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zraver

zraver

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This is a thread for members to ask specific questions of the experts who will then reply if the question is in their specialty. Non-expert members may not answer, I will delete them.

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Follow on questions may not be rebuttals of the answer provided, but you may ask for clarification.

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Field- Gunnery

Question- How much explosive filler did the average 16" HE round actually have?
 
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According to Bureau of Ordnance drawing number 440559 for a 16" projectile (H.C.) Mk 16 Mod O dated 28 May 1945 the weight of the bursting charge is (I think as the copy is blurry) 158.57 lbs of Explosive "D" with a density of 1.46. The volume for the bursting charge is 2,670.58 cubic inches.

The projectile body alone is 1,571.50 lbs. Weights of rotating band, base plug, container & nose, adapter, container charge, base fuze with tracer, time fuze, auxiliary detonating fuze and gaskets brings the total weight of the projectile up to 1,900.00 lbs.

I have other BUORD drawings of a few other projectiles as well but the question is not asking me to dig them ALL out (thank goodness).
 
Mr.L. is spot on. I have it as 153lbs of High Explosive for the HC round. This may have changed in the late 1980's or early 1990 as the USN was still working on shells that would be incorporated into the BB's inventory had they stayed in service longer.

This is also why the HC (HC High Capacity) OR "shore bombardment" round blew the huge craters in the ground measuring approximately 20 feet deep x 50 feet in dia and would also defoliate the trees such as in the Vietnam era.
 
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USSWisconsin said:
I wonder what kind of explosive would have been used in a modern version of the projo. Explosive D is pretty old stuff. My guess would be a balenced blend of modern HE, fuels and oxidizers in a more advanced casing.
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Explosive "D" is considered to be the safest to use in Artillery shells as it is not overly sensitive to the shock of enertia as it goes from 0 to 1700 miles per hour in only 66'-8" feet.
 
RustyBattleship said:
Explosive "D" is considered to be the safest to use in Artillery shells as it is not overly sensitive to the shock of enertia as it goes from 0 to 1700 miles per hour in only 66'-8" feet.
Click to expand...

That is quite an accomplishment for an explosive, I suppose "if it isn't broke - don't fix it" applies here.
 
Topic - BB shells
When was the last time that 16 inch shells and powder charges for the Iowa class manufactured? Where were they manufactured? Since the Iowa's have been stricken from the naval register and there is no chance they will see service again, is the navy still storing surplus shells? Could any existing shells be dated as far back as the 40's?

Only particular subject I could think of at the moment.
 
Ken_NJ said:
Topic - BB shells
When was the last time that 16 inch shells and powder charges for the Iowa class manufactured? Where were they manufactured? Since the Iowa's have been stricken from the naval register and there is no chance they will see service again, is the navy still storing surplus shells? Could any existing shells be dated as far back as the 40's?

Only particular subject I could think of at the moment.
Click to expand...

As I have read: the powder charges were the primary problem item, old powder is dangerous, it can become sensitive due to improper storage, some old powder stored on a barge which got too hot was blamed for the Iowa accident. Most old powder needed to be remanufactured to make it safe, and ramming procedures needed to be improved - ram very gently. Old projectiles are less of a hazard, during the 1st Gulf war, some WWII projectiles were used - I was told this by the gunners on USS Wisconsin in 1991. Our Iowa class experts will probably be able to illiminate this question better than I can, I am more of an acedemic battleship generalist as opposed to the directly involved, hands on Iowa class specialists like Rusty and Dread.
 
As for the Iowa, we all know that the deflageration (often called "explosion") was caused by five reduced service bags of propellent igniting while the gun breech was open. There have been too many arguments and speculations as to what caused it. So many that they all contradict each other. So I will not go any further than that except for the following comments on reduced service charges.

My main problem with it is that some people just REFUSE to learn from history or REFUSE to read it. Turret I of Iowa already had some misfires before that incident. Why? Apparently nobody read Paul Stillwell's book on the USS New Jersey's Viet Nam tour.

Reduced service bags (55 lbs each) are smaller in diameter than the full service bags (110 lbs each) and even if firmly packed tend to tip over when the barrel is elevated. Thus the primer charge misses the red patch of black powder that in turn ignites the main propellent. Paul's book shows an excellent photo of a misfire on NJ with a hole burned into the silk bag with the propellent granules totally intact. Admiral Schneider (then Captain of the Big "J") ordered that reduced service bags were never to be used again.

Unfortunately, that experience and advice was lost 15 years later and the ships again were being supplied with the smaller diameter bags for short range firing. It's sort of like putting a .44-40 into a .45 long colt and hoping the firing pin will hit the primer.

Now for the general question: The main explosive in the warheads of projectiles can last for many years. I recall reading a news article of a Mortar crewman in Viet Nam using ammo made in WW II. On one of the boxes had the name and phone number of the woman who packed it. After returning to the states, he looked her up and gave her the box back.

The biggest problem with the warheads are the fuses. It depends upon what type of explosives are used for the striking primer and the ignition charge. They could be age sensitive and may have to be replaced. On some of the older models of 16" shells, they had a problem of the base fuse spinning itself out halfway between the USS Massachuessets and the Jean Bart. The AP shell credited for breaking the stern casting of the French BB did not explode but went deep enough and hit hard enough to cause the ship to start settling in the water. Also, one of the "fuseless" shells rolled down a street in Casablanca and I've been told it is still on display (though the explosive has been removed).

I had a cousin who was a "supervisor" in a weapons factory up in the Saugus Hills area (spread out among several valleys with high hills in between). His "supervisory" duties were merely to walk the assembly lines, report any problems and call in the right mechanical team to fix the problem. All of the weapons loading personnel were women. Women pay much more attention to detail and do not get bored with redundancy as often as men do (ask anyone who has had to reload hundreds of rounds of ammo for a pistol range). They also all wear white coveralls with white hoods. Overhead is a series of copper rods. Each person wears a copper bracelet with a copper wire running up to a copper ring-hook on the rod overhead. This grounds them out so their own static electricity wouldn't make one of the Valleys in Saugus bigger.

But as he said, it wasn't packing in the main charges that was the most hazardous, it was the fuse assemblies. Even with the patience and detail attention of women, they were given long breaks while another team would come in.

On a smaller scale I bought some old .22 long rifle ammo for only a penny a round. But it was so old it would hang-fire almost every time. They all fired, but sometimes the powder did not ignite for half a second or so while the primer in the rim started to burn faster.

On a slightly larger scale, I had some .30-06 Military ball ammo that dated back to almost 1906. I could fire it in my bolt action 03-A3 Springfield and eject the cases just fine. But the rapidity and strength of my M-1 Garand extractor would rip right through the case rim and I would have to use a cleaning rod to knock it out. It wasn't the problem with the powder or the primer, but the brass case age-hardened and was too brittle to withstand the ejector of a Garand.

Finally I had a learning experience of old ammunition with an 11 mm Remington rolling block I had. The ammo was very old, dirty and dated back to about the Civil War days. Some rounds were so tight, I almost had to hammer them into the chamber. Those cases split every time as there was no room for expansion. However, after buying new ammo from a company in Canada (Dominion), every one fit properly and fired properly with no split cases. The old 11 mm cases actually expanded over their last century, probably due to heat in the old Arsenal on an Island back east that had tons of Civil War stuff.

So, where does this all lead to? Old ammunition from .22 rimfire on up to 16" ammo must be carefully inspected, measured and thoroughly tested before issue and use.

As Murphy's law says: "If anything can POSSIBLY go wrong, it WILL."
 
USSWisconsin said:
an article on the Iowa accident
Battleships: United States ... - Google Books

good general info on the bags and projectiles
CHAPTER-3-1.page
Click to expand...

Interesting. I've read all this before. It was my job.

Don't forget, Long Beach Naval Shipyard was the Planning Yard for the Battleships. As one of the project leaders, I had a very, very busy morning the next day. Chapter 29 of my book tells what we went through and some of the eerie history before that. But it does NOT devulge any opinions of what caused the incident.

I am associated with certain organizations and we have been requested NOT to make public any PERSONAL opinions of what we THINK may have caused the incident.

I am perfectly comfortable in following that request. I apologize for even giving the curt answers I gave above but it just bugged the hell out of me that after all the problems the ships have had with the undersized bags that the Navy continued to use them.

Therefore I would prefer this subject be dropped and we go on to other technical questions that some of us "hands on" experts can answer and forego "theories".
 
Ken_NJ said:
Topic - BB shells
1)When was the last time that 16 inch shells and powder charges for the Iowa class manufactured?
2)Where were they manufactured?
3)Since the Iowa's have been stricken from the naval register and there is no chance they will see service again, is the navy still storing surplus shells?
4)Could any existing shells be dated as far back as the 40's?
Click to expand...

Very interesting information as usual!!! So there could be shells from the 40's still in storage at Earl NWS or another facility. Don't think 1-3 were really answered though. Did I miss something?
 
Ken_NJ said:
Very interesting information as usual!!! So there could be shells from the 40's still in storage at Earl NWS or another facility. Don't think 1-3 were really answered though. Did I miss something?
Click to expand...

As far as question number 3 is, I personally do not believe any Iowa class Battleship will ever see active service again. The first clue I got was when the Navy was "ordered" to put two of them back into class B reserve and they picked the New Jersey and Iowa. Based upon my personal and professional knowledge of the ships, the Missouri and Wisconsin would have been my picks as they had the latest upgrades and were in the best overall condition.

The selection of the Iowa, however, did give it the opportunity to be towed to the West Coast (now among the "Ghost Fleet" in Benecia, California) so at least one Battleship (of ANY class) could be set up as a museum/memorial on that side of the Continental United States. The East Coast has FOUR Battleships, the Gulf Coast has TWO and Hawaii has ONE. There are only a couple of Aircraft Carriers (Hornet & Midway), a Destroyer (Turner Joy) and a Submarine (name escapes me) on the West Coast.

So, I'm afraid the days of the big gun Battleships are over. Unless the Navy wants to design a new one. If so, the line forms behind me.
 
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Ken_NJ said:
Very interesting information as usual!!! So there could be shells from the 40's still in storage at Earl NWS or another facility. Don't think 1-3 were really answered though. Did I miss something?
Click to expand...

Topic - BB shells
1)When was the last time that 16 inch shells and powder charges for the Iowa class manufactured?
Powder was re-manufactured in the 1980's according to sources aboard BB64 in 1991, new projectile types were introduced in this time frame as well, including the cargo projectiles with multiple bomblets
2)Where were they manufactured?
Not sure, that would take more digging - I remember seeing some good documentation on Eugene Slover's page about the equipment that pressed the copper bands on the projectiles.
3)Since the Iowa's have been stricken from the naval register and there is no chance they will see service again, is the navy still storing surplus shells?
Not sure, the Navy doesn't publish details of ammunition storage that I am aware of, it is possible that they have some. Since the projectiles themselves are very stable - there would probably not be any hurry to get rid of them
4)Could any existing shells be dated as far back as the 40's?
Yes, it is possible, WWII vintage shells were used in the first Gulf war - though they were re-certified and probably had new fuses. As I understood existing stocks of projectiles were not depleted

http://www.eugeneleeslover.com/USN-GUNS-AND-RANGE-TABLES/USN-GUNS-AMMUNITION-DESIGN-AND-TESTING.html
http://www.navweaps.com/Weapons/WNUS_16-50_mk7.htm
http://www.eugeneleeslover.com/USN-GUNS-AND-RANGE-TABLES/USN-POWDER.html
http://www.eugeneleeslover.com/USNAVY/CHAPTER-II-PAGE-1.html
 
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Crane Indiana among other ordinace facilities inspected them prior to re-issue into the surplus for the 1980's reactivation. When tested, they would have extra dye packs added to them if they were not considered up to the weight specifications the USN sets. There are actually a few different ordinace installations. You have them on the East Coast to service Norfolk, and ofcoarse Dahlgrens needs for testing. The West Coast to service facilities there such as Long Beach and in the Mid West as a precaution against anything ever happeneing to the other installations. There are several contractors that are capable of inspection and re-issue once past USN inspection and testing.
 
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Couple questions I've been meaning to ask for a while:
1) Are the 16" (or any) guns rifled or not, and if you know the answer, why?
2) If you'll look at the barrel of a modern tank gun or of many modern artillery tubes, you'll see a segment of the barrel that is thicker than the rest of the barrel. This thickened part of the barrel is a gas extraction system, to remove the poisonous gases from the tank and the crew that are created by the propellants after firing. Why don't any of the Naval guns I've seen have one of these systems, or is it just located somewhere else?
 
bigross86 said:
Couple questions I've been meaning to ask for a while:
1) Are the 16" (or any) guns rifled or not, and if you know the answer, why?
2) If you'll look at the barrel of a modern tank gun or of many modern artillery tubes, you'll see a segment of the barrel that is thicker than the rest of the barrel. This thickened part of the barrel is a gas extraction system, to remove the poisonous gases from the tank and the crew that are created by the propellants after firing. Why don't any of the Naval guns I've seen have one of these systems, or is it just located somewhere else?
Click to expand...

The 16" BB guns are all rifled, they refer to them as naval rifles.
They have compressed air to purge the bore, the big ships have room for compressors, and they were all designed in the 1930's when modern bore evacuators hadn't been invented. The modern guns have bore evacuators too, some do have tank like systems, the 3" OTO SRF gun, with the big knob like thing on the barrel, is an example.
 
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bigross86 said:
Couple questions I've been meaning to ask for a while:
1) Are the 16" (or any) guns rifled or not, and if you know the answer, why?
2) If you'll look at the barrel of a modern tank gun or of many modern artillery tubes, you'll see a segment of the barrel that is thicker than the rest of the barrel. This thickened part of the barrel is a gas extraction system, to remove the poisonous gases from the tank and the crew that are created by the propellants after firing. Why don't any of the Naval guns I've seen have one of these systems, or is it just located somewhere else?
Click to expand...

Hi BigRoss, an answer to your questions:

1) The 16"/50 cal Mk 7's are rifled. There are 96 grooves to her rifling. If you used a particular equasion you would be able to figure out the "lands" percentage to the rifling grooves. It will be a percentage mulitplication to put you into the ballpark.
They are officialy rifled at 1 in 25 RH (Naval Standard) twist. Which means for the 50 cal rifle, the projectile is rotated exactly two times before exiting the barrel. The reason for the rifling is to spin the projectile at about 4,000 rpm with high velocity to impart anti roll stability to the projectile in flight. In flight, the projectile for how fast its moving has many physical forces acting upon it that attempt to make it roll over in flight. These must be taken into consideration along with your solution to improve accuracy.

This is a two part answer:

2a) The Obturator Unit.
The Obturator unit is assembled in the breech plug and carrier. It consists of the Mushroom head (which your powder bags back up to and where your primer feeds into the gun tube for ignition) Gas check pad, (which prevents the backflow of gases from the breech when the gun is fired). I have posted a pic of this assembly and the Firing lock mechanism on the Battleships thread (Barrel Wear I believe). It is only visable from the open breech position. Air also feeds the breeching system for allowing the breech to be opened, then locking into position and then must be released by a foot lever to allow closing the breech of the gun. Without air assist it would be pretty much impossible for one man to cycle the breech on his own as it has considerable weight. This is the protection again the realease of gases into the gun pits and therefore your crew protection.

2b) Gas ejectors- automatic low pressure air porting system contains, airline, valves and an automatic acting valve that opens internally from orifices inside the Screw Box once the breech is cycled for opening. This expels any reminants left in the bore from the previous round or powder bags. The valve is mechanically held open to purge the gun until manually closed and released by your Gun Captain. After he trips a manual safety switch, the gun will fall in elevation back to the 5 degree loading position for reloading.

The location of these air lines is piped from the Right side Trunion of the gun down to the Projectile handling flats where it is fed from five different tanks at about 150-200 psi.

In the 1980's reactivation onward it was also offered to split the sytem and demonstrate how nitrogen purge could be used for its instant cooling effects reducing elongation of the of the barrel liner and completely smothering and burning remnants immediately.

These systems and their back ups support not only the Gas Ejector system but also the air assist for cycling the breech.

Hope this answers your questions.
 
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