Bridges & Dams
Bridges & Dams
AHS has documented thousands of bridges, and completed statewide surveys of historic highway bridges for Connecticut, Rhode Island and Vermont. In each case, we inventoried trusses, stone arches, and concrete arches, and evaluated them for their engineering and historical significance. We also prepared management plans to guide highway officials for historic bridge projects. Three publications resulted from these surveys: Historic Highway Bridges of Rhode Island, Connecticut’s Historic Highway Bridges, and Where Water Meets Land: Connecticut’s Historic Movable Bridges.
Historic dams are another area of AHS expertise. We have recorded every type, from small stone dams to complex impoundment and water-control structures. Documentation of historic dams has become more important, as old dams are increasingly breached to restore rivers to more natural free flows.
We also advise on the historically sympathetic rehabilitation of historic bridges and dams, ensuring that they remain safe while retaining historic character-defining features.
Connecticut Statewide Historic Bridge Survey
The Connecticut Department of Transportation is undertaking a survey of historic highway bridges to update and expand the inventory completed in 1991. That project inventoried 183 historic bridges, all built before 1941, which appeared to be at least potentially eligible for the National Register of Historic Places (NRHP). AHS revisited each bridge and updated the 1991 forms. Next we identified and evaluated almost 1,000 pre-1941 bridges and culverts that were not previously inventoried. These evaluations are intended to help to streamline future Section 106 reviews of Federal Highway Administration (FHWA)-funded bridge projects.
Other Project Examples
Porter Avenue Bridge, Naugatuck, CT
This concrete arch 1909 bridge, known historically as the Golf Links Bridge, was documented to Connecticut 's state standards.
Documentation of Massachusetts Highway Bridges
AHS has documented a number of historic highway bridges in Massachusetts, including to Historic American Engineering Recordation standards.
Comstock Covered Bridge
AHS provided historic research and preservation recommendations for the 1873 Comstock Bridge across the Salmon River between Colchester and East Hampton, Connecticut. One of three historic covered bridges in the state, Comstock Bridge was deteriorating and in need of rehabilitation. The project included a conditions survey and recommended methods of repair and stabilization consistent with the bridge’s historic character. AHS’s role was to identify the character-defining features of the main span (and what is probably an even older approach span), as well as developing a chronology of past episodes of repair and modification.
Quinapoxet River Circular Control Dam
The Quinapoxet River Dam (1905) in West Boylston, Massachusetts, is part of a complex system of reservoirs and aqueducts built to supply the greater Boston area with potable water. Its most distinctive feature is the semicircular spillway, with a crest length of 158 linear feet along an arc with a 75-foot radius, which decreased the speed of the waterflow to improve water quality. Adjacent to the dam is the Quabbin Aqueduct Shaft 1 Outlet Chamber and Works (1932), built when the water supply system was expanded further west with the Quabbin Reservoir. AHS documented the dam and several adjacent aqueduct structures.
Other Project Examples
HAER Documentation Burlington Woolen Mill Company Dam
AHS prepared Historic American Engineering Record (HAER) documentation of the 1876 timber crib dam described at its completion as “the best dam ever built in Vermont.”
Occum Hydroelectric Plant and Dam
The City of Norwich, Connecticut, contracted with AHS to prepare a National Register of Historic Places nomination for its hydroelectric facility located in the Occum section of Norwich. The complex included an early 20th-century brick powerhouse and a stone dam and headgate structure (1865) to power a textile mill.
Norwich State Hospital Dams and Reservoirs
As part of a cultural resources survey for the disposition of a 500-acre former state hospital in Connecticut, AHS prepared written and photographic documentation of dams, reservoirs, and water-supply features.
For more information on AHS’s experience and capabilities, visit our expertise page.