Progress on well-drilling
As noted in a previous posting, we encountered problems in drilling our first well last year because the bore hole collapsed and our efforts to shore it up were unsuccessful. We ultimately concluded that a thin-walled steel pipe was needed to keep the borehole open and that we could not obtain it in Sierra Leone. We had the equipment built in Boise and have recently shipped it to Sierra Leone. The pipe will be suspended in the bore hole using the winch system pictured below. The equipment should arrive in early December; we hope to be using it by, or soon after, Christmas.
We have also been working on new designs for the pump. The usual approach in Sierra Leone is to use an India Mark II or some other “piston pump”. Many studies have shown, however, that these pumps fail after a few years and are rarely replaced because of their high cost (>$1000). An alternative that has been gaining favor among development specialists is the rope pump. Rope pumps use a continuous rope with washers or “pistons” that just fit inside the rising main to lift water (see figure). Rope pumps are inexpensive and can be built and repaired by local groups. It is estimated that >100,000 are in operation around the world. We are cooperating with several groups to review existing designs for possible use in Sierra Leone.
