3-D system inspects railroad tracks

Georgetown Rail Equipment Company (Georgetown, TX, USA; www.georgetownrail.com) required a faster, more efficient method to analyze track and provide a detailed report of track conditions based on an assortment of factors, but principally crosstie conditions. The standard method of track inspection requires a person to walk the track and subjectively grade the condition of wood or concrete crossties and fastener hardware by sight. Georgetown challenged machine-vision integrator Nagle Research (Austin, TX, USA; www.nagleresearch.com) to build a machine that could traveled along the track at speeds of up to 30 miles per hour while analyzing up to 70,000 ties.

Because various chemical treatments applied to wooden crossties stain them and would confuse 2-D analysis algorithms, Nagle Research developed a 3-D system that could be used to gather data regardless of tie discoloration. The company used a Ford F250 track-capable pickup truck, and built a retractable chassis in the bed of the truck to house two Ranger 3-D cameras from SICK IVP (Linköping, Sweden; www.sickivp.com) and laser equipment. The system can scan hundreds of miles of track in one day-with better than 0.08 in. resolution in all axes-and have a comprehensive report on more than two dozen track conditions prepared within 24 to 48 hours.