Lowgroove

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Posts posted by Lowgroove


  1. 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 4

  2. 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

  3. 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 11

  4. On 12/19/2019 at 8:36 AM, square top said:

    Surely its a floating tack and the main hasn't been pulled all the way up? The sail looks like its on the boom so should be able to go up and have luff down adjustment. If not the sailmaker needs a measuring tape. 

    If anything this sail could have been 50mm shorter on the luff, she can go full hoist, just a halyard that needs be be pulled up harder, great shots, she's a beast.

    Tack has a lashing.

    • Like 1

  5. 8 hours ago, Indian Chief said:

    Seems like a cool solution so long as the crews make the hard work changes setting up the staysail as the conditions change. I love my new Facnor internal lock on my screecher. TG is a different boat since the lock went in. Just don't feel that ugly load trying to break the boat now when the upwind screecher is up. We've had no issues with the lock at all. To the point now I'm thinking of putting one on the main next, but still wary of the SCENARIO of building breeze, offshore late at night and the lock won't let go because it hasn't been cleaned/serviced and ceases up....

    Do you think that's a fair concern Lowgroove? 

    Chief I am sure your rig is thanking you every time you hoist the sail.

    The Main lock options are a bit harder, most have slots in the track and trip lines, I believe there is an Antal head car and track inserts that could work for your boat, but I remember a couple of boats in SA having ongoing issues with them.

    Any riggers out there that can suggest the range of Main Halyard lock options? The reefs complicate it as needs to lock at different heights unlike all the front sails. 


  6. On 10/12/2019 at 2:51 AM, Vincent DePillis said:

    Doyle has been working on a "cableless" style of code zero/screecher.  I am very interested in figuring seeing if this could help with my F31 upwind in light air. Did you look into that at all?

    This is a very interesting development happening and all the majour brands have Multiple versions of this New/Old technology depending on the sails apparent wind sailing angle. There is loads of propaganda around and I am wary of saying too much here, what I will say is just my take, not a company policy or view and is quite possibly not correct or soon will be made inncorrect by the continual development happening.

    The use of the word Cabless seems flat out wrong to me, so far even if they were originally test sailed with no cable all rhe sails I have seen have ended up with luff cables, all be it smaller, but still cables, being called by ither names. Holding a mast up by a sail only is an amazing feat but does not interest me much. Having to keep your expensive forestay still there in front of the sail taking some of the load and therefore allowing sag in a sail is also not something I am interested in (unless looking for more entry depth)and we are seeing this as a current solution being used for the J1 on the Big boat Pil mentioned I believe. combined tack load is therefore actually no less in this example for the J1, so what is the advantage for an upwind sail?

    This technology is mainly seeing gains in the area between a Code Zero and a A3, when the mid girth over 75% is required, these sails struggle to get a smooth leech exit and meet the required girth (this is why non rated boats like Imoca or Volvo have had such great reaching sails designed without girth restrictions effecting the design) by putting more structure in the luff and load sharing with a much smaller cable the sails luff can project forward (no longer a taught straight line)allowing for the leech girth to come forward and allowing flatter and straighter exits that make very fast sails. There can be advantages in the luff entry shape also, alowing a finer entry and sailing closer to the wind can be the result essentially gaining a wider range of use than a traditiinal tight cable sail. All sounds great in theory and with a top pro crew on a boat like s Maxi 72, but the sails require more trimming and faster reactions and trim and helm, when the new "Cabless" luff then collapses on a sail sailing at between 50-80 degrees apparent it is going to probably flog like a bitch until fully sheeted back on to set the luff and it will feel like your rig is going to step off the side of the boat. Also bear in mind dropping down cable size is great news for a TP owner taking that stay from a 6k item to a 3k spend (even though he already owns the 6k cable from his previous sail)but in Multihull land where most boats use lower end Torque cables that cost 1-1.5k the new "baby" cable plus the extra cost in the new luff construction required to share the load makes this technology pretty expensive. It all sounds great and I will sell some of these sails but at this point they are getting sorted at the pro level sailing, more developments to come and I don't think they are for every application.

    I do look forward to seeing what can be achieved with these sails in the coming years.

     

    • Like 1

  7. Hi Boys

    6 hours ago, PIL66 - XL2 said:

    Yep ... makes sense 

    I was wondering about the R42 Staysail arrangement

    Hi Boys,

    Since the boat is a racer and cruiser it will have to modes.

    The Jib is way bigger than both of your boats have so will need to change down at some point in the wind range.

    The Staysail is on a Facnor internal Halyard lock, it has its own stay in the luff, vertical battens and also a UV strip, so this sail can be lowered in race mode or kept hoisted in cruise mode for easy gear changes.

    This halyard/lock/ base 3:1 arrangement then also accepts the furling Storm Jib, so you can switch these two sails out, the Jib must stay hoisted as it zips onto the forestay as it has an 8T Profurl Structural furler on the forestay.

    The Jib also has vertical battens and a UV strip and will be likely used up to 20 knots true in race mode, maybe 25 knots but time will tell.

    The Upwind Screecher will then be out in front of all that, no UV to be dropped when not in use just like you boys do.

    • Like 1

  8. 6 hours ago, boardhead said:

    So if Venom goes sailing at 3,200 kg (7,000 pounds) that 42 sq.m (452 sq.ft.) soft, furling headsail will spend a lot of it's life over stressed or partially furled/reefed which is pretty destructive with all the thread paths off.

    We run a sail that size on a torque cable furler tacked on the bow. It gets rolled up and lowered in light breeze  and we get the roached, horizontal battened jib up which at a little over 30 sq.m.pulls like a train in concert with the big main. When it starts honking that four batten jib gets reefed and goes on up the range till the storm jib gets flown. I guess two forestays works but it's more weight, windage and complexity with the potential to bend the rig out of column with a loaded up staysail - on another expensive, heavy furler with the sail shape destructive issues as it gets furled/reefed.

    Not really sure how to respond to this, have you seen the french boats with multiple headsails out the front... There will be no parital furling happening, in addition t the two Jibs this boat will have an Upwind Screecher out on the bowsprit furling on a torque cable to be lowered when not in use, used hard on the breeze up to around 10knots true, then used at wider angles from there as the breeze increases.

    The Furling Jib lives on a structural furler that is the forestay, the fabric and strength of the sail is engineered to cope with conditions up to a single reefed Main, then you furl and go the heavy weather jib with reef 1 & 2 and eventually a Storm Jib.

    From, a sail design point of view the flatter shape and forestay sag(luff cut of the sail) required for best performance in the heavier breeze mean a second headsail is the best option. The tack aft position o the HWJ (staysail) is also keeping the boat quite nicely balanced when the Main is reefed.

    Add to that the engineering of the heavier Jib to suit the heavier conditions and I believe you have the best solution, for a 30ft Tri a reef in the Jib works quite well, at 42ft and with the brief being short handed offshore Racing and Cruising it is not really a user friendly or safe option to reef, plus a performance compromise. 

    Yes there is expense, but with a build like this this was the owners preferred configuration for his dream boat, enjoying his sailing and not crawling around on the foredeck is a pretty big priority.

    Congratulations to Bob and good on him for going for it to get this sweet boat on the water!

    At the end of the day projects like this are few are far between and should be celebrated, the knocking that goes on simply blows my mind.

    • Like 2

  9. 1 hour ago, gurok said:

    I do not believe those numbers for the R42. My TR36 has a main of  56.7m2, a headsail of 32.87m2. Weight 2700kg

     

     

    We ended up with an overlapping Jib om a structural furler,  final sail area is 42sqm.

    It has a second Heavy Weather Jib non overlapping on an inner stay that from memory would be around 30-32sqm.

    Add to that an Upwind Screecher (Torque Cable luff) out on the mid point of the pole for 0-10 knots n the breeze at 70sqm and all these points about under powered much surely go away.....

     


  10. 40 minutes ago, SeaGul said:

    R42 against the Shuttle 39 again - some data - and just for fun with my T-35.

     

                      R42               Shutt39               T-35

    Weight:    3300kg         2200kg              1300kg

    Beam:        9,58 -            9,7m                    8,2m

    Mainsail:     58m2               70m2              58m2

    Headsail:     28m2            35 m2                19m2

     

    So really - dont think the R42 has a lot of sailplan for the potential.  The S39 and the T-35 has daggers in the floats - the T-35 has assymetric daggers. S39 also two rudders at the floats - its set up for going on one hull. The Seacart 30 is very proned to be sailed one one hull but has the main dagger in the centre - two rudders on the floats.   

    SeaGul, The 42 Main is 70sqm and the Jib is 42sqm.


  11. On 10/8/2019 at 9:43 AM, square top said:

    Interesting you say horsepower won't be an issue. At 1.4 x boat length it seems fairly conservative for a 10 metre wide tri compared to say  XL2's new rig at 1.6 x boat length. Standing by to see the power to weight ratio as XL2's is very high at 3.2 tons weight and 60 foot rig for a 38 footer. If Venom is 43 foot and 4 tons it could be considered underpowered by comparison. Greater waterline length and the trimaran factor will come into it. It may struggle against the likes of Rushour though.

    FYI, comparison between XL2 and Venom's working Sails, I believe Venom will be 3.2-3.5 T, Jamie's builds a light boat.

    I have sailed on XL2 plenty and she does have plenty of horsepower but really struggled for waterline length and with the big rig tended to trip over her fuller oldschool bows.

    XL2 is an awesome classic boat but Venom would be long gone on any racetrack.

    Rushour has performed very well is and is a super quick boat for what it is, but from where I stand if Venom is not well faster than Rushour I would be extremely surprised. Diagrams not to scale.

    Venom Vs XL2.jpg


  12. 7 hours ago, samc99us said:

    The rig does a look a little small. For reference, a local Corsair 43 was refit early in life with an 80' rotating carbon rig for better performance in light air. The Corsair 37RS has a 51' rig. In both cases the boats are a good bit heavier than the Grainger, and often sailing in areas with less breeze than Venom. Still, it would appear the floats can support a slightly larger rig, potentially with rig canting an option for race mode :)

    The rig is 64ft, the image is from an angle that does not do it justice.

    Horsepower will not be an issue, the rig went up 1m during the early build process.

     

    G42 Final Rig.jpg

    • Like 2

  13.  

    Anyone know what the big cat currently moored off Sandy is? Crowded House?

     

    Came from NZ didn't it? Been living in Martha Cove? Is it still owned by Simon McKeon?

    I didn't see that, I thought you meant the Sandy straits, a different Crowded House....