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Tuesday, June 23, 2015

Sidecat Anchor Replacement

The broken anchor.
One of the causes for antenna one's damage during the typhoon was that the anchor for the support cable on the side of the antenna was ripped out of the ground.  This anchor is hooked into a reinforced cement block buried under about six feet of earth.  Over years of oxidation and corrosion, certain spots on the anchor became thinner and thinner until the anchor broke in half during the strong gusts of the typhoon.  This break increased the stress on the other support cables, and resulted in broken drop lines and the tangled web of metal and ceramic insulators shown earlier.

In order to prevent this from occurring on all the other anchors, we had poured a cylindrical concrete form to protect the anchor from corrosion and add additional stability and strength.  However, this had not been done to the anchors on antenna one before the typhoon.


Temporary "anchors".
To fix antenna one's anchors, we temporarily connected the side support cables to two vehicles to hold the antenna in place while we fixed the anchors.  Next, we dug holes to get to the buried concrete blocks, and chipped away concrete to expose the steel rebar so we could attach the new anchors.  Once we attached the anchors and set them at the proper angle and direction, we poured the concrete into cylindrical forms around the anchors.  The next-to-last step was to backfill the holes we had dug, and to wait two weeks for the new anchors to set.  Finally, we reattached the side support cables to the new anchors and tensioned the cables to the proper load.  And just like that, antenna one was completely repaired!







Reattaching the anchor and pouring the concrete tube.
Backfilling around the anchor with dirt.
The cables are reattached to the anchors, much to Sol's delight.




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