Weather Helm on Colvic 32 Atlanta

[Jontie999]

Hi
I am a new member. I have bought a 1979 Atlanta and love it. I do get a lot of weather helm in moderate breeze - say 20kts. Has anyone any advice on sail configuration for going windward? ie Main/mizzen/both - or let travellers off a bit?
Many thanks
Paul

 

[Metalicmike]

Weather Helm is when your sails are not balanced and trimming your sails is a continual process as the angle of attack changes. There are a lot of good instructional videos on You tube.

 

[Tranona]

Welcome.

Easing the main or reducing sail area will reduce weather helm, as will moving the CofE forward by adding a bowsprit. The small, inefficient rudder does not help. Some owners of this type of boat/rudder have made new rudders of a proper shape with a 15% or so balance area forward which goes a long way to solving the heavy/weather helm.

 

[Jontie999]

Thank you. I have a lot of learning.

 

[andsarkit]

Adjusting the mast rake might help if you have rigging screws to shorten the forestay and lengthen the backstays. This will move the centre of effort forwards and reduce weather helm. The lower stays will also need adjusting to keep the mast straight or slightly bowed forwards.
This will not correct really bad weather helm but might make sufficient improvement to make sailing a pleasure again.

 

[Wansworth]

Contact Lamina Flow of this forum

 

[Refueler]

Your boat suffers similar to mine and the usual bit of reefing or letting out sheets on the main does not usually do much ... the Centre of effort is still too far behind the mast ....

Its a party piece of mine on the SR25 ... I always give helm over to 'guests' let them be part of the whole event. They often comment on the weather helm - so I say - OK ... tell me what you want to do ... they always start by zeroing in on the mainsail ... and still it has WH .... then it slowly dawns ... furl a bit of genny ... voila .. a combo of part furled genny and slacked main sheet ....

Why ? Usually the genny is too big and has sail area that comes behind mast ...

The Colvic Atalanta like many Colvics are usually home finished and can have a variety of masts .....

If your's has ketch setup ... then sadly - mizzen will add to the problem.

 

[neil_s]

My Seal 28 has the same problem. I'm just discovering (after 20 years of ownership!) that reefing the genoa works just as well as reefing the main - as Refueler says above!

 

[Refueler]

My Seal 28 has the same problem. I'm just discovering (after 20 years of ownership!) that reefing the genoa works just as well as reefing the main - as Refueler says above!

Its a common problem on older boats .......... go sail a MacWester 26 / 27 .... same deal

 

[B27]

As the OP's boat is a ketch, I'd suggest reefing or dropping the mizzen.

Or, at least taking a good look at its sheeting and leach tension.
If the mizzen sheet has a traveller, then easing it as the wind increases may help?

If you don't have tell-tales on all the sails, they are a big help.

 

[Wansworth]

The Addition of a bowsprit is the cheapest and most effective cure for weather helm.I have seen a few old hillyards with a bowsprit added

 

[Refueler]

As the OP's boat is a ketch, I'd suggest reefing or dropping the mizzen.

Or, at least taking a good look at its sheeting and leach tension.
If the mizzen sheet has a traveller, then easing it as the wind increases may help?

If you don't have tell-tales on all the sails, they are a big help.

see post #7

 

[Jontie999]

All
Delighted with the responses. A lot to try. I would never have considered furling a bit of foresail.
I'll respond in a couple of weeks. Thank you

 

[Refueler]

All
Delighted with the responses. A lot to try. I would never have considered furling a bit of foresail.
I'll respond in a couple of weeks. Thank you

Its all a matter of balance and where the boat longitudinally wants to pivot. If you have Centre of Effort too far aft, the boat will always press to luff up. Of course a little weather helm is to be preferred to any lee helm. Then should anything happen to helmsperson - boat will round up into wind.

People tend to ignore genny's because they think of so much of its sail ahead of mast and CoE ... but its the sail area aft of mast that is the important part ... this in effect adds to the mainsail area ...
Furl that genny in a bit so clew is level with mast - along with mainsail measures and that CoE moves fwd.

You can actually experience boat speed increased .. as now you are not adding so much drag from the rudder angle fighting the weather helm.

A good example was my Motor Sailer ... Steve and I left port with one reef in main and about 80% genny ... compared to what we would normally have full both in the conditions that day. Full sail would have been heavy weather helm and usually 5.5 - 6kts. We averaged 7.5kts that day ... with slight easily managed weather helm/

Suggestions of increasing rudder area are really desperate measures when all else fails. It also has to be done with extreme care .... the rudder mountings / shafts / tiller / wheel etc are all a system ... and if you cannot balance the extra area - then you are adding stress. You may also mask the real solution such that mast and gear can be stressed unnecessarily .....

 

[Tranona]

Atlantas generally do not have overlapping headsails (although some might have fitted them in the vain hope of improving performance!). It was common with low aspect ratio rigs of the period (and low SA/Displ which is under 10 on this boat) to think that a larger genoa would increase performance with the wind forward of the beam, but as you say the area aft of the mast created weather helm and the boat is better with a couple of rolls in, and only using the full sail when off the wind. This example portsmouth.boatshed.com/colvic_atlanta_32-boat-300456.html has a short bowsprit with a furler on the outer. It is not clear whether the inner is used (and it must be a challenge tacking the genoa!) but it has the makings of a good rig with a working (90%) jib on the inner and a larger 120%+ on the outer for offwind sailing. This is the type of rig I am currently fitting to my GH for similar reasons, except that weather helm is not a big issue.

This example highwaymarinegroup.co.uk/colvic-atlanta-32-available-34995/ has a good shot of the rudder which as you will see is a flat plate with virtually no balance area. Building a proper rudder as Laminar Flow has on his Colvic Watson (same design of rudder) will transform the boat and reduce steering loads. I did similar on my Eventide which also had a flat plate rudder with the desired effect. More recently I have added balance area to the GH rudder again with the aim of lightening the load on the helm.

There is a limit to what you can do with the Atlanta to make it sail faster because of its limited sail area. Its ballast ratio is on the low side so you can't really go up with a taller mast - that is why it has a ketch rig but moving to a twin headstay rig will give a significant increase in overall sail area (as would adding a mizzen staysail!) and more flexibility in how the area is used in specific circumstances. Whether the OP wants to go down that route depends in part on the depths of his pockets and what he has in the way of sails now. However it is otherwise an attractive boat let down by poor design of the sailing parts of it - the designer was primarily a power boat specialist and his other popular sailing boat the Southerly 28 had the same faults.

 

[William_H]

IMHO in 20 knots it is purely the heel of the boat that causes weather helm. ie the drive of the sails is outboard of the drag of the hull so giving turning effect.
The theory of sail balance works well with a flat hull ie no heel light winds but becomes insignificant in a real wind.
So answer is reduce sail. Furling jib first then reef main. (or remove mizzen sail)
During a sail training exercise on a 7m racer I managed a figure 8 in light winds without touching tiller by using sail balance but mostly heeling the boat.
Re rudders yes larger area more balance better foil shape, will reduce tiller loads but as said loads then reflect in to the rudder support bearings. I increased the area and balance on my trailer sailer with good effect to maintain control with shy spinnacker. (the madness of racing) ol'will

 

[Supertramp]

I have had some pleasant sails to windward and reaching in fresh winds with a part furled genoa and a double reefed mizzen. You can play with the sheeting angle of the mizzen to achieve a central rudder position. I agree that at 20 knts even moderate heel brings on weather helm.

My part furled genoa is outshone by the Solent jib (on a separate stay) to windward - half the area but the centre of effort is kept well forward helping balance and greatly reducing weather helm.

I think the important thing is to experiment with your boat and learn what sail configuration is best in a range of conditions to achieve a central or nearly so rudder position.

 

[Jontie999]

Wow - bowled over with the quality and depth of advice. Thank you.

 

[Jontie999]

An update - 2 rolls of the foresail and letting the main sheet down the traveler as well as dropping mizzen iproved things a lot. Even got extra half knot but lost a few degrees pointing. All in all more comfortable.

Thank you all.