(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