Wooden Bridges for Today: Wooden Bridges for Today


New Hampshire’s Transportation Heritage: New Hampshire’s Transportation Heritage Swift River Bridge, Albany, NH Recently refurbished by NH Department of Transportation


New Hampshire’s Transportation Heritage: New Hampshire’s Transportation Heritage Newport, NH Railroad Bridge (Carol Harootian, photo)


NH Bridges in Trouble: NH Bridges in Trouble Concrete deteriorates Steel rusts


NH Bridges in Trouble: 10 years ago over 50% of the bridges in NH were listed as being structurally deficient, functionally obsolete, or red listed. * State of New Hampshire Ten Year Transportation Improvement Program for 2001-2010, August 1999 NH Bridges in Trouble


NH Bridges in Trouble: Of 1,959 state owned bridges, 311 red listed or structurally deficient or obsolete. Of 1,556 non-state owned bridges, 653 either red listed or structurally deficient or obsolete. * State of New Hampshire Ten Year Transportation Improvement Program for 2001-2010, August 1999 NH Bridges in Trouble


The Usual Route : The Usual Route Typical reinforced concrete and steel bridge in need of total replacement


A Road Less Traveled : A Road Less Traveled New Boston, NH Lyndeborough Road Completed August 2000 Installed by New Boston Highway Crew


A Road Less Traveled : A Road Less Traveled Completed 1993 New Boston, NH Depot Street Near Town Center


A Road Less Traveled : A Road Less Traveled Designed and constructed by Arnold M. Graton Associates, Inc. Newport, NH Corbin Bridge, 1994


A Road Less Traveled : A Road Less Traveled Plymouth, NH Smith Bridge Strongest covered bridge in the world 176-foot span Under construction, 2001 Designed and constructed by Stan Graton II, 3-G Construction, Ashland, NH


A Road Less Traveled : A Road Less Traveled Plymouth, NH: Smith Bridge 250,000 board feet of timber First covered bridge using glue lamination technology Timbers supplied by Unadilla Laminated Products, NY


A Road Less Traveled : A Road Less Traveled Gilford, NH Tannery Hill Bridge Pedestrian bridge Built in early 1990’s by a volunteer crew


New Technology Helps a Traditional Material : New Technology Helps a Traditional Material Types of Bridges: Glue lamination Nail lamination or doweled Stress lamination


New Technology Helps a Traditional Material : New Technology Helps a Traditional Material EPA-approved Preservation & Protection Options Creosote Pentachlorophenal Copper naphthenate Chromated copper arsenate


Glue Laminated Bridge: Glue Laminated Bridge 1990 –Glu-laminated bridge in New Hampton, NH. Bridge from Laminated Concepts, Elmira, NY.


Glue Laminated Bridge: Glue Laminated Bridge New Boston Lyndeborough Road Bridge, August 2000 Modern Glu-laminated bridge by Laminated Concepts, Inc.


Nail Laminated Bridge: Nail Laminated Bridge Jefferson Notch Road, 1990 Wheeler Bridge Company


Nail Laminated Bridge: Nail Laminated Bridge Bartlett, NH 1990 Agent for town was Bergeron Engineering, North Conway, NH


Stress Laminated Bridge: Stress Laminated Bridge Chichester, NH 1990 Constructed of southern yellow pine. Treated with Pentachlorophenal.


Stress Laminated Bridge: Stress Laminated Bridge Chichester, NH, 1990 Constructed of southern yellow pine. Treated with Pentachlorophenal Stressing rods compress individual planks together with pressure


Stress Laminated Bridge: Stress Laminated Bridge North Weare, NH 1991 Constructed with local wood material Designed and constructed by Kent Ruesswick of Canterbury, NH


Other Wooden Transportation Structures: Other Wooden Transportation Structures Timber bin retaining wall, Campton, NH Bin wall system is also suitable for bridge abutments Constructed with eastern hemlock, commercially treated with chromated copper arsenate


Slide24: Why wooden bridges? The public demands a safe and efficient transportation system Traffic increases through ‘80’s and ‘90’s Engineers and community leaders must find new ways to upgrade bridges with fewer resources


Slide25: Why wooden bridges? Hundreds of bridges in NH need replacing Aesthetics & appearance Ease of construction


Slide26: Why wooden bridges? Performance When properly treated Cost Cost competitive, especially when life cycle and maintenance costs are included.


Slide27: Why wooden bridges? Maintenance Long life cycle with fewer maintenance requirements Not susceptible to salt corrosion Potential new markets for NH wood Potential new secondary manufacturing industry for NH


Slide28: Why wooden bridges? Why not?