Multihull Structure Thoughts

Horrible. Sailing performance will be compromised severely by the extreme windage from the uppers not the mention the low beam to length ratio. Getting the mast up on a boat that size isnt fun. Towing it wont be either. I guess some will love it

 

Huh. That featured on a thread on SA a while back and I never thought they would actually build one. I'm glad to see they did away with those stupid-looking fender indents in the hulls which did nothing for aesthetics. Lots of freeboard for its size to allow for the accomodation, a bit like the catamaran version of a MacGregor, although hopefully built with a bit more care and attention. As cool of a concept as the mast-aft rig is, it does little to help the looks of this oddity. Still, nothing else out there really fits the bill, so more power to the builders and buyers for trying something different.

Note that my above comments apply to the sailing version only as I do think the powerboat version is one of the better-looking power cats out there.

 

Hellbent a follow up for you. The HopYacht 30 is a Dutoit Yacht Design built by HopYachts.co.za. Again, it’s a “slimline” cruising catamaran designed to fit into a monohull berth. The HopYacht 30 is 30.7 x 11.3 foot with a weight of 5,730 lbs. Displacement is unknown. The 33 foot aluminium mast is a mast aft rig that carries a 323 square foot roller furling jib. The draft is 2.3 foot over the fixed keels. The genoa sheets are led to one winch at the helm station, making sailing single-handed possible. Ccording to the builder “positioning the mast further aft optimises the sail area and significantly improves upwind performance and optimises the sail area that brings the centre of effort (COE) further aft to significantly improve upwind performance”. An asymmetric spinnaker can be added as an option. The genoa is a North sail made from cruising premium Dacron on a Profurl C 290 furler with 7mm integral forestay, furling controls are led to the helm station.

The cat is powered by 2 E-Propulsion Evo 6.0 - 6kW (9.9hp) Pod drives and two 14kWh Lithium Ferro Phosphate Batteries with built in battery management. The result is at full throttle 2.3 hours for each motor. At cruising speed range increases significantly to over 8 hours. This excludes power from the 4 x 400W solar panels inset into cabin roof. This requires 4 x Victron Smart Solar MPPT 100/20-48V solar controllers and Victron Cerbo / GX Touch monitor onboard and remote. Also Victron MultiPlus-II 48/5000/70-100 230V inverter/charger with 2 x Victron 48V Lynx distributors.

The accommodation is comfortable for 2 and viable for 3 or 4. The forward queen berth cabin has an island bed. Aft is a proper bathroom with a inside 2 seat dinette arrangement. Aft in the cockpit with hard roof is the galley, a 6 seat dinette and a steering position. The mast aft rig needs the solid roof to support it. The roof also holds the solar panels.

The construction is laminated with VAIL - Vacuum Assisted Infusion Lamination technology, which improves strength, mechanical and chemical properties of the composite parts. The Lloyds approved, Isophthalic NPG Gelcoat and Isophthalic infusion resin used to optimise chemical resistance against osmosis. Sandwich construction structural laminates make use of multi-directional fibreglass reinforcements as well as a structural closed cell foam cores as engineered by the design/build team.

HopYachts owner defines the cat as “an idea was to offer a boat premised on the idea of holiday sailing, rather than a sailing holiday”. Translation the cat is focused on being a comfortable accommodation unit that sails not a performance sailing cat. I will not go into the maths but a Raku 32, Farrier 32 etc will significantly outperform the HopYacht 30 on the majority points of sail. The HopYacht 30 is claimed to be coastal capable. I would support this statement with the right crew, it just will not be fast especially upwind. Production is expected to be available mid 2022. There is already owner interest in the design.

The jpegs give the idea. Back to more performance orientated cruisers tomorrow.

 

They really just took the NS26 and scaled it by 1.15 huh. That one somehow looks worse too, way too narrow and tall, but maybe it's just the renders. We've reached the point where someone looked at the crusing cat concept and just thought it would be neat if they took the model of a Leopard 50 and then squished it in a vice.

 

Reminds me of the bbq pontoons at Noosa.

 

Not sure what buyers these boats are aimed at. Most sailors wouldn't be interested.

I have a feeling the majority of their possible customers will ask "Could I have one without the rig and with outboards instead of electric?" I would add: "Could I also please have an extra 1.5 metres beam?"

 

The Nevermind 32 catamaran is not a completed design yet but will give an idea of a more performance orientated cruiser racer type catamaran. The Nevermind 32 is designed by Nicolas Purnu of Trois Lignes Architecture Navale designs. The Nevermind 32 is 32.5 x 18.6 foot with a loaded displacement of 7,840 lbs. The 45 foot aluminium or carbon mast carries a 480 square foot mainsail, a 299 square foot Solent jib and 683 square foot Gennaker. The hull length to beam is about 11 to 1 at the waterline. The draft over the deep fix fin keels is 3.2 foot. The rudders are fixed underslung spades. The underwing clearance is 2.2 foot. The electric motor is 10 kW with a battery capacity of 5 kWh.

The accommodation has 3 wide single berths in the hulls with a galley in the port hull and in the starboard hull a navigation station along with a full bathroom forward. The hull areas have full headroom. The main cabin has a 4 seat dinette that can convert to a large double berth but only 5 foot headroom. There is a large door between the cockpit and the main cabin to provide all around visibility. The steering is by tiller in the cockpit.

The structure of the cat is foam glass mainly flat panels produced on marble tables. The hull bottoms can be built one off or pulled off a mould then grafted to the remainder of the flat panel cat. The bulkheads are flat panel foam glass. Internal furniture fit out can be plywood or foam glass.

The numbers indicate a relatively quick cat that could reach 20 knot peak speeds and do 10 knot averages. Upwind with a tall sloop rig and the deep fixed keels should be good.

The drawings are the preliminary design and may vary if someone wants to pay for a final design. This is a well-conceived fast cruiser racer. I hope it gets built. The web site is: https://3lignes.fr/index.php/2019/06/06/petits-catamarans-habitables/

 

In response to a request about the Cross 36R and the Cross 52R. Information about these 2 tri's is in some study plan PDF's below. The person who took over the plan sales for Cross appears to be no longer interested. Page 26 of this thread is where some information about Cross tri's can be found.

 

The Palma 30 is a new catamaran designed Nicolas Purnu, built by Windpearl and will sell in Europe for 90,000 Euro’s for the base model. The Palma is 31.3 foot over the bow sprit, 27.9 x 18 foot over the hull with 3 different displacements depending on the version you opt for. There are 3 levels of cat fit out. The base which is an open bridge deck aimed at high speed day sailing or coastal trips with minimal hull accommodation. The next level is the Navigator version for cruising by adding a galley in the starboard hull, a bathroom on the port side and double berths in the aft and single cabins on the forward points. The final version is the Grand Tourisme version sees the galley installed in the nacelle on the same level as the saloon. This living space is then protected by a real hard-top and can be closed by waterproof canvases. A second bathroom is installed in the starboard hull. The Open base version weighs 4140 lbs and displaces 6,950 lbs, the Navigator version displaces 8,060 lbs and the Grand Tourisme version weighs 5,250 lbs and displaces 9,200 lbs. The 40 foot aluminium mast carries a 333 square foot mainsail, a 183 square foot self-tacking jib, a 301 square foot Code 0, a 388 square foot Gennaker and a 550 square foot spinnaker. There is an option of a 46 foot carbon rotating mast and larger sails if you want more performance. The hull length to beam is about 8.5 to 1. The fixed fin keels draw 3.2 foot in the base model. The power is two 10 HP outboards or a variety of electric options.

Each Palma 30 configuration offers two aft cabins with 1.40m wide double-berths and 1.90 m headroom. The Navigateur and Grand Tourisme versions may add two smaller cabins forwards. They are accessed directly from the companionways and have 1.20 m wide berths at the head. The Navigateur version is equipped with one starboard bath while the Grand Tourisme version may have one bath per hull. The Navigateur has a composite hoop bimimi is installed in the cockpit and a canvas hood covers the cockpit. Finally, for longer cruising, the Grand Tourisme version will be equipped with a rigid deckhouse that can be completely closed at the rear. In this case, the galley goes upstairs and faces the sea at the foot of the mast. The 2 hulls are then symmetric with a toilet in each one and has more equipped.

PALMA 30 is a modular catamaran built with a sandwich hull and deck exclusively using PVC foam and infused vinylester resin for increased strength and durability. If you buy the base Open version, you can progressively upgrade your cat to the Grand Tourisme version by buying and installing additional components like a galley unit or a rigid hardtop for the cockpit etc. Windpearl have built a lot of boats and understand construction foam glass construction.

The performance numbers of the cat again suggest the cat will peak in the 18 knot range and be able to average up to 10 knots. Windward performance will be good especially with the bigger rotating rig in the base Open version.

The jpegs give the idea. Production has started and first delivery is aimed at mid 2022. A good concept that hopefully will be a good sailor.

 

I agree some of the designs are unappealing, but how many of us are in the market for a brand new factory built catamaran/multihull ?

We are not the target audience. Most of the people who buy shiny factory built boats are either retirees buying something other than the generic motorhome/caravan etc or people with wives who's approval is required to get the purchase over the line.

Yacht builders build what they can sell, not necessarily what they want to build.

Otherwise the Elf, F1, Grainger Raider etc would be available off the shelf... The only person to really pull off that trick Was Ian Farrier. Can anyone think of another example of someone who designed a really beautiful multihull and achieved solid profitable series production ?

 

Well, yea,
but, I will not voice my opinion on the beauty, and I do not have any knowledge on the size of the Ian Farrier estate... (do you actually know how much money he made?)
My take is, he did what he loved till the very end, and we all greatly respect his work. Or, his work will be remembered by both the people sailing Farriers/Corsairs, and us, (I do not have one) when we see one going by on the water.
On the otherwise though,
Yacht builders (big corporations we mean here) build what makes them $$. Supposedly, wives go after beautiful, if it has microwave, big fridge and huge bed... (comfy heads that does not smell...) I want fast, would not care for pretty... You know, it is complicated and not everything is a compromise.

 

Buckley Yacht Design have introduced a 39 foot catamaran set of plans or a kit for the home or professional builder. The Buckley Multi 39 is 39.4 x 21.6 foot that displaces 26,400 lbs. The rig is not specified but imagine a fixed aluminium mast supporting a fractional rig with a self tacking jib of about 900 square foot in the basic rig. The draft over the fixed low aspect keel is 4.3 foot. The hull length to beam is a guess of about 8 to 1. The underwing clearance is about 2.8 foot. The engine power is 2 x 50 HP inboard diesel engines through shaft drives.

As the intention of this design is to be a serious cruiser the accommodation and layout have been optimised to provide comfort and privacy over 2 double cabins and a toilet in 1 hull with master cabin with desk study and large ensuite layout in the other hull. The bridgedeck cabin has a large forward facing galley and dinette area. The cockpit has multiple seating options. The steering position is on a raised area of the cockpit with winches etc on the main cabin roof. This is a semi protected position that would need a soft bimimi top for sun and wind protection over the long term. The steps to the transom and side decks are very good allowing useful access around the cat. The other feature of a this cat is a lot of practical storage forward for all the “sails, anchors and extras” one acquires over time.

The cat is originally designed for chine plywood timber structure. A lot of the design is “flat” panels with EG vertical bridgedeck windows etc which simplifies the build. Designed to be built as a flat pack CNC kit in ply and wood, but Composite Moulding limited are developing a assume foam glass flat panel catamaran kit packages for the 39’ cat.

The performance of this cat should be good but we are talking about an 18 knot peak with 9 to 10 knot average type of boat. It will go upwind well with an appropriate rig.

The limited jpegs give the idea, The plans cost $9,200 and are available from the website: https://www.buckleyyachtdesign.com/

 

I remember Ian Farrier stating that his first production trimaran The Tramp was too costly and complex to build (farmed out to Haines Hunter) and that they really didn’t make any money. Over a few years they produced some 200+ Tramps. Also later produced in US by a few outfits (wonder if they made any money?)

I suspect the reason they went with the F27 was to better maximize profit since the design offered a lot more than a day sailor, justifying the significant increase in price. It wasn’t until after the F27 that smaller boats were offered again.

I think the Tramps were around $15k new in the early 80’s, and the F27 around $40K by the 90’s. That’s a big difference in price. They made some 450 F27’s over more than a decade, so they must have been profitable.

I recently sold my 1982 Tramp for the same price it cost new 40 years ago. IMO, they are a fantastic bargain and for as old as they are, have held up quite well if they have been cared for by their past owners.

At the moment I’m in the middle of designing trailer slide outs to aid in the assembly of my new demountable Trimaran which I have yet to sail, and I’m already missing my folding Farrier. His folding system spoiled me.

 

This is going back in history to remind people that boats don’t have to have a complex or expensive boat to go fast and have some accomodation. I will use 2 boats as an example. The original plywood Harryproa 40 foot and Beowulf VI. The original Harryproa 40 was 40 x 23 foot that weighed 1420 lbs and displaced 2430 lbs. The rig carried 376 square foot sail area. The draft ranges between 1 and 4 foot depending on the position of the rudder boards. Beowulf VI catamaran is 38 x 18 foot with a displacement in day sailing mode of 1700 lbs and when the cat is set up for ocean racing, with its cabin attached, it weighed in on the scales at 2114 lbs. It carries a 55 foot rotating aluminium mast with a 500 square foot main, a 300 square foot jib and an approximately 650 square foot screecher. Both these boats will travel at or faster than wind speed up to 12/13 knots true wind speed. Beowulf VI can do twice wind speed until about 12/13 knots true wind speed. Both boats have the same characteristics long, very light, relatively small rig for their size and built out of common plywood with fiberglass coverings. Both these boats are simple.

In the case of the original Harryproa. The building technique is incredibly quick, a combination of the best of strip planking and sheet plywood techniques, made possible by Flexiply, a 9mm plywood with 95% of the laminate in the lengthwise direction. Each hull needs two building frames/bulkheads, and a couple of pieces of 100 x50 mm. Very simple and self aligning. No special tools are required and the finished hulls are not only relatively small in surface area, the hulls are inherently fair; sanding, fairing and torture boarding are limited. Harry was built single handed in a 6m x 3m (20' x 10') space and assembled at the waters edge. As well as the hulls, beams and original wing mast, even the steering wheel is built of Flexiply. A competent amateur should be able to build a Harry in 250 hours.

Beowulf VI build aim was to be light and strong, with the ability to withstand water incursion from damage without catastrophic failure. We started with a plywood box which represented the hull from the load waterline to the deck. The deck, mid height girder, and bottom were identical in shape. Topsides were vertical. All from 1/4″ plywood. The two hulls are turned right side up here. The triangular timber girder shown forward of the daggerboard trunk is to take bow toe in loading. There were watertight bulkheads at two foot (60cm) centers. The bottom has PVC foam glued on then shaped to required round shape. The entire exterior is then covered in six ounce fiberglass cloth, two layers over the bottom and one on the topsides. All very low tech except for some early G-10-like epoxy and S glass laminate we used as a spar in the daggerboards and rudders. We think this approach still makes sense. Those 38 foot hulls weighed just 375 pounds each when new.

Both these boats have done many miles. The Harryproa with its “Easy Rig” is an effective cruiser which started Rob Denny’s career in design. He has evolved his design and build techniques significantly but the concept is still there, light long boats with moderate rigs that will sail at wind speed or better in moderate conditions. Beowulf VI ended Steve Dashews designing of offshore catamarans as he got annoyed with beaucrats in the sailing community. The fact that Beowulf VI was winning a lot of races including the Esanda race by big margins offended many monohull people. Beowulf VI was very fast across all moderate wind ranges.

The jpegs give an idea.

 

There is a ton of info on the Dashew cats here... https://setsail.com/catamaran-history-the-early-days/ ...there is more buried on this massive website but I can't find the link right now. I wasn't aware that Dashew designed the Hobie 18. Interesting folks.