grappling vs grappling iron

grappling

noun
  • A small anchor; a grapnel. 

  • A grappling hook or grappling iron. 

  • An act in which something is grappled or grappled with. 

grappling iron

noun
  • A metal hook, attached to the end of a line, used to hold two ships together. 

How often have the words grappling and grappling iron occurred in a corpus of books? (source: Google Ngram Viewer )