Ask An Expert- Battleships

[USSWisconsin]

Some of the sources I read state it was 1958; maybe it was a typo. I do think it is possible for some of the material to have survived that long.

It could be the start and end years, having been taken appart slowly.

[RustyBattleship]

It could be the start and end years, having been taken appart slowly.

They were kept around because of the all welded hulls. It was hoped to continue construction when missile systems became more dependable.

This from NAVSOURCE ONLINE:

The keel of the fifth ship of the Iowa class, the Illinois (BB-65), was laid down on 15 January 1945 at Philadelphia Navy Yard. By 7 July the construction had progressed this far and the ship was officially cancelled a month later, on 11 August 1945, only about 22 % complete. Nothing was done with the ship after that and the remains were finally scrapped, this starting in September, 1958.

The Illinois and her sister Kentucky BB-66 differed from the four completed ships in that their design called for an all welded construction. This would have saved weight and increased strength over a combination riveted/welded hull like was employed on the completed ships. There was thought of redesigning the hull with a "Montana class " type protection system for added torpedo protection. This was rejected and the two ships were being built along the regular Iowa class hull design.

[Albany Rifles]

Reference wooden flight decks. One of the reasons I heard for the wooden flight deck was to keep the weight down and help with stability. A lower center of gravity would definitely help with flight ops. Interesting the RN took the different approach and went armored for their CVs. I wonder if that was as a result that they expected to be operating closer to land based aircraft than USN CVs?

[USSWisconsin]

Reference wooden flight decks. One of the reasons I heard for the wooden flight deck was to keep the weight down and help with stability. A lower center of gravity would definitely help with flight ops. Interesting the RN took the different approach and went armored for their CVs. I wonder if that was as a result that they expected to be operating closer to land based aircraft than USN CVs?

I believe it was, with the North Sea, the chances of bad weather denying flight opps, and normal operations within range of large land based air forces made the expectation that the ships would have to take bomb damage or face enemy gunfire more probable. Still the general post war analysis was that the larger aircraft complements and better flight operations support of the large US carriers more than offset the damage resistance of the armored carriers in overall effectiveness against the enemy.


http://www.navweaps.com/index_tech/tech-030.htm

[bigross86]

I know that the Iowa and her sisters' 16"/50 guns were some of the largest afloat, but what were the absolute largest to ever be used on a battleship from any country? The Brits Japanese and Germans all had 18" guns at some point, right?

[USSWisconsin]

I know that the Iowa and her sisters' 16"/50 guns were some of the largest afloat, but what were the absolute largest to ever be used on a battleship from any country? The Brits Japanese and Germans all had 18" guns at some point, right?

The Japanese 18.1"/45 guns on the Yamato class were the largest to see service on a "modern" battleship, the British and US both built 18" guns but never used them on a battleship, the British did mount them on the HMS Furious, but they were removed before she was completed (they were later used on monitors and the British guns were actually heavier than the Japanese guns). I am not aware of a completed 18" German gun, though the German's did build even larger guns, they didn't use them on a ship - though there were plans.

http://www.navweaps.com/Weapons/WNJAP_18-45_t94.htm
http://www.navweaps.com/Weapons/WNGER_21-52_gerat36.htm
http://www.navweaps.com/Weapons/WNUS_18-48_mk1.htm
http://www.navweaps.com/Weapons/WNBR_18-40_mk1.htm

[RustyBattleship]

For USS Wisconsin:

Very interesting and very educational links you have posted. However, I would like to go into a little more detail on the first paragraph of the first link:

The 46 cm/45 (18.1") cannons used on the Yamato class were the most powerful guns ever installed on a battleship. ------------------ The muzzle blast is said to have been able to rip the clothes off personnel who were standing too close when the guns were fired, but this story is probably apocryphal.

The last last sentence referring to muzzle blast (officially called over pressure) is correct, however it inadvertantly caused some misconceptions of the ship's design, particularly the anti-aircraft mounts. Looking at them from the outside gave us the impression that they had a dome of armor plate over them.

It turned out the dome was just light-weight metal shields to protect the gun crews from the pressure and heat of the muzzle blast of the 18.1-inchers. Not much help when being attacked in-mass by fighter and torpedo planes firing their machine-guns into the superstructure of the ship.

[Dreadnought]

Battleship Musashi "The Making and Sinking of the worlds "biggest Battleship". by Akira Yoshimura.

On or about August 18th 1944 the guns were tested on the Musashi. That day nine test firings were recorded before she returned to port. The instuments mounted on deck indicated that anyone standing topside when the guns fired would be seriously injured by the blast pressure or concusion. Guinea pigs placed aboard in cages were "literally blown to pieces".

Do note though that Gunnery training was also a rarety for the Yamato and Musashi. Even after having updated their fire control radars.

[USSWisconsin]

Based on Japanese testing:

Blast overpressure from
18.1"/45 Yamato guns
3 gun salvo:
20 kg/cm^2 @ 5 m, 11 kg/cm^2 @ 10m, 7 Kg/cm^2 @ 15 m
single gun:
10 kg/cm^2 @ 5 m, 5.8 kg/cm^2 @ 10m, 3.1 Kg/cm^2 @ 15 m


20kg/cm^2 is similar to the steam pressure in the boiler of a WWII KGV class British Battleship (284 psi)

for comparison -
Nagato 16"/45
two gun salvo:
10 kg/cm^2 @ 5 m, 6 Kg/cm^2 @ 10 m, 3.5 Kg/cm^2 @ 15 m
single gun:
8 kg/cm^2 @ 5 m, 4 kg/cm^2 @ 10m, 2.5 Kg/cm^2 @ 15 m


6.1"/60 Yamato
3 gun salvo:
2.5 kg/cm^2 @ 5 m, 1.6 kg/cm^2 @ 10m, 1.15 Kg/cm^2 @ 15 m
single gun:
2.1 kg/cm^2 @ 5 m, 0.96 kg/cm^2 @ 10m, 0.5 Kg/cm^2 @ 15 m


according to this source:
0.3 Kg/cm^2 could destroy wooden boats and 1.16 Kg/cm^2 could tear clothing off and knock men unconscious

Source: Anatomy of the Ship: The Battleship Yamato, Janusz Skulski, Conway, 1988

[Chogy]

Isn't the pressure pulse directed away from the vessel, more or less dependent on the azimuth of the great guns? How was "foot traffic" controlled in battle? Were there lights or some sort of audible signal saying "stay below deck, or you will be naked, unconscious, or worse?"

[USSWisconsin]

Isn't the pressure pulse directed away from the vessel, more or less dependent on the azimuth of the great guns? How was "foot traffic" controlled in battle? Were there lights or some sort of audible signal saying "stay below deck, or you will be naked, unconscious, or worse?"

The pressure levels here were measured perpendicular to the muzzle of the gun, the pressure pulse formed a spherical wave starting at the muzzle, with the intensity biased in the direction of the shot. I beleive they sounded GQ gunnery on US battleships, and everyone got out of the way, during this general quarters, no one would be stationed near the muzzles, but if it were an anti-aircraft GQ drill on the Yamato - where they did use the main guns against aircraft with special Sankaidan AA projectiles, there would be compromises about safety and necessesity. The USN had some plans to use the main guns on aircraft too - using timed or VT fuses on HE projectiles, but I haven't heard of a case where they actually did in combat - with all the open mount light AA guns around the turrets.

[Dreadnought]

On US Battleships, when the Firing keys are closed on the Stable Vertical the Salvo Warning key is pulled simitaniously with the Firing key for the guns in either of two modes. This gives an audio warning (buzzer) to all hands on deck and your gunners mates which much clear the back of the guns and onto the platforms to avoid the recoil of the guns. They recoiled about four feet behind the gun until pulled back into battery position for reloading after dropping back to their standard 5 degree loading position. Then your gunners mates are off the platforms and resume the loading process. For your 5"/38's there are clear audio bells at all times to make you aware that not only are the guns going to fire but also the mount is in motion in both train and elevation and cartridge shells are going to start ejecting from the mounts to the decks. All these bells and still you would have GQ alarms and others as well including AA alarms.
There is an audio Salvo warning for all gunfire aboard ship and missle fire as well. Your 20mm and 40mm guns didnt have them since they were manned by their gun crews or individual people.

I have some information that may explain the IJN's process. Have to do some reading first though on the reports of her FC motions. The Japanese Ward Leonard system it seems was somewhat different the the American Ward Leonard system for AA gun control and only extended to their 25mm machine guns not to their secondary guns unlike their American counterparts.

[USSWisconsin]

Thank You Dread,
I was sure could could illuminate the firing warnings given on the BB's better an I did.

Here is another good post by Rusty referring to this blast pressure subject
http://www.worldaffairsboard.com/bat...tml#post560590
Note: it refers to the unsecured hatches flapping open from the rapidly changing pressure of the blast wave passing by - see the picture above it in the thread.

Here is one about some damage done on BB62:
http://www.worldaffairsboard.com/bat...tml#post247783
The amount of damage would depend on the direction the guns were trained in, firing on the beam would be the least damaging (with preparations perhaps no appreciable damage), but firing on bearings close to the centerline over the bow or stern, or "over the shoulder" with the aft guns firing forward or the forward guns firing aft, could do more damage to the ship. At The 2nd Battle of Salvo Island, the USS Washington severely damaged her spotting planes by firing her 16"/45guns while they were trained to close to them.

Noise comparison:
215 db (N) BATTLESHIP NEW JERSEY FIRING ALL 9 SIXTEEN INCH GUNS
165 db (N)JET AIRPLANE, BOEING 727-15,000 LBS OF THRUST, DEPENDS ON THE TAKEOFF -REF.1.1982
100 db NORMAL AVERAGE CAR OR HOUSE STEREO AT MAXIMUM VOLUME -REF.1.1982

(N) = NORMALIZED TOTAL AIR POWER ENERGY LEVEL SOUND PLUS ANY WIND, WATTS OR JOULES PER SECOND.THESE LEVELS HAVE BEEN CONVERTED

http://www.makeitlouder.com/Decibel%20Level%20Chart.txt

[RustyBattleship]

After New Jersey was recommissioned in the 80's, this gave Dahlgren a chance to accuartly measure the overpressures of the main batteries with the barrels at various angles of elevation and azimuth. I was aboard one of those sea trials. I still have one of the old WW II antenna bases as a souvenir after the muzzle blast from turret III broke it off from the deckhouse.

It was an interesting sea trial. One of Dahlgren's employees was experiencing her first time aboard a ship at sea. She was supposed to monitor some equipment in the aft/port Tomahawk equipment room. Before the firing, General Quarters was called and the 3/4" thick armored door to her space was dogged down tight by the crew -- with her still in it.

It took her a while to use her boot to hammer the door dogs open. Fortunately I found her running across 02 level and was trying to open the starboard weather door facing Turret III -- which of course was firing at that time. It was by either dumb-A luck or the Grace of God that I saw her at that time as the overpressure from the next shot (less than a minute later) would have blown her off the ship.

When I stopped her, she was in near panic and asked, "Are we at WAR?". I guess nobody really explained to her what we were doing that day or she didn't pay attention. So I took her over to Dahlgren's control center in the stbd Tomahawk equipment room and left her with her supervisor.

Oh! Trivia bit. Yamato and Musashi were considered to be the largest Battleships ever built. This is true by tonnage of displacement and breadth of the ship's hull. But, what were the LONGEST Battleships ever built?

Now if anybody on this board cannot come up with the correct answer, they owe two Globemasters to parachute full loads of tins of butter cookies to our troops in Iraq and Afghanistan.

[Ken_NJ]

USS New Jersey at 887 ft 7 in?