Gate valves of the Theodore Roosevelt Dam in Arizona.
https://diqn32j8nouaz.cloudfront.net...s_fullsize.jpg
Previously:
https://www.homemadetools.net/forum/...880#post171413
https://www.homemadetools.net/forum/...994#post156992
https://www.homemadetools.net/forum/...158#post168849
https://www.homemadetools.net/forum/...134#post161016
https://www.homemadetools.net/forum/...758#post163556
