The next hint, was that RCU 035 took 3 seconds to fail but RCU 034 took only 1 second, starting a second after the first. This indicates a failure on the Y-polarisation first, and implies that this first failure on Y, led to the failure on X. Sure enough, that was indeed the cause.
Here is what we found on arrival at the site.
|Luckily the wires were not damaged on the peg! (Photo: D. McKay-Bukowski)|
As the data suggests, one of the guys broke causing the aerial to fall. The first second would have the northwest line (the Y-polarisation with elastic) drop down. At this instance the X-polarisation is still intact. Then, without tension on the northwest axis, the antenna begins to fall. As it reaches the ground the X-polarisation deteriorates rapidly. That is why there was a difference in timing of the failure. Also, from initial break, to hitting the ground, the fall took approx. 3 seconds. It was probably assisted by the wind.
|The fallen LBA aerial. (Photo: D. McKay-Bukowski)|