Day 18 (June 5)

Contributed by: Olivia

We arrived at the site determined to adhere the roofing felt to the panel seams and build the masonry wall for our hose bibbs. Both Johns and James from the Crew adhered the felt while I began supervision of the masonry structure. Matt and Berai walked to the local hand dug wells with their interpreter to test the water quality. Jared and Danielle journeyed via taxi to Bolga to upload the blog at Afrikids and return the oxyacetylene torch. The team was working with much gusto through the morning (assured from the previous day's success of pumping water) before John Campbell checked the CU 200 with the digital multi-meter and found that there was insufficient voltage to operate the pump. There was speculation as to whether a “short” was created when the felt was nailed to the panel and plywood. Work was momentarily halted when the team troubleshooted the problem.
A test panel was punctured with a nail around its perimeter and through its center to compromise its integrity. It was not easily compromised (which was great news) and deduced the problem to a spliced line to the CU 200. The team discussed solutions over lunch at SWOPA. Upon returning to the site, the team isolated an area of the cabana and bypassed the spliced line. Meanwhile, trenches were dug for the 5” x 8” x 16” solid concrete masonry blocks to elevate the polytank. A tic-tac-toe pattern was trenched at Dale's suggestion. Steven from the Crew of 6 assisted with his mason experience.
Danielle and Berai befriended Sherina to assist them on their home visits and women's group meetings. It was with great delight to have the people of Yua visit the work site and greet the team with “Bulika” (Good morning) and “Toma! Toma! Toma! Toma!”

Contributed by: John Yatsko

Disaster!
Perhaps the most difficult part of construction so far was finishing the roofing and waterproofing the solar array. The process consisted of cutting twelve precisely measured strips out of two felt rolls and lacing them carefully around and between the panels. We then nailed all of the strips to the panels and secured them to the edges with industrial adhesive. The sun felt especially intense today and the morning's work carried into the afternoon as we awaited the return of our teammates from Bolga.
At last, we finished the roofing and climbed down for a well deserved drink from the cooler. To our dismay, we were told the water ran out three hours earlier and the van was in Bolga...drat! One brilliant individual suggested we turn on the pump. So we sent John Cambell up the ladder and... nothing. The pump stopped working.
Thoroughly sun baked and demoralized, none of us had the energy to troubleshoot the system before lunch. We sat under the cabana and discussed the possibilities. The worst case scenario was that we completely destroyed our array by hammering nails through all the panels. If that were the case, we would have to scrap the plans for the school and return home with a half completed project. To rule out this possibility, Cambell opened up the tool shed and banged a few nails through an extra panel in an attempt to reproduce the damage on the roof. The panel was unaffected, so we had some peace of mind while we ate our lunch.
We returned to the site and began the investigation. The system registered 25 Volts on the multimeter, where it had read 130 yesterday. 25 seemed a peculiar number since there was no part of the circuit that should read anything close to that. We had no choice but to tear up the roofing and undo all the connections we had assembled yesterday. I almost cried. We diligently redid all the connections and measured the voltage of each of the eight strings of panels individually. All eight registered 130 volts. We put the strings of panels back together and again...25 volts. Cambell and I sat on the roof and stared at each other for a while until I finally realized the problem had to be in the jump wire buried underneath the array. We cut the wire out of the circuit and replaced it with a fresh one. 130 Volts. We must have hit the jump wire with a nail and grounded out the system when we laid down the felt strips.
We heat shank all the connections again (with hot embers from the camp fire of course) and replaced the damaged roofing. Cambell and I called it a day and Olivia's team began work on the masonry structure.

3 comments:

  1. Bravo! What a great experience that was, wow. Sometimes you just have to sit and think about it like you did, and how wonderful that you thought it through to the solution. You're all doing an outstanding job over there. Love you, John.

    Mom

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  2. Congratulations on great problem-solving. Isn't it Dr. Holland who always says the most important part of engineering is learning how to "set up the problem"!

    Great news but I would like to hear some news about description of when the well digging was completed. Is this water coming from the well or another source?

    All the best,
    Mary Blackett

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  3. Way to go everyone! It looks like you are doing some amazing work out there. I wish I were there too. Say hello to Joe for me.

    Best,

    Aaron Denham

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