For history buffs

[Buffer54]

Some inter-war photos of USS Arizona and USS Nevada show a large dial affixed to the forward mast. It is numbered like an analog clock face, but only from 1 to 10. See the crew photo at Arizona's Wikipedia entry for a good view of it:

http://en.wikipedia.org/wiki/Image:USS_Arizona_(BB-39)_-_1924.jpg

I'm curious: what is it, and what was it used for?

 

[rbax]

The large dial with numbers at the center top was popularly known as a "range clock." This dial, along with one on the aft side of mainmast, was used to indicate the range to the target to other battleships in line ahead and astern.

--- Rich

 

[Buffer54]

Interesting. Thanks.

 

[Buffer54]

http://www.bobhenneman.info/Rangeclocks.htm