A Union Pacific Railroad bridge in Graettinger, Iowa was failing due to limestone deterioration under 12 piers. This 100-year old bridge was in need of repair, as limestone is an outdated building method and does not hold up compared to newer materials like concrete.
Using 50-ton hydraulic jacks and shore towers to jack up the steel spans, Hawkins removed the existing limestone piers, and replaced them with new precast sections. All repairs were performed between train traffic using eight 5-hour windows. The anticipated lifespan of the project is 70 years or more.