16" Gun Firing Sequence


#1

On another thread I made a post regarding the firing sequence of the 16" guns on US battleships. I should have done my research before pulling the trigger because I had it wrong.

When firing a salvo, there is a .06 second delay between guns and the sequence is left, right, center. The delay is built into the electrical firing mechanism and is for the purpose of preventing the ballistic wave surrounding each projectile from interfering with the others. This enhances downrange dispersion.

Here’s a photo that I borrowed from another site that clearly shows this. The USS North Carolina, BB 55, Salvos from the 16"/45 forward main batteries , off of Okinawa during WW II.

Ray


#2

AWESOME!! Thanks Ray!


#3

Are those 6 projectiles in two groups of three that I see on the far left of the picture, or are they airplanes way off in the distance. They seem to be on a direct line with the angle (elevation) of the barrels. If they are projectiles, the center ones in each group of three appears to be ahead of the others, which would lead me to believe that the center barrel fired first. Of course, I readily admit it is hard to tell from such a small picture. Hell, they may be seagulls for all I know. As far as regulation firing order, I don’t know anything about ships or their armament and firing orders. If its a bigger gun than a .50 BMG, I don’t know a thing about it. Treat this as a question, not an answer.


#4

John

Yes, those are the projectiles. It would be impossible to tell which projectile came from which gun because of the camera angle , etc. I posted the photo only to illustrate the delay mechanism built into the firing circuit. The exact sequence varied between the different batteries because of things such as barrel length, distance between guns, velocity, etc. The MK 6 guns of the North Carolina may have used a center gun delay which would have been different from the Iowa Class MK 7 guns which used a left, right, center delay, according to my usually reliable Fire Control expert.

Ray


#5

[quote=“Ray Meketa”]John

Yes, those are the projectiles. It would be impossible to tell which projectile came from which gun because of the camera angle , etc. I posted the photo only to illustrate the delay mechanism built into the firing circuit. The exact sequence varied between the different batteries because of things such as barrel length, distance between guns, velocity, etc. The MK 6 guns of the North Carolina may have used a center gun delay which would have been different from the Iowa Class MK 7 guns which used a left, right, center delay, according to my usually reliable Fire Control expert.

Ray[/quote]

Ray,

I don’t have experience of the bigger guns, they were all but out of service when I joined the RN. I do know that there was no delay on the little guns that I did use such as 4.5 inch Mark III’s, both firing together. The theory was that if one gun fired a fraction of a second before its partner the recoil slewed the turret off-line and threw the other gun out. When firing in salvo (alternating left and right guns) the elevation jump at each shot and the left and right jumps could be measured easily. In fact we used to record the servo performance to check the recovery time after each shot to be sure that it was back on line ready for the next shot. As these guns only fired a 52 pound projectile the mounting and ships structure could handle all guns together. The blast of guns of this size was significant, enough to damage minor fittings such as lights and, on aircraft carriers, to damage aircraft parked too close to the line of fire. The recoil effect was felt as a jolt, sometimes crockery in nearby messdecks suffered, not much more.

gravelbelly


#6

gravel

I don’t recall seeing any references to the smaller guns having, or needing, firing delays. The older turrets for the mid-sized guns such as 8", had the guns placed close together but in later mountings they were moved farther apart to enhance downrange dispersion. Maybe that is all that was needed.

Stuff like this is what seperates a Gunners Mate from a Fire Controlman. I always said that a GM is nothing more than an uneducated FC. :) :) Once that giant sized BB left the muzzle my job was done. :) :)

Ray


#7

You ex service guys are awesome! Really fascinating insight. I appreciate your service to protecting freedom and the amazing information you share here. Learning gobs from ya everyday! It must have been increadible being a part of firing these massive guns.

Thanx
Jason