Wharram Tiki 31 Wingsail boom

[PanuV]

In Wharram Wingsail for Tiki 31 there are booms on both mainsail and mizzen sail. A boom is fastened on one side of the sail, from the clew to a point little above the tack. Below there is an image of a Tiki 31 with a boom only on the mizzen (the image is from the JWD website). The mainsail boom is identical.

Is it usual to sail without the mainsail boom? This isn't the only such image online. (When tacking) I've had a problem with the headsail sheets getting all tangled with the forward end of the boom that sticks a bit forward of the mast. Therefore sailing boomless would make tacking a lot easier - if the foot doesn't get too loose.

I've always thought that the boom is aerodynamically almost necessary, since the mainsail traveller is very close to the clew. However I'm not very experienced as a sailor and don't know too much about sail trimming.

We sail quite narrow waters on a lake. Therefore we tack a lot in light winds. I often have to jump to the mast to untangle the headsail sheet.

[boatman61]

I have owned two Wharram Tiki's and neither had a boom..
The only reason I can think of for a boom is to make reefing easier having something to lash the Sail to.
Re sailing ability I see little gain, I had no problems with mine only advantages, soft wingsails don't split your head open as the foot is much lower having no recessed cockpit to stand in.

[PanuV]

The boom is removed for reefing.

I think (but don't know) that in one-masted Tiki 30 the mainsail sheet is further aft. In Tiki 31 there is no room between the mainsail and the mizzen mast. The boom helps keeping the sail in shape, since without the boom the sheet goes almost directly down. Or that's how I guess.

[Redreuben]

Don’t allow the jib to flog when tacking, go about without letting off the jib sheet and let the back winded jib drag the bow around and then tension up the new sheet while releasing the old.
This should solve the issue it worked for us on a Corsair trimaran that had fittings on the front of the mast that would snag sheets. There a various Wharram forums and Facebook groups that may also be a goof source of info.
Cheers
RR

[PanuV]

Thanks! That is pretty much the way we tack, but the routine could probably be improved.

[calagorm]

there should be 2 sheets on a wing sail, one on a horse so it can travel across the boat, the other a handy billy that is tied down out board of the sail, so the position of the clew is completely controllable and so is the twist in the sail

[catsketcher]

Lots of high performance boats have gone boomless. One very highly tricked out carbon F31 had a high aspect main and they got rid of the boom. Some Nacra designs and A class were boomless too. Even one or two of the last Americas Cup boats were boomless (or at least it seems so)

The advantages of a boom are that you do not need the mainsheet to be in exactly the correct position to achieve correct leech and foot tension. For a cruiser this is not all that vital but you should try to get a nice intermediate position that allows the leech to breathe but not fall off too far. Use your upper leech telltale to help you achieve this.

As for the headsail getting snagged. I had the same issue and one way to get around it is to use shockcord led from the mast down to the deck, from about 1-1.5 up and out about 1 metre. This stops the sheet trying to cleat itself on mast winches and is easy to remove using hooks.

cheers

Phil

[PanuV]

We should check that shock cord idea, thanks! As well as calagorm's second sheet.

Probably we'll try sailing boomless as well. We are not racing, but a good upwind performance is quite important on these narrow waters. And of course I would like to learn to really use and optimise the rig. Since the boom is a very light spar tightened between the clew and the mast, it is easy to experiment.

Waiting for our icy cruising grounds to open in two months... Good time to study.

[PanuV]

Originally Posted by catsketcher

As for the headsail getting snagged. I had the same issue and one way to get around it is to use shockcord led from the mast down to the deck, from about 1-1.5 up and out about 1 metre. This stops the sheet trying to cleat itself on mast winches and is easy to remove using hooks.

Now I remember why we haven't tried this yet: we'd need to add a D-ring in the sail well above the boom, since the wingsail sleeve is wrapped around the mast. It should be doable.