crossbeam vs railroad track

crossbeam

noun
  • A beam laid across the bitts, to which the cable is fastened when riding at anchor. 

  • A horizontal structural beam that runs perpendicular to the primary support beams; a girder. 

railroad track

noun
  • A pair of formed steel rails, separated and supported usually on wooden or concrete ties or sleepers, forming a track along which flange-wheeled railroad vehicles may travel. 

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