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Route 302 Conway Railroad

Bartlett, New Hampshire



Hew Hampshire Department of Transportation


New Hampshire Department of Transportation


RM Piper Inc.


Summer 2008

Technical Description:

  • Span: 36 ft
  • Rise: 10 ft
  • Length: 170 ft

The Conway Scenic Railroad (CSR) was completed in 1874 when rail travel was the preferred method of transportation over stagecoaches until the early 1950’s when automobiles and improved highways caused a decline in passenger and freight service. In 1974, Dwight Smith established the CSR for seasonal excursion train rides in the Mount Washington Valley and it continues to offer scenic railroad tours today.

A bridge structure along the 21 mile, nearly 2 hour excursion to Bartlett, New Hampshire, was deteriorating and needed to be replaced. The new structure needed to provide enough clearance for the railroad below and also be able to accommodate a skew in the roadway above.

New Hampshire Department of Transportation chose a 36’ x 10’ CON/SPAN® Bridge System as its new railway underpass. The arches, with a combined length of 170, were placed on 14’ tall cast-in-place pedestal walls. This structure was the best fit due to its low maintenance, ease of installation and a large enough clearance space for the trains to pass.

“The CON/SPAN system fit the parameters of this project seamlessly” stated Samantha Fifield, PE, Design Engineer for the New Hampshire Department of Transportation. “One benefit, especially given today’s economic challenges, is the reduction of long term maintenance costs. Contech’S engineering team was professional, efficient and very helpful which contributed to the effective application of this system”

In addition, CSR was able to maintain active train service while the structurally deficient structure was removed and replaced with a precast bridge.

“This was a perfect application of the CON/SPAN system” added John Bousquet, Vice President of RM Piper Inc. “The units were placed in just two days, all while maintaining train traffic. In addition, Conway preferred to utilize the final structure right away without having to pass under false, temporary structures that would have been required for a cast-in-place product”


Technical Description:

  • Span: 36 ft
  • Rise: 10 ft
  • Length: 170 ft

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