[1] : The Collaborative International Dictionary of English v.0.48

hammer-beam \ham"mer-beam`\ -b=em`, n. gothic arch.
   a member of one description of roof truss, called hammer-beam
   truss, which is so framed as not to have a tiebeam at the top
   of the wall. each principal has two hammer-beams, which
   occupy the situation, and to some extent serve the purpose,
   of a tiebeam.
   1913 webster

Hammer-Beam >> H Words
Hammer-Beam, definition of term: Hammer-Beam
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