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Henry's Knob

York County, South Carolina

Emergency Spillway/Drainage


AMEC Foster Wheeler


AMEC Foster Wheeler


North Star Construction


August 3, 2016

Technical Description:

• 12,500 sf ArmorFlex® Class 50 Open Cell Mats

From 1947 to 1970, the 1,120 foot tall Henry's Knob mountain was the site of an open-pit kyanite mine. During the mine's closure process, it was determined that appropriate erosion protection be provided to ensure the capping system remain intact and undisturbed. Additionally, the site owner was concerned with long-term maintenance. 

As the best solution for rehabilitating the former mine, 12,500 square feet of ArmorFlex® Class 50 Open Cell Mats was selected for its proven ability to provide long term erosion stabilization with minimal maintenance. Accessibility to the remote location was a challenge. So, before installation could begin, Star Construction, the project's contractor, cut a dirt road through the mountain to the back of mine providing access to the site. 

Overall, the ArmorFlex provided more square foot coverage per truck load than riprap. For every nine trucks of riprap, only one truckload of ArmorFlex was needed. This greatly reduced delivery costs and road maintenance. The project itself was completed in just three weeks.

Technical Description:

• 12,500 sf ArmorFlex® Class 50 Open Cell Mats

800-338-1122 |


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