ˈcollar-beam
1. Arch. A horizontal beam connecting a pair of rafters, which prevents them from spreading or ‘sagging’ (bending in); it is attached about the middle of the rafters, which distinguishes it from a tie-beam.
| 1659 T. Willsford Archit. 12 Principall sparres or rafters..are made according to the true pitch of the building intended; about the middle (in common structures) each of them hath a collar-beam. 1663 Gerbier Counsel 73 The Coller beams eight and three inches. 1667 Primatt City & C. Build. 86 Choller-beams. 1837 P. Nicholson Pract. Build. I. 29 A collar-beam is..usually employed where there are no king-posts. |
2. Naut. (See quots.)
| 1769 Falconer Dict. Marine (1789), Clef de beaupré..the collar-beam, which is raised a little above the second deck, to fortify the bowsprit. c 1850 Rudim. Navig. (Weale) 95 The Collar-Beam is the beam upon which the stanchions of the beak-head bulk-head stand. |