(Term definitions are taken from George Gould's 1977 book Indiana Covered Bridges Thru the Years, and all drawings are from Arthur Gatewood's book, Indiana Covered Bridge Location Guide)


Arch: timbers cut and fitted to form a symmetrical portion of a circle, attached to posts for added strength: ends rest on abutments below lower chord


Brace: a diagonal timber which slopes upward toward the center of the bridge


Chord: the horizontal timber or timbers forming part of the truss; lower chord supports the floor, upper chord supports the roof


Counter Brace: a diagonal timber or rod which slants upward away from the center of the bridge


Deck: the floor or roadbed of the bridge


Diagonal: a timber or rod which slants, usually between two panel posts


Flared Post: a post with the top slanting toward the end of the bridge


Foot Piece: a specially designed casting, usually placed between diagonals and chords for rigid assembly of members


Laminated Arch: a series of planks bolted together with staggered joints to form an arch; used in lieu of solid timber


Overhang: portion of siding or roof extending beyond span timbers, for added protection; it can be from 0 up to 18 feet


Panel: that portion of a truss included between two vertical posts


Post: a vertical or upright timber in a truss; wood replaced by iron rods in Howe trusses


Span or Clear Span: the length of a bridge between abutments or piers. A truss span is the length between the end posts


Truss: an arrangement of timbers and rods to rigidly support each other as well as loads put on the roadway. This requires the use of a suitable combination of triangles ... in short, the truss is the weight bearing support structure of any bridge.

Indiana Covered Bridge Terms