Protoype wing rig on Artemis test tornado catamaran

One of the Artemis race teams prototype wing rigs being tested on the teams tornado catamaran. The extra weight seems to increase pitching a bit not that it will be as much of a problem with a AC72

 

"increase pitching"

Gooday - 'evening' - mate. Now we're finally close to somewhere I feel really confident to have an - at least equal comment with the likes of you, Doug, Gary & Steve. I'm in familiar territory with this one - for sure, home ground & 'at home' with this subject & at this level. So lets all learn from each-others strengths !!!

I would have some serious questions about your assumption "increased pitching" - caused by - with an inuendo about - that being caused by the wing. IMHO - not so - not at all.

Possible not so - & if so - then how come the 'Tornado' was not h-h'ing as much with the front-sail in full & drawing including the jib - is it possible the the rig -regardless of wing or not - was not balanced to the hulls or in fact that the hulls are not balanced ???

Is it possible that the 'CoE' of the wing - is much farther forward - when in a dynamic situation - that most people can possibly understand - IMHO - ha.

There is some recorded history of wing-masted 'B' class cat against a 'Tornado' - seems to be recorded that a 'wing-masted 'B' class did very well against the best of the best 'Tornado's made & sailed

Is is possible that the 'Tornado' has the front beam - mast step - to far forward ??? - Is it possible that the bows of the 'Tornado's bows are way to fine - even with out the wing -mast ???

Is it possible that the faster a wing goes forward - the more the 'CoE' moves forward & higher - - unless the wing twists off at the top - & decreases in section & does that all automatically ??? especially at the top ??? What you think guys ??? Good history lesson for you chaps !!! me thinks. All been done - & way more than that & all back in 1967 ish. Ellison - OH - how I do wish I had your money ! ! ! !

What's new ??? - well not much - with all due respect !!! which I honestly do have - 'dem AC 45's guys' still don't know how & when to 'tack the mast' & as yet - they aren't even close to learning either when or how or what - it should all happen automatically - as it did way back when. We've all got so much to learn - me thinks. In a 'AC 72' - it would save 1 crew member & thus the weight - which - COULD BE - 1/2 a foot & win the cup. Syd to Hobart's (670 kt miles) won by 7' - if I do recall ??? Ciao, james

 

No problem Silver Raven I think you could well be right it's just an observation from watching standard tornados sailing with soft rigs they would normally go through that chop no problem at all. Since this cats a testbed I'm sure they were more interested in trying out control systems than optimising the wing for the tornado platform.

 

JJ, (Silver Raven) it does seems the rig is heavier (obviously) and the platform is pitching somewhat and the leeward hull is well depressed and making a fuss at times. But we need a conventionally rigged Tornado alongside to really know - because the wing job looked to have good speed with the extras. Also upwind, it has to be more powerful and agreed, the CoE will move forward with the better dynamics of the wing. And maybe the Tornado is not the right platform to put it on. The proportionately wider (and longer) C Class might make all the difference. Interesting to hear what the C Class experts here have to say.

 

Feel free to correct me (I'm not a cat sailor), but to me it looks like that cat needs at least 30% more freeboard for the size of chop seen at around 1:30 and near the end of the video. The trampoline gets dipped too often, visibly slowing the boat down.

 

It seems like a weight and/or COE issue with the rig on a tornado platform but as noted it does seem to provide good performance I guess it just shows you have to match rigs to platforms to maximise their performance. I'm not a luddite and would like to see more wings on more performance multihulls (I had a rotating small chord carbon wingmast drawn for my Kraken 25 for example). Here is a video of a standard carbon rigged tornado for comparison they bounce about a bit in chop but it should not slow the boat down markedly.

 

The Tornado hulls, which were originally tortured ply, reduce pitching by having the ends very different in immersion rate, i.e., the transom is fat and round, the bow is like a knife blade. If you look at them sailing in heavy air, the crew are trapezed fairly well back and the boat is planing on the after part of the hull. I suspect that the wing's COE is higher and perhaps it weighs more than the normal rig, so you'd expect it to depress the bows more easily.