AC72 Heel Moment

As with a previous calculation for the moth, watching the AC72s blasting around I wondered about their heel moment characteristics. This time though I had a neat new tool to test out...Autodesk ForceEffect.


 AC72 Heel Moment Report

Blue loads from left are; crew, platform, rig. Pink are reactions.

Make of it what you will, the numbers are rough, the height of the sail restraint is dubious. The items that stand out though are the angle of the resultant hull+foil force and the total hull+foil force...
8.5 tonnes at 24.5 degrees from vertical (and that's just a static load)

Let me know if I've made any major mistakes. Shut your hole if you're an ETNZ fanboy, I couldn't find a photo of New Zealand from the right angle (I'll swap the photo if you supply a good one though.)


In other news, Markla decided that a few weeks before the nationals was a good time to do major structural modifications to his boat. Luckily it all went smoothly and the result is much better than the original

Equally crazy is my goal of coming to the nationals with a new control system...I only started on the weekend. It has been percolating in my brain for ages and now that I have a shed it can be put into practice. Wish me luck.

Photos of the above to come.

PB Speed Records

Not much in the grand scheme of things, but today Markla, Rob and myself went out at Lake Samsonvale just north of Brisbane for some big wind and flat water.

Markla and I set new pb speed records. (Below is for our archives as much as anything.)

10 seconds
Markla - 22.3 knots
Narkla - 23.6 knots
Rob - 22.1 knots

5 seconds
Markla - 23.2 knots
Narkla - 23.95 knots (because Markla won't let me round up to 24.0)

200 metre
Markla - 21.7 knots
Narkla -22.9 knots

Peak
Markla - 24.9 knots
Narkla - 25.6 knots
Rob - 22.8 knots (speedpcuk) (but he wasn't trying, pfft, boat retired hurt before the wind really kicked in)

MSL 10B Mast Bend

Does anyone have MSL 10B rigged mast bend loads and numbers? I have a feeling mine is too straight down low and am considering modifying the spreaders.

No Fucking Way!

Worlds Request

We have a friend, we'll call him Mr Late.

He has a Mach2 being delivered to Campione.

He has flights and should get to Campione the afternoon of the 16th.

What he doesn't have is accommodation.

He's blaming it on the Dubai heat...

If anyone can help him out or point him in the right direction, he would appreciate it greatly.

Contact us and we'll put you in touch with him...if he hasn't melted...

It should be noted that he is super light, super fit and has won a race of the Australian nationals. If he can keep his boat together and the weather is light, he could be a dark horse, barring any rum incidents.

Viaduct Mothing

Stumbled across this while trawling through youtube.

Viaduct Mothing

Kiwi AC72

for those sailors that have been living under rock the last couple of weeks, ETNZ are launching their AC72 this weekend.

today they're doing a test rig.

http://i.stuff.co.nz/sport/boating/7299803/Team-NZ-step-monster-wingsail

 http://www.americascup.com/en/Latest/Blog/2012/7/ETNZ-brings-out-the-big-rig/

 http://www.takeabreak.co.nz/accommodation/auckland-city.asp?cam=2

also stuff on sailing anarchy forums...if you're into that sort of thing...

tribute

"Sad news for time-wasters everywhere, after Eduard Khil, aka Mr Trololo, and the star of one of the internet's most enduring viral videos, died aged 77."

http://www.independent.co.uk/news/media/online/trending-the-world-bids-farewell-to-mr-trololo-star-vocaliser-and-viral-video-virtuoso-7815163.html

our little tribute, one from the archives...

Wing

Did someone say wing...

It's neat that "rumour" starts with rum.

HPYD next week

The HPYD conference is in Auckland next week. Who else is going?

http://www.hpyd.org.nz/

There is a moth lecture which should be interesting.

I'm also particularly interested in the lecture on side force generation of slender hulls.

Others I'll be interested in are:

• Using parametric modelling, CFD, and historic data, to estimate planing hull performance on a laptop
• Design by best engineering principles for the solar catamaran Tûranor PlanetSolar (only because I want to know why the hell they put such a weird propeller on a slow boat)
• Model testing – What is the point? A review of yacht testing and the implications for
  yacht designers (because an old mate from uni is part of the group presenting it)
• AC45: A study of high performance composite construction
• Damage initiation and evolution in marine composite laminates
• New material for sail production
• A review of unsteady hydrodynamic behaviour of sailing yachts and methods to
  study it
• Tuning of appendages for an IMOCA60 yacht
• Hydrodynamic performance of a submerged lifting surface operating at high speeds
• And the fluid structure interactions stuff about the rigs (but only because it is voodoo to me)
  

And the public discussion with the VOR circus.

The rest (if not all) will probably go over my head but hopefully will get some insight into a bit of the racing yacht design field.

nationals 2011/12 in photos

some of me have been trawled up from the depths of teh interwebz.

i think i'll find a real guy fawkes for next wongi. 

coolest thing ever

Great Race 2012

The latest news is that Steve Sherring has taken the line honours and handicap win in the 37nm Southport to Manly Great Race with an elapsed time of 2:29:58.

The Great Race

Results

Word is that it is a course record!

Conditions were generally 15-20 knots from the east. Those that experienced it can give a better indication.

Jack also competed finishing in 2:53:20, about 8th across the line.

Rob Green also competed, however succumbed to the conditions and pulled in to Victoria Point, about half way, after too many crashes.

Markla and I piked on the Great Race, preferring to sail at Lake Samsonvale on the Sunday. We had our own mini marathon that was completed in about an hour. Not much of a marathon so they sent us out again for a course race. I spent the race chasing A's, losing to them upwind (geez they can point), and catching them downwind, (hunting the wind pays in marginal stuff). Markla spent the day in the piss, I think he's forgotten how to sail on flat water since the nationals.

count teh convolutions

bow is to the right in all renders.

the pushrod input is the pair of rod ends in olive colour on the right hand side. the pushrod is not perpendicular to the centreline, hence the rod ends. 

this goes into the first rocker (pinkish). it has the same ratio and phase as the wand lever so the rotation of the bolt at the bow is exactly telegraphed (not sure if this is important, but may help with future development). 

phase can be adjusted on this rocker by spinning (nigga) the on board bolt,  draging the right hand side of the green linkage around that arc track. this is set up for adjustment on the land only. i may add a nob (ur) to the top to make it adjustable from the cockpit. 

green linkage is a turnbuckle that is needed to use the extreme range of the phase adjustment. for minor adjustments to phase, it shouldn't be required, the brown rocker just won't stand up straight. 

brown rocker is the gearing. spinning the bolt drags the input pin up it's track. going up amplifies the signal. it has a rope guide on one side only that moves with the rocker, however i expect it will be able to be adjusted from both sides of the boat, it will just need to remain rather tight, and i may need to make some sort of lead for it. 

next is a blue linkage made from a turnbuckle. this acts as a dial. just before it exits the machine there are two nuts on either side of a plate. these are limit screws that mean no matter what you do upstream, it will bottom out on this plate before damaging the centreboard pushrod. will also be a convenient way to see what the flap is doing. 

bearings are to be pressed in, then retained with worm screws. i have just bought some shock aborbers to add into there somewhere (probably on the pink one, with a screw to adjust lever to for dampening). wand length, bungie and wand stopper will also be run to the tramp, seperate to this machine but equally complicated. 

all plate parts are watercut 4mm aluminium hard coat anodized. bolted to the boat with 5x M5 countersunk fasteners into a carbon channel bonded to the deck. 

Nationals QOTD

Nationals Quote of the Day Round Up:


All of the people quoted below were heard second or third hand and are probably taken out of context if not all together wrong.


Day 1: "If another local says 'it's not normally like this' i am going to throttle them cause I have sailed here seven times and it has always been like this" (les, standing in teh rain)

Day 2: "Every wave is laughing at me" (scott's report after being sent out to check the course)

Day 3: "Is there sailing school on today? All of the boats are capsized." (random old guy on the beach)

Layday Eve Dinner: "While I was in the change rooms this afternoon I saw something very impressive" (leigh on budgie, later budgie dropped his pants to show it off)

Rough as Guts

Rough conditions yesterday, perfect for rum drinking.

Invitation Race

Jack Sherring (QLD) won in a lumpy drift-a-thon (with some marginal foiling) while the rest of us got seasick and heat stroke. Well done Jack.


Race 1
Rumour mill was rife with 20 knots predicted to come soon. After a long wait for the wind to fill in (from nothing) the starter was keen to get some racing in before a front arrived. With some boats still trying to get to the line the race got underway in sub-foiling conditions. This wasn't to last long and within a minute it was all systems go, ~15knots. Upwind was fine in the lumpy stuff but downwind was another story. Plenty of cartwheels ensued as ppl tried to sort setups.


Race 2
I don't know what happened because I pussied out of the first race but the procession of borken or flooded boats was enough to validate my decision to retire for the day and drink rum.


Today is shaping up to be a bit windier from the West. Don't know what that means for the waves, we'll soon find out. End of the week is looking good.


Oddball results to follow but we think Markla is winning, which is very odd.

Rum Squad

One from our part time contributer, Alanla?... Alanarkla?... Alla?

       Rum Squad has not had a tunning seesion together in quite some time, individuals have been training hard during the year.  With an appropriate warm up even this weekend I'm sure the performances of the squad members in apperance at the Nationals will do us all proud.

Rum Squad shall be on the attack at this year's Australian Moth Nationals 

 

Wivenhoe

Spent the last two days blasting around Wivenhoe dam in 10-20 knots with Mark, Rob and Tom. Hit new record peak and 10 second average speeds without feeling out of control. After some time off the water due to unfortunate breakages and control system modifications it was good fun and will try to do it some more after the nationals.