World Affairs Board - View Single Post - Bring Back The Iowa Class Discussion And Debate

Anon · 03-22-2005, 06:15 AM

http://www.usnfsa.org/DOD%20Document...attleships.pdf

If you want to know what the DoD itself had to say about the accuracy of the Mk7 16"/50 guns, read the link above. It is an official DoD document.

It notes the problems with the powder bags in the 80s, and the various steps that were taken to correct it(which goes far beyond just securing good powder supplies).

Overall, the .pdf document is a very comprehensive look at the capabilities of the Iowas at the time they were removed from active service.

This is a second source stating the same accuracy figures as the DoD document:

http://home.sprynet.com/~frfrog2/miscellg.htm

"Q. Just how effective were the 16" guns on the Iowa class battleships?

A. Using a full powder charge the mighty 16"/50 caliber guns of the Iowa class battleships could throw the Mark 8 2700 pound AP projectile about 42,000 yards with a muzzle velocity of 2,450 f/s and the 1,900 pound Mark 13 "HC" explosive round about 41,000 yards with a muzzle velocity of 2,690 f/s. Velocity deviation of the ammunition was under ± 10 f/s for new or rebagged powder.

The AP projectile carried a charge of only 41 pounds of ammonium picrate but it would penetrate 30 feet of high density reinforced concrete. The explosive round carried a charge of 153 pounds of ammonium picrate and fused for surface burst would clear an area 200 yards in diameter. With delayed fusing they would dig a crater 20 feet deep and 50 feet wide.

An accuracy test fired on 23 November, 1987 by the USS Iowa (BB 61) using the AP projectile gave a pattern size (shot displacement on the ground) of 219 yards in diameter (15 rounds fired 5 rounds from from one barrel of each turret) at a range of 34,000 yards. Not bad from a floating gun platform using ammunition and powder manufactured in the late 1930s and 1940s and fired from different barrels.

As an interesting footnote to history, besides the AP and standard explosive rounds, two "improved conventional munitions" (ICM) rounds were adopted in the late 1960s. They carried either 400 M43A1 wedge grenades (Mark 144/145) or 666 shaped charge bomblets (Mark 146). A nuclear projectile with a kiloton range warhead, designated Mark 23, was developed, tested and adopted in 1956 and available until 1961 . A subcaliber saboted round was also under development at one time. It utilized a spin stabilized 13" projectile weighing 1000 pounds at a design velocity of 3600 f/s and a range of 70,000 + yards.

By the way, in naval parlance the "50 caliber" in the designation 16"/50 caliber means that the barrels are 50 "calibers" long, or 50 x 16" long--about 67 feet."

The DoD document goes into much greater detail WRT accuracy and capabilities, but this is a decent synopsis if you don't feel like reading the whole 8 page DoD report.

Regardless, now anyone concerned here at least has the actual relevant facts to make a judgement.

The reasons the BBs were retired was because of man power and money. And manpower is all about money, so in the end...it was ALL about the almighty dollar.

03-22-2005, 06:15 AM	#92 (permalink)
Anon New Member Join Date: 08-03-03 Posts: 0	http://www.usnfsa.org/DOD%20Document...attleships.pdf If you want to know what the DoD itself had to say about the accuracy of the Mk7 16"/50 guns, read the link above. It is an official DoD document. It notes the problems with the powder bags in the 80s, and the various steps that were taken to correct it(which goes far beyond just securing good powder supplies). Overall, the .pdf document is a very comprehensive look at the capabilities of the Iowas at the time they were removed from active service. This is a second source stating the same accuracy figures as the DoD document: http://home.sprynet.com/~frfrog2/miscellg.htm "Q. Just how effective were the 16" guns on the Iowa class battleships? A. Using a full powder charge the mighty 16"/50 caliber guns of the Iowa class battleships could throw the Mark 8 2700 pound AP projectile about 42,000 yards with a muzzle velocity of 2,450 f/s and the 1,900 pound Mark 13 "HC" explosive round about 41,000 yards with a muzzle velocity of 2,690 f/s. Velocity deviation of the ammunition was under ± 10 f/s for new or rebagged powder. The AP projectile carried a charge of only 41 pounds of ammonium picrate but it would penetrate 30 feet of high density reinforced concrete. The explosive round carried a charge of 153 pounds of ammonium picrate and fused for surface burst would clear an area 200 yards in diameter. With delayed fusing they would dig a crater 20 feet deep and 50 feet wide. An accuracy test fired on 23 November, 1987 by the USS Iowa (BB 61) using the AP projectile gave a pattern size (shot displacement on the ground) of 219 yards in diameter (15 rounds fired 5 rounds from from one barrel of each turret) at a range of 34,000 yards. Not bad from a floating gun platform using ammunition and powder manufactured in the late 1930s and 1940s and fired from different barrels. As an interesting footnote to history, besides the AP and standard explosive rounds, two "improved conventional munitions" (ICM) rounds were adopted in the late 1960s. They carried either 400 M43A1 wedge grenades (Mark 144/145) or 666 shaped charge bomblets (Mark 146). A nuclear projectile with a kiloton range warhead, designated Mark 23, was developed, tested and adopted in 1956 and available until 1961 . A subcaliber saboted round was also under development at one time. It utilized a spin stabilized 13" projectile weighing 1000 pounds at a design velocity of 3600 f/s and a range of 70,000 + yards. By the way, in naval parlance the "50 caliber" in the designation 16"/50 caliber means that the barrels are 50 "calibers" long, or 50 x 16" long--about 67 feet." The DoD document goes into much greater detail WRT accuracy and capabilities, but this is a decent synopsis if you don't feel like reading the whole 8 page DoD report. Regardless, now anyone concerned here at least has the actual relevant facts to make a judgement. The reasons the BBs were retired was because of man power and money. And manpower is all about money, so in the end...it was ALL about the almighty dollar. Last edited by Anon : 03-22-2005 at 08:58 AM.