Rail Ride Study Underscores Need for Monitoring
Figure 1. A comparison of Chicago L lines and ASTM D4169 rail test simulation for packaged products showing the overall vibration harshness of all lines. Figure courtesy Lansmont Corp.
(click image to enlarge)
At Pack Expo International 2006, Lansmont Corp.’s (Monterey, CA) testing technology demos weren’t confined to the trade show floor. The company paired its Saver 9×30 field data recorder with its Saver GPS-Logger and boarded Chicago’s elevated (L) train system to measure the rail line’s shock and vibration.
The Saver 9×30 employs a self-powered internal triaxial accelerometer to measure dynamic shock and vibration, while recording the temperature, humidity, and atmospheric pressure associated with each dynamic event. The Saver GPS-Logger can identify the exact GPS position of those events by associating position times with the times of the shock or vibration events.
For Lansmont’s L Ride Quality study, Saver 9×30 units were affixed to the floors of eight line cars. Accompanying GPS-Loggers were positioned in the window in order to receive location information from GPS satellites. Lansmont’s professional services development engineer Kassarjian Ondrea accompanied every measured vehicle, performing one complete round-trip circuit of each rail line. The goal was to capture data on the following ride characteristics:
• Individual bumps occurring on each of eight L lines.
• Date and time of individual event measurements.
• GPS position of individual event measurements.
• Overall vibration harshness of each L line.
Lansmont sought to demonstrate more than just the Saver line’s capabilities. Many packaged products travel by railcar and encounter shock and vibration. “Some products move 3000-plus miles from central Mexico to the Eastern seaboard of the United States,” Lansmont writes in its report. “Other products may move nearly 1200 miles from Shanghai, China, to developing industrial areas on the Tibetan plain such as Chengdu. Given the volume and value of those products, it’s imperative that manufacturers clearly understand the hazards present within those specific routes of transport.”
Preparing for rail trips may require more effort than just testing transportation packaging according to ASTM D4169. According to Lansmont’s L line study, five of the eight lines studied exceeded a vibration harshness level of 0.29 G rms, the laboratory test level established by ASTM D4169. As shown in Figure 1, “Packaged products tested and approved through ASTM D4169 rail testing likely could expect damage shipping in the five right-hand L lines,” reports Lansmont. “Tested and approved packaged products shipping in the three left-hand L lines might be overpacked and thus be an opportunity for material savings.”
Eric Joneson, vice president of marketing and business development for Lansmont, explains that the study results demonstrate that packagers must measure the actual environment in order to perform adequate tests in the lab. “Measure, test, and monitor,” he says.
“Validation of both product and package design is performed in the laboratory by simulating the hazards in controlled performance tests,” Lansmont writes in its report. “Successful results provide the manufacturers with high assurance that they can deliver quality products to the various points of destination and end customers without risk of loss or damage.”