In this webinar:

 

Third Avenue Bridge (Bridge 2440)
Katherine Haun Schuring & Chris Hoberg 

 

Constructed between 1914 and 1918, Third Avenue was the first of the monumental reinforced-concrete arch bridges built by the City of Minneapolis over the Mississippi River in Minneapolis. The open-spandrel, Melan concrete-arch bridge is an iconic fixture within downtown, connecting the east and west banks together. Its graceful S-curve alignment safely avoids the Falls of Saint Anthony and preserves the fragile geology of the riverbed. The choice of a concrete arch over the falls was in direct response to public request and reflect the City Beautiful Movement sweeping across the United States. The original construction effort and recent rehabilitation by the Minnesota Department of Transportation shed light on shared building methods and challenges engineers face between centuries.

 

Chain Bridge, Newburyport, MA. Early American Chain Suspension Bridges 
Robert J. Dermody

 

The 1810 Chain Bridge in Newburyport, MA was one of the first wrought iron chain suspension bridges built in the United States. Chain bridge construction had been patented just two years earlier by James Finley, a Pennsylvania engineer. The Chain Bridge was in service for 100 years and replaced a timber arch-trussed bridge built at the site in 1792.  By 1910, the original chain bridge needed to be replaced. A replica Chain Bridge was built in its place and is still in service today. This presentation will describe early American chain suspension bridges, at "the oldest continually occupied, long span, bridge crossing" in the United States. 

 

1,160 lbs of riveted iron sliding in place – moved by muscle power 
Ulrich Boeyng

 

In 1859 the iron lattice girder structure of the railwaybridge between Waldshut (GER) and Coblenz (CH) was moved over the river Rhine. It was the very first of all railway bridges over the Rhine and the first of the soon following to connect two states.