Rail platforms offer a variety of challenges for engineers and designer; busy train schedules make construction and maintenance problematic, and a variety of passenger needs means that issues of accessibility must be considered. When the time comes to repair or replace rail platforms, logistics can be difficult. After the Massachusetts Bay Transportation Authority's (MBTA) North Billerica Station rail platform collapsed in 2015 due to concrete failure, the agency closed its North and South mini-high accessible platforms at its West Natick Station.
Rail platforms offer a variety of challenges for engineers and designer; busy train schedules make construction and maintenance problematic, and a variety of passenger needs means that issues of accessibility must be considered. When the time comes to repair or replace rail platforms, logistics can be difficult. After the Massachusetts Bay Transportation Authority's (MBTA) North Billerica Station rail platform collapsed in 2015 due to concrete failure, the agency closed its North and South mini-high accessible platforms at its West Natick Station.
Looking to restore the use of these platforms, MBTA found FiberSpan, a high-performance, prefabricated alternative to concrete. Unlike concrete, which deteriorates quickly when exposed to ice, snow, salt and deicing chemicals, FiberSpan is made of fiber reinforced polymer (FRP). The inherent corrosion resistance of FRP materials means maintenance costs are minimal and life times are long, estimated at over 75 years. FRP materials are also lightweight, which makes for easier transportation of panels and shorter install times. This is particularly beneficial in high-traffic and restricted access applications such as rail stations, where limiting downtime is critical.
In the case of West Natick’s mini-high platforms, Composite Advantage fabricated the new FRP panels to match precast concrete panels that formed the ramps and platform previously. The panels are supported by previously corroded concrete piers, which the project’s contractor removed and replaced with new concrete elevations and angles to support the FRP platforms and ramps.
FiberSpan™ rail platforms are offered in both standard sizes as well as custom made panels. For shorter spans, a standard, flat FRP panel is sufficient to bear the load, but over longer spans between 15 and 50 ft., Composite advantage uses a double T reinforced panel to accommodate the longer length.
One truck was able to deliver all the FRP panels for both platforms. The North and South platforms are mirror images of each other and each platform contains 6 FRP panels with a total square footage of 1,134. The largest of these panels was 25 ft by 6 ft and weighed only 3,000 lbs., which is extremely light compared to the other options such as concrete or wood. To span the support distances between concrete piers, some of the panels were molded with stiffeners integral with the deck to provide a lightweight, “precast” double tee panel. To avoid busy commuter schedules, the FRP panels were installed on the weekend, with the panels for the North platform installed and completed on Saturday, and the South platform completed on Sunday. Each platform took approximately 8 hours. Panels were set on the piers, and stainless-steel angles were anchored to the piers to provide support and an easy connection point. Panels bordering the tracks were engineered to accommodate a retractable edge that is used to handle trains with different widths. In the down position, the edge acts as a bridge for commuter trains making it easy for passengers to board. Hinges allow the edge to move to the up position to permit wider freight trains to pass. In keeping with ADA, the retractable edge features yellow warning tiles. The rest of the platform is covered in an epoxy-aggregate non-slip overlay, improving traction in wet or icy conditions.
Mini-high platforms such as the ones at West Natick provide accessibility to individuals with disabilities by creating a level boarding surface. They are located at the front or back doors of trains, consisting of ramps and elevated loading sections. The impetus behind features such as mini-high platforms stems from public demand and, subsequently, Federal laws mandating safe and easy access to areas such as trains. In 1990, Congress passed the Americans with Disabilities Act (ADA), prohibiting discrimination of persons with disabilities in employment, public services, public accommodations and telecommunications. The mini-high platforms offer an insightful example of how MBTA is working to meet the requirements of ADA, while harnessing the many benefits of lightweight, long-lasting, easily-installed FRP materials.
