Clearing a squib in Naval 16" gun?

[SHR970]

The Colorado had the 16" 45 Caliber Mark 1 Gun. (4) Two gun turrets.

Powder charge was 590 lbs. loaded as 4 bags.

AP Projectile weight 2,110 lbs.

Data is available @ Navweaps.com

In the 1930's it was upgraded to the Mk 5 and later to the Mk 8 gun.

Powder charge then became 545 lbs. and the reduced charge was 295 lbs. The 545 lb. charge was in 5 bags.

AP weight became 2240 lbs.

 

[Armed_Chicagoan]

Is this the footage you saw? Shot is at the 30 second mark: https://www.youtube.com/watch?v=Oigy8g7EpXQ

eta: the video description says this footage is practice for the Tarawa invasion.

eta2: or maybe it was 3:40-3:50 in this video? https://www.youtube.com/watch?v=3Ji6PSvZH2g

 

[Mike Irwin]

As far as I know, squibs that lodge a projectile in the barrel of a naval cannon are pretty much unheard of. Hang and dead fires, yes, but I've not been able to find a single occurrence of a true squib ever happening.

My best guess is that if it WERE to happen, it would result in that gun being taken off line until the ship could return to a repair facility. I sincerely doubt that there's a way to get a shell out of the gun without dismounting it from the turret.

Regarding black powder, yes, black powder was used in the heavy naval guns. On the end of one or possibly each bag of powder is a packet of about a pound of black powder that is used as an igniter for the main charge. You needed that to help ignite the main charge because a simple primer couldn't be relied on to do it.

This picture shows a typical 16" powder bag -- the red pad on the end is the igniter pad, which is quilted with pockets filled with black powder.

http://eerie-indiana.blogspot.com/2014/01/16-naval-gunpowder-bags-as-made-at.html

That image is from this set, one of which shows the igniter pads being manufactured:

http://eerie-indiana.blogspot.com/2014/01/16-naval-gunpowder-bags-as-made-at.html


This page has some neat pictures of the powder grains used for 14" and 16" naval guns:

http://bulletin.accurateshooter.com...naval-gun-try-these-really-big-powder-sticks/

 

[Mike Irwin]

Regarding the large naval guns, most used interrupted screw breeches and bagged power, relying on a flexible "mushroom" on the breech, the obturator pad, to seal the bore during firing.

The Germans, however, relied on brass shells.

Yep, brass shells with a sliding wedge breech.

Loading such a gun was actually a hybrid affair.

The shell was loaded, as normal, then several bagged charges were loaded, and finally a large brass shell was loaded. The shell contained a primer (just like you'd find in any modern cartridge), and had a pre-loaded initiator charge plus more propellant.

This page shows some information on these guns (both in naval use and as heavy artillery on the Western front), including one of the brass shells. Those guns were 38 centimeter, or just shy of 15 inches, and initially armed the Bayern class of battlecruisers.

http://www.kaisersbunker.com/cc/cc15.htm

 

[Andy Blozinski]

I have a buddy that crewed the turret of the Missouri.

"FWIW - a 3-gun turret had a crew of 79 people to operate with a crew of 13 on the loading deck. You'd think someone would have noticed a gun being loaded incorrectly..."

There was an explosion inside the turret of the Iowa. His crew figured out exactly what happened and it was a screwed up loading situation.

 

[FrankenMauser]

Thanks for the links. Should be some interesting reading.

I didn't get a chance to dig for video last night. I had to scrounge for last minute items for today's pheasant annihilation. And, today, of course, was the pheasant annihilation. So it won't happen tonight, either.
I should have a little bit of free time tomorrow to go digging.

Is this the footage you saw? Shot is at the 30 second mark: https://www.youtube.com/watch?v=Oigy8g7EpXQ

eta: the video description says this footage is practice for the Tarawa invasion.

eta2: or maybe it was 3:40-3:50 in this video? https://www.youtube.com/watch?v=3Ji6PSvZH2g

Nope, and nope.

The clip that I saw was shot from below the level of the turrets - the deck, I assume - from the bow, looking aft, with the turrets close to 90 degrees off the starboard side (unless the image got flipped, but I think I would have noticed backwards numbers/letters).
Color film (and very high quality).
Not another soul visible anywhere on the deck or bridge superstructure.
It's the forward-most turret that has the 'oddity'.

 

[FrankenMauser]

This picture shows a typical 16" powder bag -- the red pad on the end is the igniter pad, which is quilted with pockets filled with black powder.

http://eerie-indiana.blogspot.com/20...s-made-at.html

That image is from this set, one of which shows the igniter pads being manufactured:

http://eerie-indiana.blogspot.com/20...s-made-at.html


This page has some neat pictures of the powder grains used for 14" and 16" naval guns:

http://bulletin.accurateshooter.com/...powder-sticks/

Hey! You learn something new every day...
The "wear reducing jacket" explains the large debris you sometimes see coming out of the guns.

 

[Emerson Biggies]

In Washington D.C. at the Naval Gun Factory Museum and navy yard there is a section of gun turret from a Japanese warship that was hit with a 16" AP round. The wall of the turret is about 11" thick armor. The entrance hole is about one foot and the exit hole about 3-4 inches. The shell is said to have killed the entire crew of the Japanese turret from the blast entering via the small hole. They also have a rail car with a 16" barrel in display.
I was there at 8th and H streets S.E. many years ago in the navy learning how to swab decks, clean toilets, stand guard, and wax floors many years ago. If you have a chance go visit.

 

[wogpotter]

Firstly a caveat:
"I know almost nothing about naval rifles"

But I saw a documentary that may prove interesting & even explain the OP's "squib". It was a WW2 (I think) training film made by Warner-Pathe about operating a 16" turret.

In it one of the things they mention that, as an uninformed landlubber I was unaware of. There's an "air injector" that is in some way used to push a shot of air into the fired bores. In one scene where they're preparing to fire you see the muzzle covers being "popped off" the muzzles, preparing the turret to fire, so it seems the air is pretty powerful.

Supposedly its real function is to force fired gas from the tube to prevent it getting back into the turret where it can be harmful to the gun crew. In another scene its shown being tested, they fire & wait, then (however its done) I think somehow connected to the breech opening lever? they trip the "air injector" & there's a puff of smoke which might well be thought of as a squib round firing.

Maybe that what were thinking of?

 

[ahanes]

Retired Fire Controlman Master Chief here (gun system guidance)... All naval guns have clearing charges, to be used in the event of a round that doesn't clear the barrel. Very rarely ever needed, as gun failures are more likely to be the result of no firing voltage, etc.

The few truly fouled barrels I've seen have been the result of problems during the ramming cycle and have required the barrel to be removed and cleared in the lab, luckily all were with dummy rounds.

 

[FrankenMauser]

Thanks for the replies.

 

[Mike Irwin]

The chunk of armor at the Navy Yard Museum in Washington is a 26-inch-thick piece of turret face armor from the IJN Shinano, the third in the Yamato class of super battleships.

It was found in, IIRC, the Kure Naval Yard where it had been abandoned after the Japanese converted the unfinished hull to an aircraft carrier.

The 16" armor piercing shell from a 50-caliber gun, the kind used on the New Jersey class ships and intended for the Montana class, made a hash of the armor.


The rail gun at the Navy Yard isn't 16", it's a 14"/50 Mk 4, the kind used on the Pennsylvania and Arizona. The new 16" guns weren't yet available in sufficient quantities for the new classes of battleships that were building, so the military went with the 14", which was quite effective.

 

[Mike Irwin]

Regarding the air injector, modern tanks also have air injectors for the same purpose -- to keep fumes out of the crew spaces.

Fumes from a big gun, let alone three, could quickly prove to be toxic to crews if it weren't ejected.

 

[wogpotter]

I was under the impression (probably wrong) that the ship type were some kind of air pressure from an external tank of some kind, injected as the breech lever was opened, not the "big-bulge-in-the-barrel widget" of tank guns?
For the evacuation to be delayable as the old training film suggests there is quite a long delay bey comparison as the guns are lowered to loading stations? Without that the "puff" would be, like a tank firing about instant wouldn't it?

 

[PolarFBear]

Wogpotter. The "clearing" air comes from the ship's High Pressure, 3,000 psi, compressors. Five inch bores, and larger, used the HP air to clear any unburned powder or other residue from the barrel before ramming the next charge. Off Beirut ('84), I had a "dufus" seaman sleep out under the forward 5-inch mount one night. We got a call for fire and he slept right through a 5 round salvo! It is quite a sight to see nine 16 inch muzzles swing inland. You just KNOW something is going to disappear.

 

[wogpotter]

Thanks. I assumed it was something other than the AFV system from the images in the video. Those compressors will definitely blow off the tompions eh?

 

[Long Path]

What a fascinating, informative thread.