Finally getting it right
We are driving back to Khulna at 10:30 after our third excellent day in a row. However, there were still a lot of hiccups along the way. Yesterday, we were set to install the deep well, but when we arrived they were just starting to pull the pipe from the deep well. We had hoped that they would have done that overnight, but I’m glad I got to see it. Lifting 1000 ft. of drill pipe out of the hole is a big job. They have 15 people climbing up the drill rig and jumping and grabbing onto the rope, using their weight to lift the pipe. Their singing while they do it reminds me of sea shanties sung while working a ships rigging. Meanwhile, another person lowers the chain wrenches holding the pipe and two more work the pump to keep the fluid circulation going. After lifting a full 20 ft. pipe section out of the ground, they unscrew it and connect to the next one. It went pretty quickly. aftrer about four hours they took all 50 20-ft sections out of the ground and began lowering the PVC liner in its place. They had three strings of about 20 15-ft. PVC liner preassembled and quickly ran it into the hole, gluing the sections together as they went. Ten minutes and it was done. Good thing, too. With no pipe or liner or circulation, the hole can easily collapse. A 4” wide hole in the ground 1000’ long. In fact, when they installed the liner, they found the lower 40m were filled with sand. The next step was to wash and flush the well, pumping water through a long hose with a steel tube t the end and forcing down the well until the entire length is clean. We had to be ready to pour the cement and lower the fiber at whatever time they finished.
Meanwhile, we laid another pair of concrete pads. We were able to have a more relaxed day. We watched the Hindu neighbors present an offering to the Goddess of Forest and Rivers. Scott taught juggling and learned to throw a fish net, and we all had some green coconut. I’m not crazy about the taste, but it is very refreshing.
During the washing, the drill team took down the bamboo drill rig piece by piece and carried it away. Once that was done, we were able to get back to the GPS column. As I feared, the mud filled in the hole and it was only 5 ft. deep. One of the Mukul and the concrete team had the unenviable job of climbing into the pit and scooping the mud out where the column will go. He could only get it to 6.5 ft., the same as Jamalganj, but much shallower than our planned 10 ft. We are concerned about its stability, especially sine one side was excavated as a big pit. We jammed the rebar frame way into the ground and poured 6” of concrete across the bottom of the pit to help support that side.
To end the day, we installed the 20m well on the first try. We were ready for the deep well, but it wasn’t ready for us. The flushing was still going on. Still, we had gotten most of our goals for the day. We went to the workshop and the prototype for our new caps was excellent. It would work much better and the quality of the work was excellent. We went home happy.
The next morning it was time for the deep well. We carefully measured the well. We stretched out our measuring string across the countryside. It reached almost to the bridge. It checked with Barack’s estimated within the uncertainty. Tried to be careful, but we decided against a dry run. It takes 45 minutes to pull and rewrap the wire from the 300m well, plus pulling and reinserting the hose and the risk on hole collapse. We went straight to cementing but the wire stuck 8m above the bottom. Pull and flush.
While we were preparing to lower the fiber, Humayun and Kevin Krajick, the Earth Institute journalist, arrived from Dhaka. Greetings, photos, interviews. A bonus is having a second car for errands. Shortly, Dhiman arrived back from Khulna University with the completed well caps, Rakib and his 4 students. Our site, quieter with many of the drillers gone, was now packed again.
Meanwhile, Mukul had filled the hole from the GPS pillar. Packed it pretty solidly, too. He laid the pad for the GPS pillar and put a pad on the 20m. While he did, he had an argument with Dhiman. I found out later that it was over how long the GPS tower would take. Mukul said 3 days, Dhiman instisted on 1, and one day it was. They built a long wooden frame to do the pour in one shot. With Humayun’s help, we got the vertical alignment and started the pour. By now it was dark. When they were halfway up, we inserted the pipe. I climbed up and adjusted the height, and the contractor aligned it. He ran out of cement about ¾ of the way up, so we made sure the pipe was tied pervectly vertical and left it to harden.
At the same time, the deep well was now ready. No chances this time. We pulled the 1000’ hose and did a dry run. It stuck ½ way down, but we were able to free it. Got it to with a meter of the bottom and slooowwwly pulled it back up. Then Scott figured out the cause of the problem. If the floppy first link of the chain got caught on anything, some mud or the top of the cement, the others piled up like a train wreck. We needed to stiffen it. We replaced the lower half of the chain with 3 rebar rods and after a few tries got a satisfying weight. Once again, Barack, our specialist for trying tripods and everything else help make it work. Down with the hose. Mix the cement and pour. Haul up the hose and lower the fiber. We made it. Tension was a little spongy with 300m, but it was in. We won’t know for sure if it worked until the cement dries and we put in double the agent that delays the curing with the poor cement here. We could go back to Khulna for a very late dinner (Dhiman found a restaurant to stay open late for us) and sleep. We didn’t leave dinner until well after midnight.