[Towertalk] Lightning protection

[Cleeve]

Hello Pat, the film "The Phoenix Tower" is one we used to run, during the
trials between the NTSC and Pal colour system evaluation, so I remember it,
almost frame by frame,...it is an engineers film, showing everyone involved in
the design, construction and erection, and copies must still reside in film
libraries. 

	Belief in ones work came with the wind trials. The wind trials were carried
out by the senior design engineer, who simulated the wind pressures on the
tower, by means of rockets attached to sides of the tower, where the antennas
would be mounted. Then, he went to the top of the tower, and carried out the
rocket firing procedure, and to measure the amount of movement.......as I
recall, the movement was within the calculated range of around 2 feet.....all
this done with slide rules and log tables, and maybe some mechanical
calculators......I guess that he reasoned that if the tests failed, or the
tower fell, his career was over anyway.....but it was a great success, and it
is a very elegant design... built at the site of the Great Exhibition of 1851,
even the transmitter hall is below ground, to avoid further damage, and
intrusion to the site ....there was a time, when members of the public could
request a visit, but sadly, in these insecure times, that is no longer possible......

	  I have stood under that tower many times, and dreamed of what one could do,
with a 3 element on 20 metres at 750 feet and 5 watts !!!...sincerely, John Cleeve