Hydraulic Hammer Markings

Steel slabs bear the markings of the clamps inside the hydraulic hammer used to drive the slabs into the ground beneath Alum Creek. The slabs are used to build coffer dams to hold back the creek during construction of the Main Street Bridge. Next to the  fresh markings are a set of older marks that have rusted over. The older marks indicate the slabs were previously used for similar construction and reused in Westerville.