Thayer school of Engineering @ Dartmouth

Home » 2013 » January

Monthly Archives: January 2013

ENGS 390:Cost effective water pump for Fond des Blanc, Haiti

In this blog we interviewed Robbie Moss of group 6 who as the title indicates are working on developing a plan for development of a cost effective water pump for Fond des Blanc in Haiti.

Before you go onto the interview, we’ll give you a short description of what ENGS 390 is about. Engs 89-90 are the two project courses at Thayer which every students who wants to earn the B.E degree is required to carry out. The two courses refer to the same project which is spread over two successive terms. These projects are typically sponsored by external agencies including private firms and NGOs which face challenging engineering problems. Student teams select a set of projects and they are allocated a project based on their preference. Project sponsors are vetted and selected by a team of faculty. At the end of the project the student team is required to present its work to a faculty review panel and based upon the strength of their work,  students are graded.

Here’s the interview:

Group 6 members: Kevin Tahms; Annie Saunders; Robbie Cholnoky; Robbie Moss

 1)Could you tell us about the objective of your project?

Our objective is to improve reliability and cost effectiveness of the water pumping system in the community at Fond des Blanc, Haiti.

2) Could you tell us a little about Fond des Blanc as well?

Well it’s a small village with close to 1000 people. Its very isolated, so it presents a lot of challenges for the working of the present system. Primary amongst it is that it takes a lot of money to transport diesel fuel for the motor at the village.

3) Describe the water pumping system in place now

The existing pumping system consists of a reservoir fed by a stream; water from the reservoir is pumped into an overhead storage by the diesel motor from where the water is gravity fed to the households using PVC pipes. Drawback of using PVC pipes is that since it rains a lot in Haiti, there is runoff and the underground pipes become exposed and liable to breakage. We are working on solving this problem as well.

4.) So what are the primary challenges that you intend to tackle?

The existing water system installed breaks down frequently thus incurring high repair costs, also it works on diesel thus driving up the cost of operation. Our goal is to make the motor run on renewable energy thereby reducing costs and improving the efficiency.

5.) Could you describe how you intend to meet your objective?

We intend to replace the diesel motor for pumping with an electric motor which can be then powered by a renewable source. The options which look the most promising are solar and hydro power. The other options are biomass and wind which are not viable since cost effectiveness for biomass is limited and there is no wind at the location. Further, since the stream head available for damming on the stream is narrow, constructing a dam is difficult. Hence hydro power, though a plausible option is a secondary option we are considering.

6.) What are the challenges in implementing the solar power option for the electric motor?

The challenge with the solar option is that we want to avoid using batteries to keep the system simple. At the same time not using batteries would force us to use a 10Hp motor for pumping water into the tank within a day assuming we get 8 hours of sun every day. Here the motor rating is high for this particular application. And we want to keep the motor power rating low, so if we use a 3Hp motor which is more doable we’ll have to pump for 20 hours in a day, during nights as well thus necessitating the use of batteries. Usage of batteries makes the system more complex because in case of a battery breakdown there’s no immediate technical help owing to the remote location of the community.

So figuring out how best to deal with the trade-off between one of the two system approaches is the major challenge we face.

7.) Could you comment on the progress of the project?

It’s making good progress and we are still working on it but things are liable to change as of now.

8.) Please describe your involvement with the machine shop for your project and about your project sponsor.

We have limited involvement at the machine shop given that our project is more of an engineering consulting project and our project scope is limited to finding an optimal solution for implementation, so we won’t be implementing the solution here.

Our project sponsor is an NGO working in Haiti.

Thank you and we wish your team good luck with your project.

That was the interview with Robbie Moss about his team’s ENGS 390 project. We hope you enjoyed reading it. Also Robbie had mentioned that he’d be sending us his team’s group photo- we are still waiting, but once he shares it it’ll be here.

-Pavan R. Yerram


Kodiak’s ice-creep machine and Max’s new project

So here you go guys, pictures of Kodiak’s machine which measures creep in ice samples. As you can see in the pictures it is still in the process of being readied for use in the ice lab. I wondered what the pink sheets were for, and the T.A working on those explained that the pink sheets are for insulation and keeping the temperature around the ice sample constant as the temperature in the lab is going to be variable due to people moving in and out of the lab.

WP_000790 WP_000792 WP_000793

Max’s new project

After working on the light saber project, Max is now working on another equally cool project of designing a parachute for machine payloads. Sure, the pictures aren’t that impressive, but it’s a work in progress. Max explained that this a prototype made of cloth which he continually tests by simply throwing off the Rodday overlook into the Glycofi atrium and once he’s satisfied with the prototype he’s going to fashion the parachute out of nylon.

We wish him all the very best in his new project.

WP_000781 WP_000782 WP_000783

Posted by

Pavan R. Yerram

Welcome back to more machining!

While you were away:

Hey guys, welcome back to the school and the machine shop! We hope you had a wonderful break and are eager to start learning and working at the machine shop.  While you were away we had a lot of things going on at the machine shop and you’ll notice quite a few of these big changes. First off, well you can’t help notice due to the noise and the appearance; there has been a major structural change in the shop, which is still ongoing. The entire shop is now going to be one smooth, long hall with the brick and plaster pillars being replaced with steel girders. This will help in improving the visibility in the shop and thereby provide better safety.

Videos and vending

Over the break we had the 5S team hard at work on the vending machine project as documented in a previous blog entry. We also had our social media team working on high quality instructional videos for the lathe machine, so that you guys have no dearth of good learning material. The coolest thing about these videos and working on the lathe machine is that after watching these videos you can try your hand at designing your own light sabre and maybe kick off a light sabre duel with your friends. You’ll have these videos available to you on the wikipage.


Guys the blog gives you all the tremendous ability to provide feedback to us and point out what’s working out and what’s not working out for you. So do use the comments section on our blog and let us know. Also we’ll be coming out with regular surveys to keep track of how things are going for you guys. We’ll shortly be coming out with a survey for tool placement and would be delighted to hear about how you want your tools and equipment to be placed: in the vending machine or the tool crib or the work station. Also what new tools would you like being added?


The next big thing at the machine shop which we guys are working on and hope to see implemented are ipads as learning aids next to the machines. Meaning whenever you come to the machine shop and want a quick recap or even a detailed demonstration of working on the machine, you’ll have it at your fingertips- you’ll only need to tap on the ipad. Understandably such an undertaking is time consuming given the complexities of programming in the iOS environment; hence it’ll take us longer to put it in action and till then- patience.

26 teams  

Lastly we have 26 teams working on their final ENGS 90 projects here at the machine shop and we expect it to be very exciting to follow their progress in the final stages of their projects. We’ll be documenting their experiences on this blog, and we invite you follow and share in their experiences and projects right here.

We wish you all an exciting, fun filled term at the machine shop and a fun time reading our blog.


Posted by

Pavan R. Yerram