Adding Another Sheave to the Masthead

[bradley1968]

Hi,

I am currently planning a mast overhaul project for next Spring. Among other planned enhancements, I want to move to a full batten main with lazy jacks and a lazy bag.

The only problem I have discovered (so far) is that my spar has only 1 aft facing sheave with a single halyard serving double duty as a topping lift when shackled to the end of the boom, and a main halyard when moved to the head of the sail.

In order to attach a lazy bag (and ease sail handling) I would like to somehow add another aft facing sheave to the mast head to have a separate main halyard and topping lift.

Any ideas how to best accomplish this short of buying a new spar?

Thanks,

Brad

[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

[Brian Duff]

You could also fit a fixed topping lift adjusted from the boom...

so many options

[bradley1968]

Thanks, those are both good ideas.

Brian, I'm new to rigging. Can you please explain a little bit more how the boom adjustment would work?

Thanks,

Brad

[Brian Duff]

Some of the usual arrangements are to have a topping lift of wire, or covered wire, or spectra, or.... this topping lift will be terminated with an eye and shackle, swage eye, bowline or.... at the masthead, and then have a single or double block attached to the bottom end of the lift. The length of the fixed portion of the lift should be such that the block is 1' above the boom or so when the lift is alongside the mast. A bit shorter than the P measurment is usually just about right. The topping lift control is then a line secured to the end of the boom, lead up through the block on the lift and back to either a block on the boom and then foward external, or to a sheave in the boom end and forward internal, or any combination you please. Other boats use a small block and tackle of ,say, 4 to 1 avantage, with v-jam cleats to adjust , or just a lashing, but I prefer the control to be adjustable on all points of sail by leading it forward.

You can of course rig the lift however you like as long as its easy for you to use. Thats a big part of the fun in boats.