Oh uh

[utops]

What is this?

http://i.imgur.com/e7uVkAw.png

[GoldenRivet]

This is the british S-Class submarine, im not sure what the circled device is.

I have seen numerous pictures of the S-Class online and many of them feature the triangular item you are referring to

http://www.rnsubs.co.uk/Dits/Articles/ds48_04.jpg

http://www.cyber-heritage.co.uk/ironclad/sco.jpg

I have seen several images of British Submarines of the era and earlier which have for some reason placed the main compass Binnacle in that exact spot.

My guess is that this is either some sort of oddly designed compass binnacle (unlikely) OR the item has something to do with the boats intake and exhaust as it is located just forward of the diesel compartment i think.

[GoldenRivet]

http://gb-navy-ww2.narod.ru/HTM-SS-S.html

According to this site, that small structure aft of the conning tower is called an "MF/DF" which stands for Medium Frequency Direction Finder

This would have been used in radio navigation toward land based radio stations or homing in on friendly or even enemy transmissions more likely than anything

[utops]

Thx,good to know. :)