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Old 21-02-2011, 07:36   #1
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Tramp Replacement - Best Method

My 47 foot cat recently had a bad experience of being towed at 8-10 knots through steep 10-15 foot waves. I had gear on the tramp (sea anchor and folded portaboat ( folded) and the bounce broke the aluminium frame of my tramp and took out the tramp breaking the ties from the frame to the hull one by one. So, how best to replace the tramp? Flat polyester tape is strong, UV and water resistant, comfortable, and although time consuming to tie and wave each ndividual one it is easy to repair and update. Pre woven dynema cord is more open allowing water to drain more quickly but is more uncomfortable. Should the tramp be tied directly to the hull or to a frame that is then tied to the hull? Does anyone know of a woven net that is flat tape (not cord) comfortable and at least 50% open space for surface area? This would save a lot of time tying individual straps.
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Old 21-02-2011, 08:35   #2
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Re: Tramp Replacement - Best Method

Kanter has a pretty good discussion of this:

Surveyor's trampoline

Multihull Nets also has lot of information and good discussion, too:

Multihull Nets and Trampolines for Catamarans and Trimarans, main page

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Old 21-02-2011, 10:45   #3
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Re: Tramp Replacement - Best Method

See also

Very Nice Trampoline !

Trampoline Suppliers & Fabricators
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Old 21-02-2011, 11:24   #4
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Re: Tramp Replacement - Best Method

That is a nice looking tramp.

Just a point of feedback for the OP. With all that force being exerted in those conditions, I suggest you do a close inspection of your cross beam, the attachment points, backing plates and the compression post, too (if you have one). It wouldn't surprise me if there was some damage. Chances are they weren't designed to withstand those conditions with the weight on them, too.

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Old 21-02-2011, 12:07   #5
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Re: Tramp Replacement - Best Method

You've gotten some good ideas already, and I don't know if this useful or not but... I know of no easy way to fasten with webbing, if that is what you meant. The advantage of 1/8" Dacron parachute cord for us, was that after fastening the tramp's sewn in bolt rope edge, by going through the matching aluminum track, we could use the cord on the opposing corners first.

By going around 4 times, and pulling it REALLY tight, (like a truckers hitch), followed by 3 half hitches, we could get them tensioned properly. I did one part way, then the other, then more tension, etc...

We then started in the middle grommet, going left of C followed by right of C, and did similar lashings from the tramp grommets, to its hardware, 6" away... all the way around.

This allowed us to get it SO damn tight, that it only sags about an inch when walked on, and provides sure footing. We came back and put a drop of epoxy on the outer surface of the lashing's half hitches only, so they can't untie. I come back every 5 years and remove the tramp, paint it with two coats of liquid vinyl, and re-lash it with new cord. 20,000 miles and 14 years later, our two tramps, maintained in this way, are still like new!

If you can find it, black cord holds up better in the UVs, and looks better too. Either will work...

Oh yes... With much less effort we could have "laced it" zig zag fashion like most folks do, but not as tightly, and I never liked a system where only one failure made them all let go.

Just a thought... Mark
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