Greetings
Nothing is more satisfying to a craftsman than knowing a job was well done and to recognize those responsible. Laura Hilton, Visitor Services Manager for the Clifton Suspension Bridge Trust, and Andrew Martin, Victorian Engineering Connections, both from Great Britain, gave an excellent presentation in March for the last Iron & Steel Preservation webinar, featuring the Clifton Suspension Bridge, conveying a historical subject with a professional and interesting presentation.
Laura Hilton thanks everyone for a great evening and being invited to talk about the Clifton Suspension Bridge to such an interesting group, and thanks Andrew Martin for delivering a wonderful talk. Hilton has provided a link for the drone footage of the Union Chain bridge restoration works.
Andrew Martin thanks everyone for bringing together such a great bunch of people with some really good questions. Martin supplied a link (in Google books) to the proceedings of the Institution of Civil Engineers from 1867 and the Barlow paper about the completion of the Clifton Suspension Bridge (which starts on page 243 of the original document).
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Our next Iron & Steel Preservation Webinar will be a tour of Bach Steel in St Johns, Michigan. Nels Raynor, Bach Steel owner, and Nathan Holth, webmaster of HistoricBridges.Org, will conduct a presentation and shop tour of the iron and steel preservation work conducted at Bach Steel’s St Johns, Michigan, facility. This will be a "real-time" tour with opportunity for questions. This webinar is tentatively scheduled for June 30th. Those interested in attending this webinar please send Vern Mesler an email at meslerv@gmail.com.
Raynor and his crew of craftsmen-preservationists have worked on many historic metal truss bridge projects. Visit Bach Steel’s website to discover more.
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In 1985 I decided to inspect a small abandoned 19th century iron truss bridge spanning one of Michigan's major rivers. As I approached the bridge I was struck with amazement and curiosity about the many iron members that made up the bridge. They were not massive, but delicate, made with the simplest of lines to function as a bridge. At the time I did not know what these bridge members were, how they were made, or who made them. It wasn’t until 1997 when I was hired as an independent contractor to restore historic riveted truss bridges for the Calhoun County Road Commission that I discovered the craftsmen's record. Within the five historic bridges I and a crew of preservation-craftsmen restored and erected in the Calhoun County Historic Bridge Park are the unwritten words of craftsmen and women. |
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A historic pin-connected truss bridge is made up of many elements. Three of the most important are the eye-bars, bridge pins and recessed nuts. Eye-bars are used for main tension members of pin-connected bridge trusses. In the evolution of the eye-bar upsetting machine, a system of closed movable dies was developed with the elimination of forge hammering which could be damaging to the properties of steel.
Keystone Bridge Works, 1882 Eye-bar Upsetting Machine in Engineering News, August 17, 1905
The American Bridge Company’s Ambridge Works. The Eye Bar Shop [pp. 10 – 13 in The Iron Age, September 15, 1904] (Re-formatted for clarity by Vern Mesler, Nan Jackson, 2021):
Chord Pins Why Recessed Nuts are Used for Chord Pins--Reason for Turning Down the Ends of the Chord Pins-- The Use of Washers on Chord Pins Home Study (Volume 1, February 1896—January, 1897). Scranton, PA: The Colliery Engineer Company 1897 This excerpt (pp. 141-142) was re-formatted for clarity by Vern Mesler, 2011:
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“I remember the moment we put the last pin in the inclined end post to the load bearing end pad. When the bridge lifted off the cribbing and all the parts were working as intended – it was like magic.” (Wayne Conklin)
There is nothing more satisfying for craftsmen after months of hard physical labor than to experience a moment when there is no doubt your labors paid off: “Like Magic.”
Restoration work for the Gale Road Bridge began in the Fall of 2000 at the Calhoun County garage in Marshall, Michigan. It was the third historic bridge restored and erected in the Calhoun County Historic Bridge Park, a one-span wrought iron Pratt through-truss (122 ft long) built in 1897 by the Lafayette Bridge Company of Lafayette, Indiana, for Ingham County, Michigan.
Crane mats were set across the Dickinson Creek and wetland in fall of 2001 in preparation for the erection of the Gale Road Bridge in the Historic Bridge Park. The Gale Road Bridge floor beams were set on the crane mats and erection of the restored bridge began. During the nineteenth and early twentieth century, the erection of metal truss bridges on rural county roads typically started with wood piling set in the riverbed, then the floor beams set on top of the wood cribbing and a gin pole used to lift the bridge members. This historic method was brought back for use in the early twenty first century to erect the restored Gale Road Bridge in the park. With the engineering and fabrication support from Dr. Frank Hatfield, Professor Emeritus, Michigan State University, and the historic bridge craftsmen, Wayne Conklin and Rob Denniston, we fabricated and assembled a gin pole on the stringer beams of the Gale Road Bridge. It required a lot of hard physical labor with chain-falls, wrenches, clamps, and a hand-operated ratchet winch (a “come-a-long”) to maneuver and set in place the gin pole to lift large structural members of the bridge.
During the three seasons of 2001 and 2002 the restoration and erection of the Gale Road Bridge continued, and on June 13, 2002, the bridge was rededicated and open for Historic Bridge Park visitors to enjoy. It had been a challenging job. Many would say “it can’t be done,” but that never entered my mind. Maybe there was some “magic.”
Vern Mesler 2021
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Please consider contributing to the Iron and Steel Preservation Program Fund. This fund was established to support projects, research, conferences and scholarships related to the repair, rehabilitation, and restoration of metals. The Lansing Community College Foundation is a nonprofit 501(c)(3) corporation.
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