26 June 2010

We await the start of the US–Ghana match here in Mara West and I will attempt to produce a blog post that offers some details of our attempts to retrieve the pipe and pump from the well. Rob has written a post that resides, unfortunately, on one of the XO’s that are still back in Ngomano. He will either recreate it or we will post it when we get back to Ngomano. Meantime, here’s a picture of the “harpoon of death” that was supposed to slide inside the pipe, expand against the inside of the coupling between pipe segments, and then get hauled out of the well. A strong chain was looped around the hook at the right of the picture, which would provide a torque pressing the sharpened edge at the bottom right against the wall of the coupling and the bottom edge of the first pipe segment.

Rob and Peter played tug-of-war with the pipe to test the harpoon and it seemed to hold quite well. Of course, the trick would be to install the harpoon inside the upper end of the pipe, which almost certainly was resting against the side of the casing inside the well, roughly 50 m below the top of the well. To manage this guiding, we designed the “skirt of salvation,” shown in the picture below. It was made from various available materials, including the mouth of a 20-liter water bottle, some wire mesh, plastic cable ties, and the walls of the water bottle. The skirt would be lowered with the harpooned located in the mouth of the water bottle, which should end up centered over the entrance to the pipe. At least, that was the theory.



In practice, the skirt and harpoon were lowered together, but because the chain holding the harpoon was so much heavier than the rope holding the skirt, it was fantastically unlikely that though they began the descent together, they ended up that way. After lowering the pair to level of the top of the pipe, and then lowering the harpoon another 4 m, we started raising the chain hoping and expecting to feel the resistance grow suddenly stronger. It didn’t. So, we raised both and were deeply saddened to see no harpoon attached to the chain and only the small top piece of the skirt still tied to the rope. Fishing with the sand-filled Coke bottle showed that the rest of the skirt was lodged about 7 meters below water level.

We went back to the drawing board to design of sturdier hook and came up with the “rocket of reclamation,” which is shown here.



It is made of 2-inch pipe, which will be dropped over the end of the pipe. The curved structure at the right is designed to pull the top of the pipe away from the wall, and the dark portion is a funnel to guide the pipe into the rocket. When we return to Ngomano after our safari in Masai Mara we will attempt again to fish out the skirt of salvation, which has be renamed the “apron of annoyance” and then lower the rocket to draw out the pipe. Keep your fingers crossed!