Your great grandfather made some history.
My grandfather did as well. He designed his concrete pipe and all the machines to fabricate it. Kettering often asked his advice as he was making his way in the automotive business. My grandfather's favorite invention was a section of pipe the goes inside itself. It was designed to build tunnels.
My dad's favorite war story occurred on September 23, 1952 when his 5" gun crew wiped out the communist Korean ammo dump at Wonson harbor. link.
Tidbits from the family scrapbook :-)