Re: Flatcar Load: Conning Tower Tube

Daniel A. Mitchell

Since we don’t know exactly what it is, it’s hard to guess what it may have contained … probably pipes, cables, and a ladder.

The shell and powder hoists for the big guns were contained within the gun’s barbettes. What most people call a “turret” is actually a Barbette It is a HUGE assembly with the gun-house on the top. It is several decks deep, surrounded by a heavily armored wall, and the whole interior rotates as a unit. The rotating part contains the shell and powder handling rooms and hoists. A considerable amount of “ready” ammunition (shells) are stored inside, a couple decks below the guns. The gun’s magazines surround the base of the barbette, deep down inside the ship, inside the armored “citadel” that surrounds the ships vitals. Since the hoists are already inside the barbette, they are not themselves armored.

What most do not understand is that the visible surface of a battleship is almost totally un-armored. It’s just sheet metal. The main turret gun-houses and the conning tower are about all the heavy armor that is exposed. The rest is deep within the ship. The core of the ship is protected with heavy armor (12”-plus thick) … a sort of box called the "citadel”, that begins two or three decks down from the “weather” deck . This box contains the magazines, the bases of the barbettes, the engine and boiler rooms, and the ship’s command center. It typically extends about half the length of the ship. It’s sides, more or less, form the ship’s “armor belt” which extends a few feet above and below the waterline.

Things of lesser importance (gun-directors, boiler uptakes, and such) may have some lighter armor. Aside from the armor belt, most of the hull is un-armored and protected by layers of water-tight compartments (many containing fuel, some filled with water, and some just voids).
Dan Mitchell

On Oct 5, 2018, at 5:17 PM, Garth Groff <sarahsan@...> wrote:


Could this tube have contained an elevator or other lift from the magazines to the gun turrets?

Yours Aye,

Garth Groff

On 10/5/18 3:09 PM, Daniel A. Mitchell wrote:
NO, the photo presented here does NOT match the tube shown on the gun flat. Not even close. The actual "conning tower” described here is much larger, three stories high, with 18” thick walls. Not mentioned here, but it is also oval in cross section. This main "conning tower”, by itself, would weigh several hundred tons.

Someone’s earlier suggestion that the tube shown on the gun flat was a connecting tube joining the lower part of the “conning tower” to the main armored citadel a few decks below makes sense.

The thing shown on the flat is only (at most) nine feet in diameter … with 18” thick walls that leaves only about six feet of internal diameter, less any cabeling and piping running through, plus a manway (ladder) of some kind … leaving not enough space inside to do much of anything. Another problem is that this tube, if 9' in diam. with a 6’ hole through it, and perhaps 20 ft. long, would weigh almost 200 tons by itself. FAR more than a single gun-flat could carry. The tube is just NOT that heavy!

So, it might well be a lower connecting tube as suggested, smaller in diameter and thinner of wall, but is certainly NOT the actual "conning tower” of an Iowa battleship.

Dan Mitchell
On Oct 5, 2018, at 11:59 AM, Matt Smith <flyn96@...> wrote:

Here’s an article describing the conning tower tube of the Iowa class.

The description appears to jive with the picture and Ralph’s link.
Matt Smith
Bloomington, IL

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