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Engineering students happily deafened by Mwanga metalworkers

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Editor's Note: Students from Dartmouth's Thayer School of Engineering are working in Tanzania to help improve sanitation and energy technologies in local villages. This series chronicles work being done by the student-led group, known as Humanitarian Engineering Leadership Projects (HELP), to design "rocket stoves" in the village of Mwamgongo and top-light updraft design (TLUD) gasification stoves in the village of Kalinzi. The goal is to create a healthier, more energy-efficient cooking apparatus that these villagers will accept and use. HELP students are filing these dispatches from the field during their trip. This is their seventh blog post for Scientific American.

The rooster in the room next to us crowed loudly at sunrise, and we despondently got out of bed with the goal of finding Fundi [see photo at left], the town of Kalinzi's elusive stove maker. We found him farming and arranged to meet with him after work at the seventh hour of the Swahili clock, 1 p.m. international time (Swahili time starts with the first hour of sunlight and is therefore six hours behind).


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While we waited to test the skills of the local metal worker, we began to set up our testing station in the shower, since it was the only unoccupied room in the field station. We had made a modification to the current stove prototype to include a chimney in order to allow for complete combustion before hitting the pot. Under this current design, we calculated a thermal efficiency of 15 percent from a water boil test. Although this was not the result we envisioned, we were still satisfied since we started off using rather green, wet wood, which did not burn well. Aside from the type of wood used, we concluded that our modification ended up making the stove too tall and this led to a considerable amount of the heat to dissipate before reaching the pot.

The tests had taken up all our morning and by afternoon it was time to go to Fundi's house. Like most residences in rural regions of Tanzania, the walls of Fundi's house were made of mud bricks and the roof was composed of hay. Fundi enthusiastically welcomed us to his home and we proceeded to spend the whole afternoon trying to make our next stove prototype with his assistant. This turned out to be a deep, immersive experience. Our translator Rita was ill, so we heavily relied on our Swahili dictionary and the little Swahili grammar we understood. Fundi struggled to understand the notion of a prototype (a first model which can be used as the basis to develop a better model), nor did he want to work with the corrugated metal we brought him. He promised to bring along stronger metal the next day.

We returned home and decided to occupy ourselves by building a new prototype on our own. Using a hammer and chisel, we cut out pieces of the weak metal and then made them flat and circular. Since we were limited with our tools and not trained to work with such limited resources, our new prototype appeared rather crude. Nevertheless, it allowed us to start imagining alternative design possibilities.

We waited more than a day for Fundi to collect better metal, but he never came. It was only after the following day, when we went to his house, that he informed us he would come by the next morning with supplies. Fundi arrived the next afternoon instead—empty handed—and said he would try again to get metal the following day. These were not characteristics desirable of a business partner and Fundi's unreliability prompted us to return to Kigoma to work with the metal workers at Mwanga market.

After spending time in the highlands, returning to Kigoma—with its basic modern conveniences like electricity and running water and its relative density of people—was somewhat of a shock. We were reminded of the contrasts in lifestyles and access to resources that the people of Tanzania face.

Immediately after arriving in Kigoma, we went to the metalworkers at the Mwanga market with the prototype we had built in Kalinzi. We hired the metal workers to construct a replication using stronger metal with a few modifications such as a horizontal sliding door and slightly thinner outer box. We watched intently, our eardrums suffering from the intensity of the thud of hammers smashing metal on broken pieces of a railway track. We were impressed enough with their production of our prototype to commission 10 stoves to take back to Kalinzi and test with six women, who had agreed to give us feedback on our design. That night, we were invited to have dinner at our translator Rita's house. We were incredibly impressed by the warm hospitality shown by our host and were grateful to eat a delicious meal of pasta, pelau and beans.

The next day we returned to Kalinzi after picking up our stoves at the lively Mwanga Market and met with the women who had volunteered to provide us with practical feedback on the usability of our stoves. We tested different combinations of wood and coffee husks outside while a herd of goats and a man singing and dancing to gospel music passed by the field station. It was nice to be back in Kalinzi.

Images courtesy of Parker Reed