Submersible robot created to repair buried pipes

 

 

PULLMAN — Engineers at WSU’s Capital Planning and Development are testing a robotic technology with possible military and disaster rescue and recovery applications.

 

The patent-pending robotic process blends a little bit of ingenuity from industrial metal cutting, video game technology, civil engineering and battle-bots to help repair underground sewer lines.

 

Keith Bloom, director of construction services and quality assurance for WSU Capital Planning and Development, said a sewer repair project at WSU drove the need for a creative, cost-reducing approach. An old storm sewer line buried almost 30 feet deep below a parking lot and soccer field is in need of rehabilitation and enlarging. The cost to excavate a trench 30 feet deep, support the deep trench walls and replace the parking lot, asphalt, lighting and adjacent soccer field improvements was prohibitive.

 

 

Engineers began almost two years ago exploring options. After numerous brainstorming sessions, trials and errors, they’ve developed a pipe-crawling robot which features two ultra-high-pressure water jets with very narrow streams that cut along the sides of the pipe.

 

The self-propelled robot, called the HIDRA, for High Intensity Demolition and Reconnaissance Apparatus, is completely submersible, has forward and aft cameras and is propelled by two crawler type tracks. The robot is controlled remotely by a joy stick with progress monitored on several video screens.

 

The project team consists of Bloom; Phil Wright, project manager and civil engineer; Jason Harper, construction engineer and licensed plumber; Bob Nichols, design and assembly support and info tech specialist; Yoshi Kodama, informational systems manager providing robotic controls and steerage, and WSU mechanical engineering student Justin Ramm.

 

 

HIDRA in above-ground testing

 

 

The work doesn’t end with simply cutting the pipe. Over the past 30 years, many municipal sewer and water infrastructure improvements have been performed employing a method called pipe bursting or trenchless technology.

 

The method allows for most types of pipe to be enlarged in place, by utilizing a device called an expander head and brute force, either hydraulic or pneumatic. The device is inserted into the pipe to be renovated, repaired or enlarged by way of a launching pit. The expander head is pushed or pulled through the old pipe breaking or bursting it and at the same time pulls new pipe material in behind it. The pieces of the old pipe are simply pushed aside into the surrounding soil.

 

Pipe bursting is generally far less expensive for pipe replacement than traditional excavation. While the bursting method is widely used today on most types of pipe, its use on corrugated metal pipe (CMP) commonly referred to as culvert pipe, is ineffective as that material has a tendency to “bunch up” or “beer can” in front of the expander head. If the CMP can be pre-cut, the bursting technology would work as the strength of the pipe is severed allowing the expander head to move through.

 

Successful above-ground testing completed two weeks ago and the HIDRA has been operating effectively underground. A completion of the pipe-cutting preparation for bursting operations is anticipated by the end of May with actual pipe bursting should begin in the first week of June.