Thread: How long does it take to turn a battleship around?

I've heard this expression used frequently. Presumably, the answer is "a good distance" and "a significant interval of time." But how many miles, approximately, does it take for, say, an Iowa class battleship to turn 180 degrees?

How about an aircraft carrier?

I've searched for "a significant amount of time" on the web, but can not locate an authoritative answer. Thanks.

It depends on how you do it and how fast you are going.. Usually, you just turn the rudder. If you're in a hurry, though, you can twist the ship by putting the right screws at full power ahead and the left screw at emergency back (or vice-versa). This decreases the time (although doing this during meal time will make everybody very unhappy).
If you have a skilled officer on the con, can pretty much turn on the ship's length when maneuvering in harbors.

was watchin discovery and they said it took roughly 28 mins, if am remembering correctly

The turning circle of a warship is known as the "Tactical Diameter" (TD). This is basically the shortest distance that a warship can turn 180 degrees while at combat speed without heeling over.

The Japanese super-battleships Musashi and Yamato were very maneuverable, with a TD of only 640 meters.

HMS Vanguard's TD was 1025 yards, and USS Wisconsin's (Iowa Class) (also considered an extremely maneuverable battleship) 814 yards.

I believe that the TD of modern warships such as in-service aircraft carriers is classified. The USS Enterprise CV-6 that served in WWII had a TD of 790 yards when travelling at 30 knots.

CALCULATION
I'll show my working in case I make an error, but here goes:-

1 nautical mile (nm) = 2025 yards (I looked it up)
1 knot = 1nm per hour
30 knots = 2025 x 30 = 60750 yards per hour

TD = 790 yards
Therefore distance travelled is the circumference of a semi-circle of diameter 790 yards
= (pi x 790)/2
= 1241 yards

If 30 knots = 60750 yards in 60 mins
Then this = 1241 yards in 1.2 mins

Therefore with a TD of 790 yards at 30 knots it takes 72 seconds to turn a warship around 180 degrees

(which probably seems like a lifetime when you're under attack)