I don't know whatall about the differences but this does not look like a lumber ship to me. They were bulkier at the stern and midsection to handle their specific loads. Some even had windows or trapdoors that were opened so the logs could be loaded below deck. I remember watching them unload mahogany at the pier as late as the 1960's where they did have a crane to pick up the logs and drop them into the water. Lots of fish floated up. When they'd offloaded enough logs they'd make the raft and float them up Bayou Chico to the mill. All of the photo's I have seen of the lumber ships show a larger vessel than what this seems to have been.

Pam