Napier Deltic engine gearbox.
https://diqn32j8nouaz.cloudfront.net...ne_gearbox.jpg
Previously:
https://www.homemadetools.net/forum/...631#post159237
https://www.homemadetools.net/forum/...924#post137518
https://www.homemadetools.net/forum/...522#post142966
