[UK-CONTEST] Trees and All That

[Ray Hills]

Just to put in my twopennorth.  The safest way to protect against tree 
movements is to put a balance weight on the end of the halyard which runs 
over a sheave in a block which is itself anchored to the tree.  It should be 
sufficiently large to achieve the required tension and then if the tree 
moves and tries to stretch the wire, the balance weight just rises to 
compensate.  This was the scheme adopted by the BBC for the big SW curtain 
arrays (with which I had a certain familiarity some 50 years ago).. It was 
first used, I think, at Rampisham in Dorset.  The balance weight was a large 
block of concrete.  Unfortunately in 1947 the concrete blocks froze to their 
pads on the ground and all the masts came tumbling down !!  The (rapid) 
answer was to put large timbers under the blocks!

Ray G3HRH (ex BBC 1954/67)