NOVEMBER 2008

BART replaces wood rail ties with recycled plastic
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After the wooden ties are replaced with plastic, the old ties are sent to biomass plants.

The San Francisco Bay Area Rapid Transit (BART), which serves 104 million passengers via commuter trains in the densely populated California’s Bay Area, has given the recycling of plastic a major boost by embarking upon a plan to replace the wood rail ties that it currently uses on its tracks with those made from plastic products such as discarded grocery bags, old milk bottles and discarded tires.

“What we’re doing is swapping out worn wooden railroad ties with plastic ones made from recycled grocery bags, milk bottles and old car tires,” said BART board president, Gail Murray. “These plastic ties are incredibly strong, last twice as long and are three times cleaner to make than the wooden ones.”

BART has 104 miles of track that run through 4 counties and 26 cities. The metropolitan area has seven million people.

BART Board Member Bob Franklin, who chairs the Board’s Sustainability-Green Committee, stresses the importance of recycling to manufacturing products.

“BART has replaced roughly 400 wooden railroad ties with these recycled plastic ones,” he said. “That’s the equivalent of 1.1 million grocery bags that won’t be going into landfills.”

This can also be translated into 246,400 plastic bottles and 1,200 tires.

San Francisco and other Bay area cities such as Oakland, have enacted legislation that bans plastic shopping bags. This is in addition to aggressive recycling programs.

Plastic ties last twice as long.

BART notes that plastic ties are environmentally superior to wood ties, based on the following reasons:

  • •Wood ties require manufacturers to seek fresh wood products, which promotes logging in the nation forests.
  • In order to make wood ties more durable, manufacturers soak the wood in creosote, which is a byproduct of the chemicals that come from heating coal to produce a tar-like substance.
  • Compared to wood ties, it’s significantly more difficult for plastic ties to catch fire. Wood ties tend to dry out as they age and become increasingly more susceptible to catching fire.

“According to researchers,” said BART chief spokesperson Linton Johnson, “the process to make plastic ties out of discarded grocery bags, car tires and milk bottles is at least three times cleaner than the process to make a wooden railroad tie. Additionally, once the useful life of a plastic tie is up, they can be recycled into other plastic products.

Currently, BART sends worn out wooden ties to biomass plants to generate electricity.

BART’s plan is to eventually replace 14,000 wood ties with plastic ties over the next 5 to 10 years. BART’s various rail lines have approximately 38,000 ties on its track.

BART maintenance crews are currently replacing wood ties for plastic ones as wood ties reach their end-of-life stage. Depending on their location, ties in the Bay Area last between 15 and 40 years. BART estimates that plastic ties have a lifespan of 50 to 60 years.

Thus far, the cost of installing 400 recycled plastic ties has been $200,000.

“Plastic ties cost about the same as premium quality wood ties, which is approximately $15 to $20 per lineal foot,” said Johnson, noting that a standard tie is 9 feet long and a switch tie can be as long as 25 feet. “Low quality wood ties are cheaper, but have a much shorter life because the wood has minor imperfections like split cracks and twists. BART’s costs for plastic ties will be greatly reduced because of an upcoming multi-year high quantity purchase. In the end, the overall life cycle costs of plastic ties will be much cheaper as research shows that they are incredibly strong and last twice as long.”

The ties are manufactured by Performance Rail Tie, Plastic Pilings and Recycle Technologies International.

To dispose of the wooden ties, BART has partnered with Anderson, California-based Wheelabrator Shasta Energy Company. The utility shreds and burns the scrap wood.