Present at Meeting:
Project engineer Rob Young provided an overview of the bridge and its current condition in both written and verbal forms. The ensuing notes are to be read in conjunction with the written overview provided at the meeting.
General introduction to the bridge and its history: As stated in the written overview, the bridge was built in 1883, spans 67 feet over the First Branch of the White River on Russell Road off VT Route 110 and is a multiple kingpost design. The bridge is currently posted for 3 tons, has a short detour and has limited vertical clearance. The truss capacity has been determined to be 20,000 lbs and the floor system capacity is 12,000 lbs. The town has no interest in seeing the carrying capacity increased. The bridge had a new standing seam roof installed last summer as part of a statewide project. The bridge is currently out of plumb and has guy wires supporting it.
Roof System: It is the intent to salvage the new roof. Guy wires will be removed, tie beam will be replaced and damaged knee bracing will be replaced.
Truss System: Other than a portion of the bottom chord at abutment 1, it is not proposed that any members will need replacement as there is no visible rot.
Floor System: It is proposed that all of the existing floor beams be replaced in kind -- same size as presently there and with the same species of wood (Eastern Hemlock) which would be treated. It is also proposed that the current 3" Eastern Hemlock plank deck be replaced in kind -- untreated. There are currently no running boards and none are proposed. Curbing was suggested inside the structure to both protect the structure and offer some refuge to pedestrians. The project designers will investigate this further.
Substructure: Abutment 1 is concrete and presently in good condition. There is evidence that water is being trapped at the bottom chord. It is proposed that a new concrete bridge seat and backwall be installed which will raise the elevation a bit to alleviate this situation. Abutment 2 is laid up stone and there is some evidence of settlement and scour. It is proposed that it be rechinked as necessary, that the top layer of stone be removed, which does not appear to be original, which would then be replaced with a new concrete bridge seat and backwall.
Approaches: Proposed to use weathering-steel w-beam approach rail.
Siding: There are currently 2 layers of 3/4" hemlock planking for the siding. Replacing this with 1" shiplap was discussed. Objections were raised over this as historically it is not felt that shiplap was used on covered bridges. It is proposed that the current siding be replaced as is - with 2 layers put back on as there isn't much overhang on the roof and this will afford the bridge extra protection from the elements.
Overall, all were pleased with the current condition of the structure and the fact that we are able to move forward with a project at this time. No objections were raised with the scope of the project and the work proposed. It was requested that fire retardant and insecticides be considered. Ms. McCullough did state that the bridge could be closed while the rehabilitation work is underway; the town does request, however, that all work is completed prior to the start of the Tunbridge Fair. The project manager will be following up with an informational meeting with the town in the near future. We do not anticipate meeting again on this project; rather any future details will be finalized through the Section 106 process.
The efforts by the project engineers to provide comprehensive material for committee review were acknowledged and very much appreciated.
Chair, Historic Covered Bridge Committee
[This article was originally posted August 14, 2003]