Very neat. Here are 2 practice projectiles I took home.
Questions for Ray or anyone who has fired the BIG guns. Why do the barrels dip down and then back up after each firing? I understand the firing order of the 3 guns is Left-Right-Center with a small delay between each. Can all 3 be fired simultaneously and if not, why not?
I believe its for loading. They go horizontal so that the projectile and powder bags can be rammed into the barrel.
I can’t remember if it’s l-r-c or some other combination. I’d have to look it up. The delay between guns is only a small fraction of a second. It’s built into the firing system although I suppose it could be overridden and allow you shoot all 3 at once. Roundsworth would be the guy to ask. Or one of the Fire Control guys.
Here’s one of my favorite photos, showing the bullets in flight.
After the gun is fired, the Gun Captain manually positions his ‘Ready Switch’ to Load. The guns automatically assume the load position. The GC steps out on his platform, opens the breech, wipes the mushroom and shuts off the gas eject air once he verifies the bore is clear. Once the gun is loaded, the GC puts his switch back to ‘Ready’. The gun will assume its position in accordance with signals from the FCs or the Gun Layer. LBNSY installed a little box on the aft bulkhead of the Turret Officer’s Booth that controlled firing delays. I believe that C-L-R was the order(?). Originally, it was L-R-C. I thought it was changed. It has been 22 years since I left Missouri, so my recollection may be off! The delay was barely noticeable, but after awhile you could tell. When a three gun salvo was fired, it pert near sounded like one shot. The guns each had a recoil cylinder with 100 gallons of fluid, along with counter-recoil cylinders (2) with 1500 PSI of compressed air. These two systems did a great job softening the 4 feet of travel during recoil/counter-recoil. Even so, if the right gun fires while the left gun is doing what I just mentioned, I bet the shot would be off a bit at 20 NM. There was a wee bit of rotational force imparted to the Turret when an outboard gun fired. If you are wondering about the long delays in the Iowa video, it can be controlled manually by the Turret Officer. The firing of each gun can be controlled at the TO’s switchboard. The firing signal arrives in the Turret and the TO rotates the firing switch for each individual gun.
Roundsworth–Great explanation of exactly what goes on during firing. I could almost see it all happening in my mind. I really appreciate the detail.
This is from OP 769, 1968 reactivation of the USS New Jersey.
[i]GUN FIRING ORDER L, R, C, BARRELS.
FIRING DELAY 0.06 SECOND. THERE IS NO DELAY FOR THE LEFT BARREL.[/i]
Ray–Thanks for the additional information. Why have any delay at all. Was there an operational reason. The one thing I can think of is to help avoid the projectiles running into each other in flight since the delay would allow separation of several feet as can be seen in the photo you posted showing the projectiles on their way.
Ron - Dispersion, increasing the hit probability.
You know this stuff better than I do, but a report on the re-activation of the three-gun 16in turrets (AD-A183947 by Arthur Romano, downloadable from DTIC) says some of the newly installed equipment on the battleships could not stand the pressure from volley firing. So the sequence of firing was introduced together with limiting the arc of fire for each turret.
If the photograph really shows projectiles in flight, they are not fired in 0.06 sec intervals, which would correspond to a 150 feet interval at 2500 fps muzzle velocity.
There’s no doubt in my military mind that you’re seeing projectiles in flight. Here’s another photo taken in 1945 that shows at least 7 projectiles. In the first photo I think you’re assuming that you see all of the projectiles from a salvo whereas some of them may be off the photo frame. And you’re assuming that the group of three is from the same turret.
Interesting information. I went to my 1939 edition of “Naval Ordnance” which was the standard textbook used back then at the USNA. It goes into all aspects of naval artillery design in mind-numbing detail, including large-caliber electric firing circuitry and fire control systems. I found no mention of staggering the firing of guns in the same turret during salvo fire, although salvo firing itself was discussed. Perhaps staggering of firing of individual guns was not practiced before WWII? Or maybe it was just not considered as being a topic worthy of discussion.
I know that in some cases (particularly in turrets in which the guns were very close together) it was found that with simultaneous firing, the shock wave of the muzzle blast from one gun could affect the flight of the shell from the adjacent gun, increasing shot dispersion. This was solved by slightly staggering the firing.
When the guns are loaded with bagged charges like this can they easily be unloaded ?
Powder bags are easily removed. The projectile, however, is a different story. We had this big brass/bronze tool hanging in the center gun room that was designed for knocking projectiles loose from the rifling. We never used it, but it looked awful heavy! Once the powder is removed, a bunch of heavy duty ‘pillows’ are placed in the chamber. The breech is closed and secured and attention is given to the muzzle end of the gun. The backing out tool is placed in the barrel and a line is fastened to it. A plug is placed in the muzzle that has a pulley built into it. The gun is elevated to maximum and the backing out rammer is dropped against the projectile. The center of the tool is designed to pass over the ogive and nose/fuze. The tool is hoisted (most likely with a capstan) and released until the projectile is broken free of the rifling. After that, it is simply reversing the loading process to restow the projectile below.
As we are on this topic, what’s the procedure for bore cleaning after firing? My Navy experience involved nothing associated with naval artillery.
We used a very large bore brush and quite a few gallons of CLP per gun. The forward capstans were used to pull the brush through. We had to put down an acre of tarps to keep the crud off the teak. I had the pleasure of holystoning the deck under the kind supervision of a BMCM that joined the Navy in April of 1945. After Desert Storm, we had our barrels inspected and the liners trimmed from the muzzles. We crawled through the barrels and made sure that we didn’t have any big chunks of copper left behind. I do not consider myself claustrophobic, but the 66 feet from one end to the other seemed like an eternity!
The smaller guns could usually be cleaned by depressing the barrel and brushing and swabbing from the deck. But, on the high mounts, such as the 5"/54 seen on my photo, everything had to be done from inside the mount. We used sectioned cleaning rods. Each section was about 3 feet long so you had to run one in, then screw on another section, run it in, screw on another, and so forth. Then you reversed the procedure, all to get just one swipe of the bore. It was not fun. We used diesel fuel for scrubbing the bore, followed by a wool mop and a gallon of oil, and a bucket of heavy grease to coat the muzzle as far down as you could reach.
As a GM, what I hated most was when the Gun Boss wanted someone to fire just one round, say a star shell, and he picked my gun to do it. It meant all the usual prep work plus the post firing procedures and then having to clean the bore afterward.
Those were the good old days. I wouldn’t have missed them for anything.
While in Korea in November 1951 I was assigned to what we called Luke the Gooks Castle a position 500 yards ahead of our main line on a ridge within grenade throwing range of the NKA. A forward observer team from a battleship came to the position to sight a target a few miles north of us. We were never told what the target was but were told where here it was. After a few ranging shots the broadsides started. You could either see the 3 projectiles or their shadow on the snow and hear the freight train sound of them. Probably 36 rounds were fired and when finished there was not a sign of snow for about 200 yards square. Not a nice thing to be on the receiving end of. For you Navy types I was in the Navy Mule corps as Truman called us.