In June 2003, a custom-designed REMUS swam several hundred feet below the Catskill Mountains and Hudson River to inspect a 45-mile section of the Delaware Aqueduct. It was the culmination of a three-year journey for the REMUS team. As the largest and most crucial link in New York City’s upstate water transportation system, the Delaware Aqueduct carries as much as 900 million gallons of water daily. For a decade, the NYC Department of Environmental Protection (DEP) has been monitoring leaks in the aqueduct’s Rondout-West Branch Tunnel, which have allowed 10 to 36 million gallons of water to escape each day. Yet inspectors could not simply shut off the water and walk inside for a visual inspection because the water pressure in the tunnel-about 240 pounds per square inch-might be the only thing that keeps the aqueduct from collapsing.
In 2000, the DEP issued a call for proposals to develop an untethered, unmanned vehicle that could inspect and photograph the 13.5-foot wide tunnel while the water kept flowing. The REMUS team saw it as an unprecedented challenge, and bid for the contract. They won.
Over the next three years, the team designed and extensively tested an oversized, customized version of REMUS, known as the Tunnel Inspection Vehicle. The TIV was equipped with five digital cameras angled for 360A? imaging, as well as pressure sensors, hydrophones, and navigational gear.
On June 6, 2003, the TIV completed the 15-hour survey, emerging from the aqueduct with 160,000 digital photographs and 600 gigabytes of data that fills 150 DVDs. Engineers will now analyze the TIV data to determine the nature and location of the leaks, said DEP Commissioner Christopher Ward.