Composition of Roberts’ Torpedo

The first Roberts torpedo was a rather simple device consisting of a tube-like sheet iron case about four feet long and filled with gunpowder. The cylinder or shell had a percussion cap exposed on the top. The shell was lowered by a wire to the selected depth in the oil-bearing rock and then the charge was tamped by fluid. An iron follower (later called a go-devil) was sent down the wire by the shooter resulting in a blast (in Giddens, ed., 1946, quoted from the New York World, Feb. 25, 1865). Commonly more than one shot was executed in the well, sometimes weeks or months apart.

The size of the torpedo shell changed over the years especially when liquid nitroglycerin was substituted for gunpowder. Tin sheeting was later substituted for iron cases and heavy wire coils held the tin case firmly against outside (water) pressure.

A torpedoed well at Bradford, Pennsylvania, 1870’s. The camera was hastefully mounted (at an angle) and the glass plate broke. Mather photo.