Sailing Hammock

[YVRguy]

No, this is not about my onboard choice in swimsuits.

I've long thought about buying a hammock for the boat to mount on the deck when at anchor. The challenge is the lack of a good forward point of attachment. The forestay seems out because our furling genoa extends too far down and it seems wrong to wrap around the furled sail. I'm thinking about the pulpit but I'm not sure if that is too much stress for it. I'm a big dude - 6'4" and 300lbs. Does anyone have any experience with this?

 

[sail sfbay]

Buy them here: The 5 Best Hammocks for Sailboat Use [Get rid of Your Seasickness!] (royalhammockheadquarters.com)
How to rig a hammock: How to fit a hammock (or two) on a small sailboat (sailuniverse.com)

 

[Alan Gomes]

Buy them here: The 5 Best Hammocks for Sailboat Use [Get rid of Your Seasickness!] (royalhammockheadquarters.com)
How to rig a hammock: How to fit a hammock (or two) on a small sailboat (sailuniverse.com)

As far as the video on rigging the hammock: I think I'd be a bit nervous about attaching that line around the forestay with a furling unit or other foil on the forestay. I'm wondering whether it might subject the foil to concentrated forces that could cause it to get bent. I'd be curious as to what others might think about this.

 

[sail sfbay]

Do a search on this forum on "hammock" to see threads on this subject

Also take a look at post # 5 in this thread about feasibility of attaching a hammock to a forestay: two hammocks hung between forestay and mast? | Sailboat Owners Forums

If you are concerened with attaching the hammock to the forestay with a "wide strap to spread the load" then consider a lounge chair suspended from a spare halyard as shown in post #6 in this thread: Boom mounted hammock? | Sailboat Owners Forums

 

[YVRguy]

Buy them here: The 5 Best Hammocks for Sailboat Use [Get rid of Your Seasickness!] (royalhammockheadquarters.com)
How to rig a hammock: How to fit a hammock (or two) on a small sailboat (sailuniverse.com)

Thanks, as I mentioned I have a furling headsail so tying to the forestay is a little more tricky

 

[Scott T-Bird]

Being concerned about the furling headsail, I would hang one end from a halyard and use a strap to confine the halyard to the forestay. That way, the vertical load is carried primarily by the halyard, and the horizontal load captured by the forestay would be significantly reduced. You can adjust the height more easily as well.

 

[Captain Larry-DH]

The tension on the headstay is multiplied from pulling a perpendicular load (hammock). Here is a calculator.

Forces and Tensions in Ropes due to Angle

Reduced load capacities in ropes, cables or lines - due to acting angle.

www.engineeringtoolbox.com

 

[Scott T-Bird]

The tension on the headstay is multiplied from pulling a perpendicular load (hammock). Here is a calculator.

Forces and Tensions in Ropes due to Angle

Reduced load capacities in ropes, cables or lines - due to acting angle.

www.engineeringtoolbox.com

That may be true ... but tension on the head stay isn't really the issue. In fact, it's fine if there is increased tension on the head stay (it can handle it). Strapping a halyard to the head stay shares the load so there is less bending on the furling extrusion, I think. That would be the concern.

Also, increased force on the rope isn't really the issue either. The only thing that matters is whether or not the strap reduces the bending force on the headstay/furler extrusion. The angle of pull off the headstay definitely changes if you strap a halyard to it versus hanging a hammock directly off of it. It changes the angle from strictly vertical (hammock only) to more or less perpendicular (strapping the halyard). It's an interesting calculation that I'm not sure I know how to do (too far removed from my statics!). This Engineering Toolbox doesn't really apply. My intuition is telling me that the halyard AND the headstay are sharing a load, therefore, there would be less pull against the headstay/furler than if you hung the hammock directly.

 

[Davidasailor26]

There are systems for asymmetrical spinnakers that rely on strapping around the forestay. Look at the ATN Tacker and Neil Pryde Parrel Bead setups for example. If a forestay and furler foil can sustain those loads I think a hammock would be no worse. Those systems probably carry the load even lower on the forestay too, where there’s less wraps of sails to pad the forestay than where a hammock would strap.

 

[YVRguy]

Being concerned about the furling headsail, I would hang one end from a halyard and use a strap to confine the halyard to the forestay. That way, the vertical load is carried primarily by the halyard, and the horizontal load captured by the forestay would be significantly reduced. You can adjust the height more easily as well.

Hmm this seemed very promising until Larry's response.

 

[YVRguy]

Thanks for your thoughts on attaching to the forestay but what about the pulpit? Ours has a cross bar near the tip that would be perfect.

 

[Davidasailor26]

I’d be much more concerned about the loads on the pulpit compromising its deck bedding than I would be about using the forestay.

 

[jssailem]

So if the forestay is a NO NO. What about running a halyard from the mast head to a bow cleat. Tie a simple Alpine Butterfly in the halyard and suspend the hammock on the halyard. The knot can be easily shaken out when you have finished napping, and you’ll be ready for that night time sail.

Here’s a link to tying the knot.

The knot is explained at the 4:33 point in the video.

 

[YVRguy]

So if the forestay is a NO NO. What about running a halyard from the mast head to a bow cleat. Tie a simple Alpine Butterfly in the halyard and suspend the hammock on the halyard. The knot can be easily shaken out when you have finished napping, and you’ll be ready for that night time sail.

Here’s a link to tying the knot.

The knot is explained at the 4:33 point in the video.

This could be a winner. Assuming I can master the "alpine butterfly."

Thanks for the input!

 

[Davidasailor26]

Can someone check my math?

If my math is right a 200 pound hammock load only exerts about 50 pounds of force perpendicular to the forestay. Pretty sure that would be well within its design limits considering the spinnaker arrangements that are available.

 

[sail sfbay]

If you go with this set up......lounge chair attached to and supported by a spare halyard with a lateral line between the halyard forestay to center the chair on the foredeck..........almost zero stress on the forestay.

 

[Scott T-Bird]

That's how I do it with my air chair!

 

[sail sfbay]

That's how I do it with my air chair!

Thanks for confirming the chair name!! You can buy an "AirChair" here: The Original AirChair, Hang Chair with comfort (hammock chairs / zero gravity chairs) Take it anywhere. All hardware provided. Sharp Colors, #1 Selling in the world! Culture Shock/Airchair, 8877 Akins Road Cohocton NY 14826 | 607-566-3885 | AirChair.net

 

[YVRguy]

If you go with this set up......lounge chair attached to and supported by a spare halyard with a lateral line between the halyard forestay to center the chair on the foredeck..........almost zero stress on the forestay.

View attachment 196436

Yeah, I scoffed at first but this may be the ticket. Thanks for the suggestion

 

[Richard19068]

Being concerned about the furling headsail, I would hang one end from a halyard and use a strap to confine the halyard to the forestay. That way, the vertical load is carried primarily by the halyard, and the horizontal load captured by the forestay would be significantly reduced. You can adjust the height more easily as well.

That's essentially the way I do it. The aft end is attached to the mast and the forward end attached around the furled jib but the forward end is also held up by a halyard so it reduces the strain on the forestay. In addition, to spread the force on the forestay foil I use a 6 inch length of PVC pipe that has a split opening cut lengthwise. The pipe fits around the furled sail and the hammock line goes around the pipe thus spreading the load. I think it is five or six inch diameter PVC pipe but you can get an appropriate size to fit around your jib. I've done this for years and not had a problem.