FRP Rides The Rail, Giving Train Stations a 100-year Lifespan With Composite Mini-High Platforms
We all want products that last a long time and save us money. Composite Advantage’s Fiber-Reinforced Polymer (FRP) composites are being adopted by a diverse group of users for the same reasons. When 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.
MBTA found FiberSPAN-R, a high-performance, corrosion-resistant alternative to concrete, which deteriorates fast when exposed to ice, snow, salt and deicing chemicals. This was the engineered solution providing fast installation and long-lasting performance for the mini-high platforms at West Natick Station in the Boston area.
Mini High Platform
Mini-high platforms provide level boarding for individuals with disabilities. They are located at the end of low-level platforms and provide accessible boarding at the front or back doors of a train. The platforms consist of ramps and elevated loading sections.
FiberSPAN is lightweight, pre-fabricated decking that reduces installation time and costs. With the inherent corrosion resistance of FRP materials, maintenance costs are minimal and life times are long. 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. The panels are supported on concrete piers that were rebuilt to remove the corroding caps. The panels had attachment points for handrails that fit the same locations as the previous railings.
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.
Design parameters are:
Live load of 100 psf
Deflection limited to L/500; with spans up to 25.2 feet
Uplift load of 30 psf
Panel weight of 20 psf; largest panel at 25.2 ft by 6.1 ft weighs only 3100 lb
The North and South platforms are mirror images and each platform contains six FRP panels with a total square footage of 1,134. 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.
The project’s contractor removed and replaced corroded concrete support pile tops and replaced them with new concrete elevations and angles to support the FRP platforms and ramps.
One truck delivered the FRP panels for both platforms. To avoid busy commuter schedules, the FRP panels were installed on the weekend. FRP panels for the North platform were installed and completed on Saturday with construction of the South platform completed on Sunday. Panels were set on the piers, stainless steel angles were anchored to concrete piers to provide support and an easy connection point. Clip plates were bolted to the bottom of the FRP panels. Retractable edges were fastened to the platform panels. Each platform took approximately 8 hours.
The new FRP platforms opened for business in November 2017.