INNOVATION September-October 2018

F E A T U R E

not supported in North America. To solve that problem, BAP Acoustics developed an in-house program that was able to import acoustic and GPS data collected from a locally supported, multi-channel data acquisition system directly into RailInspector. The company then worked closely with BCRTC personnel to safely wire cables between the data acquisition system and four precision-measurement microphones mounted near the wheels of a test car. Each line sweep in the test car took about two hours, travelling at a fixed speed of 40 kilometres an hour. Combined with detailed GIS information for the Expo Line and Millennium Lines, the custom solution was then able to map noise and GPS information to specific points along the track, and to identify ‘hotspots’—track sections with significant corrugation. Those hotspots were then visually inspected by de Santis and BCRTC. “With the system we developed,” says de Santis, “we can map roughness profiles in intervals as fine as one metre across a large network from data collected in a relatively short period of time. It wasn’t easy, but it was an extraordinary learning experience. We learned that you can do a rapid estimate of rail roughness on a running rail system, properly and accurately, while covering large distances of track for both left and right rails. And that can translate to benefits for the operator and, in turn, passengers and communities.” As an acoustical engineer, says BKL’s Mark Bliss, “you enhance the good sounds and reduce the noise to levels that make sense for each situation. When done right, good acoustics often don’t get noticed”—but they may just help us live happier and healthier lives. j

BAP Acoustics' unique approach combined an instrument designed to measure rail roughness, GPS data, track GIS data, and actual noise measurements from precision microphones carefully attached to near the wheels of a train. The rail roughness instrument—called 'CAT'—is designed to operate at walking speed. BAP's solution involved finding a way to acquire the rail measurements and all the data at 40 kilometers per hour. P hoto : BAP A coustics

To help absorb sound without ruining the décor, the hallways of the Pacific Autism Family Centre are outfitted with wood slats, which have a 38-millimetre-thick layer of fibrous glass duct liner installed behind them. The fibrous material absorbs sound and controls the build-up of reverberation. The amount, thickness, location, and type absorptive material is precisely calculated to create a quiet, calm interior. P hoto : M ike C rane

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Instead, de Santis built a whole new solution, beginning with specialized software called RailInspector, developed by M+P|MBBM Consultants of the Netherlands to analyze twice-yearly acoustic rail roughness monitoring data collected on the Dutch High Speed Line Zuid. “Regular rail condition monitoring,” says de Santis, “tracks rail roughness and

rolling noise emission changes over time, and enables rail operators to identify when and where they need to periodically grind the rail to reduce noise.” However, choosing the software turned out to be the easiest part. RailInspector software was designed to work directly with M+P|MBBM’s own proprietary hardware system, which is

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