Historic Brownsville bridge part of 'unique' project
The Dunlap's Creek Bridge in Brownsville holds several distinctions. And now it will be the focus of a PennDOT bridge preservation project.
It was completed in 1839 as the first all-metal bridge in the United States and, 175 years later, it is still carrying traffic without weight restrictions.
The cost of the original bridge was $39,811.63, a large sum at the time. The cost of the bridge preservation project, scheduled for completion by Oct. 1, 2018, will be more than $3.7 million.
“Due to added funding (through Act 89 of 2013), we can go ahead with more projects,” said Valerie Petersen, community relations coordinator for PennDOT District 12.0 in Uniontown. “We are always excited when we can do this type of unique project in the district.”
Petersen said the project is now in the preliminary planning stage.
“The plan is to do an historically correct preservation of the bridge because it has such a high historic significance,” Petersen said. She added the bridge is regularly inspected, just like any other bridge, and no structural problems have been found.
The actual project will start in 2015 with the pre-engineering phase. The final design work will be completed in 2017. Work on the utilities, right of way and construction will be done in 2018.
It was a while before an all-metal bridge was approved for the location, then on the National Road from Maryland to the western frontier. There were four previous bridges built at the location between 1808 and 1820. All were made of wood and all did not stand up to what was then very heavy traffic.
Capt. Richard Delafield of the U.S. Army Corps of Engineers had informed his superior that no bridge was needed at the site. His commanding officer agreed. However, the U.S. Attorney General at the time, after hearing arguments from the states over the poor condition of the National Road, overruled that decision and it was determined that a bridge should be built.
So Congress instructed the Corps of Engineers to fix the National Road and to build a bridge over the creek.
A review of the history of the bridge at the Flatiron Heritage-Visitors Center was extensive, especially with paintings and photographs of the structure throughout its 175-year history. Delafield, later to become chief of the Corps of Engineers and then commandant of West Point, came up with the unique idea of building an all-metal structure. His design was approved, and work began in Brownsville under his direction with the help of his assistant, Lt. George Cass.
The pieces of the structure were cast from the best cast iron available at the time by John Snowden, an ironmaster and steam engine builder, at his iron works and at Herbertson Foundry, both in Brownsville. Work began in 1836 and was completed in 1839.
Brownsville, located on the Monongahela River, had become a center for boat construction for those headed west.
After the completion, the location of the National Road was moved to the north in Brownsville. Traffic on the bridge decreased, actually helping to preserve the structure. Norma Ryan, a Brownsville Area Revitalization Corp. volunteer at the Flatiron Heritage-Visitors Center, said Marc Henshaw from the Brownsville area has done extensive research on the bridge.
Henshaw agreed with the history at the visitor's center and that supplied by PennDOT, adding the bridge is actually what he would call the Delafield design, a departure from the French and English metal bridge designs that preceded it.
“It was a fresh idea of Delafield's,” Henshaw said.
Karl Polacek is a staff writer for Trib Total Media. He can be reached at firstname.lastname@example.org or 724-626-3538.