The lead researcher on the project is Ever Barbero, a West Virginia professor whose specialty is the use of advanced materials in engineering. Dr. Barbero was contacted in 2006 by a homeland security official looking for innovative ways to keep a subway system from flooding.
It’s not an easy job, I mean it’s not good to maintain, to operate a tunnel is not a trivial thing. It’s a complicated system, there’s no space, it’s very demanding, the operation. There is no time, the trains are coming all the time.
In theory, the idea is simple. Rather than retrofitting subway tunnels with metal floodgates or other expensive structures, the project aims to use a relatively cheap inflatable plug to hold back raging waters. But in practice, developing a plug that is strong, durable, and foolproof is a difficult engineering task.
The three layer plug consists of an inner layer, it’s basically a bladder that contains the air or the water that’s used to inflate the device, then the second layer which is just a single layer of super strong ventran fabric which provides added resistance and protection to the bladder layer. But the most critical layer is the outer layer which is a woven layer made of ventran fabric.
On the day of this test, Dr. Barbero and a colleague inspected the front of the plug and discovered a two inch gap in one corner. The test called for filling the plug with water to pressurize it further while simulating a flood from behind. But a plumbing error unrelated to the plug ended the test prematurely.
Our time frame on this project, we’re looking at I think a couple more years of testing, development, and coming up with with a final design. This is still a test prototype so we’re not there yet, but these types of tests are moving us in a positive direction.