Jump to content

Grainger R42 - 12.8mts Performance Cruiser Trimaran


Recommended Posts

Cicala, a 38 ft sporty condo cat was the only official multihull finisher in the Lincoln race. I have sailed on it, but forget who the designer/builder was.

It is owned by long time good friend John Muirhead. His old boat Enchantress (designed and built himself) was 3rd out of 4 in IRC 2. Have done a half dozen or so Lincoln races, including one on Enchantress.

Cicala’s elapsed time of 16 hrs 21 mins (Average Speed 9.5 knots) vs TP52 Ichi Ban’s 10 hrs 53 mins (Average Speed 14 knots) is interesting...... Going across the bottom of Yorke Peninsula can be very gusty and flukey, especially at night..... Nasty in a hard southwester.....

Link to post
Share on other sites
  • Replies 240
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

I did the Nationals on Carbon Credits and the Lincoln Race on Venom. The short course racing for the Nationals suited us on Carbon, we had a fully dialed in crew, all the sails you need and I bel

Pil and Wess, Everything is a sliding scale with fast boats and around this size handling issues start to become very important. The Mid Girth of well designed sails is a great way to place 

She is a beautiful boat and a credit to Tony Grainger and Jamie Morris the builder. This is the Hounds Code Zero, meant to be flown off the inner point on the bowsprit, at the time of this photo

Posted Images

19 hours ago, MRS OCTOPUS said:

Nice,

The total elapsed times for the regatta with one drop  shows the Farrier, Carbon Credits to be approximately 10 % faster than the much larger Grainger, Venom.

Early days?

Short courses really favor smaller boats.

In the Newport Unlimited on my forty footer the only time we were able to correct in front of the hot Farriers was when I had Brian Thompson and Lars Christianson off Steve Fossetts Lakota crewing for a change of pace - never saw the chute go up and down that quick before - averaging ten windward/leeward does the trick!

Offshore, shorthanded with my lesser skills we run away from those guy’s.

It takes so much more time to change gears with bigger sails.

So what happened in the Adelaide to Port Lincoln? Weather conditions?

Link to post
Share on other sites

Just spoke to John on Cicala.....

Apparently Venom was way, way ahead and looking to finish well before midnight when it broke a rudder not far from Lincoln. Crosshair appeared to have sail/ rig problems early and retired, presumably back to Adelaide. Plenty of S-SE 20 knot plus winds to start with, but died and went further east becoming more or less a dead run from Cape Spencer. their ETA up to then was ~ 2300 hrs. They lost all the ground coming in and also took it easy earlier.... John is new to multihulls and was worried about pitchpoling at night.... This from someone who won a Melbourne Hobart a few years ago on Enchantress by carrying a kite around the bottom of Tasmania in a blow when no one else in the race could/would. But then, he could sail it blindfolded....

  • Like 1
Link to post
Share on other sites
9 hours ago, bushsailor said:

Carbon rudder shafts on powerful multis ........ been there done that, never again.

Venom looked really good off the start line.

Whats wrong with them?  All serious offshore multis have carbon stocks and blades we had one on Spirit and it was by far the best rudder system I've used in thirty years super light with plenty of power.  Like most things they seem to have issues if they're not done right.

Pic is of Spirits rudder and stock from 2010 when she was first hauled in Newport RI.

IMG_1087.jpeg

  • Like 3
Link to post
Share on other sites

How much is super light? How many multis? The effectiveness of the rudder is more a function of the design, not the construction.

I think Ester at Greene Marine  made that replacement for the one lost when Spirit drove ashore in Stonington Ct. and the  saildrive got driven up through the hull.

My buddies TRT 1200 came with carbon shaft/blade rudders. One sheared off at in pretty light chop in the Delaware Bay. He replaced it with an identical factory replacement and found them too small fo control offshore. He replaced them with upsized, factory furnished carbon shaft/blades off the bigger TRT. Always leery about another shaft snapping (he sailed in and around Seattle with logs floating around) he asked my opinion and I suggested, designed and made solid alloy shafted/foam glass skinned replacements. They were lighter and more impact resistant and he loves ‘em. Anybody need some oversized carbon rudders for TRT? They are available.

There is something of an issue of scale here. For bigger boats/rudders the undeniable better strength of carbon pays off. For little rudders and their associated smaller shafting not so much - particularly if impact resistance is considered - and losing a rudder is VERY serious even if you have a spare out there on the other ama stern.

The rudder on my forty foot tri is similar size wise to Spirits with a solid alloy shaft/foam glass skinned blade and it’s a hell of a task for me to muscle it down under the stern to insert into it’s home - it slams up beneath the hull and lifts the stern a bit - read it has a lot of float and keep your fingers clear!

Greene Marine made a fine rudder for Spirit but I don’t think it’s comparable to Venom’s except being made of carbon hanging on a tri.

Link to post
Share on other sites
On 2/20/2020 at 11:25 PM, MRS OCTOPUS said:

Nice,

The total elapsed times for the regatta with one drop  shows the Farrier, Carbon Credits to be approximately 10 % faster than the much larger Grainger, Venom.

Early days?

 

On 2/21/2020 at 7:10 PM, boardhead said:

Short courses really favor smaller boats.

In addition to the short course thing I've found it really takes at least a year to get a new boat and crew really dialed in, and the Farrier teams have likely been doing it much longer and are much more dialed in.

I really think we need to give the Venom team a year to sort themselves out...

  • Like 3
Link to post
Share on other sites
15 minutes ago, gspot said:

 

In addition to the short course thing I've found it really takes at least a year to get a new boat and crew really dialed in, and the Farrier teams have likely been doing it much longer and are much more dialed in.

I really think we need to give the Venom team a year to sort themselves out...

For sure.

Link to post
Share on other sites
3 hours ago, gspot said:

 

In addition to the short course thing I've found it really takes at least a year to get a new boat and crew really dialed in, and the Farrier teams have likely been doing it much longer and are much more dialed in.

I really think we need to give the Venom team a year to sort themselves out...

Yes, good points.

It does put into perspective though how a boat design , constrained by its trailability, can still perform well against much larger and newer designs with out these constraints.

Waterline length will always be KING in waves.

Just say'n.

Link to post
Share on other sites
5 hours ago, boardhead said:

How much is super light? How many multis? The effectiveness of the rudder is more a function of the design, not the construction.

I think Ester at Greene Marine  made that replacement for the one lost when Spirit drove ashore in Stonington Ct. and the  saildrive got driven up through the hull.

My buddies TRT 1200 came with carbon shaft/blade rudders. One sheared off at in pretty light chop in the Delaware Bay. He replaced it with an identical factory replacement and found them too small fo control offshore. He replaced them with upsized, factory furnished carbon shaft/blades off the bigger TRT. Always leery about another shaft snapping (he sailed in and around Seattle with logs floating around) he asked my opinion and I suggested, designed and made solid alloy shafted/foam glass skinned replacements. They were lighter and more impact resistant and he loves ‘em. Anybody need some oversized carbon rudders for TRT? They are available.

There is something of an issue of scale here. For bigger boats/rudders the undeniable better strength of carbon pays off. For little rudders and their associated smaller shafting not so much - particularly if impact resistance is considered - and losing a rudder is VERY serious even if you have a spare out there on the other ama stern.

The rudder on my forty foot tri is similar size wise to Spirits with a solid alloy shaft/foam glass skinned blade and it’s a hell of a task for me to muscle it down under the stern to insert into it’s home - it slams up beneath the hull and lifts the stern a bit - read it has a lot of float and keep your fingers clear!

Greene Marine made a fine rudder for Spirit but I don’t think it’s comparable to Venom’s except being made of carbon hanging on a tri.

Wow, I would never have thought that solid alloy would be suitable for rudder shafts, is it a very high tensile alloy that you use Boardhead?

Link to post
Share on other sites
3 hours ago, gspot said:

In addition to the short course thing I've found it really takes at least a year to get a new boat and crew really dialed in, and the Farrier teams have likely been doing it much longer and are much more dialed in.

I really think we need to give the Venom team a year to sort themselves out...

Totally agree....... But I am a bit surprised that a new leading edge 42 ft all carbon trimaran rates less than an older 32 ft all carbon trimaran.

Using the numbers upthread, if it is theoretically, on average ~ 6% faster, you would expect the rating to be ~ 6% higher, not ~ 1% lower?

  • Like 2
Link to post
Share on other sites
27 minutes ago, he b gb said:

Wow, I would never have thought that solid alloy would be suitable for rudder shafts, is it a very high tensile alloy that you use Boardhead?

No, good old 6061 T6, cheap and readily available with good structural strength and toughness, high yield point, responds well to hardcore anodizing for excellent corrosion resistance and a hardwearing bearing surface. Weighs less than 35% of stainless with a higher tensile yield. Decent elongation to break for shock loads and 500 mil cycles at 30% ultimate tensile (way over service load) for long life. 

Getting off subject here - sorry!

  • Like 1
Link to post
Share on other sites

I had some problems with Carbon rudder shafts on Cynaphobe / 66 binding up under loads.... But i think it's all more due to the shafts flexing and binding in the tubes and bearings... The bearings on XL2 are very high quality and eliminate any issues at all... by far the best i've used
Venom is new will have teething problems like every new boat.... 

42..2.jpg

42...1.jpg

  • Like 1
Link to post
Share on other sites

Venom will get way quicker over the next 12 months. I dont think she has  even got a spinnaker yet.

On carbon rudder shafts I believe the secret is large diameter which reduces flex. Monos have way less failures due to large diameter shafts.

On my cat we load tested the shafts before final machining with 2 ton and had  20mm deflection over 2m which at the time I thought was pretty good but turns out was not good enough.

Flex is really bad over many cycles as each cycle weakens or breaks the structure down on fibre at a time. 

I never thought about aluminium shafts before!! My cats are 50mm diameter solid high tensile stainless which are very heavy.

Link to post
Share on other sites
1 hour ago, bushsailor said:

Venom will get way quicker over the next 12 months. I dont think she has  even got a spinnaker yet.

Totally agree. OMR data says she has a small kite, about the same size as the screecher on Carbon Credit, and no screacher.

But the rating?

Link to post
Share on other sites
6 hours ago, he b gb said:

Wow, I would never have thought that solid alloy would be suitable for rudder shafts, is it a very high tensile alloy that you use Boardhead?

An article you may find of interest, complete with material comparisons.

https://www.jefa.com/products/materials.htm

Link to post
Share on other sites

I think boardhead nailed it....carbon is great if you get it right, talk to the F1 teams building carbon torque tubes...I would also want solid core or at least +50% lamininate thickness tapered at the bearing points for compressive loading, and at some point the weight savings on a 40 footer don't really make sense. Overall though, it is hard to beat 6061 as a fabrication material, though the strength to weight ratio of 17-4PH stainless is also hard to argue with in an isotropic material....it's better than titanium FYI, the only reason to go Ti is the very inert and high temperature resistance of Ti, but in our applications coatings can get you pretty dang close for corrosion resistance.

Link to post
Share on other sites
On 2/22/2020 at 1:10 PM, boardhead said:

Short courses really favor smaller boats.

In the Newport Unlimited on my forty footer the only time we were able to correct in front of the hot Farriers was when I had Brian Thompson and Lars Christianson off Steve Fossetts Lakota crewing for a change of pace - never saw the chute go up and down that quick before - averaging ten windward/leeward does the trick!

Offshore, shorthanded with my lesser skills we run away from those guy’s.

It takes so much more time to change gears with bigger sails.

So what happened in the Adelaide to Port Lincoln? Weather conditions?

I did the Nationals on Carbon Credits and the Lincoln Race on Venom.

The short course racing for the Nationals suited us on Carbon, we had a fully dialed in crew, all the sails you need and I believe we sailed the boat well for a great result.

We were able to get off all start lines well and had the sails and crew to continually change gears and get the most out of the boat.

Venom was sailed quite well at Vincent but the short courses and lack of a full sail wardrobe played into our hands to make it possible to beat them over the line in all races.

The long passage race from Adelaide and the return leg was a totally different story with Venom showing significantly more speed in the open water sailing and more breeze. 

The boat was awesome in the lincoln race, we still suffered a little from not having a Screecher for around an hour and also could have used a MH sail in the earlier stages if the VMG run. The big surprise for me was the depth we achieved out of the hounds Code Zero and proved that boat may be faster than I anticipated.

Venom does only have a hounds Code Zero at this stage so there is quite a performance gain to come yet.

The wardrobe is still missing a upwind Capable Screecher and this will light the boat up super early.

This is a new custom boat, the build is awesome and the platform is crazy stiff, the rig is also a great piece of work by Lorima and AYS.

The OMR ratings at Vincent were originally published with a mistake, the actual final OMR for Venom was just over 1 quite a bit above the Farriers.

All new boats take time to sort out, especially one of customs....

  • Like 12
Link to post
Share on other sites
  • 2 months later...

Following online & regularly checking boat speeds Venom was always between 1 & 3 kts faster than any other competitor.! Up till the rudder broke they were doing a horizon job on the rest. Also only the main hull rudder was being used due to some sorting needed on the float linkages. She will be much more venomous yet! 

  • Like 1
Link to post
Share on other sites
  • 1 month later...

Here is the Tracker video

Trimaran Venom (R42 Grainger) had an amazing run in the 2020 Adelaide to Port Lincoln Race after establishing a lead of about about 20 nautical miles over the top monohulls including Naval Group (70'6" Reichel Pugh), Chinese Whisper (Judel Vrolijk 62), Ichi Ban (Botin 52) and Secret Mens Business (TP52). The tracking images are from the YB Yacht Tracker.

Venom was denied the Race Record when the rudder stock snapped 30n.m. from the finish line.

Venom's performance was all the more impressive given that she wasn't carrying a large screecher or gennaker in the reaching and downwind conditions.

 

  • Like 3
Link to post
Share on other sites
On 5/9/2020 at 6:36 AM, Trimariner said:

........only the main hull rudder was being used due to some sorting needed on the float linkages. 

The float rudder linkages do look suspect...lots of articulated and moving parts, the rudder spanner looks too slender?.

Can’t be a good feel or response on the float tillers either?

 

Link to post
Share on other sites
  • 8 months later...
1 hour ago, huey 2 said:

151931273_1912411038908475_4521758385242968574_o.jpg

 

That shot is a beauty! And damn that is a flat cut for a chute.  Is that designed to be a reacher or are you using that as a runner for downwind VMG sailing?

  • Like 1
Link to post
Share on other sites
6 hours ago, Wess said:

That shot is a beauty! And damn that is a flat cut for a chute.  Is that designed to be a reacher or are you using that as a runner for downwind VMG sailing?

Mundt is right, looks like a code zero, which rates as a spinnaker under OMR. Venom on the OMR website is rated with a spinnaker, no screecher, but the rating shown must be suspect anyhow. Since when does a top of the line 42 ft Grainger tri rate less than a 24ft Diam tri?

http://www.mycq.org.au/omr/omr-preamble  Sections 12 and 13.

http://www.mycq.org.au/documents/omr/omr.xls

Venom 6th up from the bottom, Wilparina 3, a Diam, 3rd up from the bottom.

Venom: 0.944, Wilparina 3: O.983 and Carbon Credit (F31SRCX): 1.030!

Hard to believe it is all to do with the weight: 3775kg, 597kg and 1583kg respectively.

 

 

Link to post
Share on other sites
9 hours ago, Wess said:

That shot is a beauty! And damn that is a flat cut for a chute.  Is that designed to be a reacher or are you using that as a runner for downwind VMG sailing?

She is a beautiful boat and a credit to Tony Grainger and Jamie Morris the builder.

This is the Hounds Code Zero, meant to be flown off the inner point on the bowsprit, at the time of this photo the boat was still missing two sails from the inventory, the Screecher off the same hoist and inner tack point would have been the sail for this hot angle.

Attached is the design of the sail in this image, off the correct tack point the foot is not so tight. it can be used through the whole wind range, sail suits 55-90 AWA, so shy reeching in the light right through to being the sail for VMG runnning angles in 22- 30 knots. This sail measures as a Screecher in OMR.

The boat now has a new sail we named the MHA3 which is also measured as a Screecher on OMR for 65- 110 degrees AWA, and to be used from 0-22 knots true.

Quite similar sails by design as the boat always pulls the apparent forward of the beam, but different areas and fabric engineering.

The Zero is a tight luff bottom up furling sail, and the A3 eases the tack up to set the slightly soft luff and you tack down tight to top down furl with the cable in the luff.

The Screecher is yet to be done for the boat and would complete the sail wardbrobe.

The MH A3 was added into the OMR spreadsheet under spinnaker and throwing the numbers out, attached is the correct OMR with the sail added into the screecher section and no spinnaker. I think the boat will sail to this rating quite competitively offshore.

Just remember the crew weights are not added into the spreadsheet until an event, so the likes of a Diam 24 rating drops significantly when you insert the crew weight.

So you need to add in crew weights to compare properly.

Hounds Code Zero.jpg

MH A3 paels.jpg

OMR Venom.jpg

  • Like 6
Link to post
Share on other sites
2 minutes ago, Lowgroove said:

She is a beautiful boat and a credit to Tony Grainger and Jamie Morris the builder.

This is the Hounds Code Zero, meant to be flown off the inner point on the bowsprit, at the time of this photo the boat was still missing two sails from the inventory, the Screecher off the same hoist and inner tack point would have been the sail for this hot angle.

Attached is the design of the sail in this image, off the correct tack point the foot is not so tight. it can be used through the whole wind range, sail suits 55-90 AWA, so shy reeching in the light right through to being the sail for VMG runnning angles in 22- 30 knots. This sail measures as a Screecher in OMR.

The boat now has a new sail we named the MHA3 which is also measured as a Screecher on OMR for 65- 110 degrees AWA, and to be used from 0-22 knots true.

Quite similar sails by design as the boat always pulls the apparent forward of the beam, but different areas and fabric engineering.

The Zero is a tight luff bottom up furling sail, and the A3 eases the tack up to set the slightly soft luff and you tack down tight to top down furl with the cable in the luff.

The Screecher is yet to be done for the boat and would complete the sail wardbrobe.

The MH A3 was added into the OMR spreadsheet under spinnaker and throwing the numbers out, attached is the correct OMR with the sail added into the screecher section and no spinnaker. I think the boat will sail to this rating quite competitively offshore.

Just remember the crew weights are not added into the spreadsheet until an event, so the likes of a Diam 24 rating drops significantly when you insert the crew weight.

So you need to add in crew weights to compare properly.

Hounds Code Zero.jpg

MH A3 paels.jpg

OMR Venom.jpg

Very nice; thank you.

Link to post
Share on other sites
1 hour ago, Lowgroove said:

She is a beautiful boat and a credit to Tony Grainger and Jamie Morris the builder.

This is the Hounds Code Zero, meant to be flown off the inner point on the bowsprit, at the time of this photo the boat was still missing two sails from the inventory, the Screecher off the same hoist and inner tack point would have been the sail for this hot angle.

Attached is the design of the sail in this image, off the correct tack point the foot is not so tight. it can be used through the whole wind range, sail suits 55-90 AWA, so shy reeching in the light right through to being the sail for VMG runnning angles in 22- 30 knots. This sail measures as a Screecher in OMR.

The boat now has a new sail we named the MHA3 which is also measured as a Screecher on OMR for 65- 110 degrees AWA, and to be used from 0-22 knots true.

Quite similar sails by design as the boat always pulls the apparent forward of the beam, but different areas and fabric engineering.

The Zero is a tight luff bottom up furling sail, and the A3 eases the tack up to set the slightly soft luff and you tack down tight to top down furl with the cable in the luff.

The Screecher is yet to be done for the boat and would complete the sail wardbrobe.

The MH A3 was added into the OMR spreadsheet under spinnaker and throwing the numbers out, attached is the correct OMR with the sail added into the screecher section and no spinnaker. I think the boat will sail to this rating quite competitively offshore.

Just remember the crew weights are not added into the spreadsheet until an event, so the likes of a Diam 24 rating drops significantly when you insert the crew weight.

So you need to add in crew weights to compare properly.

Hounds Code Zero.jpg

MH A3 paels.jpg

OMR Venom.jpg

So the A3 is a top down furl....?  The cable I guess spins inside the luff tape..?  As opposed to the older version where the cable is always tight and the luff of the sail is longer than the cable...?     If so is this version having less problems with furling than external cable...?   This also means a little less sail area as the luff is shorter than it would be an external cable with A3. (When sailing the tack is 0.5-1m higher off the prodder when sailing deep...? )     I would like to know more 

 

  • Like 1
Link to post
Share on other sites
11 hours ago, PIL66 - XL2 said:

So the A3 is a top down furl....?  The cable I guess spins inside the luff tape..?  As opposed to the older version where the cable is always tight and the luff of the sail is longer than the cable...?     If so is this version having less problems with furling than external cable...?   This also means a little less sail area as the luff is shorter than it would be an external cable with A3. (When sailing the tack is 0.5-1m higher off the prodder when sailing deep...? )     I would like to know more 

 

LOL, I was thinking of the same questions for @Lowgroove if its not imposing. I was guessing (?) that its a top down with an internal cable and the theoretic lost SA compared to an external cable not an issue if the boat is so fast that even VMG running the apparent is forward of 90.

But in the statement "A3 eases the tack up to set the slightly soft luff and you tack down tight to top down furl with the cable in the luff" I was lost or not following how the tack was being eased to soften the luff?  Is the whole bottom of the furler is eased along with it and how does that work in lighter air? 

No criticism intended or implied.  I am curious to learn more.  Cool boat and program.

  • Like 1
Link to post
Share on other sites

Pil and Wess,

Everything is a sliding scale with fast boats and around this size handling issues start to become very important.

The Mid Girth of well designed sails is a great way to place them along the sliding scale of Apparent wind angles and suitable handling systems.

Pil, when you say the "old external system" it is not old it is just what is required for a sail that has a mid-girth of 85-100% and therefore a soft luff, forward luff projection and can only be dropped by hand, with a snuffer or a external cable top down system. Venom would turn that sail into a flag with apparent wind, or it would be restricted to sailing so deep and slow to stop the apparent from collapsing a big deep sail, area is not everything.

So most Farriers and Corsairs and most Grainger's, Dragonflies and so on are at a point along the sliding scale of speed and apparent wind angles that they require a soft luff spinnaker for light to medium wind VMG running, with a mid girth between 85-95% and a generally flatter cut than a mono sail, but almost all of these boats if choosing to furl that kite would only be able to use a top down furling system but it would need to be an external cable. If any of these boats had a sail similar to Venoms MH A3 with a mid girth of 60-75% then they could have a sail (but not achieve the best downwind VMG as not fats eough)with a luff length that is slightly longer than the straight line (with the furler and some tack ease space reduced) and ease the tack or halyard to set that luff as a soft luff sail making it more versatile and potentially giving a mode where more depth can be achieved, it is only just a soft luff sail. In that case the top down system can have the cable internally in the luff tape, the head is lashed tight to the head thimble and the tack is not floating away from the top down adapter but on a short strop. The adapter then spins the cable only leaving the tack of the sail to sit in place whilst the rope up the luff tape spins furling the sail from the top. So you tack down hard to make the cable go tight when you need to furl or unfurl, it may be 150-300mm between sailing and furling mode.

A tight luff sail like a Screecher that has a 50% mid-girth and is better as a bottom up furling sail so you don't need to spin the furler as many time to get the sail away and is more efficient. 

If you go further along the speed scale than Venom for boats that sail their VMG downwind angles with narrower AWA you start to come to boats with quite triangular VMG running sails, like Multi 50, Extreme 40, M32, TF10, many of these boats biggest running sails have mid girths of just 50-65%, they are mostly therefore running a bottom up system, but we are starting to see Sailmaking design and construction advancements that are making load sharing sails, Helix is the North Sails option that can have a slightly soft luff set with narrow girths and flat shapes but still be on a top down system with an internal cable or additional structure with heavily reduced cable sizing. This is not "Cabless" but is kind of half way there and makes an awesome sail for very fast boats which tack up and down make a significant different to the set shape and versatility of sailing angles.

The MHA3 sails on the previous Volvo 65's where used as their biggest most powerful VMG running sail and would have had a Mid-Girth of around 65%, these sail are not dissimilar in design shape to the Zero and MH A3 aboard Venom and really paved the way for us to get the trickle down into boats at the everyday level.

https://www.northsails.com/sailing/en/2017/11/sail-profile-vo65-a3

Sorry to turn this into an advert but this link explains the approach quite well, this is the cruising version of this type of sail in it's cruising form, but the basics are very similar to Venoms downwind sails and because Venom is quite fast it really is the best VMG option for a wind range of 0-25 knots from the one sail.

https://www.northsails.com/sailing/en/2021/02/cruising-sail-the-helix-furling-gennaker

Wess, when we say tack up or down we are talking the 2:1 or 3:1 system below the furler, most of these boats run locks up top and a tack system down the bottom.

Venom does not have a lock up top on the MH, but does on the fractional but for both sails to work correctly adjusting the tack up and down is critical.

Does that make sense boys?

The old put a bigger fatter kite on it simply is not the way it works on fast boats.

These sails are not very OMR friendly either, big areas with a MG under 75% rates terribly but makes a great sail that suits the boats performance which is the owners preference.

Helix Downwind key gains.jpg

Forward luff projection.png

  • Like 8
Link to post
Share on other sites

Thanks @Lowgroove.  Most appreciated and helpful. Also just calling our @PIL66 - XL2 in cases he otherwise misses your great response. 

What are you using as a light air VMG runner and what gybing angles do you see (if you can share)?

  • Like 1
Link to post
Share on other sites

@Lowgroove Great response.... I planned go mostly away from kites as well but this year we had many days of 5-15 knots and my courses are shorter so i have used the kite quite a bit so I had neil (Barracouta)  install a luff / foot zips so we pack it and launch from the bag.... Too many problems with the top down and i run 2 other screechers on the prodder so it became a maze of furlers and lines
Thanks again

Link to post
Share on other sites

Thanks for the info Lowgroove,

I have come to the same conclusion except we have pushed our new sail out to 75.01% because of the omr rule. 

I have a furler that can either do bottom up or top down. Am going to try and do bottom up first as I dislike the super tight furl in the top of the sail with top down.

We will be running the sail tack up about500mm and will crank it down to furl.

That helix sounds like the go ...if only I had bought bitcoin 5 years ago.

  • Like 2
Link to post
Share on other sites
  • 3 weeks later...

Lowgroove has said, "So most Farriers and Corsairs and most Grainger's, Dragonflies and so on are at a point along the sliding scale of speed and apparent wind angles that they require a soft luff spinnaker for light to medium wind VMG running, with a mid girth between 85-95% and a generally flatter cut than a mono sail, but almost all of these boats if choosing to furl that kite would only be able to use a top down furling system but it would need to be an external cable."

I have been experimenting with a external cable with a bottom up furler on my boat.  It works very well (but my luff is only 30 feet).  Just wanted to suggest another option since (in my experience) top down furling has its own issues with back furls and numerous turns of the furler before the furling starts from the top.  

Link to post
Share on other sites
9 hours ago, huey 2 said:

162232474_5660522223973106_2647832737022730406_n.jpg

That pic shows extreme (45 degrees?) flare on the main hull that I hadn't noticed or forgotten about, but a thread review shows it's been there all along.  I wonder how that behaves in swell where sudden, massive changes in displacement could result from each passing wave?

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Announcements


×
×
  • Create New...