WEIGHT

[freddy]

We have a Trintella 36 IIIA. We have recently put 60 kgs up the masts (radar and wind generator) do we need to compensate by putting 60kgs below the waterline? We have read lots of conflicting information. All advice, comments gratefully received.

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[snowleopard]

it's a lot more complex than that.

a) if you put 60kg 5m above the waterline you'll need to put 300kg on the keel to compensate for the loss of stability.

b) extra weight aloft will affect the period of roll. it will slow the motion down but also make rolling heavier.

it's easy to compromise stability by putting weight aloft. many boats were designed for hanked-on headsails and slab mains and are badly affected by changing to furling headsails and in-mast reefing. adding radar etc on top of that can be a serious problem

i think you would be wise to talk to the designers about the effect on stability.

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[freddy]

We have contacted the designers too. Thanks for the advice

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[qsiv]

I'd also be concerned about the increased loads on the rig, particularly in a seaway

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[DMGibson]

Are you sure those bits weigh 60 kilogrammes? According to the spec, the Raytheon 24" scanner comes in at 7.4 kg, and I would have thought a wind genny would be less than that. That gets us to 15 kg - where's the other 45kg?

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[colvic]

We had a wind generator on the mizzen mast of our small ketch and noticed how she rolled when moored whenever a wind got up. Contacted Ampair and they worked out that above 15knotts the blades presented a solid wall to the wind and created over 50kgs "weight" on the mast, a little off centre, making her roll more.


Phil

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[Birdseye]

"That gets us to 15 kg - where's the other 45kg? "

The Honda 4 stroke powering the genny?

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[freddy]

You are right it isn't 60kg more like 16kg. Thanks for the info though

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