The Viper has the back-to-back blocks running up the mast. It goes like this: Dyneema ties off to the forestay sheave (?), down the mast, through the back-to-back block, up to the block for the spin halyard and to the head of the spin. A separate line runs from the the spin tack, into the pole, exits the main beam end of the pole on a block inside the spin pole, up the mast, through the back-to-back block, down the mast, through the mast mounted halyard cleat, through a small block on the main beam, back through a ring on the tramp and back forward through a hole on the tramp and into the spin snuffer.
Nice... A 1:2 on the halyard instead to have it on the outhaul. The spi must go up really quickly with such a system, one pull get the tack in place, two pulls and it's up? Not to mention that everything up the mast could be single braid dyneema as you never pull on it... Nice! The only disavantage I see is that it uses more line and one more pulley if you want it on the front beam.
Now you got me thinking about some hybrid, with a loop up the mast, another along the pole and a third line going from one to the other, then to the tramp and back to the snuffer... Some thinking is in order... I'm not sure this will leave enough line for the retrieval line.
