Trampoline Material

[Fanie]

Hi Everyone,

The trampolines you get on the multihulls (where the girls tan on :D) -

What material is it made of, and how thick is it ?

[northerncat]

go and buy some trawler net with small holes from a trawler supply co, cheap comfy and very very durable
sean

[Fanie]

Hi Sean,

Thanks, good idea. What is a trawler supply co ? Guys sels fishing nets ?



I still need to know what it is made from.

[tspeer]

Trampolines are made out of a number of different materials. One issue is how porous you want the tramp to be. Porous fabrics are comfortable, but shed water slower and can produce more windage when the yacht is heeled at large angles. Netting doesn't have these problems, but isn't as comfy on bare skin.

I used netting from Net Systems (http://www.net-sys.com/) when I made the tramps for my cruising trimaran. I went with Dyneema netting with a cell size of 1" squares. Nylon netting with 2" squares is also used on cruising boats.

Sunrise Yacht Products (http://www.multihullnets.com/) is one of the largest manufacturers of trampolines for multihulls. They have a wide variety of materials and colors.

[Fanie]

Netting doesn't have these problems, but isn't as comfy on bare skin.


He he... I like your thinking, Tom :D

The netting sounds better and better. You don't want them to just lie (lay) there all the time. Who'll make the food ?

Does any of the SA guys know of a trawler net supplier ? I'll google and see what comes up. Thanks for the responses.

Tom, bothers me a bit the yacht heeled at large angles ;) Mono's use netting as well now :D

[Fanie]

The 25mm and 50mm large holes are quite large. I've seen some video's where the trampoline looks almost like shade netting, and you can see the sparay goes through it.

The trampoline on my friend's small trimaran is fine and smoother than shade netting, leaves no pattern as Tom said 'on the bare skin'. Can't say that it is thinner than shade netting, but it looks more like a nylon and it is finer woven.

[northerncat]

mine has about an inch hole and is very very confortable
sean

[deepsix]

I really like the bainbridge heavy duty mesh, it is a woven polyester mesh with a vinyl coating. The tramps are made by welding the material, not sewing where the stitching eventually fails due to UV. This is very expensive though.

http://www.sail-making.com/dbimgs/Mesh%20UK.pdf - last page.

The mesh that you saw on the windrider is probably the standard hobie tramp material, but it is probably not strong enough for bigger boats.

[Fanie]

Thanks... yes the ultrasonic welding makes sense, it would be stronger than sewing.

Only one person can go on the windrider's tramp... it won't be strong enough for much more.

I'll find out about the netting. If it's strong, durable, cheap and can leave some interesting imprint on bare skin ;) then it may be what to get. Maybe even catch something if you burrough into a wave :D

[Splash Gordon]

Howzit Fanie!
Get hold of Alnet or better still get hold of I&J Trawling here in CT and see what they can do for you, otherwise try Johann at Ropeworld- he'll make you custom nets out of whatever you want, any size you like.
FWIW, I know the hardcore and wannabe-hardcore cats use Vectran netting ($$$$!!!) which they roll up at the edges, then they lash the bundle to the boat. I think it looks kak, but then I'm not hardcore- cruising-cats aren't meant to be either!

[Fanie]

SPLASH Gordon eh :D

I phoned Alnet, they are around the corner here in jhb from me. I think they forgot to phone back. Will remind them to phone back ;)

It will help if one knows someone at I&J...

Could try ropeworld also... thanks.

Check out the rigging on the pics :D

[Trevlyns]

... Trampoline material? Flash Gordon? How DO these threads get so out of hand :D

[Fanie]

Hi Trev... aaaww you know how it is... takes all sorts :rolleyes: Found them on the net ;) Good example of too much trampoline. As Splash said you have to be hardcore to like it :D

[Trevlyns]

Bluebottle (from the Goon Show - circa 1952) had the perfect reply...


... You Silly Twisted Boy, You :D

[Fanie]

Sorry Oom Trev, sal nie weer nie :D

[Trevlyns]

Awww rite boet, dis Ok

[Trevlyns]

Hey Jeff! How come I always end up on the start of a new page and then everyone loses the context, gets mad, starts world war 3 (or is that 4)...

[Maciek188]

Tramp made by Sunrise Yacht Products on F39

[tspeer]

...FWIW, I know the hardcore and wannabe-hardcore cats use Vectran netting ($$$$!!!) which they roll up at the edges, then they lash the bundle to the boat. ...

Actually, high-modulus fiber makes economic sense for tramps. Compared to nylon, an ultra-high molecular weight polyethylene (UHMW) like Dyneema is five times the cost per pound as nylon. However, it is far stronger than nylon per pound and has many times the UV resistance. So over a long period, it is actually the less expensive alternative. And the high modulus makes it a joy to walk on - you don't sag down with every step the way you do with nylon.

I don't think just rolling up a bunch of netting at the edges makes much sense. It's far more common to install a bolt rope. If the cells of the netting are oriented so they are square to the centerline of the boat, then the bolt rope can be lashed to the edge of the netting. I chose to orient the cells on the bias, and double the netting over the bolt rope, as shown here:
http://farm3.static.flickr.com/2415/1807672720_f00b45d2f7.jpg
The hem was secured with UHMW twine in two rows of running clove hitches. There was actually a lot less wasted net doing this, since the netting is woven such that it expands in the bias direction, and you have to cut off big corners to get a square orientation to the cells.

[Trevlyns]

Fanie, pop down to Durbs, swim out and cut yourself some shark nets. We used to as kids and make bangles out of them. Very cool, but not too clever.:p

[Fanie]

Hi everyone, thanks for the advice and pictures. I can get a capenta net with an 8mm hole in it which seems about like the thing I want. The nets with large holes could be less comfy to walk on... the other net they offered me has a 110mm hole, and is really heavy.. The lady said all us guys can sit on it :D and I didn't doubt it ;) I haven't had time to find out from the other suppliers though.

[Fanie]

[QUOTE}Actually, high-modulus fiber makes economic sense for tramps. Compared to nylon, an ultra-high molecular weight polyethylene (UHMW) like Dyneema is five times the cost per pound as nylon. However, it is far stronger than nylon per pound and has many times the UV resistance. So over a long period, it is actually the less expensive alternative. And the high modulus makes it a joy to walk on - you don't sag down with every step the way you do with nylon. [/QUOTE]

That is exactly the thing I'm looking out for Tom, thanks, it would be better value for money. I'm not a nylon fan. Aparently the polyethilene nets are also very strong and UV resistant. When I'm ready to buy I'll go and look at them to see what they actually look like and get an idea of their weight.

That F39's net looks as neat as the price tag :D

[tspeer]

The downside is the new nets put a lot more stress on the attachment points. The old nets were secured to eystraps that had self-tapping screws into the fiberglass fairing on the beam, so they were only supported by the threads. I've just spent several boat-bucks and two months in the boat-yard having fiberglass flanges added to the beams that will take the loads to the beam in shear and be vastly stronger than the old attachments.

Here's what a cross-section of one of the flanges looks like:
http://farm4.static.flickr.com/3207/2686256931_b44aed2152.jpg

The rounded bit is a fiberglass rod (batten material), with the carbon cloth wrapped around it. Holes are drilled between the rod and the flare for the beam to take the laces. The upper flange is almost aligned with the direction of pull, so most of the load will be taken in shear along the bonding surface. And the rod will help spread the load across the attachment points, not to mention being more robust to damage and friendly to people.

[Fanie]

Hi Tom, thanks. I think one should impliment the povision for the trampolines from the start rather than as an afterthought as in your case... and I do see the duct tape you are going to use there :D I have a few pictures of a fourier being built with pictures of how they did it.

[tspeer]

...I think one should impliment the povision for the trampolines from the start rather than as an afterthought as in your case...
Oh, yeah. The cost of this little sojourn in the boatyard has cost as much as a new mainsail! In general, the boat is very well built, but this is one area where they messed up.

As for the tape, they use that green masking tape in the yard to mark work that has to be done. Can't miss it!

[boat fan]

I'll find out about the netting. If it's strong, durable, cheap and can leave some interesting imprint on bare skin ;) then it may be what to get. Maybe even catch something if you burrough into a wave :D


" Haul in the mainsail guys , let`s get this baby moving so it buries the bows...
We are going FISHING ! " :D

[BigCat]

I am going to make my own out of seat belt material-10,000 pound test per 2" strap. Why sew it at all when you can have an arrangement like that found on backpacks all around the edges? Just attach each piece to the boat at the ends and basket weave them-:o