Install Guide · By ATN, Inc.
Install a New Trampoline on Your Multihull
Congratulations on your new trampoline net. You're probably thinking it looks small. That's ok, it's supposed to. Here is the ATN method for installing a rope border net, start to finish.You have received your net from ATN and stretched it out where it is going to go. Your first thought is probably that the net is much too small. Before cussing and giving us a call, read below. The net is supposed to be on the small side so that it can be stretched into shape to make a taut net you can walk on.
When installing, give yourself some time. Etienne Giroire, who designed these nets and has installed hundreds of them, allows about 3 hours per net working alone. Your first will take longer than that, so plan on a couple of mornings rather than one long day. You will be glad not to be fighting a net in the hot part of the afternoon. If you are still choosing a net, sizing, materials and pricing all live on the Multihull Nets page. What follows is how to put one on.
ATN founder Etienne Giroire wrote this method up for ALL AT SEA Magazine back in December 2016, and the original is still worth reading: Install a New Trampoline on Your Multihull. Ten years and a great many installs later, and with Sunrise Yacht Products now part of the family, we have learned a good deal more about how nets behave and how best to design and install them. What follows is the current ATN method rather than a reprint of the article.
This page covers one installation: the ATN style for a rope border net. Other net types and other lacing patterns are done differently, and Sunrise documents many of those in detail on their netting installation pages.
What you need
- 3/16 inch (6mm) covered polyester lashing line
- Gloves. You will want them.
- Pliers, a fid, and a hot knife
- A scrap of wood to cut on
- Water, and plenty of it
- A marlin spike. Not required, but it can be handy.
On a Dyneema net, 2mm Dyneema with three to four wraps per point does the same job and does it well.
The method
1. Consider hanging the Multi-Awning first
If a Multi Awning is in your plans, put it up before the net rather than after. You get shade over the work, which you will realize is pretty dang nice to have a few hours in, and you end up with double the outdoor living space waiting for you the moment the net is done. We now bring an awning to most installs we do.
2. Set the corners
Get the four corners where they belong and attach nothing else yet. The corners are the anchor for every lashing that follows. Start from the middle of an edge instead and you pull the net toward that point, the corners never make it to theirs, and you will not get the net shape you want.
3. Break the net in
With only the corners on, give the net a reason to give. If you are not rushed for time, on a polyester net, wet it down and load it: an anchor, chain, a coil of rope, the dinghy. Leave it overnight and it will have relaxed some by morning. Skip the water on a Dyneema net, it does nothing for you there.
The faster version, if you have hands aboard: put three or four people on the net and let them bounce on it between rounds of tensioning. Do not do this until you have at least half the lacing points on, because bouncing puts far more force into the net than dead weight does. It breaks the net in the same way and you are not waiting until tomorrow.
4. Lash, one point at a time
Work outward from the corners, one lashing at a time. Each lashing is its own piece of line, passed three times through the same point, which gives you a three to one purchase to pull against. Space them roughly every five inches around the perimeter. On many boats the lacing points on the boat will determine the spacing, on some French boats this could be as wide as 7-8" (~200mm), but where possible 5" spacing is excellent.
Pass every lashing around the three strand rope woven into the edge of the net, not through the serged edge itself. That rope is there for exactly this reason: to take the chafe so the netting never has to.
5. Tension in passes
Do not try to finish any single lashing in one go. Go all the way around and snug everything, then go around again. And again. The net keeps giving as long as you keep asking. You are done when the edge sits about an inch from each attachment point, whether that is a slide, a pad eye or a NetNob.
On the early passes, finish each lashing with a temporary half hitch rather than anything permanent. It holds the tension you have just taken while you work your way around the boat, and it pulls straight back out when you come round for the next pass. Save the permanent finish for the end.
The knots and the tensioning are easier watched than described.
6. Leave the tails long, then finish
A new net keeps stretching for the first few weeks of use. Leave the lashing tails long, sail on it, then come back and take up the slack you will certainly find. Once it has settled, finish each lashing with two hitches all the way around and a flat knot melted with the hot knife so it cannot work loose.
If two edges are tight and two are not
You likely started somewhere other than the corners. It is the most common way an install goes sideways, and it does not tension out later. Undo the lashings and start again from the corners. That is faster than trying to rescue it in place. In general, do not pull the net all the way to one side. Keep it roughly centered as you work, taking tension out of every side relatively evenly in rounds.
Boats with lacing buttons
Some boats are fitted with lacing buttons, which ATN calls netknobs. They are a specific piece of hardware on the boat rather than a slide, a pad eye or a mushroom post, and most Fountaine Pajot and Leopard models carry them, as do some earlier Lagoons. Customers regularly ask how to attach to them. It is easier shown than written.
Questions we get
Independent lashings, one at a time, starting at the corners. Use 3/16 inch (6mm) covered polyester, one lashing every five inches, each one passed three times through the same point so it acts as a three to one purchase, and run them around the three strand border rope rather than the serged edge. Attach the four corners first, then break the net in before you work the rest: wet and load it overnight if it is polyester. Alternatively, break it in as you go by having two to four people bounce on the net, but only after at least half the lacing sections are at least temporarily installed. On a Dyneema net, 2mm Dyneema with three to four wraps works well in place of the polyester.
Almost certainly not. We are not perfect, but 98 percent of the time someone calls about a net that is too small, it was built as designed and just needs some good old-fashioned elbow grease. Our nets are built roughly 10 percent smaller than the opening they fill, the exact figure depending on the design and the material, so that they finish tight rather than slack. Both the netting and the border rope stretch appreciably, the 3 strand 12mm border by around 20 percent, but you have to work them into place. Corners first, never from the middle, then break it in by wetting and loading it overnight, or by bouncing on it once at least half the lacing lines are installed. It comes in pull by pull after that. To confirm the net was cut for your boat, sizing is covered on the Multihull Nets page.
From the sailing community
Most owners do it themselves. It is patient work rather than technical work: the skill is in the sequence and in being willing to go around one more time. Etienne allows about 3 hours per net and he has installed hundreds of them. For a first install we generally suggest giving yourself a couple of mornings so you are not working in the hottest part of the day.
Need the net itself?
ATN builds replacement trampolines for over 300 catamaran and trimaran models. Find your boat, see the recommended net type and pricing, or send us your dimensions for a quote.
Stuck partway through an install? Talk to ATN.