Archived News

Iron and Steel Preservation Newsletter Discusses Issues With Fracture Critical Members

Posted September 16, 2015

Lansing Community College and Iron & Steel Preservation Coordinator Vern Mesler have released a newsletter that focuses on issues with Fracture Critical Members (FCMs) which often are found in historic metal truss bridges as well as some other historic bridge types.

A fracture-critical member is a tension member or component the fracture (failure) of which would cause the bridge to collapse.

Please click here to read the newsletter which offers an overview of fracture critical members and important ongoing research to better understand these members.

Dr. Robert Connor of Purdue University will be presenting at the Iron & Steel Preservation Conference & Workshop, May 18-20, 2016 at Purdue University.

Also, please check back in the future, as the Historic Bridge Foundation will also be releasing its own article discussing Fracture Critical Members as they relate to historic bridges.

TxDOT Open Houses On Historic Metal Truss Bridges

Posted July 17, 2015

If you traveled along a local Texas road in the late 19th and early 20th century, you would more than likely come upon a new metal truss bridge spanning a creek or stream. These strong and inexpensive bridges were built by the hundreds in Texas, promising a safe crossing to continue on your journey.

Flash forward to today, when current traffic needs, safety concerns and deterioration continue to push these historic metal truss bridges out of vehicular service. To limit the losses, TxDOT, is developing a management plan for about 130 survivors in cooperation with the Texas Historical Commission (THC), and Historic Bridge Foundation (HBF).

“We need your feedback,” noted Bruce Jensen, TxDOT’s Cultural Resource Management Director. “TxDOT only manages about 15% of these historic trusses; with the balance owned by local governments. We hope county judges and commissioners, historical societies, and other interested folks will join the conversation online or at one of our upcoming open houses. We believe it is critical that these decisions include opinions that reflect local priorities.”

Local sponsors graciously offered facilities for the following open houses:

  • Bastrop on Thursday, July 23, from 4-6 p.m. at the Museum and Visitor Center of the Bastrop County Historical Society, 904 Main Street
  • Waco on Tuesday, July 28, from 4-6 p.m. at the Texas Ranger Museum, 100 Texas Ranger Trail
  • Abilene on Tuesday, August 4, from 4-6 p.m. at the Elks Arts Center Ballroom, 1174 North 1st Street
  • Victoria on Tuesday, August 11, from 4-6 p.m. at the Victoria Public Library, 302 North Main Street

Additionally participants are encouraged to bring photographs, articles, and other materials related to historic bridges to these open houses. Materials will be scanned for inclusion in the THC archives and a local history collection, with the originals returned to their owners.

More information about the open houses and the overall project is on TxDOT’s website: (

Contact TxDOT Cultural Resources Management Director Bruce Jensen, at (512) 416-2628 or

Historic Bridges in Texas: The Post-War Years

Posted July 29, 2014

Bridges in Texas built after World War II represent a rich example of important innovations by renowned Texas bridge designers. The Texas Department of Transportation (TxDOT), the Texas Historical Commission (THC), and the Historic Bridge Foundation (HBF) have collaborated to identify these bridges, evaluate their historic significance, and develop a plan to manage them.

How were significant bridges identified?

Texas retains approximately 15,000 bridges built between 1945 and 1965. Over the past several years, TxDOT researched these bridges, interviewed retired bridge engineers, and evaluated the bridges for National Register of Historic Places (NRHP) significance. TxDOT finalized NRHP eligibility determinations, and the THC and HBF concurred that more than 100 of the post-1945 bridges are eligible for listing on the NRHP for their historical and engineering significance.
Why are these bridges historically significant?
These bridges can be historically significant for a range of reasons including:
Association with important post-World War II highway programs
Early use of newly developed bridge types or construction materials
Award-winning design or design by an important bridge engineer

How will TxDOT manage these historic bridges?

TxDOT, the THC, and the HBF have established a treatment plan for these 100-plus historic bridges. This plan includes dividing the bridges into three groups based on their historic and/or engineering significance. This approach would dictate the type of regulatory compliance and mitigation that TxDOT would be required to complete if any future projects would result in adverse effects to the bridges. These three groups are:
Group I: Bridges requiring TxDOT’s full compliance and mitigation under federal law
Group II: Bridges receiving programmatic mitigation under this public involvement effort, and no further mitigation is required under federal law
Group III: Bridges for which existing documentation is sufficient mitigation for any future adverse effects

What happens now?

TxDOT, THC, and the HBF want your opinion on the identified post-1945 historic bridges and the proposed treatment approach. Please complete the comment cards available at this open house or visit the TxDOT or THC websites below to email a comment. We look forward to hearing from you!

Want more information?

Please click here to view a detailed presentation about post-war historic bridges in Texas.

TxDOT’s website:
THC’s website:
Contact: TxDOT environmental consultant, Maryellen Russo 512-264-1095 or mrusso @

Historic Bridge Foundation Facebook Page Launched

Posted April 11, 2014

The Historic Bridge Foundation is proud to announce it now has a new Facebook page. At this time, we plan to feature a monthly “Focus Bridge” on the Facebook page, which will include a description of the bridge and why it is of interest to the Historic Bridge Foundation. Each Focus Bridge will be posted as a photo gallery which will contain photos and other media relating to the bridge.

The Facebook page can be viewed at the following address: and we invite you to “Like” the page to show your support.

New Video About Arkansas Historic Bridges

Posted May 17, 2013

The Arkansas Historic Preservation Program has produced a short new video documentary that discusses historic bridges in Arkansas. Visit their blog or view the video directly below.

Historians and residents preserve historic bridge in Collin County, Texas

Posted October 2, 2012

A historic stone-and-brick bridge built by the Houston and Central Texas Railroad company in 1872 in Collin County, Texas has been Listed on the National Register of Historic Places and preservation work is planned for this historic bridge. Read more here:

This historic stone-and-brick bridge was built by the Houston and Central Texas Railroad company in 1872.

In Appreciation

Posted June 26, 2012

The Historic Bridge Foundation thanks Jim Cooper for his service to the Foundation as board member and president. In the above photo, board member Vern Mesler (right) presents Jim Cooper (left) with an appreciation plaque during the 2012 Iron & Steel Preservation Conference at Lansing Community College in Lansing, Michigan.

Historic Bridges of Yosemite Valley Placed On 2012 List of 11 Most Endangered Historic Places

Posted June 8, 2012

Yosemite National Park is one of America’s most beautiful and cherished national parks, and three beautiful concrete bridges with stone facing constructed from 1928-1932 and crossing the Merced River have been both functional and beautiful elements of the park since their construction. However their future is now threatened by short-sighted demolition plans. In response to this threat to the historic bridges, the National Trust for Historic Preservation has included the Bridges of Yosemite Valley this year as one of their annual listings of the 11 Most Endangered Historic Places in America. Click here to view the official listing on the National Trust website. The source of this demolition threat is the development of a comprehensive management plan for the Merced River in Yosemite National Park. The plan needlessly calls for the demolition of these historic bridges. Details about the Merced River Plan are available at the official website.

Rivet Demonstration Part of Golden Gate Bridge 75th Anniversary Celebration

Posted June 8, 2012

As the famous Golden Gate Bridge in San Francisco turns 75 this year, a celebration was held to honor the bridge. Among the many events that were part of the celebration was a demonstration of heating and driving rivets. Rivets were the type of fastener used to assemble the parts of the Golden Gate Bridge, as well as most metal bridges built before 1970. Riveting is not used in bridge construction anymore except in historic bridge restoration work. The rivet demonstration was put on by Vern Mesler, who is a board member of the Historic Bridge Foundation. Click here to view a television news story that provides details of the rivet demonstration.

Students Attend Iron & Steel Preservation Conference With Scholarships Funded By Historic Bridge Foundation

Posted March 28, 2012

Two college students were able to attend the 2012 Iron & Steel Preservation Conference at Lansing Community College in Lansing, Michigan with scholarships funded by the Historic Bridge Foundation. The recipients of the scholarships were David Trayte, a student at the Savannah College of Art and Design and Andrew Evick, a student at the University of Vermont.

From left to right: Dr. Jim Cooper (Historic Bridge Foundation), David Trayte, (Savannah College of Art and Design), Dr. Brent Knight (Lansing Community College President), Andrew Evick (University of Vermont), and Nan Jackson (Lansing Community College).

It All Started With A $10 Bill

Posted January 3, 2012

Sunday, November 11th at 2 pm is a big day for the Stearns Truss in Delphi.  It culminates nearly two years regular M-W-F work by an ingenious volunteer crew  This whole project started December 16, 2005 in a Pulaski County Commissioner’s meeting at Winamac.  Four Canal Association volunteers were present.  An offer to purchased the 78 foot long relic for $10 was met with a stipulation that it must be removed from the Big Monon Ditch in just three months.  That winter the weather was cooperative and the volunteers rallied to disassemble and transport all the pieces to Delphi by March 3rd.

CELEBRATE!!  Volunteers are ready to present their pride and joy.  This bridge is a “one-of-a-kind” lightweight, portable, once rusty, wrought iron span brought from near Medaryville.  It is a special lightweight span designed by Wm. Stearns and the last known of its type to exist in the US.  The special place where the BIG BLUE BRIDGE spans the canal is in west Delphi behind Pizza Hut / Dairy Queen.  It sits over a reconstructed section of the Wabash & Erie Canal.

The last task being completed is the handrail and some touch-up of the beautiful blue paint.  The bridge sports another color as well as the blue.  All iron that was added for safety, but not part of the original, is painted black.  This comprises the safety siderail which is made of angle iron with a similar look as the integrated original handrail thus the added materials are black.

With parking near the bridge a premium on dedication day the participants can enjoy parking downtown Delphi around the Court House and being chauffeured by Brian Stirm and his popular Trolley.  Ride to the dedication then back downtown and “Discover Delphi Days” at the participating stores.  The Trolley will also travel to Canal Park and the whole circuit every 20 minutes.  It runs from 12 noon to 4 pm both Saturday and Sunday (10th and 11th).  Take time to enjoy the small town flavor with a visit to this county seat that still looks like it did in the historic canal era.

Take a walk along the trial from the bridge and jaunt south on the towpath to Lock #33 or the Irish Construction Camp  — or go north and arrive by trail in a half mile at the Canal Interpretive Center.  The volunteers are developing several sites with relevant canal connections to the 1840s through the mid 1870s.  Just west of the Blue Stearns Bridge were Papermills and Delphi’s shipping connections brought goods from the east while local products of salt pork, grain and lime were sent afar on this manmade waterway.

Come to the dedication and visit with the many volunteers that have rallied to this restoration project.  Nearly a dozen of the 76 volunteers listed on the program have been as regular as “clockwork” and have keep the pace throughout the last 7 seasons with their M-W-F workdays.  Without this dedication and the personal donations and grant support for supplies and materials this would not have happened.  Thank the volunteers when you meet them in the reception line spanning this 78 foot long wrought iron bridge.

If you are coming to Delphi on Saturday you have several treats to expect.  First the Trolley is running from downtown to the Stearns Truss from 12-4 pm and it is an informal “look-see” of the bridge — a few volunteers will be present.  Second there is another dedication of a downtown historic property’s shinny new facade — the Opera House.  The Delphi Preservation Society is cutting a ribbon to highlight to the public this completion at 2 pm on Saturday.

Take some time and exploring the shops and their specials during Discover Delphi Days all weekend.  You can park on the Square and board the trolley in front of the Opera House building on either Saturday or Sunday 12-4 pm and ride out to see the bright blue Stearns Truss Bridge.

Hays Street Bridge Restoration

Posted February 3, 2011

Patrick Sparks, Sparks Engineering, Inc. (

In the early 1900s the Galveston, Harrisburg, and San Antonio Railway was in the midst of an expansion from the City of San Antonio, Texas, westward, and as its tracks intersected the city’s existing roadways, the railway was required to construct above-grade crossings for horse-drawn carriages and, later, motor vehicles. In 1910 a viaduct was required to carry Hays Street over two active railroad tracks and two city streets, and to economize, the railroad decided to move two narrow-gauge iron trusses that formed a bridge over the Nueces River in southwest Texas to the San Antonio location. One truss was a 130 ft long 1910 Pratt truss and the other a more historically significant 225 ft long Whipple truss, both produced in 1881 by the Phoenix Bridge Company of Phoenixville, Pennsylvania. In the process of connecting the trusses to form the new bridge in San Antonio, the railway widened both spans from 16 ft to 25 ft, and constructed 1,000 linear ft of concrete approach spans. The Whipple truss, one of only six such trusses remaining in Texas, and one of the few remaining trusses with Phoenix columns in the country, featured segmental wrought iron columns, cast-iron joint blocks, and early laminated steel pins.

The bridge served its purpose dutifully as the region grew, but by the early 1980s it was determined to be structurally deficient and was closed to vehicular traffic. A movement began to replace the bridge, but in the 1990s, Douglas Steadman, P.E., formerly the president of W. E. Simpson Company in San Antonio, identified the trusses as historically significant and successfully lobbied for their inclusion on the list of Historic Civil Engineering Landmarks of Texas in 2001.  Steadman then led an effort to obtain grant funding and private contributions to save the trusses and convert the bridge for use as a pedestrian and bicycle crossing.

Thanks in part to those efforts, the bridge was recently rehabilitated and transformed by the City of San Antonio under a grant from the Texas Department of Transportation. Sparks Engineering, Inc., of Round Rock, Texas, served as the design consultant for the project. The work involved rebuilding the bridge’s two elevated concrete approaches, structurally rehabilitating the truss spans, and adding lighting, landscaping, and interpretive signage. The design team identified the following key goals for the project: safety, utility, beauty, permanence, and economy.

The design assures compatibility with the bridge’s historic character, in accordance with The Secretary of the Interior’s Standards for Rehabilitation (36 CFR §67.7). The iron trusses are the principal historic features of the bridge and had to be preserved.

Because of extensive deterioration, entirely new approaches were designed.  The characteristics of the approach spans that the team chose to maintain in the new design are the basic 1910 alignment and profile, although slight modifications were made in slope to improve the crossing’s accessibility and its vertical clearance above the two street crossings.  The new approaches are 15 ft wide, much narrower than the 30 ft width of the 1910 approaches, which opens up the space beneath the bridge visually and creates greater opportunities for plantings, seating, and interpretation installations at ground level. This design is compatible with the size, scale, and character of the neighborhood and surrounding environment, as recommended by the Secretary of the Interior’s Standards. The new approaches are of cast-in-place concrete, with a slender profile and tapered brackets that recall the character of the 1910 work.  Using mostly single-column supports at 40-ft on-center lends elegance to this dominant part of the project.  This scenario also represented the least cost, longest life-cycle, greatest utility, and best potential for aesthetic excellence.

The two historic trusses were in essentially good condition but with some areas of serious corrosion. The original materials were wrought iron and cast iron (used in the joint blocks in the Whipple span), which have very good durability The elements having the highest amounts of corrosion were those steel elements that were added in 1910, including lateral struts on the Whipple span and miscellaneous stiffening angles and cover plates on the floor beams.  The unusual laminated steel pins of the Whipple truss had detectable corrosion pits in some locations.

Because the geometry and sections of the main members are relatively simple to model, material characterization became the key issue in the structural analysis of the bridge. A rigorous evaluation was necessary because the materials were of unknown quality, the critical fabrications were never quality-checked by modern standards, design loads have increased over time, and the effects of decay and fatigue may have reduced the members’ capacity. On the other hand, the importance of bridges such as this one as significant icons of history requires that our evaluation methods be as least invasive as possible. So it was not feasible or appropriate to remove sufficient material to test the material properties in a laboratory. Instead, we used in-place nondestructive methods. In addition to a visual assessment and structural analysis, we relied on a combination of materials characterizations and nondestructive testing. In this approach, data regarding the elements’ microstructure, hardness, and chemical composition, together with other historical data, are used to characterize the behavior of the material without the need for physical sampling.

On the basis of the findings above, the team determined that the two truss spans could indeed be rehabilitated for use in the pedestrian crossing. The trusses themselves did not have to be strengthened, but corrosion was repaired and those diagonal members that had bent over the years were straightened. The center and top lateral struts of the Whipple span had been lengthened in 1910 with steel, not wrought iron, and these were severely corroded. The team therefore replaced them with weathering steel, a substitute material that is resistant to corrosion. All of the floor beams of the Whipple truss had to be rehabilitated and their corroded cover plates replaced. Two of the floor beams were removed from the truss for repair, but the remainder were rehabilitated in place.

In keeping with the practices used in constructing the truss, the team used traditional hot riveting methods rather than, as is more conventional, replacing the rivets with bolts. A special crew was trained in hot riveting in order to accomplish this, and the process was videotaped and posted on Hot riveting was also used to replace corroded rivets throughout the trusses. Pack rust was removed from many of the floor beams and vertical members; in some cases the team removed the rivets in order to do this, but in some cases a technique developed by the riveting consultant was used whereby the rust was loosened from the crevices with the aid of a rivet hammer.

The deck was replaced with lightweight, foot-friendly 2 × 6 pressure-treated lumber.  Only the floor beams were painted and the upper truss members were given an appearance coat of linseed oil.

The project was funded by a TxDOT Enhancement Grant, private donations, and the City of San Antonio. Plans and specifications were completed in September 2006, and the project was bid in early 2009. Construction began shortly thereafter and was completed in the spring of 2010.

The design required flexibility to meet current code requirements, ensure compatibility with the bridge’s historic character, and stay within budget.

In addition to the truss rehabilitation and the reconstruction of the concrete approaches, the project included architectural and pedestrian lighting, interpretive signs, and a landscaped entry plaza.  The $3.2-million project also included badly needed drainage improvements and repairs to broken and clogged storm sewer pipes in the neglected neighborhood nearby.

As a pedestrian bridge that will serve as a link between the east side of San Antonio and its downtown, the newly renovated Hays Street Bridge is inviting to all, providing not only a sense of community as an area of recreation but also as an attraction for visitors.

S. Patrick Sparks is the principal of Sparks Engineering, Inc., Round Rock, Texas.

Bridge Facts:

Total length of viaduct:  1,400-lf

Historic spans: 225-lf Whipple + 130-lf Pratt

Cost of project: $3.2 Million

Owner: City of San Antonio

Prime Consultant: Sparks Engineering, Inc., Round Rock, Texas

Site/civil engineer: Garcia & Wright, San Antonio, Texas

Contractor: Jay-Reese Contractor, Inc., Austin, Texas

Landscape architect: Bender Wells Clark, San Antonio, Texas

Electrical Engineer: Joshua Engineering Group, San Antonio, Texas

Riveting Consultant: Vern Mesler, Lansing, Michigan


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