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Bridge Watch Workshop¹

by John Weaver, P.E.

Agenda

  • Discuss problems:
    1. Typical scenarios, conditions
    2. What to look for
    3. How to analyze the bridge for important components, discern what is secondary or sacrificial.
  • Discuss specific situations:
    1. History and background use and development of the bridge
    2. How to get help
    3. Preservation tips for treating (fire, insects) wood
  • Discuss strategies for action
    1. How to organize
    2. How to report to/advise local authorities
    3. How to develop historic bridge plans and partnerships for preservation and use of covered bridges
  • Course reference: The Bridge Watch Handbook.

Workshop

  • Problems
    1. A typical scenario would be a covered bridge on a town highway in Vermont. The town is sometimes doing minimal maintenance - replacing siding, patching the roof, etc. Bridge trusses and floor members are collecting layers of dirt, trash is piling up at joints, water is running onto the bridge from the approaches, approach railings are missing, the bridge is not insect, fungi or fire protected, etc.
    2. The most important things to look for are deterioration to the basic bridge structural components - the trusses, floor beams, top lateral bracing between trusses, etc. These same items are usually identified in the Vermont Agency of Transportation bridge inspection reports. Each town office should have copies of these on hand.
    3. To identify the truss type and other components make reference to the Bridge Watch Handbook and the 1995 consultant report diagrams. Remember that covered bridges were constructed with sacrificial elements that were intended to be replaced from time to time - the roof, floor and siding components.
  • Situations
    1. Try to establish a historical record of the use and developed uses of the bridge. Document and verify any changes to the bridge structure to accommodate original and later uses - such as the adding floor beams, reconstructing floors with heavier wood decks, adding arches to the trusses, etc.
    2. Help in regard to a) above may come from contacts with local and state historians or long time town residents, old photos, etc. Help in regard to bridge component identification and analysis can be obtained from the VCBS statewide covered bridge coordinator.
    3. Preservation tips for treating wood can be found on the website vermontbridges.com and by contacting the VCBS statewide covered bridge coordinator.
  • Strategies
    1. How to organize and what to do depends on the size and abilities of your local Bridge Watch group. Groups may be as small as one member or as large as ten members. Members might be able to attempt on-site cleaning or brush removal projects or simply provide observation and reporting functions.
    2. Select board members should be contacted and consulted before attempting any significant local activities. This may be done through the town clerk or road foremen. Report any noted problems to the same authorities.
    3. Offer to help local authorities develop stategies for use and maintenance of covered bridges in your area. Encourage town authorities to participate in the Historic Covered Bridge Preservation Plan and The Vermont Historic Bridge Program. This Plan and Program are products of a collaborative effort between the Vermont Agency of Transportation and the Vermont Departmeent of Historic Preservation. Through the Program funds can be secured for continual major maintenance and rehabilitation of Vermont covered bridges. VCBS participation in all of the above activities will help towns fulfill their portion of easements (agreements) between local governing bodies and state agencies.

[This article was originally posted February 20, 2002, revised June 25, 2002]