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11th Street Bridge

Photos 

General View From East Canal Bank, Looking North

Photo taken by Historic American Engineering Record

View photos at Library of Congress

BH Photo #128084

Map 

Street View 

The Unique Design of the Eleventh Street Bridge 

Condensed from a Report by Lola Bennett for HAER, August, 1990

The Eleventh Street Bridge is a unique configuration of a double-intersection Warren through truss, with a pair of trusses on either side of the roadway, and lateral bracing between each pair, but none over the roadway. The bridge was engineered by the Eastern Bridge & Structural Co. of Worcester, Massachusetts, a significant twentieth-century bridge manufacturing firm. The bridge was paid for and erected by the Turners Falls Company for the town of Montague, during a very significant period (1912-1915) of the hydro-electric development of Western Massachusetts.

Documentary evidence for the Eleventh Street Bridge seems to indicate that it was originally designed to be very similar to the bridge at Sixth Street. The original plans for the bridge, drawn up by the Eastern Bridge & Structural Company in May of 1914, show a double-intersection Warren through truss, with a 21-foot wide roadway, upper lateral bracing, and no sidewalks. A second set of plans for the same bridge, dated May, 1915, shows a pair of double-intersected Warren trusses on either side of a roadway 27 feet wide, with a 6-foot wide sidewalk running between each pair of trusses. Rather than the standard upper lateral bracing over the center barrel, the second set of plans shows lateral bracing only over the sidewalk barrels. The two inner trusses are referred to, on several of the sheets, as "old trusses," with a job number that refers back to the previous set of plans. Why did this change in plans occur? Even after a considerable amount of research, there does not appear to be a conclusive answer, but apparently, some discrepancy arose between the Turner Falls Company, which was paying for the bridge, and the residents of the town, who were the beneficiaries of the whatever infrastructure changes the company were [sic] required to make.

On October 23, 1914, at a town meeting, the town voted:

"that the bridge to be built across the new canal at Eleventh Street in the Village of Turners Falls shall have a roadway of not less than thirty (30) feet in the clear, it shall have two sidewalks one on each side, each walk shall be six (6) feet in the clear, with suitable guard on the outside of such walks to prevent children from falling from bridge into the the canal and that the town of Montague demand that the bridge be built by the Turners Falls Company as mentioned above..."

A few months later, on March 25, 1915, that vote was rescinded, and another vote was passed, authorizing the Turners Falls Company "to construct a steel bridge across the new canal at Eleventh Street in Turners Falls which shall have a roadway twenty-seven (27) feet in width and one (1) sidewalk six (6) feet wide on each side of the said roadway."

Clearly, there was some discrepancy between what the Turners Falls Company had made plans for, and what the town felt it needed. While this suggests that general basis for the changes in plans for the Eleventh Street Bridge, there are apparently no written record as to the specifics of those changes. The original plans called for a narrow bridge (21 feet wide), with no sidewalks; the later plans showed a much wider bridge (27 feet), with a 6-foot sidewalk on either side. While this change could have been made quite easily on the drawing board, a considerable amount of time had passed since the initial plans were drawn up, and the reference on the drawings to 'old trusses' indicates that they had already been fabricated, and perhaps even shipped to the site by that time. Increasing the size of the bridge and adding sidewalks meant that the already-fabricated trusses would have had greater dead and live loads to carry, probably more than they could bear. Instead of designing and fabricating a new bridge and scrapping the old, which could have been quite costly, the engineers apparently decided to increase the load-carrying capacity of the old trusses by adding two identical trusses to the design. Once that was done, and the width of the bridge was increased, new lateral bracing was necessary. By spanning the shorter distance between the outer and inner trusses, rather than the entire distance between the two outer trusses, the strut sizes could be considerably reduced. As finally constructed, the Eleventh Street Bridge represented a unique engineering solution to a project influenced by both public and private interests.

Documentation of the Eleventh Street Bridge is part of the Massachusetts Historic Bridge Recording Project, conducted during the summer of 1990 under the co-sponsorship of HABS/HAER and the Massachusetts Department of Public Works, in cooperation with the Massachusetts Historical Commission.

Lola Bennet, HAER Historian, August 1990

Facts 

Overview
Triple-barreled through truss bridge over Utility Canal on Eleventh Street in Montague
Location
Montague, Franklin County, Massachusetts
Status
Open to traffic
History
Built 1915; rehabilitated 1996
Builder
- Eastern Bridge & Structural Co. of Worcester, Massachusetts (Fabrication)
Design
Triple-barreled (four plane) double-intersection Warren through truss
Dimensions
Length of largest span: 167.0 ft.
Total length: 205.1 ft.
Deck width: 24.0 ft.
Recognition
Eligible for the National Register of Historic Places
Approximate latitude, longitude
+42.60222, -72.56500   (decimal degrees)
42°36'08" N, 72°33'54" W   (degrees°minutes'seconds")
Approximate UTM coordinates
18/699753/4719517 (zone/easting/northing)
Quadrangle map:
Greenfield
Inventory numbers
MA M28017 (Massachusetts bridge number)
BH 19286 (Bridgehunter.com ID)
Inspection (as of 09/2014)
Deck condition rating: Good (7 out of 9)
Superstructure condition rating: Satisfactory (6 out of 9)
Substructure condition rating: Satisfactory (6 out of 9)
Appraisal: Functionally obsolete
Sufficiency rating: 59.9 (out of 100)
Average daily traffic (as of 2004)
2,500

Update Log 

  • June 19, 2017: Updated by Dave King: Added category "Lattice railing"
  • August 10, 2016: Updated by Christopher Finigan: Added category "Riveted"
  • June 17, 2015: New photos from Michael Quiet
  • August 30, 2011: New Street View added by Ben Tate
  • January 11, 2009: Essay added by J.R. Manning
  • November 22, 2008: New photos from James Baughn

Sources 

  • HAER MA-107 - Eleventh Street Bridge, Spanning Turners Fall Canal on Eleventh Street, Montague, Franklin County, MA
  • James Baughn - webmaster [at] bridgehunter [dot] com
  • J.R. Manning - thekitchenguy [at] sbcglobal [dot] net
  • Ben Tate - benji5221 [at] yahoo [dot] com
  • Panaramio HDR Shot
  • Historicbridges.org - by Nathan Holth
  • Michael Quiet - mquiet [at] gmail [dot] com

Comments 

11th Street Bridge
Posted June 17, 2015, by Nathan Holth (webmaster [at] historicbridges [dot] org)

Tony: the same sort of discussion can be found with the concrete McMillin Bridge: http://bridgehunter.com/wa/pierce/mcmillin/

Both are essentially the same concept.

I think worthy arguments can be made for each. Depends whether you consider the bridge two separate through truss units with a roadway in between... or whether you consider it to be a two truss line unit.

Another bridge to consider is the L&N Bridge in Cinci (former Purple People Bridge)... although the two truss units are connected by bracing over the narrow central walkway, look at how minimal the overhead bracing/struts are for this central walkway... they almost could have configured the L&N bridge like the 11th Street Bridge if they wanted, with no bracing over that central walkway. http://historicbridges.org/ohio/purplepeople/pict1535.jpg

11th Street Bridge
Posted June 17, 2015, by Tony Dillon (spansaver [at] hotmail [dot] com)

Since there are no struts or lateral bracing over the roadway of this bridge, one would be hard pressed not to deem it a pony truss.

Eleventh Street Bridge
Posted August 30, 2011, by Ben Tate

There's an amazing picture of this bridge at this site:

http://www.panoramio.com/photo/44382110

Eleventh Street Bridge
Posted January 11, 2009, by anthony dillon (spansaver [at] hotmail [dot] com)

J.R.

Thanks for letting me know about the report on this bridge, I'll have to look at it this week sometime. It's a very unique structure that deserves to be saved.

Tony

Eleventh Street Bridge
Posted January 11, 2009, by J.R. Manning (thekitchenguy [at] sbcglobal [dot] net)

Anthony, it appears this is a case of a government body setting a standard, the builders fabricating a bridge to the standard, and the government body changing the specs after the bridge was fabricated.

The whole story is in 28 page HAER Report that accompanies the HAER Documentation, you can read it by following the link in the profile. I took the liberty of condensing the report and posting it in the essay section. Drawings of the bridge, before the required changes and after, are in the full report.

Eleventh Street Bridge
Posted January 9, 2009, by anthony dillon (spansaver [at] hotmail [dot] com)

This has to be a one-of-a-kind bridge. The walkways on either side are through trusses, but the roadway has no lateral bracing overhead. Looks like a giant pony truss.