Hammocks cinched to roller reefing jib

[Tmacmi]

The front of Latitudes and Longitudes reminded me of something from last summer.

My son put up one of those hammocks that cinch off of of each end. At the bow it was cinched around the roller reefed jib. It looked like a nice relaxing spot to enjoy a beer and the world.

After a bit I started getting itchy about possibly damaging the reefing system and the sail.

Am I being a nervous nelly? A wet blanket? Or am I being prescient about damage?

[psk125]

Depends a good bit on the size of the gear involved. A setup that works fine on a Swan 65 may not hold up on a J/24. Something that might kink a r/f extrusion might make no difference to a 1x19 wire. Bean-bag chairs may work better on a smaller boat.

[wingssail]

When I was working on Renaissance, a 72' racer with hydraulic roller furling, there was a hammock and sunshade tied between the headfoil and the mast.

While working on the hydraulic winches I didn't realize that every time I turned on a hydraulic winch it was also turning the furling drum (yes, there was a bug in the system, it wasn't supposed to be doing that).

Imagine our surprise when the hammock turned into a giant slingshot.

"Hey, what was that? Did anybody see where Tony went?"

[fxykty]

Originally Posted by Tmacmi

The front of Latitudes and Longitudes reminded me of something from last summer.



My son put up one of those hammocks that cinch off of of each end. At the bow it was cinched around the roller reefed jib. It looked like a nice relaxing spot to enjoy a beer and the world.



After a bit I started getting itchy about possibly damaging the reefing system and the sail.



Am I being a nervous nelly? A wet blanket? Or am I being prescient about damage?

I assume you mean that one end of the hammock was tied to the clew ring of the jib, which is fully furled and only showing a small bit of sail.

If so, even on a 28 foot boat, I bet the regular sheet load is a whole lot more than the 200 pounds or so of tension that your body weight will put on it when you’re in the hammock.

If you mean tied all the way around the furled sail, that’s also fine. Your weight is a small fraction of the loads the forestay sees, even if concentrated at a single point and through many layers of sail and a rigid foil.

No damage to be worried about in either case, though happy to be corrected by a rigger.

[Sonrisa]

I worry about this too. I'm not sure if we're right to worry or not, but next time I'm going to test an alternate arrangement.

I'll fix the aft end of the hammock to the mast. The fwd end will be attached to a halyard, and another line running forward. (or even just a single halyard that is tied off forward).

Might swing a bit more, but I won't worry about kinking a foil, or stressing my jib in some way.

[EarlWer]

Originally Posted by fxykty

If so, even on a 28 foot boat, I bet the regular sheet load is a whole lot more than the 200 pounds or so of tension that your body weight will put on it when you’re in the hammock.

It can be a lot more that the person's weight if the tension on the hammock lines are tight.

https://theultimatehang.com/hammock-hang-calculator/

The pulling force on each end will vary from 50% if the lines are both straight up and sharing the weight... to over 6x the weight if the lines are in tension with a Hang Angle of 5 degrees.

The regular sail load is spread over the length of the forestay, so there is not a concentration of tension except for the ends.

Bad idea.

Any engineers want to do the calculations? ;-)

[guyrj33]

Originally Posted by EarlWer

It can be a lot more that the person's weight if the tension on the hammock lines are tight.

https://theultimatehang.com/hammock-hang-calculator/

The pulling force on each end will vary from 50% if the lines are both straight up and sharing the weight... to over 6x the weight if the lines are in tension with a Hang Angle of 5 degrees.

The regular sail load is spread over the length of the forestay, so there is not a concentration of tension except for the ends.

Bad idea.

Any engineers want to do the calculations? ;-)

check here to see the tension on a line caused by a weight in the middle.
https://www.ropelab.com.au/highline-tension-calculator/

We hang the hammock from our spinnaker pole.

[guyrj33]

Originally Posted by guyrj33

check here to see the tension on a line caused by a weight in the middle.
https://www.ropelab.com.au/highline-tension-calculator/

We hang the hammock from our spinnaker pole.

[Sailorman Ed]

We hang the hammock from our spinnaker pole.

I bought a hammock chair to hang out over the water just like this, haven't been able to try it yet.


I also tied my regular hammock to the roller forestay, no issue at all I could tell but I am not very heavy.

[fxykty]

Originally Posted by Sailorman Ed

I bought a hammock chair to hang out over the water just like this, haven't been able to try it yet.


I also tied my regular hammock to the roller forestay, no issue at all I could tell but I am not very heavy.

Hammock chairs are awesome. We hang ours from a halyard and tie it to another halyard, or shroud, or jib clew. Super comfortable too, albeit not usually very flat.

This is in our back yard, testing the fit.



And this is on our boat in the fore triangle.



I bought it from these guys: https://hamuhk.com/. Bought without the bar for travel, then made it from some 1” dowel.

[TackSeason]

I didn't like the idea of putting stress on the jib furling extrusion either, so I built something that looks like it is mounted on the jib but actually doesn't even touch it: I took a mini chain and two broomsticks and drilled holes thru the the sticks near each end of each stick. At one end of each stick I put a long bolt that goes thru the boat's toe rail with a washer and a wing nut, one stick on each side, resting on the inside of the rail. At the top, I have a longer bolt that goes thru both of the sticks at the other end to make a "A" frame. Also, that bolt should go thru a link of the chain. I have a hook on one end of the chain that hooks on the anchor roller, and the other end is attached to the hammock. Once I got the chain in the correct place it just takes a minute to hook this all up, and it holds all 300 lbs of my wife and I (combined weight!) without any stress on anything but the hammock. If this is confusing I have a picture where you can see the A frame but thats about it, so let me know and I'll take a better pic in spring if the snow ever melts.

[TackSeason]

This is the only pic I could find, but all it will do is give you a general idea of the "A" frame at the upper right.

[ArmyDaveNY]

Originally Posted by TackSeason

This is the only pic I could find, but all it will do is give you a general idea of the "A" frame at the upper right.

That looks like a pretty good set up! Simple, easy to set up, easy to store, and it won't put any stress on important components. Good job!

[John_Trusty]

TackSeason, in your real life are you an engineer? That is a clever setup. Patent the thing and start selling them for $80 at West Marine.

[guyrj33]

Originally Posted by John_Trusty

TackSeason, in your real life are you an engineer? That is a clever setup. Patent the thing and start selling them for $80 at West Marine.

It is a clever design, but awfully hard to patent after the idea has been published :>(