Towing the East Port pram

I plan to tow the EP pram I'm building behind a cruising boat from time to time but can't find any info about the recommended placement of the towing eye.  I will put a backing plate on the aft surface of the forward transom, so I need an answer before I close off the forward area.

Thanks, Joe


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RE: Towing the East Port pram

   I am also interested in occassionally towing the Eastport nesting pram I'm currently building, but I'm concerned that the forward transom is just not strong enough for this purpose.  Looking forward to a response to Joe's question.

RE: Towing the East Port pram

Here's a post I found in the archives:

>>> I have towed my Eastport Pram behind my 32 ft sailboat in winds of up to 20 knotts and speeds of 6.5 knotts. The pram tracks perfectly, partially due to the deep long skeg. My padeye is just at seat level and has a bronze through bolted backing plate. This seems to be a perfect location and the pram rides at a perfect angle. I also needed to fill the daggerboard slot with mini cell foam to keep the water from spurting up the opening and filling the boat.

Mark <<<

I'll be towing my Eastport & will follow these suggestions for installing the towing eye.

Haven't decided yet whether the eye will be in horizontal or vertical configuration. Horizontal will look proper but I think vertical might be a little stronger. The ones I've seen in pictures, though, are always horizontal it seems.

Frank

RE: Towing the East Port pram

 

Frank -  could you possibly post a picture of your towing setup?  Or send it to me at dmk56@outlook.com.  Thanks!

 

RE: Towing the East Port pram

DMK,

Working on my Eastport now. I hope to be close to being done by the end of this week. I'll definitely post a picture or 2 of the towing eye install when I'm done. 

The one thing that keeps popping up about towing eye placement is to keep it fairly low on the bow. From what I can tell at this point in construction, somewhere close to, or a little lower than, seat height looks about right to my eyes.

Frank

RE: Towing the East Port pram

I know I am 6 weeks late to this discussion , but horizontal pad eye in this situation will result in more equal load share on the screws. in vertical arrangement only a directly orthagonal pull to the mount surface will give you equal load share to the fasteners.

As per "doc" , instead of a backing plate I glued a 2"x4"x3/4" mounting block for my pad eye that served a dual purpose as glue block/ stop for forward part of the seat thwart (ripped with 14 deg upper surface). Worry not about the forward transom strength, the thwart stiffens and stabilizes the whole bow area such that, if you keep the pad eye close to the seat/ transom bond, you are distrubting the tow load throughout the whole bow structure.

Brian Mc  

RE: Towing the East Port pram

Hi all,

I have a question about a backing plate to support installation of a bow-eye.  I also plan to tow my ENP and some kind of bow-eye seems a good idea anyway for a painter...?

I see the posts about eye placement (at or just below forward seat height), and orienting the "U-bolt" horizontally to distribute the pulling load to both holes.  These transom holes will be DFD'd. 

When installed, the U-bolt already goes through the transom doubler (making for two thicknesses of plywood).  Is another plywood disc necessary to distribute the pulling strsses on the forward transom?  If so, the backing plate would be constrained to a couple inch-diameter disc to avoid overhanging the forward transom doubler edges - and it seems such a small disc wouldn't offer much more stiffening than the transom doubler does itself.  (I see one EP builder epoxied a backing plate to the forward edge of the forward seat but that's not a nesting pram build.)

Thanks for any advice.  Photos are wonderful too.  :-)

Mark

RE: Towing the East Port pram

Due to the bow transom of an empty pram riding so high, the bow eye should be as low as possible, just above where the bottom meets the transom.  I do highly recommend a backing plate and erring on the side of caution, bigger is better (check the length of the thread vs. total thickness).  You might also want the final installation to use nylon lock nuts (which are only good the first time you thread them). 

Get your boat all put together, but just prior to sealing the forward seat, goop in a substantial piece of plywood, then drill n' fill, etc.  Whether the bow eye should be oriented horizontally or vertically is another rabbit hole, but every dinghy I've ever encountered has it vertical.  I think it might have to do with vertical shock loading in a sea state vs. yawing side to side, but I could argue it both ways.

The fact that it's nesting is a whole other ballgame.  I'm talking about ideal towing geometry.  You'll need to figure out the clearances.  This would be great info to share for future ENPers.

RE: Towing the East Port pram

For the benefit of other builders of Eastport Nesting Prams who are concerned about towing loads and installing a backing plate....

John Harris (CLC): "No need to add any additional reinforcement to that bow transom.  The "doubler" is there specifically as reinforcement for the painter, and I've never heard of a transom pulling out.  The hole for the painter should be about halfway up the transom."

Thanks be to John and the CLC crew.  Now on to sanding.  :-)

RE: Towing the East Port pram

Here's a couple lictures of my tow eye install:

[IMG]http://i67.tinypic.com/34p0yus.jpg[/IMG]

[IMG]http://i65.tinypic.com/2nt94i.jpg[/IMG]

The forward seat will cover the bolt. I drilled-filled-drilled the holes.

Frank 

RE: Towing the East Port pram

   Dang I have trouble posting pictures! I'll try again.

Frank

 

RE: Towing the East Port pram

I'm done.

Sorry to waist your time. I can't even delete posts that don't work.

Frank

RE: Towing the East Port pram

 

You were pretty close to success, Frank.  The trick is to use the picture button in the post window, and then paste in the TinyPic link labeled "Direct Link for Layouts" which is a bit counterintuitive, since the text with the IMG tags front and rear says it's for message boards.  What can I say?  "Different ships, different long splices."  There're instructions for this somewhere on the CLC site.  Resize the photo in the properties box (appears when you click the picture button) to 500 wide or a bit more to keep it from going too wide.

Good photos, and nice work.  Looks plenty stout enough to hold her to me!

I wish you all joy of safely towing her to happy places!

.....Michael

RE: Towing the East Port pram

Michael,

Thanks for the help in posting pictures! I don't know why I have such a tough time of it. I found the instructions once but haven't been able to since. Oh well.

Hope these pics help.

Take care,

Frank

RE: Towing the East Port pram

Yes, of course John is correct.  I had forgotten that the doubler for the forward bulkhead goes all the way to the bottom panel.

I will say that the forward seat intersects the forward transom at some point, so you have to install the bow eye where it doesn't interfere (including the fillet).  I seem to remember that the seat hits pretty low up front, so you've got unfettered access to the back side. 

My Wichard bow eye comes with it's own gasket and backing plate.  I would also use nylocks on the posts or some LockTite.  This is also a drill/fill/drill application.

 

 

RE: Towing the East Port pram

My Eastport's bow transom doubler stops at the seat. My bow eye fits just below the seat bottom & not through the transom doubler. That said, with a careful install & the oversized stainless backing plates I'm not worried that the bow eye will be problematic any time soon. I personally don't think reinforcement was neccessary.

That Wichard looks very nice! I went ahead & got the one that CLC was selling & am pleased with the quality of the piece. The gasket is a nice touch, though. In my previous post's pictures I show the u-bolt only dry-fitted to the boat. Before the final install I epoxied the exterior area around the eye to seal the wood under the plate. A gasket would have maybe offered additional protection.

I boubled up the nuts & locked everything up that way. I might have LocTited them, too.

Frank

RE: Towing the East Port pram

Hmmm. Re-reading these posts give me the impression I should have installed my bow-eye *above* seat height. Guess I didn't see that before. I didn't think it was a good idea to have the bolts entering into the interior of the boat to snag stuff or poke people.

Well, we'll see. I'm on track to get the dingy into the water this summer so I'll let everyone know how well she tows! :-)

Frank 

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