Turret Crawl on USS Iowa

[HankB]

I found it interesting that the powder bags weighed 110 pounds each, and the video showed individual sailors simply picking them up from the transport elevator and carrying them over to the gun. Seems that could become tiring under those conditions during a long battle.

[K Frame]

Oh yeah, definitely could be fatiguing, especially given how hot those spaces could get.

[K Frame]

Hey Terry,

I think I have some more information for you, at least on the firing of British heavy guns. This is from the video I posted of the guy closing the breech on a WW I-era 15" naval gun... I've done a bit more research/reading, and I THINK I have the following information correct...



I've circled two areas in red.

The circle over the center of the breech shows the primer area. In this case, the full assembly is there and is closed as if the primer is in the mechanism and is ready to shoot.

You note the black cable going to the brass clip on the breech block . As the breech rotates counter clockwise, it meets up with another brass clip on the standing breech (the other red circle), which also has a cable going to it.

I'm about 95% sure that that is the electric firing interlock. When the breech is fully closed that interlock sends a signal back to the fire control center that the gun is ready to fire. When the gunner in the fire control center presses the firing trigger, an electrical current passes back down through the same cables to the primer cartridge and the gun fires.

If the breech block isn't fully closed the firing interlock circuit isn't complete and the gun can't fire.

After losing several battle cruisers during the battle of Jutland, in large part due to grave errors in the handling of the powder bags, including leaving the flash proof doors open, the British REALLY ramped up safety on their post war designs leading into WW II and created a whole series of electrical interlocks that would, were any of them not showing ready, prevent the gun from firing (others would prevent the power hoist from operating, etc.)

The system was complex, but it helped ensure that an accident in the turret couldn't flash down to the powder magazines.

The complexity of the interlocks (as well as other issues) were still being ironed out when the battleship Prince of Wales sortied out to meet the Bismarck and those issues cut PoW's effective rate of fire. Because the issues were ongoing the PoW's captain requested civilian technicians from the Elswick Ordnance Company, which developed and built both the gun and the mounts, to remain on board. I've read varying numbers, but apparently upwards 100 technicians were on board during the battle and actively participated in operations, helping keep PoWs guns firing until one of the quad-mount turrets jammed.

[230RN]

Mike, that was all fascinating.  The loading and closing of the priming breech is shown in your link,

https://youtu.be/lPEI6pQc4Sc

at 26:10ff, where they deal with firing "Atomic Annie" with a conventional shell.  I note the "triggerman's" lanyard is about 30 feet long. :)

Another interesting part of that video is around 3.42 where they deal with acoustic sensors to locate the position of enemy fire way back in Korea.  They refer to the "computers" in the sound van which do the calculation.  What is interesting to me is the current efforts of various police departments to use similar methods to locate gunfire in our cities.  There's a wee bit of phase detection and geometry involved in that.

A great big THANK YOU to Mike Irwin for providing the hard data regarding my dumb question about that priming cartridge/breeching.  Apparently, I'm not the only one who was curious about that.

And also, for providing so much "color" surrounding all types of artillery.

Outstanding !

Muchas Danke,

Terry, 230RN

[K Frame]

Not really a dumb question at all. There's a lot about how they fire those big guns that just isn't available readily, but is sort of out there if you know where to dig and have the time to dig deeply.

I knew that the guns were electrically fired, and that they used a primer cartridge, but that was about it. Didn't know much at all about how it worked, didn't know that there was one guy whose job it was specifically to set the primer, etc.

[brimic]

After losing several battle cruisers during the battle of Jutland, in large part due to grave errors in the handling of the powder bags, including leaving the flash proof doors open, the British REALLY ramped up safety on their post war designs leading into WW II and created a whole series of electrical interlocks that would, were any of them not showing ready, prevent the gun from firing (others would prevent the power hoist from operating, etc.)

The system was complex, but it helped ensure that an accident in the turret couldn't flash down to the powder magazines. The complexity of the interlocks (as well as other issues) were still being ironed out when the battleship Prince of Wales sortied out to meet the Bismarck and those issues cut PoW's effective rate of fire. Because the issues were ongoing the PoW's captain requested civilian technicians from the Elswick Ordnance Company, which developed and built both the gun and the mounts, to remain on board. I've read varying numbers, but apparently upwards 100 technicians were on board during the battle and actively participated in operations, helping keep PoWs guns firing until one of the quad-mount turrets jammed.

I saw a show about the USS Forestal just recently. The investigation showed that a few safety interlocks for arming missiles on planes were ignored+ old munitions of unknown cook off time + not enough trained firemen (who were pumping water on jet fuel fires instead of foam) is what killed over 100 men and almost sunk a carrier. Just a bunch of small overlooked/disabled things that stacked together to make a really huge accident.

[230RN]

Murphy has several advanced degrees in engineering from the Malevolent Institute of Technology.

[HeroHog]

Some of them used Mercury "Triggers" to make sure the elevation angle was correct at firing. The Main "trigger" was energized and and when the ship rolled to the right angle, the Mercury completed the circuit and the primer was ignited. The Mercury was in a slight "U" shaped tube that had electrical contacts in it and was adjustable for the desired firing elevation.