Traveler car/track as tether?

dLj

.
Mar 23, 2017
4,264
Belliure 41 Back in the Chesapeake
My granny bars are about 34" high. About 24 inches away from my mast from the side. Let me take a photo or two.

dj
 
Nov 6, 2020
379
Mariner 36 California
I can't really tell on your Mariner 36 how you would install the granny bars, but you'll figure out the design that works on the outside. That boat has a cored deck. So when you drill through for the attachments, make a slightly oversized hole. Then make a L shaped cutter you can put in a drill or your tool of choice that can cut out the core between the top and bottom fiberglass. Then using some kind of backing like tape on the inside. Fill the entire space with structural epoxy. Once set, drill the hole through that epoxy "plug" for your fasteners. Use either fender washers or make a backing plate on the inside for the nuts.

That way you create a sealed structure so there can be no water ingress into the coring and you are making a structural connection point across that cored structure. Does this make sense?

dj
Yup perfectly. I have done this to most of the deck hardware that I have removed already. Luckily they removed the core and made a solid fiberglass layup under the cleats, winches and blocks so i dont need to touch those. For the granny bars I was considering cutting away the interior of the coach roof underneath the installation points and laminating pieces of solid 3/4 G-10 behind the fasteners with epoxy and drilling through that. I was thinking I would then add large washers or a backing plate behind those and bolt right through the entire thing. The vinyl headliner has zippers installed so I can get access to most of that area without destroying the headliner.
 

dLj

.
Mar 23, 2017
4,264
Belliure 41 Back in the Chesapeake
Seems my Internet connection isn't good enough to drop in images. I'll try later...

dj
 

dLj

.
Mar 23, 2017
4,264
Belliure 41 Back in the Chesapeake
Yup perfectly. I have done this to most of the deck hardware that I have removed already. Luckily they removed the core and made a solid fiberglass layup under the cleats, winches and blocks so i dont need to touch those. For the granny bars I was considering cutting away the interior of the coach roof underneath the installation points and laminating pieces of solid 3/4 G-10 behind the fasteners with epoxy and drilling through that. I was thinking I would then add large washers or a backing plate behind those and bolt right through the entire thing. The vinyl headliner has zippers installed so I can get access to most of that area without destroying the headliner.
Would you be laminating to the top fiberglass layer? Not sure which is easier..both would work.

dj
 
Nov 6, 2020
379
Mariner 36 California
Seems my Internet connection isn't good enough to drop in images. I'll try later...

dj
Ha! no worries. Thank you for the info. I'm not ready to add them yet anyways. Actually, I have seen tons of pics of them but had no idea what height would be best. Are you happy with the height/width and distance of yours or would you change any of those parameters?
 
Nov 6, 2020
379
Mariner 36 California
Would you be laminating to the top fiberglass layer? Not sure which is easier..both would work.

dj
Yeah, it may be overkill to cut away the interior roof and add solid G-10 like I described. Not to mention a LOT of work. If I have enough mounting points, drill and fill with a big aluminum or stainless backing plate might be plenty strong and a lot easier. Not ready to do the project so lots of time to think about it.
 

MFD

.
Jun 23, 2016
189
Hunter 41DS Pacific NW USA
I would also recommend getting out on other people's boats.
There is value in seeing how they are run/rigged, even if different boats and run better or worse.
Racing is a good way to do this, although often it is the poorly run and rigged boats that always need crew.

Finally - I strongly recommend attending a full session Safety at Sea course.
You won't get any official certifications out of that, but you will gain practical knowledge from experienced people. Or at least as much as can be condensed into a small session shoreside format.
No - do not do the online class, you are wasting everybody's time.
Yes - do the in-person classes, with the additional sessions where you need to jump into the water and climb into a life raft yourself, and help others.
 
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jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,788
CAL 35 Cruiser #21 moored EVERETT WA
I have used the traditional jack lines that run from stem to stern along the boat's sides. We tried webbing and rope. Rope was easy to find, but it was a tripping or rolling your ankle issue. Webbing was better, but if you fell, it was over the edge of the boat, and then you were dangling, hoping one of the crew saw you and helped you back on board.

In 2015, I found the writings of John Harries, "Attainable Adventure Cruising". He had used the same foreaft setup and discussed the analytical issues with the traditional setup. He provided a much better idea, "Center Line" jacklines. Bow to mast, Mast to cockpit with rationale about such a structural setup. It makes sense to me. He also says he thinks of the boat's edge as a 500-foot fall into the abyss. Tethers and jacklines should be designed to keep you inside the lifelines.

I manage my sails at the mast. I will install custom granny bars to help stabilize my standing at the mast. I tether up whenever I sail. I use multiple tethers and switch from one to the other as I move from the cockpit to the mast or the mast to the bow. My tethers have a release at my harness. I also carry a knife and a seatbelt cutting tool in my life vest, just in case the tether release fails.

Last year, John Harries worked with an engineer to put some numbers together regarding the stresses associated with jacklines, tethers, harnesses, and a falling crew member. The numbers may scare you. The comment by @thinwater about cracked ribs is a real factor.

We each need to decide what works for us and our sailing activity. It is better to understand the forces involved as you develop your plan.

Safe Sailing.
 
Nov 6, 2020
379
Mariner 36 California
I have used the traditional jack lines that run from stem to stern along the boat's sides. We tried webbing and rope. Rope was easy to find, but it was a tripping or rolling your ankle issue. Webbing was better, but if you fell, it was over the edge of the boat, and then you were dangling, hoping one of the crew saw you and helped you back on board.

In 2015, I found the writings of John Harries, "Attainable Adventure Cruising". He had used the same foreaft setup and discussed the analytical issues with the traditional setup. He provided a much better idea, "Center Line" jacklines. Bow to mast, Mast to cockpit with rationale about such a structural setup. It makes sense to me. He also says he thinks of the boat's edge as a 500-foot fall into the abyss. Tethers and jacklines should be designed to keep you inside the lifelines.

I manage my sails at the mast. I will install custom granny bars to help stabilize my standing at the mast. I tether up whenever I sail. I use multiple tethers and switch from one to the other as I move from the cockpit to the mast or the mast to the bow. My tethers have a release at my harness. I also carry a knife and a seatbelt cutting tool in my life vest, just in case the tether release fails.

Last year, John Harries worked with an engineer to put some numbers together regarding the stresses associated with jacklines, tethers, harnesses, and a falling crew member. The numbers may scare you. The comment by @thinwater about cracked ribs is a real factor.

We each need to decide what works for us and our sailing activity. It is better to understand the forces involved as you develop your plan.

Safe Sailing.
Thanks. I recently subscribed so will look for the articles. I was thinking something similar recently about running a jackline right down the center of the boat on dedicated connection points with hefty backing plates. My decks are nice and uncluttered.
 
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Sep 24, 2018
3,282
Catalina 30 MKIII Chicago
This is no longer an issue unless one is using archaic tethers or worse, a piece of rope. Modern tethers have a quick release shackle at the human end of the tether and a double action clip at the jackline/attachment point end.
There was an article, I believe in GOB, where a guy who was tethered went overboard in mediocre conditions. They were going 5 or 6 knots and he ended up pinned against the bow. It took his wife a long time and a lot of struggle to get him back on board. If I remember correctly, they couldn't stop due to conditions. I'd imagine a tether of the proper length would substantially reduce MOB's?
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,788
CAL 35 Cruiser #21 moored EVERETT WA
I'd imagine a tether of the proper length would substantially reduce MOB's?
Yes shorter not longer. Or moving the jack one to the center line of the boat, not along the edge (which is easier to set up not better)
 

dLj

.
Mar 23, 2017
4,264
Belliure 41 Back in the Chesapeake
I'd imagine a tether of the proper length would substantially reduce MOB's?
It's interesting how we get so wrapped up with tether systems and don't talk as much about setting up the boat to reduce the possibility of going overboard simply by design.

If you make your boat very hard to fall off of, that also makes life better. Things like toe rails, correct stanchion height, solid rails or larger diameter life lines, those kinds of things. There is a lot that can be done to keep people on board in addition to tethers...

dj
 
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Sep 24, 2018
3,282
Catalina 30 MKIII Chicago
It's interesting how we get so wrapped up with tether systems and don't talk as much about setting up the boat to reduce the possibility of going overboard simply by design.

If you make your boat very hard to fall off of, that also makes life better. Things like toe rails, correct stanchion height, solid rails or larger diameter life lines, those kinds of things. There is a lot that can be done to keep people on board in addition to tethers...

dj
Toe rails have saved me more times than I can count. Is there such a think as too high of lifelines so long as it doesn't interfere with anything?
 
Apr 25, 2024
364
Fuji 32 Bellingham
Is there such a think as too high of lifelines so long as it doesn't interfere with anything?
I would say, know your boat and your sailing.

There definitely can be such thing as too high. You should consider how the windward lifeline restricts movement along the windward side of your boat, when heeled. Consider angles that you might be heeled during less-than-ideal conditions. When the boat heels, the top of the windward lifeline angles leeward of the gunwale, thus narrowing your walkway and restricting movement on the windward side. The more you heel and the higher the lifeline, the more pronounced the effect.

Also, it is hard to prevent going over the top unless your lifelines were absurdly high. But, it is just as common (if not more) to go under or between the lifelines, and that is something that is easier to prevent.

It seems intuitive that higher is generally safer. But, does anyone have any information that suggests that higher lifelines made a difference or would have made a difference in actual COB or near-COB situations?