The Ponakin Bridge is a historic Post truss bridge spanning the
Nashua River
The Nashua River, long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed October 3, 2011 is a tributary of the Merrimack River in Massachusetts and New Hampshire in the United States. It i ...
in northern
Lancaster, Massachusetts
Lancaster is a town in Worcester County, Massachusetts, in the United States. Incorporated in 1653, Lancaster is the oldest town in Worcester County. As of the 2020 census, the town population was 8,441.
History
In 1643 Lancaster was first ...
. The bridge was built in 1871, and originally carried the main north–south road (now Ponakin Road), which was bypassed by the construction of
Massachusetts Route 70
Route 70 is a north–south state highway in Worcester County, Massachusetts. Its southern terminus is at Route 9 in Worcester and its northern terminus is at Route 2 in Lancaster. Along the way it intersects Interstate 290 (I-290) in W ...
.
It is now unsafe and closed even to pedestrians. The bridge, with a design once common but now extremely rare, was listed on the
National Register of Historic Places
The National Register of Historic Places (NRHP) is the United States federal government's official list of districts, sites, buildings, structures and objects deemed worthy of preservation for their historical significance or "great artistic ...
in 1979.
Description and history
The Ponakin Bridge is located in a rural setting several miles north of the village center of Lancaster, spanning the Nashua River in a roughly east–west orientation between
Massachusetts Route 70
Route 70 is a north–south state highway in Worcester County, Massachusetts. Its southern terminus is at Route 9 in Worcester and its northern terminus is at Route 2 in Lancaster. Along the way it intersects Interstate 290 (I-290) in W ...
and Ponakin Road, a dead-end residential street paralleling the river's west bank. The bridge trusses consist of eight paneled sections with a total span of and a width of . It rests on granite stone abutments formed out of rough-cut stone long. The decking consists of a base of cross timbers which are attached to the trusses, with wood stringers, then transverse cross timbers, and finally three inch deck planking. The truss panels have pinned end diagonals that are under compression, diagonal bars spanning two panels under tension.
[
The bridge was built in 1871 for town by the Watson Manufacturing Company of Paterson, New Jersey. It was built at a location where wooden bridges had stood since the 17th century, on the major road leading north from Lancaster. The route was bypassed by the present alignment of Route 70 in 1965. The bridge design was patented about 1866 by Simon S. Post, and was one of the major bridge forms used in developing the national railroad network, including major crossings such as that of the ]Union Pacific Railroad
The Union Pacific Railroad , legally Union Pacific Railroad Company and often called simply Union Pacific, is a freight-hauling railroad that operates 8,300 locomotives over routes in 23 U.S. states west of Chicago and New Orleans. Union Paci ...
over the Missouri River.[ The bridge deck is now compromised, and the bridge has been closed to all forms of traffic.
]
See also
*Atherton Bridge
The Atherton Bridge is a historic iron truss bridge in Lancaster, Massachusetts, spanning the South Branch of the Nashua River. It is a rare example of a hybrid pony truss that is similar to the 19th century truss design of Simeon S. Post. It was ...
*
*
*
References
External links
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{{National Register of Historic Places in Massachusetts
Road bridges on the National Register of Historic Places in Massachusetts
Bridges in Worcester County, Massachusetts
Buildings and structures in Lancaster, Massachusetts
Historic American Engineering Record in Massachusetts
National Register of Historic Places in Worcester County, Massachusetts
Truss bridges in the United States
Metal bridges in the United States