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Sources: David Steward, 785-532-1585,;
Paul Bruss,; and Brady Hedstrom,
Photos available. Contact or 785-532-6415.
News release prepared by: Kristin Hodges, 785-532-6415,

Monday, May 18, 2009


MANHATTAN -- In locations without electricity, ram pumps can be built to pump water to a higher elevation than the water source at a lower elevation. Kansas State University engineering students were interested in learning about the apparatus, and their interest has resulted in a successful pump.

David Steward, associate professor of civil engineering at K-State, teaches a course on hydraulic engineering, which is the control of water, and assigns a class design project. This spring, his students designed and helped build a ram pump.

"We've gotten the students actively involved in designing an apparatus for the hydraulic engineering laboratory," Steward said. "As I've taught the class, I've tried to pick a new area that would be of interest to the students each semester."

Steward said the students take two weeks to design a new apparatus; next, it is built with some student involvement; and then it is tested. This semester, Steward did not have a selected topic and asked the class for suggestions.

Paul Bruss, senior in civil engineering, Lenexa, is a member of K-State's Engineers Without Borders, a nonprofit organization that partners with developing communities. He heard about the concept of ram pumps when the founding president of Engineers Without Borders-USA spoke at K-State in November 2008. Bruss told the class about the idea, and the students decided they wanted to try to design a ram pump.

"It's kind of a way to exploit the idea," Bruss said. "I was interested in building one, but this way we could have the whole class do it. We could use everyone's ideas."

Steward said ram pumps are used in locations with no electricity, such as in developing nations. They take water from a lower elevation and discharge it at a higher elevation through the inertial forces associated with moving water and the properties of elasticity of water and pipes to lift water.

The 38 students in the class made teams of three or four and created designs. A voting process was used to decide which apparatus to build, and then the class went back through the calculations to make sure everything would work.

Brady Hedstrom, senior in civil engineering, Chapman, was a student in the class and worked in the K-State civil engineering shop. He put together a comprehensive parts list for the pump, and then the students were ready to build.

"In one of our lecture sessions, we all went into the civil engineering shop," Steward said. "The students got hacksaws and everything we needed. We built the entire pump in an hour. We took it out at the end of class and tried it out, and it worked."

Hedstrom said a ram pump has to be four or five feet lower than the water source. The students' pump has a spring-loaded check valve, and when the water flows past it, and when it builds enough velocity, the valve will slam shut and create a water hammer effect, which sends a pressure wave back through the pipe.

He said this forces water up into a smaller reservoir, which also has a one-way check valve. That pressure forces up into the reservoir and compresses the air. When the pressure dissipates below, water can't flow back down because that valve will shut. The water is then forced out the top through the sprinkler head.

"I understood the concept in class, but I was surprised that we got it to work," Hedstrom said.

The pump was displayed at K-State's All-University Open House in April. It will be installed in K-State's hydraulic engineering lab and will be used in subsequent classes to demonstrate water hammer properties.

Steward's course is a senior-level design class. He said he started assigning a class design project when equipment in the hydraulic engineering lab was damaged. Past students have created a pipe flow demonstration, an apparatus to demonstrate levee failure, and a wave tank designed to understand tsunamis and the mechanisms between deep and shallow water waves.

"The students have really felt empowered I think in every experience by creating something, designing it, having it work, and then knowing that what it is they're creating is going to be used in subsequent semesters," Steward said. "They feel like they're doing something useful and meaningful, and they understand why it is that they study math, physics and all those courses they had in their early undergraduate career."