Ohio-class nuclear submarine reduction gear.
https://diqn32j8nouaz.cloudfront.net...ction_gear.jpg
Previously:
https://www.homemadetools.net/forum/...993#post156981
https://www.homemadetools.net/forum/...209#post141732
https://www.homemadetools.net/forum/...207#post145883
https://www.homemadetools.net/forum/...330#post150494
https://www.homemadetools.net/forum/...357#post154472
