Bridgeplate Development
In the spring of 2002 Michigan Scientific Transportation Products, LLC began investigating the possibility of designing a bridgeplate that could meet the new requirements provided in the Association of American Railroad's Recommended Practice 951-03. The challenge was to build a bridgeplate that was 200% stronger (10,800 lbs. vs. 3,600 lbs.) yet weighed no more than the current units (40 lbs.). The dimensions for the new bridgeplate were the same as those of the current bridgeplate.
Initial analysis suggested it would be very difficult (if not impossible) to make a bridgeplate that met the new requirements out of aluminum. An assortment of other materials and manufacturing processes were considered. This work suggested the most promising material was a composite. The cost and durability of the composite plates lead to examine steel.
The MSTP team visited several loading sites where the bridgeplates are used to better understand the service environment and to solicit a "wish list" from the users. A number of representative bridgeplates were inspected to assess their performance during actual service.
Several design iterations were developed and assess using advanced solid modeling and finite analysis tools. Several materials and joining methods were evaluated in the test laboratory to confirm published tensile and shear strength properties.
Parts manufactured using production-intent materials, tooling and processes will be provided to the Association of American Railroad's Specially Equipped Freight Car Committee for testing. The goal is to obtain "Conditional" and then "Unconditional" approval from the AAR over a period of time.
Last Revised: 04/18/2008 03:18:09 PM
