For the reader here is a link to the AIR 40

http://harryproa.com/?p=1761

It is hidden on harryproa.

| Erutan,

Eric is fine too. Also anyone feel free to jump in anywhere.

| >> |   I mentally have a tough time contemplating telescoping beams because of my experiences with my current trailer.

| > If I may, that's metal on metal, right? Much higher friction coefficient, I think, than slippery plastics and the right lube.

|   You're right for the most part, but there are also rollers involved. It works a lot better when the boat isn't on the expanding/contracting trailer. 

Lol

| The boat would be largely unloaded, so less force on the mechanism, though I imagine that the mast(s) would want to sway back and forth.

Ha! Rock boat to rock the masts to load and unload the beams, winch the beams tight and watch them jump some inches each cycle as the tension comes off the beams and you crank.

|   UHMW PE on UHMW PE should be fine in terms of smoothness.  I wouldn't want any lubrication other than SailKote or another dry lubricant.
|
|   The trick would still be in keeping things parallel.  With enough bury it might not be a problem.

Wikipedia suggested to not lube UHMW. Also not supposed to leave it loaded all the time, cause it creeps.

<insert creepy laugh>

Do you think parallel beams is hard? Do you Rob?

| > I am not sure an expensive, heavy, super cool, marine screw is the best fix.. But I can see a thing to tighten is needed. But perhaps coolness trumps all.
|
|   Lashings like the Wharrams are probably the simplest, lowest-tech, cheapest, and least failure-prone option.

Don't you think lashing would stretch? Rotating incline planes are easy to get TIGHT.

|  But after that, I still like the screw.  Huge threads so you never have to worry about cross-threading it or getting it jammed with a touch of salt and grit.  Lots of metal so there's little worry about with stress fractures or crevice corrosion.

I can see cranking in a pair of those screws to pull the beams tight. And large diameter/threads make sense. And 2 per joint makes sense. I just have this idea Rob's gonna drop a lighter, cheaper faster version. But if not, they would make me, and most anyone else feel secure.

Could they work loose in a bad storm/vibration? Some sort of nyloc called for? Aviation suggests cotter pin, but perhaps this is too much. Perhaps that's what that plastic ring under the head is.

|   For the folding mechanism on the Ex40 and Air 40, you'd only need one screw per beam assuming the hinges are snug.  Carry four and you've got two spares.
|
|   (Though to argue against myself, four screws in a telescoping or sliding arrangement would be rock solid assuming the ends are bonded to the hulls)

Yep.

| > And I think you loose interior to the swing, perhaps?
|
|   I think the loss of space in the hull on the Mark 1 version of the Ex40 was due to putting the masts through the beam ends to tie all the sailing loads and structures together into one super-solid whole. You could probably keep everything outside, but that said, I'm not sure that the internal space outside the beams and masts is useful in a hull that size.

Good point. And masts through the beam ends is awesome.

|   Speaking of which, Rob and Steinar's take on the Mark 1 folding version is really growing on me.  It's simpler than cat2fold and it allows for a shorter folded LOA.

The Ex40F-folded01.jpg one? Wish I could just link it.

|   Which actually makes me re-think the tender.  It's a really elegant design, but most years I probably wouldn't use the tender for anything other than driving the boat.  In which case, building that outboard well in the lw hull would probably end up being a less costly and simpler solution.  In which case I could go with folding instead of telescoping.

That well video you showed, is just an outboard on an vertical lowering device. Easy to rig such a thing off the beams to allow it to lower till you're happy?

Or, perhaps I ask, why put it in the ww hull?

With no tender, how would you plan to reboard the boat after swimming/overboard?

Would a simple box on a pivot, one cat hull-ish?, be simpler and lighter to deploy/lift the motor?

|   I suppose at this point I could be lightly nudged to one side or the other by another stroke of design ingenuity.

The times we live in...

| > Water?
|
|   Not for me.  Each hull can have its own tank.  Heads will be compositing, so no water or plumbing needed there.  Just a small tank for washing hands in the lw hull, if there is indeed a head in there..

If I wanna go places, and don't want to need a marina, I think we might need showers and a water maker.
I have yet to figure how to eliminate those. If you got ideas...

I was thinking showering-able heads over the composting toilets.

I guessed longer trips would want a shower.
I had thought about filtered salt water (water maker brine) for showers with a fresh water rinse.

So that's 2 water connections.

| > I was guessing there was no way to have tender clearance under the ww hull. But perhaps that guess is off? Or we make it so.

|   There's probably not enough width for a standard 8.5' width trailerable, but if we don't mind pushing out to 10' to 12',

12 is a given, right? Like we are committed to 12.

| there's probably enough between the hulls for a tender with 5' of beam.  The trick would be as you point out -- clearing the foot well and steps down into the main ww hull.  Maybe if the tender were attached only at the nose, the transom would end up being low enough to allow the rest of it to clear the footwell.

You lost me here. Or perhaps I lost you. So let me step back.

My intent was to ask if, when folded, the tender could go under the boat between the hulls.
As I understand it, the ww cabin floor comes off the ww hull, basically, some small amount above the waterline, then continues across the deck to the cabin wall, and then up.

My guess is you got 12-14" of clearance under it when on the trailer folded. The T60 is 1 inch shy of 24" high.

The width is not a problem, I think. The T60 is 6'

So do we lift or step the cabin floor, lower the tender, or find another place for the tender?

And where ever we put it, it need to also go there when marinaing.

If you have 40' flat bed to trailer, perhaps hang the tender aft, off the aft beams when trailering and marinaing.

| > Was there not a rendering that had a rendering (AIR40?) with the tender between the hull when folded?
|
|   The Air 40 is a great design.  I'd still want an Ex40 myself, but every time I look at the Air 40 I'm impressed.
|
|   I believe the renderings showed the tender to the side of the boat when folded.  Though it also looks as if there's enough room between the hulls for a tender as long as it's low enough to avoid the stairs/footwell.

Yep

| > Nice! You know, we cannot run with scissors.
|
|   Good one.  But... we might be able to reach.  (sorry)

Lets agree to mutually disarm

| > I was thinking we seem to want highest beam clearance to lee, as the ww clearance is very little/not needed?
|
|   That's what I would normally think.  But if the tender is connected to the higher beam on the leeward hull, and you telescope down to collapse the boat, the tender is going to run into the cabin/deck. 
| If the lower section is to leeward, the tender can just slide under the main hull once you drop its aft end into the water.

I don't think it's gonna fit there.

| > Where do we put the toy box and bench seats when marinaing?
|
|   On the Ex40 you could probably build the box in a way that lets you stash it between the masts, provided you weren't planning to get on and off the boat in that section.

You kind of have to get off there. The cabin door is the width of the lee hull from the dock. If you put it there how do you get to the cabin?

|   Seats would work.  Or a toybox.  I'm bot sure about both.  Perhaps they fit together like Russian dolls.

That implies you have nothing in them when ever you marina/trailer, or you move it all. Which means you dont need/want them.

How about strap them to the tender? Then float it back and hang it off the aft beam. Then trailer/marina, then lift the tender back into place and reset boxes?

|   I'm not sure about the Air 40, with its (very nice) design of putting those seats over the leeward hull when folded.

I kinda thought that was awesome. I can sit on my boat bench seat right outside my cabin door, at the marina and, I guess, chat with the people. Sitting just like I do when sailing, watching the ocean, except now its boats and people.

And there is a lee hull hatch there. Not sure about that, but perhaps when folded I can stand in the cabin door, lift the hatch, and go down. So that hatch would kinda be the, whats it called where you enter and leave a boat?