Double stack designs

I'm redesigning my double stack trailer for F18s and F16s. Search feature stinks. Can someone direct me or provide pics, etc. Thanks!

this one is probably a year old now and is still working a treat with it on the road most w/ends.



Trailer can be used for one or two boats as the 2nd boat carrying setup is all slip in.
Basicly the 2nd setup is a duplicate of the lower setup.

I don't see any for/aft or side-to-side angle bracing. You're not concerned about the frame racking?

sm

Andy, I'm extremely pleased with how well my setup has worked.

I like mine. similar to the ones Fun in the sun sell.

I've got a second iteration of my first one in my head...but regretfully, no sketches. It consists of a flip down rear rack and mast support that hinges on the rear cross bar and might even include a locking system on the hinge (locking vertical). Two members attach to the trailer forward of the rear and hinge up to be bolted in place with some speed knobs.

The front rack would be completely welded (as was my last one) and rest on the cross member just in front of the beam of the lower boat. It too would have a brace that goes rearward to bolt to the trailer to give it some fore/aft stability but that brace would be welded to the doublestack rack and be bolted semi-permanently in place.

I've seen some designs that have a box built around the lower boat with a diagonal cross member between the top and the bottom. I like that solution because it gives you complete access to the lower boat...but, the tradeoff is that it makes it forever difficult to get to the trailer boxes.

Thanks for the input. Please keep the suggestions coming. I have a Mac Daddy box from Trey that changed things because of the height.

If you use strong enough material, you shouldn't need diagonal bracing. You may want to use gussets, but I've seen some strong trailers without that as well. The tradeoff is weight, of course.

The outside box idea is great if you want to sail the bottom boat more often, especially if you routinely store two boats on the trailer.

Can't wait until my kids are old enough to need a doublestack!!!

Mike

My trailer set up you can remove the bottom boat without removing the top boat. You do however need to take the masts off as the rear support blocks the boat in.

This is the poor mans triple stack trailer, highly not recommended, extremely slow to pack and reassemble. but that is what happens when you buy two boats at a national titles. It got us home but really didn't like it!

What about a hexa stack trailer? With an ATV?





This is one of Fun in the Sun's trailers coming back from ABYC in Long Beach for the Alter Cup a few years ago.

Used motorcycle tires work as good between-boat pads in a pinch. I've seen some a-caters do that before.

I've done the 2x4 wrapped in beach towels trick before, and it works well. But, the OP is talking about designing (or redesigning) a real double stack trailer.

One other thing to consider is flexibility in the design to accommodate a third boat. Not something that's done every day, but gives you the option to buy a new boat, help with a sale delivery, get another boat to a big regatta, etc. Sort of like us with the single trailers jury rigging up a double stack, you could plan ahead to turn your double into a triple on demand.

Mike

Building a rack on the front that could carry a set of cat-trax to use as cross bars has been on my list for a while now. I think that 2 separate stands in the back could support another set of trax for the 2nd boat. I think that it would work well enough, if you were dedicated double stacking most of your trips, then you would probably want an option that didn't lock in the lower boat.

I would be worried about the strength of the catrax for the front part since the 80% of the boat weight is carried there and it sees considerably higher cycle loading while on the trailer. But, that is a really interesting idea for the rear cradle and one I might steal. My trailer is already configured with uprights to store my cat-trax so if I'm double stacking, I only need to transport one extra set. Interesting thought. It might lead to needing extra height to clear the wheels...or maybe not.

Can you make the centerline sailbox slide (on rollers like a drawer) out behind the trailer? Maybe a swing-down wheel to support the aft end while it's extended?

Then you might get to the sailbox without moving any boats (not sure if you'd ever need to do that but since we're brainstorming....)

My theory was that with 2 boats you will want 2 sets, and they do take considerable room on a trailer, might as well make use of it.

A removable external upright would solve any issues with the tracks not handling the load, but that sounds like a bandaid to me.

If you could sneak the upright of the front stand between the hull of the lower boat and to the outside of the trax tire, I bet it would survive.

Here is my other elegant solution.

This is a popular double stack trailer we use over here.
The top hull supports are removable when you are just using one boat, and the box is big enough to fit a complete set of gear for two boats.

So you have zero access to the box if there are boats on the rack?

I guess you'd get used to that, but something is almost inevitably forgotten at least once in a while.

Mike

Same here. I would have a bunch of those "damnit!" moments that way.

I cut an "idiot door" on the back panel for just that reason

If you have two boats it will not be possible to get into the box, the box will be completely filled with sails etc anyway.
With just one boat access is easy as the box can be pushed open when the boat sits on top of it

Like I said, you've probably gotten used to packing up the box before putting the boat on, and it's no problem. I can see myself forgetting to put a board or rudder crossbar in and not noticing until it's too late.

Mike

Or, getting home and reviewing your boat to-do list and realizing spacers for the trapeze shackle and repair the chips on the foils are on the list. Or maybe you decided you want to try your 10:1 F18 mainsheet system on the trimaran you are getting ready to sail and all that stuff is trapped under two boats....Or...I need a ring ding and a shackle for my J22 and my sparts (spare parts...must be said with thick southern drawl) box is in there too!

The real question is what is the advantage of having the hull crossbars supported by the trailer box? I don't see any. The box needs to be stronger (read, heavier) to support a double stack of boats. The boats are higher up off the ground meaning more lifting to get them up on the trailer. And then there are all of the box access issues previously mentioned. The design doesn't make much sense to me.

sm

The higher the boat is the less likely it is to get hit by anything the vehicle kicks up though.

I suppose. I've personally been trailering cats for about two decades and never had any significant issues with stuff getting kicked up from the tow vehicle. If it's a concern, get a set of mud flaps, and if it's a major concern, get some hull covers. Both of those options still seem a lot more convenient than having to lift the boat up an extra foot to foot and a half each time and not being able to get into your trailer box. Heck, if you want the boat higher off the ground, weld up some extensions to raise the trailer crossbars up an extra foot. Incorporating the crossbars into the box just makes no sense to me - I don't see any real compelling reason to build a trailer that way.

sm

I'm just trying to point out an upside. I'd do enclosed for everything if I could afford another $20k boat expense, but I'm pickier than most.

Probably not what you're looking for but I love this guy's work.

https://www.google.com/search?q=sta...mp;ved=0CFYQsAQ&biw=1280&bih=632

F that. Cool, but F that.
I kicked around building a slip in camper for my pickup out of wood then glassing it. Way too much screwing around.

hehe...he made a pun.