collar beam vs crosspiece

collar beam

noun
  • A horizontal piece of timber connecting and tying together two opposite rafters. 

crosspiece

noun
  • A bar or timber connecting two knightheads or two bitts; a timber over the windlass, with pins for belaying the running rigging. 

  • A horizontal or transverse beam or similar member that extends across or perpendicular to something. 

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