Multihull Structure Thoughts

The TimeSquare 20 is a twin-hulled electric catamaran designed for lake or sheltered water use. The Frauscher company who produce the cat is based on the shores of lake Frauscher, result they design boats to suit the local needs.

The TimeSquare 20 is 27.7 x 8.2 foot and weighs 2,535 lbs and can carry 7 people. The hull length to beam is about 15 to 1. The draft over the hull is 1.2 foot and over the outboard is 2.4 foot. The power is 1 or 2 electric 10 Kw outboards. The battery capacity is up to 30 Kw. No performance figures are mentioned but with the slim hulls, relatively light weight and 20 Kw of power this cat should make over 15 knots.

The accommodation layout is all on the bridgedeck. There are many seats with storage under allowing a fridge, liquids, clothing and toys to be put away. There are options for sun shades and limited windshields but you are basically hoping for sunny weather. The deck area could be converted into a limited camp cruiser with a tent and a portapotti.

The structure is fiberglass but little detail is available.

The TimeSquare 20 is an interesting day boat for those who want to have silent fun. The jpegs give the idea.

 

lucky it has those reverse bows,, otherwise its performance would suffer exponentially

 

The lack of volume and freeboard of those bows would most definitely be a problem on lakes where wake surfing is popular, which is a sport where the goal is to throw out as fat a wake as possible behind a boat at slow speed for people to ride.

If you’ve never had the pleasure of sharing a body of water with wake surfers, you’re in for a real treat (not), especially if you are on a paddle board, in a kayak or fishing at anchor. At least their loud music gives good warning to prepare for the tsunami.

 

This is about a Canadian guy who had built a 36 foot cruising catamaran and decided it would be better as a solar powered catamaran. In 2021 “Harvest” completed a 2000km (about 1200 miles) loop around Ontario. Lake Huron to Lake Erie through the Welland canal to Lake Ontario through the amazing Trent Severen to Georgian Bay and back to Bayfield. The entire trip was done under electric power.

The catamaran looks like a Scionning Cosmos 11 (guessing) and appears to be 36 x 23 foot, has low aspect ratio keels and is electric powered (details later).

Harvest accommodation has 2 double berth cabins in each hull with a toilet in the bow in each hull. The bridgedeck cabin has a U shape dinette and large galley. Helming is done from the cockpit which is protected by a very large solar array above it. This cat is a serious cruiser that has an electric fridge, stove, microwave etc.

The construction is unknown but looks like well done fiberglass over foam or strip plank WRC.

Now to the motive power. First find yourself a wrecked Tesla S car. Take the 85 Kw battery packs out of it plus some other items. Handle with extreme care as the battery pack can cause harm if you touch the wrong thing. The Tesla battery is water cooled in the car but appears not to need water cooling in a steady draw boat situation (do your own research).

Now you have your battery. Next organise you solar array. You need 7000 watts from the 18 x 380 watt solar panels set up on an aluminium frame arrangement over the main cabin and cockpit. The panel controllers and heavy duty wiring has to be suitable for a marine environment.

Next have your batteries set up in series to provide 48 volts to your electric motors. The motors are steerable 15kw Krautler pods (Aquamot Trend 15 Kw). These motors cost 8200 euro for base unit and with controllers, limited battery, controllers and wiring etc cost about 12000 euro per unit. The motors substitute for rudders.

Finally you set up an inverter to provide the cat with electric power for all the domestic appliances.

So what is the performance capability? There is a jpeg graph below. At 100 amp draw the cat will do 6.2 knots, at 300 amp draw you can peak at 9 knots. The range is dependant on the speed you want to travel at and how much sunshine there is on a given day. With the amount of battery power available and running at a slow speed EG 5 knots you should be able run 24 hours/day.

This is an interesting cat as it is a well done build and serious electric power installation that has proven to work over a reasonable cruising range. Also the power installation etc appears to be “competitive” to a good diesel installation at a cost that is not to prohibitive.

The jpegs give part of the idea.

 

The final electric catamaran for a while. This is to indicate how far electric power technology has advanced. The cat is a fully electric powered ferry that will do a regular ferry run between Argentina and Uruguay with run distances between 30 miles and 130 miles. The interesting part is this ferry will be carrying 2,100 passengers/crew and 225 cars (yes, the numbers are correct). OK

The Incat design and build with the assistance of Corvus (battery technology) and Wartsila (overall power drive technology). Number 96 (Incat designation) is 426 x 105 foot with a guess displacement of about 5,000 tons. The 2,100 people/crew will weigh 210 tons and the 225 cars will weigh 450 tons which will be minor compared to the Corvus developed lightweight batteries, Dolphin NextGen. The 40MWh (read megawatt not kilowatt, for perspective think 50 Tesla S car batteries per battery module) battery modules provide the battery power to drive the 4 electric 5.0 MW (6,700 HP) and 4 electric 9.6 MW (12,900 HP) propulsion systems motors that drive 8 Wärtsilä’s axial flow WXJ1100 waterjets (4 water jets are pure drive and 4 are steerable drive).

No performance is stated but Buquebus (the customer) already run fast ferries on these runs that can do 50 knots. Most Incat ferries are fast and this ferry I would assume will do at least 40 knots which means on the 130 mile route it can be done in 3.5 hours which is very competitive for that route.

Now we get to the problem of recharging. Since this is the largest fully electric power installation in a boat in the world by a factor of 4, the recharging stations at each berthing location is big, very big. The Dolphin NextGen, which adopts a stacking arrangement rather than the more typical battery rack, is based on nickel, manganese, cobalt (NMC) and uses cylindrical cells. This means its C rating of 0.5 means it can charge with 20MWh of shore power, making it ample for such a large battery system. 20MWh hour charging stations are the world’s highest capacity chargers requiring a very good onshore power generation and grid support.

Now we get to the minor details of construction, think up to 2,000 people who understand how to build in aluminium very well. The ancillary contracts for seating, furbishing’s and the 2000 square metre onboard shopping precinct would be interesting as well.

The jpegs give you the idea. This is electric power on a mega scale. PS Wärtsilä is working with another company to provide a 100 MWh power system to another vessel.

 

Wow, that is HUGELY impressive.
2000 guys who are very competent working with alum ?? even 200 would have been impressive.....
The electrical storage/drive systems make ANYTHING else seem trivial.....
I'm guessing/hoping this was built in tasmania ?
If so, they must be the biggest employer (by a factor of ? ) in the apple state ?
thanks, Oldmulti

 

Yes, it is being built in Tasmania. Incat is one of the biggest employers in Tasmania and has a line up of work into the future. If this cat succeeds I am sure there will be many more contracts to come. Their 78 meter cat models (conventional power) are capable of averaging 50 knots in the right conditions which is very impressive also. For a company that came close to collapse at one point the recovery has been impressive.

 

2 things ;
1. their technical colleges must have been swamped with applications to learn alum welding/fabrication ?
2. how do they deliver an electric cat to sth america ? there can't be any charging stations along the way ?

 

Peterbike. There are shipping companies that can ship very large boats globally, you may have seen the ships that can load many yachts and large power cruisers on a regular basis. INCAT could also sail the cat over with several high powered generators on board to recharge the battery as they go. The range of this cat at 10 knots would be very good with such large batteries. Many options are available.

 

"20MWh hour charging stations are the world’s highest capacity chargers requiring a very good onshore power generation and grid support."
would be interesting to know at what voltage the charging is carried out, how this huge amount (20MW!!!)of power arrives at the charging station (our 110kV overland lines can supply a max of 2000A = 220MW) & most of all: how is the electricity generated.

 

A 66 year old man wanted some adventure, he persuaded a 49 year old lady who was a part time sailor to go on a small boat race with him in 2022. The race was the Race to Alaska, 750 miles from Port Townsend, Washington, to Ketchikan, Alaska. He had already built a small tri to do the trip and enjoyed his time running 18 th out of 19 entrants in his “division”.

“Kairos 4Two” is a “camp” trimaran that is 24.5 x 10 foot with a weight of 350 lbs. The mainhull beam is 3.9 foot wide at the gunnel. The floats are 8 foot long. The sail area of the 3 carbon mast rig is 130 square foot depending on which sails are up at the time. The draft ranges from 0.3 to 3 foot with the off centre daggerboard down.

The “accommodation” is a forward single berth space and some storage space, a centre cockpit and an aft smaller single berth cabin with some storage area. The cockpit has seating to allow rowing. To power up mobile phones, some minimal lighting etc there is a 130 watt flexible solar panel and small battery.

To race in the R2AK you have to finish with what you started with so it’s a great advantage to keep the boat light as R2AK is human or sail power only. Also if you can sleep on board do some cooking etc you can keep going 24 hours/day if there are 2 people. Result is a well designed boat for the race can be an advantage. “Kairos 4Two” crew choose to stop overnight to get some rest and row or sail during daylight hours to avoid logs and wildlife.

The construction is plywood with e-glass cloth inside and out. The mainhull is multichine, the floats are a single chine V bottom. The crossbeams are timber bolted onto the floats and lashed onto the mainhull. The masts are freestanding and I suspect windsurfer type rigs.

No indication of performance beyond it can be rowed at about 4 knots for short periods and they preferred to sit out bad weather than try and fight bad currents or strong winds. Result success was measured by the 35 miles/day done but by completing the course. Will they do the trip again. No. The tri performed well but the physical/mental effort was a “once in a lifetime” event.

The jpegs give the idea.

 

I was going to talk about a high performance cat and I still will but in the research I discovered a little history that changed multihull sailing forever. The very high performance cat is the SL 33 which was developed by SL Performance Race Boats GmbH in 2008 and designed by a consortium of Morrelli & Melvin/Labek/Ridley/Sanderson. The cat was created as a “mini” AC boat prior to foiling. But as we will see later it has an interesting history.

The SL 33 is 41.34 foot overall with prodder. The hull is 32.8 x 22 foot with a weight of 1600 lbs. The rotating 60 foot carbon fibre mast carries a 657 square foot mainsail, 129 square foot jib, a 269 square foot genoa and a 807 square foot Code 0. The draft ranges from 0.8 foot to 7.2 foot.

The SL 33 is a pure fun day racing cat with no accommodation beyond some storage in the hulls.

The mast, main boom, center tube, beams, daggerboards, rudders and tillers are all built out of solid carbon fibre Epoxy prepregs which are cured in an autoclave with 6 bars pressure and 120 degrees temperature. The hulls are built out of carbon fibre Epoxy prepregs with a Nomex honeycomb core and cured under standard vacuum and 100 degrees temperature. All reinforcements and bulkheads are made out of solid carbon.

So we have the cat, now a bit of history. In 2010/2011 the NZ AC team were throwing around ideas for the next AC challenge and a suggestion was made, lets see if we can make an AC 72 fly on foils, if a Moth can do it, can we do it? The NZ AC team said OK, lets try. To keep the idea secret the team used a SL 33 as the base and experimented at Lake Arapuni in the Waikato region, far away from Auckland and spy camera’s. Initially tow tests were done then a fully foiling SL 33 was developed. The foiling would only happen on a limited range of conditions and angles to the wind but when the SL 33 foiled, it was fast. The SL 33 was small enough for a series of foil shapes and sizes to be tested resulting in good data for the AC 72 to be optimized for a foiling cat.

Then Team NZ put foils on the AC 72 in Auckland harbor. When a grainy spy photo was published of the AC 72 foiling there was disbelief. “It must be photoshopped” was the cry. When other teams saw the NZ AC 72 foiling, they went into rapid development mode and multihull sailing was changed forever. It still took several years to develop full foiling on all points of sail and 50 knot speeds, but this was the start.

The benefit to the SL 33 building group was they collected all the Team NZ test data and information about the foiling experiments and were able to release a foiling version in 2013/14. The rest is history.

The jpegs give the idea. The first jpeg is the grainy spy jpegs of the NZ AC 72 flying publicly for the first time.

 

Hi. I am taking a couple of days off, see you soon.

 

Wow, what an intriguing thread! Reading about Devils 3, a 36 x 24.5 ft racer/cruiser tri, brings back memories of my own adventure in a similar vessel during a trip to the Galapagos Islands. I had the pleasure of sailing aboard a multihull boat with Cruise in Galapagos (Cruises in Galapagos - Ecuador Trips https://www.cruiseingalapagos.com/), and the experience was nothing short of exhilarating.

The innovative design described here, particularly the use of a lightweight aluminum space frame at critical load-bearing points, reflects a commitment to efficiency and performance that resonates deeply with me. It's fascinating to see how different designers, like Gary Baigant and Lex Nicol, push the boundaries of traditional boat-building techniques to create vessels that are both fast and durable.

Moreover, the longevity and success of Devils 3, lasting 35 years and winning numerous races, underscore the effectiveness of these innovative design principles. It's a testament to the ingenuity and craftsmanship of those who conceive and build these remarkable boats.

Thank you for sharing this insightful description, and it's wonderful to see such passion and expertise within the sailing community.

 

Hi. A very short one but a bit of history. A guy has just crossed the Atlantic in a small tri (23 foot) that was powered only by a Kite rig. The kite was connected to an automated kite control system which had a wifi electronic controller. The Youtube video is: The Final - Kite Boat Atlantic Crossing - YouTube www.youtube.com