V.A.O.T. Historic Bridge Committee Proceedings

Historic Covered Bridge Committee Notes of October 24, 2007 for:

KINGSBURY COVERED BRIDGE (#40) IN RANDOLPH

Present at Meeting:

• Committee members:
  • Mike Hedges
  • Warren Tripp
  • Eric Gilbertson
  • Nancy Boone
  • Bob McCullough
  • Pam Thurber
  • Scott Newman
  • Sue Scribner
• Also in attendance were:
  • John Weaver representing the Vermont Covered Bridge Society
  • Sean James of Hoyle, Tanner & Associates

Sean James provided a PowerPoint presentation to supplement a previously distributed Engineering Study summary report. Following is a very brief summary – more detail can be found in the engineering report.

• Roof System: It is the intent to salvage the existing metal roof. It is assumed that approximately 8 rafters will need replacement and 1 will need repair. The roof boards appear to be in good shape with no action necessary. It is recommended that wood blocking be installed between the support beam and the top chord of the trusses at 16 locations adjacent to each kingpost for which there in no crossbeam. It is also recommended that additional'X' bracing be added along the top chord between existing crossbeams.
• Truss System: Approximately 2 member of the north king post need replacement as well as 4 truss diagonals which have split ends. More replacement will be needed if an H6 live load capacity is desired (currently H4 capacity). It is estimated that approximately 10% of the chord members will need replacing. Some other repairs such as with epoxy and through bolts may be necessary. Some minor amount of siding may need replacement as well as the siding on the portals.
• Floor System: Complete replacement of the decking with 3" x 8" planks is recommended as well as 4 deteriorated floor beams. More extensive replacement would be required if there was a need for an H6 capacity. In addition, a new wood curb is recommended.
• Substructure: Abutments are in good shape. Some repairs will be needed to the abutment stems and all 4 wingwalls. Remaining cracks should be sealed, graffiti removed and weep holes installed.
• Approaches: It is recommended that some paving of the approaches occur as well as installation of weathering steel guardrail.
• General: There is a dry hydrant located at the southeast corner. It is proposed that fire retardant and insecticide be applied. As well, a Protectowire system is recommended by the consultant.
• General Discussion: It was suggested that the Town be asked whether or not snowmobiles use the bridge; if so, runners may be warranted. Also, will curbing hinder the farmer who regularly uses the bridge? In that there is a very low traffic count and it doesn't appear that there is a need for the bridge to carry heavy vehicles (there aren't any homes on the other side of the bridge), there appears to be an opportunity to perform minimal repairs with no structural changes due to loading and traffic. In many cases changes are needed to meet current traffic needs, so this appears to be a good opportunity to minimize change and work. Nancy questioned paving the approaches – others agreed that it would alter the setting and is not desired. Also, does the curbing need to be treated? Opposition to the use of weathering steel guardrail was voiced. Some like it, other don't. Can we use steel-backed timber guardrail – not sure there is room for the posts. Could steel posts be used? Could decking be of oak? It will last longer. 4" x 8" decking was suggested.

It was agreed that an oak deck would be used with no runners. Also, no paving of the approaches. Non-treated curbing would be installed. Approach rail is needed but the type is still undecided.