I have seen a couple of posts about front tramps, but had some ideas for one and wanted to get some opinions.

I have a Nacra 5.0 and need a place for some gear (light) and my 7 yr old to hang out. Thought process was as follows:

1) Make a square suspended tramp (smaller than the space in front) from the same material as the tramp with reinforced grommets on each corner.
2) Use the front hull/bridle attach points and add two stainless steel lines and attach to the front of the new tramp. My assumption is that the additional stress of 100lbs or so on the front hull/bridle attachments won't be a strain considering the forces on those points anyway.
3) Attach the rear of the new tramp with stainless steel lines over the front beam in a loop.
4) Use either line or stainless steel lines - thoughts? If I used line/rope I could have a pulley system and cleats on the rear attachment points to get the required tension

Any thoughts on this in terms of engineering? Ease of use? I would probably not remove every time as the cat remains fully rigged when it is stored at the lake.

Thanks,
David
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NACRA 5.0

Andrew Scott has a cool setup similar to what you are talking about.

My thoughts:
1) You could also rig up a cargo net, probably less likely that people will try and use it as a place to stand then (but less secure). Mesh tramp material would work too. I would NOT try to rig it for a passenger, you will probably end up cracking the hull at the attachment points due to the shear stress (that's why the tramps are connected on all 4 sides and by rail connections that distribute the load on the hulls).

2) I would try to avoid that, the bridle attachment point is meant for up/down loads not shear. You can do a decent reinforced through-bolt connection into your hulls using stainless steel Snaptoggles (don't have a good on-line source right now but here's a link to the manufacturer http://www.toggler.com/pr…/snaptoggle/overview.php). A little pricey but easier than cutting holes to put a reinforced eye strap in.

3/4) Use a decent rope, StaSet or equivalent poly/low stretch will work fine for your purposes no need to go with wire unless you plan on putting some serious tonnage on there.

I would also make it fairly narrow (2' wide or less) just becuase you don't the stuff in it to drag in the water when you are going at a good clip and you don't want people to be tempted to use it as a step or seat and crack the hulls at the attachment points.



edited by: Wolfman, Jul 04, 2010 - 03:33 PM

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Dave Bonin
1981 Nacra 5.2 "Lucile"
1986 Nacra 5.7 "Belle"
Winnipeg, Manitoba, Canada
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I would agree with Dan if you are not going to reinforce the front connection points, I would limit the front tramp to a small area to store things. Before putting a full coverage front tramp on it seems like a front cross bar at the front bridle points would be needed. That is a lot of additional force even from a 100 pound kid sitting out there.

I am not familiar with hull volume of the 5.0 or your sailing conditions, but if the bows get near the water a large front tramp would be a big scoop in waves or high wind. I know my H18 bows will slap down into the waves and if I had a front tramp it would really slow me down.

--
Scott,
‘92 H18 w/SX wings
‘95 Hobie Funseeker 12 (Holder 12)
‘96/‘01/‘14 Hobie Waves
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http://www.thebeachcats.c…iewtopic-topic-2168.html

Thanks Andrew for the link. I think to do it, that's the way I would go. Maybe I'll put him out on the trap as he weighs a lot less than 100lbs he won't unbalance the boat any - and that'll make some extra room on the tramp for the cooler

Thanks all,
David

NACRA 5.0

Another sailer recommended to me that you can get tracks that can be installed on the inside of the front hulls to allow a tramp to slide into. We did not get into any detail however.

--
Dustin Finlinson • Magna, UT
Member: Utah Sailing Association
1982 Prindle 18
1986 Hobie 17
1982 Prindle 16
1980 Prindle 16(mostly)
1976 Prindle 16(mostly)
Check out "Prindle Sailors" on Facebook.
--

I?ve started building the following:

I wanted something that is strong, requires little modification to cat, can be removed easily, and takes into consideration structural properties of cat.

To do this:

1. @8x4 frame of aluminum. The frame is sized to sit atop and run along outside edge of hulls on foam to evenly distribute weight on load bearing portion of hull. Frame will weigh 30-40 lbs.

2. Affixed fine mesh netting to frame.

3. Affix lines from dolphin striker, hull/bridle attach points and front beam to secure, but not support, frame in place for zero side-to-side and vertical movement.

When out solo the frame will be removed. When out with family jib will optionally be removed. Looked into carbon fiber poles but weight gain couldn?t justify cost.

I envision a max supportable weight of approximately 200lbs depending on resulting sailing characteristics of my prindle 19.