Hi Big Jim,
The WWII Fleet Submarine circa 1944-45 had two periscopes which were not the same. First of all, they were of different heights when fully extended. The forward most periscope refered to a the #1 'scope was a Type IV Night periscope and was the shorter of the two. The next periscope in line was the #2 'scope and was a Type II Attack periscope. Attack 'scopes differ in that they have a minimum head diameter. Both periscopes had a lower outer tube diameter of 7 1/2 inches.
The Type IV Night 'scope had two windows, the upper window was at an angle of 17 1/2 degrees and the lower window was vertical. The Type IV also had provisions for a ST radar antenna inside of its head. The 7 1/2 inch outer tube was 29 1/4 feet long with a 5' 9" taper to 3 3/4 inches in diameter. On top of this is a 15 inch tall head that houses the two windows and antenna. This adds up to an overall length of approx. 36 feet.
The Type II Attack 'scope has a single window at a 22 degree angle. The 7 1/2 outer tube is 34 feet long with a 5' 6" taper to 1.414 inch diamenter. On top of this is a 5 3/4 inch head that houses the single window. This adds up to an overall lenght of approx. 40 feet.
The USS Cod has both of its periscopes fully raised (well, they did at one time) and I got photos and measurements that show that the #2 Attack 'scope height above the top of the periscope sheers is 236 inches. The photos do show the 4 foot difference in height between the two scopes.
Qualified in Submarines 1965
"D..n the pressure, Six-Zero feet!"
"Most men would rather die than think, Most of them do!" - Bertrand Russell
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