About This Structure
Remnants of searcher-built cofferdam found by Bowdoin expedition
--- CONTEXT FROM CARBON DATING RECORDS ---
The 1850 cofferdam at Smith's Cove is attributed to the Truro Company's treasure recovery operations. However, Dan Blankenship's 1969-1970 excavations inside the cofferdam area revealed much older wooden structures beneath and alongside the cofferdam remains. The Geochron Laboratories dating of an oak peg from a timber structure in this area returned 1090 ±140 BP (~860 AD, range 720-1000), and an inclined beam returned 815 ±110 BP (~1135 AD, range 1025-1245). These medieval dates suggest the 1850 cofferdam was built over or near pre-existing structures of considerably greater antiquity.
Blankenship's September 1970 report describes finding the remains of a stone-paved road from the cofferdam area toward the Money Pit, a large horseshoe-shaped stone and cement foundation approximately 150 feet south of Smith's Cove beach (roughly 12' wide, 25' long, 3' deep with cemented stones), and evidence of extensive heat and burning along the shore with charcoal and coal deposits. He speculated this could be the site of a steam boiler used by searchers, or alternatively an original hearth furnace for metalwork.
Historical Context
Bowdoin/FDR expedition 1909. Additional context: Les MacPhie compilation (July 2006). Blankenship report "Results of digging done in Smith's Cove, November 1969" (pp. 7, 9-10). Blankenship "Summary of Work Performed at Smith's Cove, August 31 - September 18, 1970" (pp. 16-19). Geochron reports GX-1691, GX-1692 (December 1969).
Where It Was Found
Found at Smith's Cove — the north shore of Oak Island where the flood tunnel system was discovered.