Adding Another Sheave to the Masthead

[benz]

My last boat (Irwin 27) had a small block at the masthead, attached to an eyestrap, that the topping lift went through. It could rattle against the mast when the topping lift was slack (that is to say, when underway, and everything else on the boat was rattling too), but when the lift was tight it coudn't rattle, being held out a bit by the tightened line. Very simple and foolproof. A cheek block bolted to side of the mast at the head would also work.
Ben