Prototype Barge Impact Experiments, Allegheny Lock and Dam 2, Pittsburgh, Pennsylvania

Abstract : "Prototype" full-scale barge impact experiments were conducted in late August 1997 at Old Lock and Dam 2 on the Allegheny River, just north of Pittsburgh, PA. The purpose of these experiments was to assist researchers in examining and quantifying the behavior of a barge system during impacts to a rigid lock wall. These types of full-scale impact experiments-using a working towboat and inland waterway barges-have never been attempted before. Therefore, detailed research and development of instrumentation and data collection equipment was required to properly capture the behavior of an inland waterway tow during an impact into a rigid lock wall. The state-of-the-art instrumentation program used for these experiments was also developed with the idea that a similar instrumentation program (at yet a larger scale) could be applied to a true full-scale impact experiment using a fully ballasted 15-barge flotilla. The experiments were conducted using a four-barge tow system that was composed of standard open-hopper rake barges. The tow was ballasted to 8.5 ft (2.4 m) of draft with an approximate mass of 4,000 short tons (3.6 million kg). A total of 36 prototype experiments were successfully conducted during the 3 days of testing. Twenty-five of these experiments were on a rigid concrete lock wall, and nine experiments were on ultra-high molecular weight (UHMW) plastic bumpers. These UHMW plastic bumpers were used to examine the energy transfer effects of barge systems impacting on a near-"frictionless" surface. The experiments yielded velocities ranging from 0.5 to 3.2 fps (0.1 to 0.9 m/sec) with angles of impact that ranged from S to 27 deg. The report includes descriptions of the experiment site, test schedule, and the towboat and barges used for the experiments.