"Dave Smith" <
adavid.smith@sympatico.ca> wrote in message news:NkPJz.32900$
6D2.13526@fx08.iad...
On 2016-10-07 9:12 AM, Rich Rostrom wrote:
"Geoffrey Sinclair" <gsinclairnb@froggy.com.au> wrote:
At the other end there were 123,984 rounds of 16 inch.
That's _very_ interesting.
The U.S. had a total of 114 16-inch barrels,
not counting any coast artillery, only barrels
mounted on the three COLORADO-class BBs, the
two WASHINGTONs, the four SOUTH DAKOTAs, and
the four IOWAs.
So that would be over 1,000 rounds per barrel,
even allowing for a substantial number left
over at the end of the war.
I hate to throw a monkey wrench into things, but you would have to factor barrel life into the equations. From what I found online, the barrel life
of a 16" gun was 395 rounds when using AP. Wiki says 2860 with target
rounds. It has been a long time since I trained in this stuff but with
field artillery the barrel life was measured in full charges. Those guns
had a range just over 23 miles, so when engaging long range targets they would be using full charges. If bombarding to support land troops, they would be much closer and using smaller charges.
Yes, it is clear most USN 16 inch gun ammunition was not fired during
WWII and probably thereafter. With maybe 200 or so guns built.
If you can look up Naval Weapons of WWII by John Campbell, all
the technical details in one place. The USN chrome plated its
barrels producing a useful increase in life.
There were 4 versions of the USN 16 inch gun around in WWII.
The 45 calibre fitted to the three Maryland class. Life 395 full
charge (EFC) rounds, 36,000 yards with 2,240 pound APC
shell at 30 degrees 40 minutes elevation, using 556 pounds of
propellant, so 24 guns plus prototypes and spares. Weight 105
tons including breech mechanism.
The 50 calibre meant for the next generation of ships cancelled
by the Washington treaty, 71 built, 44 being built when the order
was cancelled in February 1922. Some used for shore batteries.
Life maybe 200 full charge rounds, 45,100 yards with 2,240
pound APC shell at 46 degrees elevation using 556 pounds of
propellant as coast defence, weight 128.15 tons including breech
mechanism.
With the ability to use 832 pounds of propellant maximum range is
put at 49,140 yards at 48 degrees elevation, lifetime maybe 150
rounds, weight 152.05 tons including breech mechanism.
The 45 calibre gun for the 35,000 ton battleships. Life 395 full
charge rounds, 36,900 yards with 2,700 pound APC shell at 45
degrees elevation, using 540 pounds of propellant, so 54 guns
plus prototypes and spares. Weight 85.85 tons including solid
breech without mechanism. Maximum range with 1,900 pound
HC round 40,180 yards at 45 degrees elevation.
The 50 calibre run for the Iowa (and Montana) class. Life 290 full
charge rounds, 42,345 yards with 2,700 pound APC shell at 45
degrees elevation, using 655 pounds of propellant, so over 36
guns made. Weight 106.8 tons without breech mechanism.
Maximum range with 1,900 pound HC round 41,604 yards at 45
degrees elevation.
According to the War Production Board 17 triple 16 inch 50 calibre
gun and mount assemblies were delivered to ships side, which I
take to mean 51 guns, between November 1942 and July 1945.
There were 21 such 16 inch 45 calibre assemblies, which would
mean 63 guns between October 1940 to December 1944. Note
while it is possible other 45 calibre guns were built before the War
Production Board start date of July 1940, North Carolina was
launched on 13 June and Washington on 1 June 1940 and guns
were fitted after launch. Given crane precision limits the mounts
were lowered near to the ship then the incoming tide used to raise
the ship for the final mating.
Ammunition production was 33,014 2,700 pound AP from 1940 to
May 1945, 4,909 2,240 pound AP from July 1942 to April 1945
and 86,061 1,900 pound HC from January 1943 to August 1945.
Shore bombardment anyone? A further 16,528 1,900 pound,
4,935 2,240 pound and 6,565 2,700 pound rounds were reworked
from December 1944 to August 1945.
I did not bother looking up the number of times those barrels were
replaced or relined. The navy would have some tricky planning to get
their crews trained in life fire exercises and have enough life left in their guns. They would want them to be well enough practiced to be able
to hit a target on the horizon, but not wear out the barrels so much they would be diminished and incapable of sustaining fire in combat.
Yes, essentially pre radar a thorough set of training exercises could
force the need for relining, with radar ranges could be more accurately
found.
The book mentioned as an interesting table for the 16 inch guns on
board HMS Rodney during the Bismarck action. The gun itself had
a lifetime of 250 full charge rounds, numbers 1, 12, 14, 16, 21, 23,
25, 26 and 28 were on board. As of 4 May 1941 the 9 guns had a
use of between 17 and 4/16 (as in 4 sixteenths) and 129 and 8/16
EFC rounds and wear of between 2.2 and 10.8 mm. Rounds per
gun fired 4 to 30 May ranged from 22 to 52, raising use to between
57 and 10/16 and 168 and 2/16 EFC, wear to between 6.4 and
11.3 mm. The fraction ratings shows the use of part charges for
things like training, all the shells fired during the above period were
full charge.
Geoffrey Sinclair
Remove the nb for email.
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