Ship propeller shaft work using chain blocks.
Fullsize image: https://s3-us-west-1.amazonaws.com/h...t_fullsize.jpg
https://s3-us-west-1.amazonaws.com/h...ller_shaft.jpg
Previously:
https://www.homemadetools.net/forum/...676#post123646
https://www.homemadetools.net/forum/...2518#post96512
https://www.homemadetools.net/forum/...790#post133254