Bow eye for bridle

[Jeff F]

I'm about to order an eye to install on my bow about where my hand is in this picture.

My intent is to have a permanent nylon tether attached to the eye, long enough to reach the pulpit, with a chain hook. At anchor the tether would take the load with slack on the windlass.

Does this sound like a good plan? I'm sure its been discussed here but gave up searching.

[menzies]

Irs very common to run your snubber to an eye or block at the waterline. Gives a more lateral pull on the chain or rode.

You might have more luck searching for "Snubber."

[Flatswing]

A very good idea. I (like a lot of DeFever 49 RPH owners) added one since my bow roller is otherwise 8’ above water.
A few things to consider: look at the interior location very carefully. You will need a big a** backing plate because of the load. The configuration of your bow interior may require some addition of a contoured block/FRP/G10/Aluminum or SS. Each boat is different so measure carefully. Remeasure several times before drilling. We did mine in the water- challenging to drill perpendicular to stem without dipping drill in the water with a 12”bit!
Some fit a custom SS plate over the exterior to prevent shackle/thimble hitting the gelcoat. I did not - just used a nylon thimble on the bow end of the snubber & attaching to bow eye with a soft shackle, no rubbing and quiet at anchor. Similarly a soft shackle/ thimble at outer end attaches the snubber quickly and securely to the chain. In my hands, chain hooks tend to fall off at critical times & the Mantus hook is quite spendy. A few feet of Dyneema to make the soft shackles is $20.Measure your chain, you will find the largest (doubled) diameter of dyneema that will pass through the links is way stronger than the chain itself. I replace mine every 2 years in case of UV damage and microchafe.

[Comodave]

It is a good plan, but I would make it longer than just up to the deck so you get more stretch and shock absorbing ability.

[Jeff F]

Found the thread I was thinking of. Thanks all.

https://www.trawlerforum.com/forums/...ad.php?t=31011

[FF]

A bow eye just above the WL might need to hold 2 or 3 times the weight of the vessel so will need a large well installed backing plate. And a damn good bow eye think 3/4 shaft or better..

2 or more leaders installed will allow the line size to match the load to get stretch to ease the shock load on the anchor.

Metal hook on the end is quick , but if it goes overboard can beat up the hull big time.

And be sure the lines are long to reduce anchor shock, but not long enough to get into the prop should they go overboard.

[caltexflanc]

I always thought it would be a "nice to have" because it reduces scope requirement greatly. But I was never able to cost-justify to do it right; plus it is the type of thing I would drop in the water on a regular basis. If it can be dropped, and can sink, I will drop it.

[Jeff F]

Originally Posted by FF

A bow eye just above the WL might need to hold 2 or 3 times the weight of the vessel so will need a large well installed backing plate. And a damn good bow eye think 3/4 shaft or better..

2 or more leaders installed will allow the line size to match the load to get stretch to ease the shock load on the anchor.

Metal hook on the end is quick , but if it goes overboard can beat up the hull big time.

And be sure the lines are long to reduce anchor shock, but not long enough to get into the prop should they go overboard.

Good points. But 2-3x boat weight? That seems overly high to me. The eye I'm planning to use has a breaking strength of 24,000 lbs, which is higher than the 3/8" chain on my rode.

I appreciate the need for robust backing and have good access on the inside.

[psneeld]

Be careful as bending could be a problem.

Many a boat I tried to pull off a sandbar had an eye that withstood a straight pull, but bent when pulling at an angle.

[caltexflanc]

It's not so much the strength of the eye, but the strength of the hull which leads you to the area required of the backing plate. Have you talked with to a good surveyor or yard about this about this? If not, do!

[fgarriso]

Originally Posted by Jeff F

Good points. But 2-3x boat weight? That seems overly high to me. The eye I'm planning to use has a breaking strength of 24,000 lbs, which is higher than the 3/8" chain on my rode.

I appreciate the need for robust backing and have good access on the inside.

Breaking strength and WLL are two vastly numbers.
We use full 5/8 G80 chain of 400' on two 145# claw anchors with 18,000 WLL each.

[fgarriso]

Originally Posted by Jeff F

Good points. But 2-3x boat weight? That seems overly high to me. The eye I'm planning to use has a breaking strength of 24,000 lbs, which is higher than the 3/8" chain on my rode.

I appreciate the need for robust backing and have good access on the inside.

A good strong bow eye like " 1-1/2" X 5" doesn't cost much more than a small one. Besides it's YOUR boat swinging from it. Use a clothes line clip if you want.

[koliver]

A two part bridle, securely fastened to the anchor chain and to the bow cleats on deck inside the forward hawse holes will lower your chain to the waterline, within a couple of feet of the location where you might have a bow eye.

[caltexflanc]

Originally Posted by koliver

A two part bridle, securely fastened to the anchor chain and to the bow cleats on deck inside the forward hawse holes will lower your chain to the waterline, within a couple of feet of the location where you might have a bow eye.

Yeah, but it requires more scope. A bridle like you describe (and I use too) is just part of the overall rode being deployed from the deck of the boat. Remember scope is calculated based on depth plus the height of the boat attachment point above the waterline. It's a geometry thing.

[trawlercap]

Another option, but better if it's in the original build. 330 lb. anchor.

[FF]

"But 2-3x boat weight? That seems overly high to me."

Stuff happens , a quiet anchorage can quickly have a thunderstorm pass which can cause waves large enough to move the boat , and when the boat stops going sideways or back the G loads can get high.

I have seen bow plates put in with SS , instead of bronze or titanium bolts that thinned and lost most of their strength. SS is for on deck pretty stuff , not underwater.

Its true that the anchor cable will still be attached to the boat, even if the plate departs.

The hassle is the plate is to stop "Chinese fire drills " and make life easier , not add to the work.

[Jeff F]

Originally Posted by FF

"But 2-3x boat weight? That seems overly high to me."

Stuff happens , a quiet anchorage can quickly have a thunderstorm pass which can cause waves large enough to move the boat , and when the boat stops going sideways or back the G loads can get high.

I have seen bow plates put in with SS , instead of bronze or titanium bolts that thinned and lost most of their strength. SS is for on deck pretty stuff , not underwater.

Its true that the anchor cable will still be attached to the boat, even if the plate departs.

The hassle is the plate is to stop "Chinese fire drills " and make life easier , not add to the work.

Gotcha. Thanks for responding.

I'm very much into function on this. My boat is seriously deficient on deck - no chocks or cleats on the bow, just a windlass and roller. So whatever I build is going to be my go-to for anchoring or being towed.

I'm now wondering about a formed metal plate on the outside with an attachment point. That would be much stronger than a single point throught the bow, and wouldn't require any backing work. Will discuss with a fabricator.

[FF]

Remember all these pad eyes, cleats , chain stopper , and windlass will be high load points so will need to have the bedding goop replaced more often.


Install everything so its a day job to renew , not a weeks work.

[Porgy]

A plate on the outside might help if you had a significant shear load like getting towed off a shoal at a ninety degree pull. Otherwise, it’s all tension where the backing plate is the critical element to distribute loads. Could be a hefty chunk of steel plate. Could be a built up block of epoxied or glassed in G-10 shaped to fit in the inside V behind the stem. I’d go with whichever works best considering cost and complexity and what your fab person wants you to do.

As far as size of the eye, as part of the anchoring system, it shouldn’t be the weak link. That is usually going to be the anchor itself and depending on what it’s dug into is going to be in the neighborhood of a few thousand pounds max.

I have 3/8” G40 chain with a WLL of 5400 lbs and breaking strength of 16,200. (If you are using 3/8” BBB it’s half that.) The Crosby 209A 7/16” shackles are WLL 5,865 and breaking strength 26,393. I’m no engineer or boat builder but, it seems to me a bow eye with 24k lbs breaking strength would exceed the anchor and rode limits. You’ll drag before anything breaks.

If we conservatively use the shackle’s ratio of 4.5:1, the WLL of the eye would be 5,333 lbs. If you use chain’s 3:1, it’s 8,000. You could go up a size in the event you ever need to get towed sideways with several thousand pounds of force.

I don’t know the detail specs of your bow eye but, for comparison the shackle with a ninety degree side load loses half its WLL. However the proof load of that shackle is twice the WLL so will still carry 5,865 lbs without deformation. More food for thought.

[caltexflanc]

I've seen the work of these guys on a few big center consoles. Might be worth consulting with them. Towingeyes

These guys are very helpful too.

https://www.ropeinc.com/anchor-chain-snubber-line.html