About Project Darwin

Darwin is a 29' Sailboat that has adapted to a dry lakebed environment by developing giant mechanical legs to help it move around without water. Read more details about Darwin here ...

Monday, May 23, 2016

Big boned boat...

What is a polite way of telling someone their boat is fat?  I don't know... but Kari and I took our Ericson 29 to the Healdsburg Transfer Station to have her officially weighed and she's - uh - above spec.


Here's Kari handling a huge load.  Roxy kept a close eye as we towed her to the scales.
Then, whilst in the shop, I carefully measured the tongue weight - that's the weight held by the hitch on my truck:
The tongue weight is only 850 pounds.

The boat on the trailer weighed in at 9,390 pounds, a full 2,090 pounds heavier than she's supposed to weigh.   But what's a ton of extra weight between friends?  It's more boat to love (and less likely to get blown over in a dust storm).

And of course, sometimes you have to take a break from looking up the shear strength of polyester resin fiberglass, the yield strength of mild steel and your beam deflection calculators because... fruit.

The apricot tree said it was ready, and we couldn't resist the call of nature.  Yummy!

So much more has been going on behind the scenes - engineering (well, under-educated guessing to be honest).   The harness design is coming along nicely.   With the laser boat measurements, I was able to get a pretty good fix on the CG of the boat (196" from the bow if you must know) and verify that leg placement near the forward bulkhead is a reasonable idea.

Also - the 3d model let us know that the hull/deck line is probably co-planar, with a 36 foot radius arc!  Photos make it look like it curves in two planes- but that's probably a trick of the eye and perspective (I like to think Da Vinci would nod approvingly)!
So here's a rough sketch of the harness plan....
The main longitudinal beams will be C7x9.8, which means standard C-channel 7 inches tall, 9.8 lbs of steel per foot.   Van Bebber's in Petaluma is rolling it into a 36' radius arc, right now and with luck, we'll have help buttoning it onto the hull this weekend!

Finally, I have to give a big nod to Earl (aka Dodger), who has been really helping me double-check my design.  He spent his Sunday afternoon machining a part to get a big metal saw operational so we can use it for the project:
This saw used to be at the old Exploratorium, and probably helped make many of the older exhibits you all love - what a pedigree!   And a special thanks to Monkey Boy who's smaller saw really got me cutting up some serious steel before putting it back together different.  Sometimes you don't realize you'll like the big tool until you play with the smaller one.






Thursday, May 19, 2016

Safety Third and Plumb Bobbing

"You want to do what? Are you sure that's safe?"

Those were my first thoughts when Chad said we needed to bring the 35 foot mast down from the top of the boat. Mind you I'm a mere 5'2" tall and it was just the two of us, so the idea that I could help lift this massive mast off the boat and safely onto the ground without killing myself seemed unlikely. Well, I am happy to report I'm still here AND we got the mast down! Now onto plumb bobbing!




The next task at hand was to get as many precise measurements of the hull as possible so Chad could create a 3D model of the boat and do all the necessary calculations to determine the size and strength of the legs and joint mechanism (among many other things). This was a tedious but very important task which involved drawing chalk lines on the ground, using a laser level to measure precise heights and dropping the plumb bob down to capture about 100 different points on the ground.

1ft x 1ft chalk lines for measuring
Plumb bobbing!



Measuring each dot
Laser leveling


Then once all the plumb bobbing and measuring was complete, we entered every point in a spreadsheet and Chad created this AutoDesk drawing.

Each point connected together to make the hull shape

Chad created a 3D surface with lofting





Thursday, May 12, 2016

The Journey to Healdsburg

When you know you know. 

That's how we felt when we finally found the perfect boat for creating 'Darwin - The Walking Sailboat. After many months of searching, we found "Mistral". She's a 29' 1970 Ericson sailboat that was in great shape. In fact she was in such great shape that she actually was sailable! Her first sailing adventure was to bring her from Redwood City up to Berkeley Marina where she would dock until we were ready to bring her up to Healdsburg. 

Happy new boat owner!
Chad, Eric and Tom ready to sail!
Off they go!

Fast forward a few months and a few fun days out on the Mistral in the Bay and it was time to bring her up to Healdsburg to begin Project Darwin. This would be no small feat to drive a 29' sailboat down the freeway to Healdsburg. 

Thanks to the amazing crew at KKMI in Pt. Richmond, we were able to get the boat hoisted out of the water, the mast stepped down (taking the tall mast off the boat), and the boat pressure washed and put on the trailer. With our wide load permit in hand, we took off down the road to the forest. Big thanks to Tom, Marie and Steve who all helped get the boat to its workshop!

Stepping down the mast
Her last sailing voyage ... on water :)
Tiger steering from the bow
Pulling Mistral out of the water

Preparing to pressure wash

Got her on the trailer! Phew!

Wide load coming down the road!

Is that a sailboat in the forest?

Tom backing her into the shop like a pro!

Can't believe how perfectly she fit!