Fractional Rig vs. Mast Head Rig

[Gary M]

As Plumper says the jumper struts are to keep the top of the mast above the hounds from bending too much. What this does is allows the backstay to tension the forestay on a fractional rig just like it does on a mast head. With out them the portion of the mast where the forestay is attached may move forward which relaxs your forestay right when you do not want it to.

I had a 26 foot fractional about 7/8 I think. It had the spreaders angled back about 25 deg. and you had to tighten the hell out of them to get some reasonable tension on the forestay.
I really did not like this arrangement, there was always, even at the dock a huge force on the chain plates and rig. I just could not get my forestay flat enough to have decent performance upwind in heavier air.

I changed my spreaders to have only about 5 deg of swept back and put jumper struts above the hounds. Made a huge difference up wind and I could now ease off on my back stay and relax the rig down wind.

With a perfomance fractional rig you can learn a lot about tuning a rig and shaping a main.

I now sail a masthead 30 footer with a large main which I am very happy with, well except for the cost of head sails.

Gary

[OutThere]

Can someone tell me if the jumper struts on a fractional rig keep the mast from working for and aft in a sea way?

Are these struts necessary on a mast with a permanent back stay?

[Plumper]

What kind of rig is it? on what boat? The rig should not work fore and aft ( pump) at all. Many big frac rigs have check stays or runners to prevent this, but not all do. It depends on how the lowers are rigged. The jumpers keep the top of the mast in column when tension is put on the backstay. The middle may come out of column if the shrouds are all athwartships of the mast (none run slightly aft). In that case there should be a baby stay or check stays to prevent pumping.

[bob chaisson]

Just a quick quote, "The masthead sloop has established itself as most yachtsman's rig of choice. Equally clear is the reason for its popularity: it's simple and uncomplicated." Peter Hahne; Sail Trim Theory and Practice

[Jeff_H]

When was that written?

[lharmon]

We have a 30 foot masthead sloop. It is an easy boat to sail. The jibs are roller furled. We usually select either a 150% genoa or a 110% jib and use that sail for the day. By choosing the right headsail we usually do not need to try to sail with the headsail furled any. We frequently change the sail on the furler to match the conditions.

Our boat is stiff so the main reefs at 22-25 knots and the second reef is needed at 35 knots. at that point the 110% jib is a liability and is furled up a bit. We have good control. As it starts to deterrioriate or we get gleeful from our speed we reef. It is simple and works for us.

[bob chaisson]

Originally Posted by Jeff_H

When was that written?

First published 2001 in Germany, english edition published 2005. Small book with lots of good information. Hahne is very level headed with a turn of humor. A heck of a value at 20 bucks american.

[Jeff_H]

Bob,

"Equally clear is the reason for its popularity: it's simple and uncomplicated."

That strikes me as a very strange statement. There is nothing simplier about a masthead rig than a fractional rig. Arguably with a masthead rig's need for forward lower shrouds a fractional rig is actually simplier to build, maintain and tune.

I also disagree that the masthead rig is the most popular rig being produced today. If you look at the majority of new sloop rigged being produced at this time, fractional rigs are far and away more common. The one thing that has prevented a bigger switch to fractional rigs is the popularity of inmast furling which is a bit harder to do on a fractional rig, although Hunter, Beneteau, Hanse, Tartan and Bavaria have found a way to make it work.

Jeff

[bob chaisson]

You appear to have failed to notice that it was a quote from Peter Hahne's Sail Trim: Theory and Practice. I cannot in good concience reproduce the entire chapter Rig Trim, Pages 49 - 55, but I highly recommend the read. He makes a good case for his statement.

[Giulietta]

BWAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA

THIS THREAD IS FUNNY

Should be in the Off Topic