Twin Keels - Hunter

[Guest]

I am looking for a 28-32 footer for cruising East Coast and am wondering about a bilge keeler. The only bilge keeler I ever sailed was a shocker. I'm told that they are particularly inefficient in stronger winds and that there is a lot of slamming in those conditions. The excellent "How to Choose the Right Yacht" (J.Muhs - Adlard Coles) shows its disdain by not even referring to them!

However ...Hunter Boats claim that their "twin-keeled" Channel 31 is practically as good as the fin keel version. Before I am blinded by their science at the So'ton Boat Show, could anyone advise me whether "twin keels" (particularly on a Hunter) are indeed a good idea or whether they would be incompatible with decent sailing performance?

 

[jamesjermain]

A very high proportion of the boats Hunter sells is twin keeled. Designer David Thomas has worked hard at improving the performance of this configuration and he does seem to have been successful. However, it is an inescapable fact that twin keels will not be as efficient to windward as a single fin. There is also the inescapable drawback that, when heeled, waves get in under the windward keel and cause 'slapping' to a greater or lesser degree.

The Hunters are among the best twin keelers with a high ballast ratio and good performance. The Channel 31 sails well by any standards but would sail slightly better with a single fin which the company also offers.

You should also consider the other problems of a twin keel - notably that they can be positively dangerous if they dry out on uneven or sloping ground. In particular, if you dry out against a wall where the bottom slopes sharply, they are more susceptible to falling over than a fin keeler. They will also tend to dry out at an angle if sitting in mud of uneven consistency.

The great advantage accrues to those cruising the Brittany coast where there are a number of drying harbours with nice, even, firm bottoms

JJ

 

[steve_cronin]

\"Wild Horizon\" now residing in Hull Marina....

... a Hunter Horizon 30 (predecessor to the Channel 31) was until March my proud "command". She always got there ahead of the fleet (cruising only) and her best trip was Cherbourg to the Needles in 8hrs 30 mins single handed with a following F6-7. Luckily I arrived at the Bridge with the tide on the flood which made in boisterous but manageable as she didn't broach but just rolled out.

Have no fears about a Hunter twin keeler (don't let Peter Poland hear you call it "bilge") . They point well are very slippery through the water and will get you home in comfort. Initially they heel ten degrees or so but stiffen up. You will find the David Thomas design appears to need reefing early but this is because like most seft tackers (is the Ch31 a self tacker) they rely on the main for most power so it needs to be big enough to sail well in light airs (but get the scooper for sparkle). Reef 1 in >f4 makes her go faster!

We had seven great years with our and I can unhesitatingly recommend a Hunter.

Steve Cronin

 

[ChrisJ]

RE: \"Bilge\" keels

Officially, "bilge" keels are (IMHO) those little short stubby keels on the side of the boat that stick down as deep as the main keel - although in these designs the main keel typically only draws about 2 ft.
The better designed twin keelers do not have a centre keel, relying on the two keels. These keels can therefore:
a) slope outwards at the bottom. This allows a 10 to 15 degree heel, and the leeward keel becomes vertical - THEORETICALLY better than a fin keel that is now at a 15 degree angle. Also the windward keel is now at a 30 degree angle - so any weight in it is greatly aiding the righting moment.
b) the two sides of the keel do not need to be symetrical. On a fin, both sides must be the same to cope with both tacks. On a twin-keeler, the keels can be shaped more like an aeroplane wing to give better lift on one side than the other.
c) the keels do not need to be truly fore-aft. They can be at a slight (3 or 4 degree) angle, to assist with reducing the leeway.

OK so far, but does it work? Compared to a bilge keeler. YES. Compared to an older, vertically arranged twin keeler, yes. Compared to a fin keel, no.

You do get some slamming as the waves hot the hull inside the windward keel (different boats do better at different wind strengths here). The theory seems to be best in smooth waters - i.e when sailing along an estuary, rather than when beating in the middle of the channel.

Personally I like my twin keeler (Westerly Konsort), as on the East Coast I like to be able to creep over the estuary bars with little clearance underneath, and to know I can sit on the mud when I need to.

Cheers, Chris

 

[Guest]

Thank you for three absolutely excellent replies - spot on, exactly what I needed. What a brilliant forum - I shall be back!

BS

 

[Guest]

Also see,,,,

,,,,the thread headed "Keels," dated 30 August.

mikefield@woodenboatfittings.com