Install Bow Eye-Bold on Fixed Keel Sailboat

[Danmcgaffin]

I own a Tanzer 7.5 sailboat which is just under 25 feet long. It has a fixed keel and was designed to be launched and retrieved with a crane, so it doesn't have a bow eye-bolt. However, I keep the boat every summer at a state park lake where there is no crane to place the boat onto my cradle trailer during retrieval in the fall. Although the water depth at the launch ramp is sufficient to allow the boat to be floated directly over the pads before pulling the trailer out, there is no really good way to prevent the boat from sliding back into the water as the trailer is towed up the launch ramp. Therefore, I am hoping to be able to install a first-time bow eye-bolt that can enable holding the boat into place with the trailer winch.

My two main concerns with this project are 1) whether and how an eye-bolt should be installed without damaging the hull and 2) at what location the eye-bolt should be installed relative to the waterline and the rub-rail. I am told that Tanzer built rather thick and solid hulls, but I am not confident I can safely add an eye-bolt to a boat that was not designed to have one. FYI, two photos from winter storage are attached that show the relative configuration of the water-line, trailer winch and rub-rail.

I am open to opinions/suggestions on whether, how, and where to install a bow eye-bolt. Maybe it shouldn't be done at all and I should continue to muddle through by holding onto bowlines while lying back in the pickup truck as it pulls the trailer up the launch ramp.
Thanks,
Dan

[Sailor Doug]

I believe I have seen tanzers with eye bolt. They are solid glass but not heavy. Should work but I have no pics.


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[Danmcgaffin]

Thanks.

[SkiprJohn]

Shouldn't be a problem. I'm certain there are many trailor sailers there that you could look at to get an idea where the eye should be located. Just google a bunch of boats and you'll get the idea.

Use a stainless backing plate or big thick washer on the inside with a lot of 3M 4200 for adhesive sealant. You'll have no problem.

[Danmcgaffin]

I found a few photos. It looks like the standard way to do it is about half the distance from the waterline to the foredeck.

[bsurvey]

why not a cleat at the bow on deck at the breast hook with a good size backing block. easier to install than working inside up in the apex of the stem

[Dave Lochner]

Used to own a Tanzer 22, Tanzer tended to over build their boats, heavy but solid.

One factor to considers the height of the winch on the the trailer. I would think that the lead from the u-bolt to the connection point should be fairly straight, not an a severe angle.

The U Bolt will need a backing plate.

Given the weight of the boat and the friction on the trailer it is unlikely that the u-bolt will be strong enough to pull the boat across the trailer, but it should be strong enough to keep it from moving.

[Danmcgaffin]

bsurvey,

I already have a cleat on the foredeck, but the winch is way too far below that level to connect there. That would make the boat slide back as the trailer moves up the ramp. Then bow would dip down and then stay that way unless released on land, which would result in 3,800 pounds of boat dropping back onto the trailer. (We've been doing this manually without a winch or fixed bowline for years, except that we let go of the cleated bowlines before the boat is entirely out of the water yielding mixed results.)

The reason I asked about eye bolt location is because the winch would work better if the eye bolt were as low as possible, but I'm not sure what level is prudent from the perspective of leakage or other possible considerations. The other option would be to extend the front trailer post and raise the winch higher, but I think I would also need to reinforce it due to resultant higher bending stresses. That would probably be more expensive than installing an eye-bolt.

I'm glad you mentioned the cleat, because it helped me to verbalize why the eye-bolt location is important.

Thanks,
Dan

[Danmcgaffin]

Dave,

Thanks for the benefit of your experience with the Tanzer 22. Am I correct in assuming that your 22 had an eye-bolt?

My thinking was as you indicated that the eye-bolt would be probably sufficient to hold the boat in place, but not to drag the hull through the water over the trailer. Fortunately, we've ben able to get the trailer deep enough that the boat can be moved all the way forward.

You may have noticed in the photos that the trailer post is about 12-18 inches ahead of the bow. I actually moved the post forward to allow some wiggle room when using the manual method (described in my response to bsurvey above). My hope is that the post can be moved back to the correct position and allow me to use the winch and eye-bolt to hold everything in place while the trailer moves up the launch ramp. However, I will need to make a trade off between horizontal orientation of the winch line and closeness to the waterline. Given the forces involved, I'm not confident that the bolt penetrations will stay water tight after a few retrievals, regardless what brand of sealant is used.

Regarding backing plates, the eye-bolts I found on line have no more than a strip of SS about 7/8" wide and 2.5-3" long. I think I need more than that and I will probably look for a custom substitute. However, the Tanzer 7.5 has a narrow bow stem which may limit my options there. (Since the boat is in storage and not accessible, I have not looked inside yet to see how tight that space is.) Any suggestions?

Thanks,
Dan

[W3GAC]

I added a 3/8" stainless U-bolt + stainless backing plate on a 27' O'Day about 8" above waterline as my mooring attachment point. Been through one hurricane with it no issues. My v-birth is open to back of bow and had complete freedom of where to drill/ mount. Decided lower was better for its purpose but wanted it above normal waterline. Also the deck recessed anchor/ rode storage area that hangs down into the v-birth space blocking access to the higher inside bow area would have made a higher installation more difficult.


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[Cheechako]

Put the eye so it ends up located at the winch attachement level when on the trailer.

[SkiprJohn]

I agree with W3GAC that it should be lower than halfway. It would make a great mooring eye if lower as well. If you notice many old boats (of which I've had a few) there are fittings at the base of their bobstays that are at near waterline. These boats don't leak if you use the proper sealant.

That backing plate you described for the u-bolt is adequate.

For loading on your trailer you'll have an easier time of it if there is a straight line pull and you are not trying to pull the bow down if the eye is too high.

A U shaped bolt or U-bolt makes a better eye than an eye bolt because it won't twist.

kind regards,

[Dave Lochner]

Dan,

A quality ⅜" u-bolt with a backing plate should be adequate. Using the u-bolt and and the winch to bring the boat on to the trailer should work, so long as most of the weight of the boat is supported by the water and not the trailer.

If you every get stuck and can't get the boat all the way on the trailer you can use some cement blocks, 4x6s and a pair of bottle jacks to lift the boat above the trailer and back the trailer under the boat. Drop the trailer tongue with a bottle jack under it. Block the stern of the boat. Jack the front of the trailer tongue as high as it will go and block the bow with the 4x6 and cement blocks. Lower the tongue, slid the trailer in position, and reverse the process. Depending on the configuration of the trailer you may need to vary this process. I used this method to take my Flying Scot off its trailer in my back yard. You'll only need to lift the boat high enough to clear the trailer, maybe a quarter to half-inch.

[Danmcgaffin]

Everything all of you have said above has been very helpful. Thanks so much. I'm certainly open to more suggestions if more are forthcoming.

I hadn't thought about limitations due to V-berth accessibility. So I'm not sure yet how much access I will have in the V-berth until the boat comes out of storage, but there are panels that can be removed to reach the bow stem.

[Terra Nova]

Yes on the U-bolt type bow eyes made specifically for this purpose. Yes on a substantial backing plate and fairing pad, inside. Locate it like you see on other trailer boats. Relocate your trailer winch high enough for a straight pull.