Mizzen Boom

[martin scott]

Having had a good sail this afternoon in gusty conditions with just the jib and mizzen, I've been wondering about the correct setting for the mizzen. I've tended to fix the boom below the sail tack so the mizzen's shape stays more or less the same regardless of the tack I'm sailing on. But on recent sails I've rigged it as most photos show with the boom raised to just below the sail sleeve ie well above the tack. This seems ok when the boom is on the windward side but on the lee side it interferes with the shape of the sail which seems unlikely to be working as efficiently as it should. So, what's the right position for the boom? Any thoughts?
Martin
BRe 'Blue Moon'   

[david]

Hi Martin, Here is a mizzen setup from an early BayRaider. I generally set my mizzen boom closer up the sleeve. Still, an interesting set up.

[David Hudson]

I'm using a small windsurfer boom. This gives the mizen sail a super shape.

[Graham W]

Martin,

The official SB way of doing it for both the BR20 and BRe is shown in the BR20 manual, which can be found here http://www.swallowyachtsassociation.org/?page_id=251.  See page 15 or thereabouts.

However, there is an entirely different way of rigging it which some owners prefer.  This can be found in the library here http://www.swallowyachtsassociation.org/?page_id=790, towards the bottom.  There used to be a complicated explanation on the forum about why this was better but this was removed by its author (together with all his other contributions) a while back. 

[Julian Swindell]

The mizzen boom is designed as a sprit boom, with the heel of the sprit part way up the luff of the sail. This means the triangle of sail below the boom acts like a kicking strap and keeps the boom down and the sail flat. I have never tried to sail with the boom along the foot of the sail, but I suspect that you will find that the boom lifts when it is let out any amount and so gives you too full a sail. The distortion of the sail is insignificant where it crosses the boom compared to too full a sail when the wind blows up.
Fitting a conventional boom and central multipart sheet may give you more control of the sail shape, but you completely loose the ability to back the mizzen by pulling one sheet right in. This is a really useful facility as it allows you to sail backwards off a mooring or pontoon, and is a god send for getting out of irons. When you are head to wind and stationary (a regular position for me) backing the mizzen always gets you out of it. Far more important overall than a slightly improved theoretical sail shape when blasting along.

[maxr]

Is there a way to douse a BRe mizzen quickly? I read a suggestion here that in windy conditions, a mizzen may increase the tendency of a boat to broach when sailing downwind.

Second - if you furl the mizzen with main and jib up, then come upwind, does the boat develop lee helm?

[Julian Swindell]

On a BC20, she sails perfectly well without the mizzen. If I am sailing a long way down a strong wind I often furl the mizzen as that does reduce any broaching tendency, which is not great in any case. If I am doing a long series of tacks again I often furl the mizzen, as she tacks faster without it. But for most sailing I love having the mizzen as you can lash the helm, balance the boat with the mizzen and then sit back and have a drink whilst she sails herself.

[David Hudson]

Good evening Julian

+1 for sailing without mizzen sail.

Although I have only sailed "Amy Eleanor" twice in a decent blow, she was well balanced without the small mizzen sail: trimming of jib and mainsail being my priority.

Experiences of more experienced sailers would certainly add to my leaning experience. Perhaps I should put my mizzen boom back in my windsurfing bag?

David H

[maxr]

Thanks Julian and David. Can anyone who's had occasion to do it, please tell me their feelings on sailing BC or BCe with jib and reefed main, or just jib and mizzen, when it gets windy - e.g. does the reefed main help the boat point higher?

[Julian Swindell]

In my experience, sailing with one reef and the mizzen up is absolutely fine and the boat points and tacks well. Two reefs I haven't tried much as if it is getting that blowy I tend to use the engine. When I have done it, I think that she doesn't point very high. Might be better without the mizzen, and I plan to try that this year. Jib and mizzen is fine, but doesn't point high or tack very well, but you can do it. She will sail on a reach for miles like this and you feel very stable in a strong wind. I have never done this in a genuine "get you home in a storm" situation, as I just use the engine. Motoring with the mizzen up is good too, the boat just seems more solid with some sail putting a bit of pressure on the hull.

[IanCollinson]

I have noticed a couple of times in a Force 4 that my BR17 tries to broach in very strong gusts so I furl the mizzen on anything broader than a reach in very gusty conditions just by lifting out the sprit boom from the prussic knot on the mast, furling the sail round it and lashing to the mizzen mast with a sail tie. Takes a couple of seconds. It seems from other posts that perhaps the BR17 is lighter and more likely to respond like this than the other BRs?

[maxr]

I was on board a heavy long keel 'modern classic' 40 foot yawl for the day a few weeks ago (in the Antigua Classics). We were racing with full sail up including the mizzen plus mizzen staysail, in about 20 knots of wind, and we had a near broach. However that happened when a gust from astern coincided with a steep 2m quartering sea lifting the stern. I've also seen a 45' schooner broach there in similar circumstances. So maybe it's less to do with weight and size than the overall dynamics of the situation?

Sounds like rolling the mizzen away is quick and easy - thanks.

[Julian Swindell]

Yes it is absolutely about the dynamics of the real situation. What often happens is a large wave, or just swell, lifts the rear of the boat in a following wind. This raises the mizzen into the higher, stronger wind, whilst simultaneously exposing some of the rudder, as the wave passes under. The mizzen pushes harder and the rudder steers less, and round you go. Can be very frightening as you can just loose control completely. You can't do much about the rudder, but you can dowse the mizzen.

One or two people have tried rigging the mizzen mast as a roller reefing unit, wrapping a rope around it so that pulling it rotates the mast. I have tried it once, but without great success. I can rotate the mast by hand quite fast when I'm scared, and the rope didn't seem to speed it up much. Others may have a better idea of how to do it.

[Peter Taylor]

I've sailed my BC20 quite a bit with two reefs plus jib and mizzen and she sails well and points high but, on a beat or reach Seatern has more weather-helm than I would like.  On the 12th of this month I tried beating with two reefs, jib, and no mizzen and she was much better balanced, so I plan to do that more often in future. Returning to Southampton that afternoon the wind was at the top end of force 5, bottom of force 6 (between 21 to 24 kts on the Bramble Bank met station) and I sailed down the Solent with the wind broad on the quarter under jib and mizzen only.  Seatern was showing between 7 and 8 kts on the GPS (one peak was 9.5 kts) - however probably 2.5 knots of that would have been current!

We did broach at one point but I discovered the rudder had lifted.  I suspect that the break-away action of the downhaul cleat had been partly triggered through touching the bottom in Hurst River earlier in the day... then the strains of downwind sailing had made it give way completely and caused the broach.  I furled the mizzen and continued on under jib only to be on the safe side. However,  I haven't broached when sailing downwind on jib and mizzen before, admittedly it has always been in the Solent where the waves are not that large even when it's windy.

Coming up Southampton Water it was a close reach and Seatern sailed surprisingly well on jib alone. If I'd used  the double reefed main I would have been spilling wind most of the time.  From past experience I know she would have been faster with jib and mizzen but I was too lazy to unfurl the latter.

In fact, I don't find furling (or unfurling)  the mizzen that easy when it's windy - the boom thrashes around and/or I get it caught up with the boom gallows, and/or it hits me on the head. It's hard to reach the mizzen from the cockpit because of the outboard and sometimes I end up standing on the aft deck (firmly clipped on to the boom gallows but not an ideal place to be standing when it's rough!).  So I'm presently trying to devise a roller furling system for the mizzen (better than just wrapping a rope round the mizzen mast which I tried once in the past).  I'll let you all know what, if any, success I have!

Peter

p.s. there's a  video from 12th May at  https://youtu.be/Q0zOYSz-S44 The first 2m15s are upwind with 2 reefs, than at anchor at Hurst Roads, then downwind under jib and mizzen. It gets rougher by 3m30s and at 4m15s there's a track plot where you can see the kink where we broached! No mizzen after that! Lovely afternoon - strong wind and sunshine!

[Graham W]

I've wondered in the past about whether some sort of brailing line could be used to bring the mizzen under control and gather it up once the boom outhaul (snotter?) and mizzen sheets have been let go.  Someone may even have suggested this here in the past.  It might be less complicated than trying to furl the mizzen (and a lot safer than standing on the aft deck wrestling with it in rough seas).