Loose footed main with Mid-boom sheeting

Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
I have a C30 that has 6:1 mid-boom sheeting with 3-attachement points for the main sheet to the boom which is lead to a 16ST winch. The original sail plan had a typical bolt-rope footed main sail. In this configuration, I assume that there there is some upward force applied to the boom by foot of the sail which would not be there if the main is loose footed.
Is there any problem with using this type of boom / sheeting for a loose footed main sail? The boom is pretty robust. The section used is the same extrusion that was used as a mast for the C25 and they were never considered to have a wimpy rig.
 

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Jun 11, 2004
1,621
Oday 31 Redondo Beach
I don't have a Catalina but do have essentially the same mid-boom mainsheet setup as you. I went from a bolt-rope to a loose foot main several (10?) years ago and have not noticed any unusual stress on the boom.
 
Jan 19, 2010
12,362
Hobie 16 & Rhodes 22 Skeeter Charleston
I don't have a Catalina but do have essentially the same mid-boom mainsheet setup as you. I went from a bolt-rope to a loose foot main several (10?) years ago and have not noticed any unusual stress on the boom.
Same with my H26
 
Jun 25, 2004
1,108
Corsair F24 Mk1 003 San Francisco Bay, CA
I assume that there there is some upward force applied to the boom by foot of the sail which would not be there if the main is loose footed.
The sail applies only a few pounds of upward force on the middle of the boom, which is not enough to make any practical difference. You can safely substitute a loose footed sail for a footed sail. I have sold many loose footed mains for Catalina 30s over the years, but not a single footed sail.

The strains produced by the sail converge at the three corners. There is a force upward and parallel to the leech concentrated at the clew of the sail, and upward force parallel to the mast at the tack. There's a very small compressive force on the boom, running parallel to the boom.

Judy B
Retired Sailmaker
 
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Jul 12, 2011
1,165
Leopard 40 Jupiter, Florida
@DrJudyB gave you theoretical answer. Practically, I changed my C36 from footed to loose-footed four years ago, and there certainly is not 'bending' or stress of the boom, if that's what you're worried about. Join use 'footloose' people at the dance!
 
Jan 7, 2011
4,727
Oday 322 East Chicago, IN
My O’Day 322 is set up similar to your Catalina. I switched from a bolt rope main to a loose-footed main last year, and no issues.

38579A94-9BDF-4D8B-9130-8B979122074D.png


Greg
 
Jan 11, 2014
11,323
Sabre 362 113 Fair Haven, NY
Yet another, no problem. We have a loose footed main with mid boom sheeting.

The loose foot has some advantages when purchasing and when using, It is easier to shape the lower part of the main because there is less friction on the outhaul. When sailing in rain, water does not collect in the foot of the sail and dump on deck when tacking.
 
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Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
Thanks @DrJudyB. I assumed that the foot did not apply a great deal of force to the boom so had come to the same conclusion but wanted conformation from someone more knowledgeable on the actual loading. It makes sense that it would not be a problem because I suspect that the vang can exert a greater load on the boom given the angle of the load.
 
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May 25, 2012
4,333
john alden caravelle 42 sturgeon bay, wis
hayden, your going to love the increase in horsepower from your loose footed main. there really is a bump in power.

enjoy
 
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Jun 8, 2004
2,841
Catalina 320 Dana Point
Got a loose foot main last winter, love it, friends with a 320 took these pictures yesterday in very light winds.
2021011495122838[4841].jpg2021011495122937.jpg
 
Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
I took the bolt-rope foot out of the boom a couple of years ago and fully agree that it is a game changer in light air. I was just curious about if there was any concern about bending the boom. I added a couple of cascades to my 3:1 outhaul to make it 12:1 and it is very easy to adjust.
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
Hayden, my new sail is loose footed. It is working great. It replaces my footed mainsail. I have boom end Mainsheet sheet.
Your system spreads the forces to control the boom. Where the issue develops is if the boom has a minimal points of mid boom controls. A single mid boom block puts the stress in a single point. This creates the opportunity to break the boom.