Loading a mast through the stern port of a mast ship. A tackle from a yard on the ship takes the weight of the mast and the men control it. Loading takes time as the band attaching the mast to the tackle has to be shifted periodically and the rollers inside and outside the ship adjusted.
From the book, New England Masts and the King's Broad Arrow, by Samuel F. Manning, 1979. Illustrations courtesy of the author and illustrator.