guns, our destroyers and cruisers discovered that they could all but jink out of the Japanese fire solutions by simply steering towards the splashes - therefore invalidating the lead and range computations.  The Japanese never, to my knowledge and research, fielded naval fire-control radar during the war, even on the most modern of their battleships (the Yamato and Musashi).

Also keep in mind that besides the Yamato class, Japan did not launch a single battlewagon during the entire war.  Practically their entire battlewagon fleet, from the Kongo to the Nagato classes, were WWI-era designs with huge WWI era design philosophy flaws, and few saw significant overhauls the way our inter-war ships did.

Just look at what happened to the Kirishima, one of the Kongo class, to understand how entirely antiquated the Kaigun fleet battleships were compared to ours.  Many of them were actually battlecruisers re-classified as full battleships when the truth couldn't be any more different.

The 2700 lb 16" AP rounds did have an explosive filler.  The whole point of an AP round was to defeat the armor and then explode deep inside the ship, wrecking things and starting fires.  The AP cap was simply there to get the explosive through the armor.  HC rounds were used for land targets and also for firing on lightly armored ships like destroyers, support ships and merchantmen.  AP rounds would transit completely through the ships before functioning.  AP rounds were base detonating whereas HC rounds were point detonating, IIRC.

I read of an instance that happened I think during Korea.  One of the Iowa's was shelling some enemy concrete positions and the first round they fired was an AP round.  They fired the round, observed the hit and it didn't go off like it should.  They thought it was a dud and then it functioned and blew a concrete bunker off the cliff face.  They decided it was an AP round accidentally fired in place of an HC round.

I seem to recall the center has a delay coil to add 60 thousands of a second to its firing.  So it fires outside barrels, then the middle.

Iowa wouldn't even have to fire - it could just ram the entire armada.

Iowa smashing a wooden ship of the line at 33 knots would be epic.

Or just sit back and let the quad-Bofors shred the whole armada.  Make an afternoon of it...

Is the length to diameter ratio important?   A 9mm and a .40 cal both have the same length barrel and same SAMMI pressure rating, but if you look up their respective common bullet weight with lets say Universal Clay's max charge, they both have the same muzzle velocity.  Even though the .40 cal has a lower barrel length to diameter ratio.  

You need enough barrel length to impart the rotation and stabilize the round - which generally isn't much length at all to do so.  The rest is to allow more dwell time to continue acceleration of the round.  But that's just a function of time, which is length.  

Here is my best guess on what's going on.  Let's start with a .223 round, for comparison.  The below pressure graph shows that the round achieves real high pressure at first, and then the pressure tapers off pretty quick.  The bullet is accelerating the whole time it's in the barrel (hence longer barrel gives higher velocity).  And of course, the more pressure it has for the longer time, the more it's going to accelerate.

So the pressure starts really high, and hence the chamber area is always really thick, to handle it.  And as the powder burns down (and the bullet moves down the barrel - letting the pressure come down from the expansion).  A .223 round is pretty efficient, the cartridge size isn't so big.  But a magnum round, they hold a lot more powder, so you can keep the pressure up real high, for longer.  And you use a slower powder to do that, so the initial peak pressure doesn't go crazy.  The trade off, is it's less efficient, so you end up burning a good portion of the powder after the bullet already left the barrel.  But so what, powder is cheap.  

So I'm guessing that's the deal with this cannon too.  The put a crap load of powder in there, that burns really slow.  So that yes, while much of it ends up wasted as smoke and fireball, you were able to keep pressure up real high the whole time, and thus get better velocity.


(which is why barrels taper in thickness by the way.  They can be thin out front because the pressure is so low by the time the projectile gets to that area, so that area never sees as high of a pressure spike).

"X.O., Fire up the wood chipper..."

 

There's a pic out there (I have a copy somewhere) that caught the projectiles in flight just after firing (USS Massachusetts I think) and it's very obvious that there's a three way delay as the three shells are strung out slightly.

Well...  I wouldn't recommend it, but they could use Bullseye ONCE!!  

"Hey Cleatus, just how far do you think that big ol' breech block can fly?"  "Well Billy, I just got 'er loaded up with 660 pounds of Bullseye behind one of them there 2700 pound HE projectiles.  Hold my beer and watch this!"  

Actually, you probably could use Bullseye.  Just like you can use Bullseye in a rifle if you really wanted to.  But you'd need to reduce the heck out of the charge to keep the peak pressure in spec.  And so most of it would burn up in the first portion of the barrel, and give you a very low velocity.  It'd be more "efficient", in that you'd have a very small charge, and use it all up within the barrel (no fireball), at the expense of defeating the whole point of the gun though.

Gigantic Pyrodex tabs instead of black powder bags?

Does anyone know the ignition method used with these guns?

What is the puff of smoke released a few seconds after firing? Is that when the breach is opened, or is there some kind of barrel-clearing mechanism?

Awesome thread, thanks

If my calculations are correct, 24 miles is too close for a nuclear detonation...





 

The "primer" for the 16"/45 caliber guns on the USS North Carolina look suspiciously like a .45/70 blank with a sawtooth case mouth.  I suspect the same primer was also used on the 16"/50 caliber guns too.  I think the turrets are pressurized, so the puff of smoke you see is when the breach is opened.  You could probably suffocate a person if that volume of gas was allowed back into the small space inside the gun turret.

Steel Beach time.

"Hamburgers for the crew are now being served on the fantail."

Don't know about the primers but the puff of smoke is used to clear the guns of gasses and possible burning embers before they load the next round.  Don't want any burning embers igniting 110lb bags of powder; bad things might happen.....

After the gun is fired it automatically starts to return to it's load position.  During this time compressed air is blown down the barrel to remove burning embers.  As a gun captain my father had a bucket of water and a hose at his duty station.  His arm was also wrapped in a wet towel.  After the breech is opened the first thing the gun captain does is inspect for any remaining burning embers.  These are taken care of by swabbing the breech with the wet towel.  Once he is satisfied that no embers remain, loading can proceed.  

Interesting.  I found some other information that says this:

"GUN FIRING ORDER L, R, C, BARRELS.

FIRING DELAY 0.06 SECOND. THERE IS NO DELAY FOR THE LEFT BARREL."

As far as I know, no 16" Mark VII were mounted in shore mounts, with the exception of some ordnance  used for tests and the HARP project.  There were both Army and Navy 16" guns mounted in disappearing mounts as coastal batteries, but they were earlier guns.

You're probably right.  I know they had 16" shore batteries - but not sure what Mark they were.  Makes sense to have the best ones on the boats, and use the old stuff for on-shore.

Building a cannon that large is a real feat, and there are a couple of different wasy to go about it.  Back then, artillery was divided into two types.. "Field" artillery, (pretty much what comes to mind when you hear "artillery"), "Coastal" artillery - typicaly big guns in "disappearing" mounts.  Pretty soon they added "Air Defense" artillery as a third branch.  The advent of aircraft with a meaningful payload, and the modification of battleships to shot at 30 degrees of elevation, instead of 15, sounded the death knell  for the big coastal batteries, as their open mounts were now vulnerable to plunging fire from ship cannon and dropped aerial bombs.  Although a few mid-range cannons and in some cases anti-shipping missiles carry on the tradition.



The U.S. Army built 6 of these model 1919 16"/50 caliber guns, and then got 20 or so 16"/50 cal.  Navy Mark II/III guns as a result of cancelations of ships duie to the Washington Naval Treaty of 1922, which they fielded in similar mounts.

After firing, each barrel would blast compressed air down the bore to blow any sparks  and small debris left lingering and evacuate gases left in the bore before the breach was opened.

I bet that sounded awesome.

 

Not to be a nit-picker, but it seems I read that the big guns on battleships are actually considered to be rifles (maybe rifled guns?), and not cannons?

Seems like I read that somewhere, if I'm wrong I apologize in advance.

Nomenclature can be such a bitch sometimes.

LC

Cool.  Where'd you find that?  Also, to clarify-by 'three way delay' I meant that no two barrels fired at the same time rather than 'outers simultaneously then center'

I'm trying to find the pic since it's pretty cool.

I've heard them called Naval Rifles to.

 

The last part there...nice touch.

I just looked it up  and the MK 8 AP round had a filler of 40.9 pounds of Explosive D. The small explosive fill was there to give the shell an added "kick" to punch through armor. There was no "solid" AP round for the 16"/50 MK 7 guns on the Iowa class.

FWIW, the Army calls anything 20mm or larger a cannon.  The only non-rifled gun that I know of is the 120 on the M1A1 and M1A2.  (the 105 on the M1 was rifled)  I am pretty sure 155's have rifling.

They're probably confusing the testing purposes only AP round with Inert filler.

Does anyone know what solvent they used for bore cleaning? I'm pretty sure I've seen film of gangs of sailors pushing cleaning rods down the bores from the outside of the turret, but does anyone know what solvent they used? If the powder charge was black powder I guess it could have been soap and water, but does anyone know for sure?

I agree woith you - according to this source, the guns do not ever fire simultaneously.




Info on 1968 New jersey reactivation

While there was some black powder used, to help insure ignition, IIRC, the main charges were modern smokeless powder.

Hell that's how a Chief is supposed to look , all he's missing is a coffee cup in his hand.