Hey, all! Rachael here! Since I’ve learned it’s very difficult to capture how much I’ve learned and experienced over my time in Madagascar thus far, I want to share an experience that sticks out to me and has allowed me to grow as a person and as an engineer! As a civil engineer, one works with contractors to give design and technical expertise on the functionality of a project that needs to be built. In this case, the project in question of course is the pipeline. At one point during the past month, the contractors wanted to purchase 40 mm pipe instead of 63 mm pipe in fear that the water might not make it over one of Manantenina’s topographical landmarks, referred to as “Jackson’s hill”. The idea was that the velocity of the water would increase and have more energy and be able to make it over Jackson’s hill. This concept is similar to when you put your thumb over part of the hose end and the water comes out faster.
In more technical terms, the relationship the contractors were thinking of is Q = vA, where Q is the flow rate, v is the velocity, and A is the cross-sectional area. However, as the velocity increases inside of the pipe, the frictional head loss (energy loss inside of the pipe due to friction) increases as the water rubs more against the inside of the pipe. The energy of water in the pipe actually decreased with smaller pipe, despite the increase in velocity. We wanted to sort this out with the contractors as soon as possible, since it was really important that we ordered the correct size of pipe. We all met Monday morning inside the abandoned library where we had a chalkboard and could have an open conversation (with translators of course).
This posed an important question to me ethically – I didn’t want to come into this conversation attempting to prove the contractors (who were based out of Andapa) wrong, necessarily, and I didn’t want it to come off that way, either. Rather, I made sure I listened to what the contractors had to say with the intent on listening (rather than responding) and responded with my initial thoughts and go into my argument for a large diameter pipe. Although the meeting took up a greater part of my day (as we discussed other important aspects of the pipeline), it proved to be one of the most rewarding experiences I’ve had over the past month in Madagascar. Eventually, we came to the consensus on the 63 mm pipe, but really allowing myself to listen for the sake of listening and not responding and understanding the contractors point of view not only enhanced my ability to understand other perspectives but also challenged my technical understanding of network hydraulics.
Stay tuned to hear more about my pipeline adventures in Madagascar!
Rachael Lau
Duke University ’20
Civil Engineering (E/W)