Broken Tubes and False Starts?

Today was the final day of preparations for the rammed earth phase.

We assigned a crew to start sieving the large pile of sand and this seems to work fairly well. I was concerned that the aperture size of the sieve was too large (10mm) and instead of completely replacing the wire mesh, we overlaid it with another mesh of a different aperture. This reduces the quantity of large diameter stones and clay balls that make it through the sieve whilst the smaller sizes remain unaffected. Larger pieces still have a way to get through, but their options are significantly reduced.

Several coats of waterproofing have been painted on the stem walls. They are now ready for the rammed earth and the outstanding matter now is the endboards and custom sized forms. The endboards have been fabricated and we are waiting for the sealant to dry. The wet weather has arrived and we have to make doubly sure that the forms are resistant to water in the coming months.

Poen, our millwright made a tool to test the hardness of our compacted earth based on the Zimbabwean rammed earth standards. I thought it would take him a few days as it had a fairly low order of priority in the scheme of things but the novelty of the item seemed to capture his imagination and it was ready the same day. I have just calibrated it but am yet to be convinced of its effectiveness. The rammed earth immediately after ramming is still quite malleable and I do not see it withstanding a force of 2N per sq. mm until after it has cured - which is too late to test the level of compaction. But I'm sure we'll adapt it to our needs and in the end, will get a consistent level of compaction.

We have been anticipating the arrival of the solar panels and today they were delivered. It was a long wait but worth it in the end. It burnt having to pay more to transport the container from Durban to White River than from Shanghai to Durban but this is Africa.

The container was well packed but despite this, 47 of the vacuum tubes were broken. All of the broken units were placed at the top of the container and it seems that they were broken whilst loading them into the fairly confined space. The rest of the consignment seemed fine including the bulk of the vacuum tubes. The photovoltaic panels were in four boxes which were too heavy to pick up by hand so we had to open the boxes and carry them panel by panel into the storeroom. This and sorting out the broken vacuum tubes meant that we took a much longer than anticipated to offload the goods. However, at least it has been done and they are here. Now we just have to finish the building in order to put them to good use and as I have lots of spare tubes, the damaged items do not constitute a crisis.

The apprehension is building for tomorrow and I can see that unless everything is just perfect, we will delay the start until it is. The rammed earth phase is not difficult and we've done everything to make it painless and foolproof. But despite this, we are apprehensive. It's like jumping into a dark pool not knowing what lurks beneath the surface. Let's just hope there are no man-eating crabs.