History of Covered Bridges in Dauphin County.

• Wooden roofs protected bridges from the elements, prolonging their use.covered bridge interior image by Jeffrey Sinnock from Fotolia.com
  
  Records show that 71 covered bridges spanned waterways of Dauphin County between 1812 until the present day. The earliest bridge was an amazing 2,876 feet in length and spanned the Susquehanna River in Lemoyne township. Theodore Burr built the Camelback or Market Street West Tandem Bridge, as it was called. It was replaced in 1903. Only two covered bridges still exist in Dauphin County.
  
  Covering timber bridges protected the main trusses from the elements and inevitable rotting, prolonging the life of the bridge. Wooden covers also shielded nervous horses from the moving water and provided refuge from sudden storms.
  
  

Henninger Farm Covered Bridge

• Constructed circa 1850, the Henninger Farm Covered Bridge or Stroup Covered Bridge, spans Wiconisco Creek with a Burr Arch design. The bridge, located northeast of Elizabethville in Washington Township in a small picnic area, stretches 72 feet in length. As of 2011, foot traffic only crosses the bridge, restored in 2003 after heavy vandalism.
  
  

The Everhart Covered Bridge

• Built in 1881 to span the Little Buffalo Creek in Oliver Township, Perry County, the Everhart Covered Bridge was saved from demolition by Mrs. Margaret Wister Meigs in 1940. As she worked to preserve Fort Hunter in Dauphin County, she purchased the bridge for $70 and moved it to the grounds of the mansion. In 2006 the bridge was rededicated after total dismantling and reconstruction. Located in Harrisburg at Fort Hunter Park, the bridge spans 36 feet over dry land. With a multi King Post Truss structure, visitors on foot only, use the bridge.
  
  

Bridge Truss Structure

• Variations in truss design signify the builder or location of bridge.Into the Light image by margie from Fotolia.com
  
  The true truss system of bridge construction consists of huge timbers assembled in a triangle. This is the only two-dimensional figure that holds up to stress of weight and time. Each bridge consists of two truss systems, one on each length of the structure. There have been many deviations to these designs depending upon setting, builder and resources available.
  
  One of the earliest and most well-known bridge builders in Dauphin county was Theodore Burr from Torringford, Connecticut. Hailed from New York, his first bridge spanned the Hudson River in 1804. The Burr Arch Truss used two long arches, resting on supports at both ends with Multiple Kingpost Trusses between. There are more bridges in Pennsylvania using the Burr Truss design than all the other truss designs together.
  
  The Multiple Kingpost Truss design spanned longer distances, often up to 100 feet. The design consists of one kingpost, or support, in the center with several right angle supports on each side of the center. There are 15 remaining multiple kingpost structures scattered throughout Pennsylvania in eight different counties.