Two-flue harpoon

The two-flue harpoon or two-flue iron (which, together with the one-flue harpoon, were known as common harpoons) is a type of harpoon used in whaling for at least 1000 years. It appears in works of art dating back to the 14th century.

An engraving showing a two flue harpoon used in whaling

In the early 19th century the design was modified, and the one-flue harpoon was created. By removing half of the point, the chance of the point cutting its way back out of the whale was greatly reduced.