Not So Slippery When Wet: Metro Finds New Tiles
If you ride the Red Line through the Takoma Station, you may have noticed the different look of the terra cotta tiles on the north end of the platform. The color seems somewhat lighter than the tiles covering the rest of the platform. But the difference really shows up when it rains. The tiles look dry when everything else looks wet.
This was a test area, away from where most passengers would stand while waiting for a train. Metro announced today that the test worked, and it's going to start using this new style of precast concrete paver to replace the original tile.
Make that tiles. The transit authority has been using the terra cotta, hexagonal style for so long that it's had to go through a bunch of manufacturers. The department of Plant Maintenance says that when its crews go out to replace crumbling tiles, the first thing they have to figure out is which design they are replacing. The tiles have different thicknesses.
Aside from the promise of lower maintenance costs, the new version isn't as slick when it's wet. How great is that? Anyone who has walked along an outdoor platform in the rain -- or an indoor platform after that Zamboni-like machine goes over it -- is going to appreciate what the engineers call a better "coefficient of friction" on the new tiles.
Tests from December through April convinced Metro that these concrete paver sections are more durable, more economical and safer while still -- and this is always crucial in the Washington transit system -- preserving the traditional look.
David Couch, Metro's manager for engineering and capital projects, said the transit authority didn't find any cracks in the concrete pavers during the Takoma experiment, which lasted through the winter and into spring. Think how often you see the old ones chipping and crumbling on the exposed parts of platforms.
The estimated cost of replacing the tiles at an outdoor station not covered by a canopy will be in the $1.2 million to $1.4 million range, said Metro spokesman Steven Taubenkibel.
The life expectancy of the current tiles exposed to elements is about five years. After every winter, Metro has to go out on a wave of tile repairs, because of the salt, the expansion and contraction and the cracking. So Metro is convinced that the new tiles will save money in the long run.
Metro plans to install the new tiles at other stations this fall as part of its platform rehabilitation program. The new tiles also will be used in building future stations, such as those along the Metrorail extension through Tysons.
Posted by: dwahlstrom | June 4, 2009 10:33 AM | Report abuse
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