conning tower vs bridge deck

conning tower and bridge deck both are nouns.

Word	Noun	Adjective	Verb	Adverb
conning tower	Yes	No	No	No
bridge deck	Yes	No	No	No

As nouns, bridge deck is a hypernym of conning tower; that is, bridge deck is a word with a broader meaning than conning tower:

conning tower: a raised bridge on a submarine; often used for entering and exiting
bridge deck: an upper deck where a ship is steered and the captain stands

Other hypernyms of conning tower include bridge.

conning tower (noun)	bridge deck (noun)
a raised bridge on a submarine; often used for entering and exiting	an upper deck where a ship is steered and the captain stands
an armored pilothouse on a warship