Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 10-03-2021, 04:27   #1
Registered User

Join Date: May 2020
Location: Sarasota
Boat: Lagoon 42
Posts: 20
Images: 2
Trampoline replacement.

I have a Lagoon 42, and the trampoline is made of string quite thin, exceptionally strong (ignoring errant whacks with machetes on coconuts), and uncomfortably stretchy/springy.
Whilst fun for children with little to do, it is unacceptably, well, trampoliny when walking upon it, especially so when banging into oncoming seas.


So being a handy guy, possessing an ancient degree in physics, and being armed with a sewing machine and a credit card, as well as being retired, I decided it would be great fun to make a new one.


So keeping in mind that opinions obey the first law of economics: Does anyone have data, or negative experience with going from a trampoline with 95% permeability, to 25%?
(My new design would have only 25% permeability.)


It suddenly came to me that an unusually unfriendly wave busting upwards on a now 25% permeable tramp might gain enough purchase to rip out some (all?) of the hooks the tramp is attached to.
Does that ever happen? Is that why the design is that way?


I looked on Sailrite of course, and some other sites, and they all offer material which is quite closed, and I have seen a lot of trampolines which are dense and not attached with exceptionally robust hooks/hangers, so I think it would be okay.


But I thought it wise to ask if anyone has any real life experience with disasters in this arena.
Thanks.
manisland is offline   Reply With Quote
Old 10-03-2021, 05:12   #2
Registered User

Join Date: Mar 2009
Location: Southern Chesapeake Bay
Boat: Norseman 430, Jabberwock
Posts: 1,433
Re: Trampoline replacement.

Not personally, but I've heard of problems even with more permeability than what you are contemplating.

Of course you could just stay at the dock and close to shore, and be fine.
ggray is offline   Reply With Quote
Old 10-03-2021, 05:28   #3
Moderator
 
tkeithlu's Avatar

Cruisers Forum Supporter

Join Date: Feb 2012
Location: Carrabelle, Florida
Boat: Fiberglas shattering 44' steel trawler
Posts: 6,084
Re: Trampoline replacement.

I think that for purposes of your use, netting would work better than cloth. I built a cargo net out of fishing net with a rope edge bound on with nylon twine. It's lasted 20 years, and colors my thinking on this. The rope edge seizes each segment of the net, so it distributes load much better than grommets in cloth would. Take a look at the netting on this site and see if it leads your mind in new directions. Good luck with it.

https://www.seattlefabrics.com/50-86...AaAi_FEALw_wcB
__________________
Never let anything mechanical know that you are in a hurry.
tkeithlu is offline   Reply With Quote
Old 10-03-2021, 07:58   #4
Registered User

Join Date: May 2020
Location: Sarasota
Boat: Lagoon 42
Posts: 20
Images: 2
Re: Trampoline replacement.

Sorry sorry....


I posted too quickly, and should have looked at what the experts have to say.


Here is the answer:
https://multihullnets.com/Product/tech/netOpenness.aspx
manisland is offline   Reply With Quote
Old 10-03-2021, 08:14   #5
Moderator
 
tkeithlu's Avatar

Cruisers Forum Supporter

Join Date: Feb 2012
Location: Carrabelle, Florida
Boat: Fiberglas shattering 44' steel trawler
Posts: 6,084
Re: Trampoline replacement.

You're not the first. Best wishes on a successful project.

I would not have imagined that there is that much technical information available on the mesh size of catamaran trampolines.
__________________
Never let anything mechanical know that you are in a hurry.
tkeithlu is offline   Reply With Quote
Old 10-03-2021, 17:06   #6
Registered User

Join Date: Mar 2009
Location: Southern Chesapeake Bay
Boat: Norseman 430, Jabberwock
Posts: 1,433
Re: Trampoline replacement.

Sunrise made our tramps, they do good work.

The webbing w/ diagonal weave gave me pause at first, but I was converted. One continuous piece of webbing. No stitching, the weak point, but at the two ends.

I'd like to watch them weave it.
ggray is offline   Reply With Quote
Old 10-03-2021, 19:31   #7
Elvish meaning 'Far-Wanderer'
 
Palarran's Avatar

Join Date: Jan 2008
Location: Boat - Greece - Me - Michigan
Boat: 56' Fountaine Pajot Marquises
Posts: 3,489
Re: Trampoline replacement.

This is what you get with 40% open in real heavy seas. Plus the $4k in fiberglass repair work.
Attached Thumbnails
Click image for larger version

Name:	Mesh Tramps after storm.jpg
Views:	104
Size:	446.2 KB
ID:	234302  
__________________
Our course is set for an uncharted sea
Dante
Palarran is offline   Reply With Quote
Old 10-03-2021, 21:11   #8
Registered User
 
Kiwi Dave's Avatar

Join Date: Apr 2018
Location: Whangarei, New Zealand
Boat: Armstrong 42' Catamaran
Posts: 65
Re: Trampoline replacement.

Hi all

I made new tramps for my cat from dyneema fishing net, dyneema peripheral rope and dyneema lacing. I expect them to last for ages.

See 9:00
__________________
David

https://www.youtube.com/user/eyes333333
Kiwi Dave is offline   Reply With Quote
Old 10-03-2021, 21:43   #9
Registered User

Join Date: Sep 2014
Location: On the boat
Boat: LAGOON 400
Posts: 2,352
Re: Trampoline replacement.

Quote:
Originally Posted by manisland View Post
Sorry sorry....


I posted too quickly, and should have looked at what the experts have to say.


Here is the answer:
https://multihullnets.com/Product/tech/netOpenness.aspx
i am not expert but have been in large angry seas. When you get that 10m freak wave directly in front of you without a warning, you want to be as buoyant as possible (not load bows too much, lagoons are good in that respect) and have net that let water thru very easily, else that extra 1/10 of a second that your bows are under water, may turn into tragedy. But as other said, if you do not plan sailing in black holes (lots of nasty weather) , you should be fine.
arsenelupiga is offline   Reply With Quote
Old 11-03-2021, 00:28   #10
Registered User
 
fxykty's Avatar

Join Date: Apr 2016
Location: Indonesia
Boat: Outremer 55L
Posts: 3,924
Re: Trampoline replacement.

Quote:
Originally Posted by manisland View Post
I have a Lagoon 42, and the trampoline is made of string quite thin, exceptionally strong (ignoring errant whacks with machetes on coconuts), and uncomfortably stretchy/springy.
Whilst fun for children with little to do, it is unacceptably, well, trampoliny when walking upon it, especially so when banging into oncoming seas.


So being a handy guy, possessing an ancient degree in physics, and being armed with a sewing machine and a credit card, as well as being retired, I decided it would be great fun to make a new one.


So keeping in mind that opinions obey the first law of economics: Does anyone have data, or negative experience with going from a trampoline with 95% permeability, to 25%?
(My new design would have only 25% permeability.)


It suddenly came to me that an unusually unfriendly wave busting upwards on a now 25% permeable tramp might gain enough purchase to rip out some (all?) of the hooks the tramp is attached to.
Does that ever happen? Is that why the design is that way?


I looked on Sailrite of course, and some other sites, and they all offer material which is quite closed, and I have seen a lot of trampolines which are dense and not attached with exceptionally robust hooks/hangers, so I think it would be okay.


But I thought it wise to ask if anyone has any real life experience with disasters in this arena.
Thanks.

Check with Lagoon, they should be able to tell you the minimum openness that your boat requires. Generally smaller trampoline areas can have less openness, but again, check the specs for your boat.

Note that itís not just water passing through thatís the issue, though that can cause issues like with Pís cat earlier (wow, Iíve never seen something like that!), but air. Think about going on a beam reach or upwind in big seas and wind and the bows lift over a sea and all that wind gets under the trampolines. It could capsize you.

Nets at 70+ openness are completely comfortable as long as they are tensioned very tight. Polyester and Dyneema in dark colours will last years. Webbing nets should only be used on small areas and only if they meet the minimum openness of your boat. 25% may as well be solid - that just doesnít seem safe.
fxykty is offline   Reply With Quote
Old 11-03-2021, 00:59   #11
Registered User

Join Date: May 2014
Boat: Shuttleworth Advantage
Posts: 2,366
Images: 3
Re: Trampoline replacement.

If you want to lounge at anchor I have seen people use over sheets. A fabric sheet with bungees to hold it in place over the existing tramp. Unclip and fold it up before going to sea.
Tupaia is offline   Reply With Quote
Old 11-03-2021, 02:21   #12
Registered User
 
chrisr's Avatar

Join Date: Dec 2016
Location: Somewhere in French Polynesia
Boat: Dean 440 13.4m catamaran
Posts: 2,333
Re: Trampoline replacement.

this is the only stuff to use on your tramps

https://www.sergeferrari.com/product...-meshes-492-s2

cheers,
__________________
"home is where the anchor drops"...living onboard in French Polynesia...maintaining social distancing
chrisr is offline   Reply With Quote
Old 11-03-2021, 02:27   #13
Registered User
 
Chotu's Avatar

Join Date: Jan 2018
Boat: 50ft Custom Fast Catamaran
Posts: 11,832
Re: Trampoline replacement.

Hmmm. I’m not sure why no one mentioned it yet, but the primary purpose of the net is to avoid pitch pole. It’s not really about water from the underside. It’s about water from the top, when you’ve dug your bows into a wave.

With plenty of open space in the net you can plow forward with the sterns in the air and the bows dug in deep. With a solid deck or closed trampoline, the deck catches in this close call situation and helps flip you over the rest of the way into a full pitch pole.

Best to keep the net as open as possible for safety
Chotu is offline   Reply With Quote
Old 11-03-2021, 17:30   #14
Registered User
 
fxykty's Avatar

Join Date: Apr 2016
Location: Indonesia
Boat: Outremer 55L
Posts: 3,924
Re: Trampoline replacement.

Quote:
Originally Posted by chrisr View Post
this is the only stuff to use on your tramps

https://www.sergeferrari.com/product...-meshes-492-s2

cheers,
Only if your trampolines are very small - thatís a very low openness for that fabric. OK for a marina queen or heavy boat with small bow openings, but not medium to large trampolines.
fxykty is offline   Reply With Quote
Old 11-03-2021, 18:42   #15
Registered User
 
chrisr's Avatar

Join Date: Dec 2016
Location: Somewhere in French Polynesia
Boat: Dean 440 13.4m catamaran
Posts: 2,333
Re: Trampoline replacement.

Quote:
Originally Posted by fxykty View Post
Only if your trampolines are very small - thatís a very low openness for that fabric. OK for a marina queen or heavy boat with small bow openings, but not medium to large trampolines.
we don't fit into either category and find it perfect...but we don't bury the bows that deep that often. prefer the security of this material, which is not going fail

anyway, each to his own

cheers,
__________________
"home is where the anchor drops"...living onboard in French Polynesia...maintaining social distancing
chrisr is offline   Reply With Quote
Reply

Tags
men, ramp

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Trampoline Replacement Parts? jlstoddard Multihull Sailboats 4 22-10-2012 17:16
Trampoline replacement Sid22 Deck hardware: Rigging, Sails & Hoisting 4 26-09-2012 07:29
Trampoline replacement Teej Multihull Sailboats 3 14-06-2012 18:17
Trampoline replacement Teej Construction, Maintenance & Refit 0 12-06-2012 14:52
General Info: Lagoon Trampoline Replacement Sunray31123112 Lagoon Catamarans 3 19-08-2011 14:33

Advertise Here


All times are GMT -7. The time now is 14:41.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.