masthead sloop or fractional ll rig?

[sthurley]

My Dufour 30 is described as having a masthead rig, however I have been told it is rigged as a fractional? I think the person is saying this because it has a large mainsail, small foresail, single swept back spreaders. Both the cap shrouds and lower shrouds afix to the same point on deck and it has a backstay (no running backstay), only one forestay (no babystay) . The reason I ask the question is I have to tune the rig and according to the book I am reading the amount of tension requires varies between the two types of rig!

 

[[3889]]

If the forestay attaches at the masthead it is a masthead rig, if not it is fractional, described according to distance below; e.g. if attachment is 1/10th of mast length below the top it is a 9/10th fractional rig.

 

[doug748]

I had a fractional boat with this simple mast set up. However, as you point out, you have a masthead rig so it is quite unusual.

I would set the rig as per your fractional instructions which generally means more shroud tension. I personally never went as far as some of the suggestions but tried to avoid excessively loose downwind shouds when sailing in, say, in 15 kts of wind.
If you let off the backstay off completely, in brisk winds, you risk turning the rig inside out (with the shrouds flicking forwards and the mast taking up a S shape) which could well bring the lot down. So watch that one.

 

[mrming]

If it's this Dufour 30 (Classic), it's masthead:

 

[sthurley]

Yes, its the Dufour you suggest. Thanks

 

[yoda]

The fundamental difference is that in your boat the forestay tension is effectively regulated by the backstay. In a 3/4 rig like mine the shrouds have to maintain the forestay tension together with runners if required. The backstay just gets used to depower the main in windy conditions.

Yoda

 

[Laurie]

I had a fractional boat with this simple mast set up. However, as you point out, you have a masthead rig so it is quite unusual.

I would set the rig as per your fractional instructions which generally means more shroud tension. I personally never went as far as some of the suggestions but tried to avoid excessively loose downwind shouds when sailing in, say, in 15 kts of wind.
If you let off the backstay off completely, in brisk winds, you risk turning the rig inside out (with the shrouds flicking forwards and the mast taking up a S shape) which could well bring the lot down. So watch that one.

Not that unusual, some Feelings were so rigged, and from what I've been told by a rigger with an excellent reputation, I would agree totally with what you say. Such a rig should be looked at the same way as a slightly less bendy fractional rig:encouragement: