Transom Construction

[Dave Bristle]

I am looking seriously at a CD26 or maybe a CD25. The town dock where I slip my current boat uses transom brackets (a commercial version is Frog Hooks) that hook to something like a pair of bow eyes mounted as wide as possible on the transom--no bow lines at all. I need to know whether, with appropriate backing, a pair of eyes mounted through the transom will hold a CD26/25 (withstanding some minor stresses from neighboring boats moving in and out). Most boats in the club are power, with transoms designed for large outboards, and therefore plenty strong. If the CD transom is a glass shell, I should probably look for something else. (BTW, we have several Catalinas, a Precision, and a couple of Hunters using the transom brackets with no problems. But these boats are also designed to support outboard brackets off the transom, so there's probably some support behind the glass.)

Does anyone know what's in there? I really would like to join your ranks, but I don't want to break a beautiful behind!

Dave



bristle@att.net

[Larry DeMers]

Dave,

MY CD30 has a balsa cored transom, and I would bet that your proposed boat would be likewise. The transom is a major structural element in keeping the boat together, and requires strength, so the balsa coring is used. Also, my transom has a slight curvature to it, and the end grain balsa is ideally suited for this purpose. Attaching anything through the transom will require a compression tube slipped over the bolt threads, then large backing plates on the nut ends..ugly way to do it in my opinion. Also, the drilled passage will need to be drilled oversize, filled with epoxy, then redrilled at the right diameter for the bolt. This will seal the holes off from the waves that will pound your transom. So remember, seal it up and add a compression tube (brass tubing should be ok).

Now why on earth are they using this method of docking? I can't picture it exactly..you have two eyebolts screwed into the transom, with lines led to some dock or pole I suppose, but the bow is not tethered at all? How is the bow controlled then? I have to say that this is the oddest way to dock a boat I have ever heard of. Not saying it's bad or anything, but unheard of in my 35 years of boating.
Does it seem secure, and how does it hold up in a large blow? That free bow bothers me. I hope you can shed some light on it for me.

Thanks,

Larry DeMers
s/v DeLaMer
Cape Dory 30

I am looking seriously at a CD26 or maybe a CD25. The town dock where I slip my current boat uses transom brackets (a commercial version is Frog Hooks) that hook to something like a pair of bow eyes mounted as wide as possible on the transom--no bow lines at all. I need to know whether, with appropriate backing, a pair of eyes mounted through the transom will hold a CD26/25 (withstanding some minor stresses from neighboring boats moving in and out). Most boats in the club are power, with transoms designed for large outboards, and therefore plenty strong. If the CD transom is a glass shell, I should probably look for something else. (BTW, we have several Catalinas, a Precision, and a couple of Hunters using the transom brackets with no problems. But these boats are also designed to support outboard brackets off the transom, so there's probably some support behind the glass.)

Does anyone know what's in there? I really would like to join your ranks, but I don't want to break a beautiful behind!

Dave

demers@sgi.com

[Dave Bristle]

Thanks, Larry. Your points about the epoxy for the core and the compression tubes are well-taken. As you might guess from my question, the last thing I want is a rotten or compressed transom!

The best way I can clarify the docking arrangement is to point you to www.froghooks.com. Our club is in a protected estuary off Long Island Sound where only a virtual hurricane will generate wave action, and we've weathered a couple of those (with just a few broken brackets that, incidentally, weren't Frog Hooks.)

I've been amazed that some of the Catalina 25s, with outboard brackets that complicate the placement of the eyes, have their transom eyes mounted only a few feet apart--seemingly reducing their leverage against any turning forces (such as from a boat backing in next to them). I would want the eyes spread as far as possible, and even near the hull/deck joint for rigidity.

Thanks for your suggestions and your interest--I'll try not to do anything that would spoil a beautiful CD!

Dave



bristle@att.net

[Larry DeMers]

Hi Dave,

wow...dbl. wow. I don't know, that seems like a poor way to moor a boat..unless you are a marina operator of course. THe torque on the transom has got to be horrible! With *no* lines to the bow, the entire windage of the boat will be trying to rip the windward hook off the boat! You said that you are in a very protected water, so that may be what is keeping this marina from court, but I cannot imagine doing that to my boat. Small power boats..ok, maybe, smaller dinghies..ok..but larger boats? no way...sorry. The torque is in the several thousands of pounds range I bet. If you are going to use this system, make those backing plates enormous..even then, the torque will try to pull the eyebolt out of the boat. Failing that, it will be satisfied with pulling the bolt to the side. It will end up enlargening the hole you drilled..over time, this will disturb the bedding compound, allowing water in. Because of the sideway forces due to torque, the fiberglass will get crushed over time. Combine crushed fiberglass surface with a compromised bedding, and you have water intrusion into the core.
Boy, wish I could be more upbeat about this method of parking boats, but if it were me, I would find a different marina that had finger piers that you can tie off on, fend off from, and defend the boat when needed.

Best of luck..

Larry

Thanks, Larry. Your points about the epoxy for the core and the compression tubes are well-taken. As you might guess from my question, the last thing I want is a rotten or compressed transom!

The best way I can clarify the docking arrangement is to point you to www.froghooks.com. Our club is in a protected estuary off Long Island Sound where only a virtual hurricane will generate wave action, and we've weathered a couple of those (with just a few broken brackets that, incidentally, weren't Frog Hooks.)

I've been amazed that some of the Catalina 25s, with outboard brackets that complicate the placement of the eyes, have their transom eyes mounted only a few feet apart--seemingly reducing their leverage against any turning forces (such as from a boat backing in next to them). I would want the eyes spread as far as possible, and even near the hull/deck joint for rigidity.

Thanks for your suggestions and your interest--I'll try not to do anything that would spoil a beautiful CD!

Dave

demers@sgi.com

[Don Craig]

I second Larry's comments. This is a diabolical way to secure a boat to a dock. The twisting movements would seem to put eventually destructive forces on your vessel. I would be extremely skeptical of any marina that requires hull modifications to "tie up." What happened to cleats, fairleads, and lines fore and aft? Oh, I forgot...this is the New Era of High Tech.

Hi Dave,

wow...dbl. wow. I don't know, that seems like a poor way to moor a boat..unless you are a marina operator of course. THe torque on the transom has got to be horrible! With *no* lines to the bow, the entire windage of the boat will be trying to rip the windward hook off the boat! You said that you are in a very protected water, so that may be what is keeping this marina from court, but I cannot imagine doing that to my boat. Small power boats..ok, maybe, smaller dinghies..ok..but larger boats? no way...sorry. The torque is in the several thousands of pounds range I bet. If you are going to use this system, make those backing plates enormous..even then, the torque will try to pull the eyebolt out of the boat. Failing that, it will be satisfied with pulling the bolt to the side. It will end up enlargening the hole you drilled..over time, this will disturb the bedding compound, allowing water in. Because of the sideway forces due to torque, the fiberglass will get crushed over time. Combine crushed fiberglass surface with a compromised bedding, and you have water intrusion into the core.
Boy, wish I could be more upbeat about this method of parking boats, but if it were me, I would find a different marina that had finger piers that you can tie off on, fend off from, and defend the boat when needed.

Best of luck..

Larry

Thanks, Larry. Your points about the epoxy for the core and the compression tubes are well-taken. As you might guess from my question, the last thing I want is a rotten or compressed transom!

The best way I can clarify the docking arrangement is to point you to www.froghooks.com. Our club is in a protected estuary off Long Island Sound where only a virtual hurricane will generate wave action, and we've weathered a couple of those (with just a few broken brackets that, incidentally, weren't Frog Hooks.)

I've been amazed that some of the Catalina 25s, with outboard brackets that complicate the placement of the eyes, have their transom eyes mounted only a few feet apart--seemingly reducing their leverage against any turning forces (such as from a boat backing in next to them). I would want the eyes spread as far as possible, and even near the hull/deck joint for rigidity.

Thanks for your suggestions and your interest--I'll try not to do anything that would spoil a beautiful CD!

Dave

[Dave Bristle]

Thanks, guys... I would have thought the same thing, but as I said, we have 3 Catalina 25s weighing in at around 5000 lbs each, with eyes that, IMHO, are too close together on the transom (because of their motor mounts). They've lived through major storms with not a hairline crack or dent around the eyes. I'll have to talk to their owners some more... Windage is not much of an issue with boats about a foot from each other, but boats will lean on each other while backing in. I figured that with no outboard bracket on the CD transom, at least I could set the eyes wider on the transom for better leverage. But the CD25 and 26 may not even have the core that the larger CDs have, since they have the engine well structure forward of the transom.

The "marina" is our town boat club 3 minutes from our house, with slips for a few hundred bucks a season. My other alternatives are 20 minutes away for a couple of thousand, or an hour away for a little less. Maybe I'd better find a Catalina. When I move to the Chesapeake in a few years, where I can use lines, cleats and chocks, I can think about a CD. Lots to think about.



bristle@att.net