second posting High Velocity using Block & Tackle

Thanks for the help.
We have thought of the inertial forces in the spinning pulleys, and
the fact that there will be significant stretch in the cable. 
Actually the cable will be under a working load of as much as 20,000
lbs.  Using kinetic energy we have figured our power requirment just
for the pulleys at 2000 hp.  I will also mention that we will have a
large capstan (winch) at the other end of the cable to reset the
system.  These capstans are equipt with a brake and can provide a
slight constant damping force to oppose the oscillatory action of the
cable.  The capstan will also be responsible for slowing the cable
when the required velocity is reached.  The hydraulic rams should stop
themselves easily enough.
A couple more questions:
Any thoughts on accelerating cable over a pulley that fast?  will it
slip? heat up? etc.
Any thoughts on accelerating hydraulic pistons that fast?  It will
require huge flow rates. (300gpm)
Shock loads on the cable?

Thanks again

Joshua