Historic Structures

Bridge Description Honeymoon Covered Bridge, Jackson New Hampshire

The Honeymoon Bridge is a fifteen panel, 119'-9" long (measured from center to center of the end posts), Paddleford truss covered bridge augmented with laminated arches. A 4'-10" wide cantilevered walkway is on the upstream side of the 15'-8-3/4" wide traffic lane. Unfortunately, a 3'-2" high box encloses the bottom part of the truss and prevents measurement of the overall truss depth. The dry stone granite ashlar abutments are 104' apart as measured between the facewalls. Concrete pads and backwalls rest on the abutments and support bedding timbers (inaccessible) and the bottom chords.

In form, if not in structural behavior, a Paddleford truss is a multiple kingpost with counter braces that span about one-and-one-half panels. Fourteen of the Honeymoon Bridge's panels are 8' on center, while the fifteenth, easternmost, panel (excluding the partial panels of the overhanging portals) is 7'-9". Each kingpost, brace, and counter brace is 8-1/2" x 8-1/2", 5-3/8" x 8-1/2", and 3-5/8" x 6-5/8" respectively. The top chords are composed of four sticks. On the north truss the outer two sticks of the panel measured were 2-3/4" x 11-1/2". The inner sticks were 3" x 11-3/4" and 3-1/4" x 12".

Fully executed Paddleford trusses require elaborate and extensive joint framing. Indeed, the counter braces are pinned and framed into each member they cross: top and bottom chords, braces, and kingposts. In addition to treenails, a 3/4" diameter metal spike of unknown date further reinforces each connection. Two 3" x 4" angles, with signs of electric arc welding, currently serve as knee braces. They replaced wood knee braces that were mortised, about 1- 3/4" x 5", and tenoned into the kingposts and the tie beams. The upper lateral bracing system is not safely accessible, but consists of tie beams and cross braces tightened with wedges.

The laminated arches consist of twelve leaves with overall dimensions of 8" x 24-1/2" bolted to the truss. Metal hanger rods (presumably 1930s vintage) suspend the deck beams from the arches and are 1" in diameter. They are so heavily rusted that they must be steel.

A substantial amount, perhaps a quarter to one third, of the original structure has been replaced or repaired. The entire deck system and bottom chords are replacements. The counter braces have been severed from the bottom chords. The four easternmost upper lateral bracing system panels are also newer.