Power assisted climbing

[Ai7b at teleport.com]

I have built a number of tall towers during my amateur career.  I have three 
more to build but the ole' body, especially the shoulder joints ain't what 
they used to be!

I am looking for anyone with experience or advice on power assisted climbing. 
ie. winch powered lift etc.  I have some good ideas on lift mechanisms but not 
much idea on good (safe) winches for this purpose.  Any input wud be 
appreciated.  73's de Bravo