1750 T. R. Blanckley 155 Spanshakle is a large Clasp of Iron, which goes round the End of the Davit upon the Fore-Castle, having a large Bolt, which goes through a Fore-Castle Beam.
1846 A. Young 290 Span~shackle, a large bolt with a triangular ring attached to it for lashing anchors or spars thereto.