“While winches were used to move boats out of the water, this object’s purpose was to secure ropes to either a vessel or a dock. Known as a bollard, it kept vessels safely in port during loading and unloading of passengers and cargo.”-Lake Champlain Maritime Museum
“History of bollards
The term “bollard” first appeared in the Oxford English Dictionary in 1844, describing a post used to attach a maritime vessel’s mooring line. The etymology is unclear, but it is likely it was derived from the word “bole,” meaning tree trunk…
Bollards often reflect or enhance the environment they are in. Many traditional styles are influenced by seventeenth- and eighteenth-century installations, when it became common practice to make use of decommissioned cannon barrels by half-burying them. These cannon bollards were handy on wharfs for mooring, and inland were adapted to directing traffic and protecting stonework.
When the cannon was buried with the muzzle facing up, a too-large cannon ball was often used to seal the cannon against water and debris, creating a distinctive rounded top. The varying shapes of these old cannons still influence styles today…”-https://www.reliance-foundry.com