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Get a Cosorio twin Air Fryer you will never need an oven.
Think you guys are unwise not including the trusty diesel into your system brilliant idea having two props just for safety redundancy have one diesel
No grease/TevGel on the bolts of the aluminum/stainless steel connection?
Why did you not try an infrared heater? That would heat the surface of the boat as well..
What happened to sailing….for the last two years every time I check in your remodeling over again, or replacing your motor…again.
Great video as usual! For your future solar panels, it might be worth looking into Oxford PV's tandem solar cells that combine perovskite and silicon materials, achieving efficiency levels exceeding 30%. Their factory is in Brandenburg an der Havel, about 70 kilometers west of Berlin. Their panels might fit nicely into your plans to go all electric. Unfortunately, widespread availability to the general public may be limited, but worth the wait.
What’s the status of that WISKY Barrel. I don’t recall the episode. ??? 🙂
👏
huge fan, great vid
You two are absolute legends! Laying out the sailboat system of the future!!!
The split-screen glass work effect was excellent. Clever. Nicely done!
These ReGen Numbers you are Quoting are NOT ACCURATE nor Achievable.
I'm not sure if OceanVolt is Coercing or Forcing you to say these things.
I mean they are Gifting you $80,000. worth of toys.
But where is your Integrity ??
You would have to achieve Full Hull Speed or Higher to achieve 50% of what you quoted.
I am seriously curious WHY you are telling these outlandish Fantasy Figures to the Public.
People. ––
OceanVolt is an Overpriced Novelty Item.
You could buy a HANDFUL of reliable diesel engines from BETA MARINE for that price and LAUGH at Electric Nonsense that is only meant for very short distances.
This is all Fantasy Land Dan. Shameful. 😮
would a radiant heater on a stand not have been better to heat the curing fibreglass?
Did you consider installing LH & RH props? You could then find the most efficient regen direction of rotation given the water flow along the hull and keel taking advantage of changing pressure regions. Cost of props may not be worth it? Is the Oceanvolt system optimised for one direction to be fwd and the opposite direction to astern?
I'm curious as to how you knew the correct torque to apply to the flange bolts.
Although, I really got a kick out of the gas/diesel generator powering your electric motors on occasion during your trip way up north to Svaalbard!
Interesting physics: V=k(P)^0.5. Thus, twice the power only produces 1.4141 more velocity. This simply equation remains a close approximation for flight until the aircraft produces any significant waves, and by waves, I mean sonic compression, roughly 60% to 70% of the speed of sound aka Mach. This "Mach drag rise" is an increase in drag associated with compression of air producing a standing sound wave.
Boats with displacement hulls produce surface waves at far lower velocities, essentially with all motion. Thus, much earlier on, a displacement hull's drag requires both frictional drag and wave drag. The trick will be selecting both propeller and generator characteristics such that both systems are are their peak efficiency at about 2-3 knots slower than Uma would travel in your average wind without them.
Some formulas for you and your spreadsheets. 🙂 Keep in mind your Total Drag will be equal to your sail's total centerline vector thrust in a good breeze. You know what velocity that makes good, so you can solve for the Reynold's number of your hull of your boat.. With that, you
Frictional Drag (D_f):
D_f = (0.5) * ρ * (v^2) * C_f * A
ρ (rho): Density of water (kg/m^3)
v: Velocity of the boat (m/s)
C_f: Frictional drag coefficient, approximated by:
C_f = 0.075 / (log10(Re) – 2)^2
where:
Re (Reynolds number):
Re = (v * L) / ν
L: Characteristic length of the hull at the waterline (m)
ν (nu): Kinematic viscosity of water (m^2/s)
A: Wetted surface area of the hull (m^2)
Wave-Making Drag (D_w):
D_w = (0.5) * ρ * (v^2) * C_w * A
C_w: Wave-making drag coefficient, which varies with the Froude number:
Fn (Froude number):
Fn = v / sqrt(g * L)
g: Acceleration due to gravity (approximately 9.81 m/s^2)
A: Here, it represents an effective area influencing wave creation, which might be roughly analogous to the hull's transverse area at the waterline, but this can be nuanced depending on the hull design.
Total Drag (D) once again, combining both:
D = [(0.5) * ρ * (v^2) * C_f * A] + [(0.5) * ρ * (v^2) * C_w * A]
This equation gives a conceptual understanding of how drag is calculated for a displacement hull, considering both frictional and wave-making components. Keep in mind:
The drag coefficients (C_f and C_w) are not constants and must be derived or measured for specific hull shapes and conditions.
The actual application might require adjustments based on empirical data or more sophisticated hydrodynamic models.
An example of an empirical formula could be:
C_w = k_1 * (Fn ^ k_2)
Where k_1 and k_2 are constants derived from experimental data for specific hull forms. However, this is a significant simplification; actual values would come from detailed analyses or databases of hull performance.
Strongly consider maximizing your Total Effective Insulation:
Total Effective Insulation = Conventional Insulation + Reflective Insulation + Draft Minimization
Thick, closed-cell foam covered on both sides with aluminized mylar provides the best total effective insulation, but there are two condensation surfaces with which you must contend.
The exterior reflective surface at or below the waterline isn't necessary as ocean water is very rarely more than a few degrees warmer than ambient comfortable cabin temp.
On the other hand, IR reflection and insulation are must in the cabin ceiling, which is beaten with sunlight by day and exposed to chilly nights.
What is your insulation plan? Hey! Another video!
"Big Projects Coming Up…" You're headed to Antarctica?
Only lithium batteries that ignite with a penhole in them, say from corrosion!
Just be sure guys that these batteries can handle extreme heat and extreme cold temperatures that has been the biggest problem in lithium batteries
Just stay inshore. The kool aid you are drinking doesn’t work on long offshore passages.
I never comment on any of these but that split screen shot of the fiberglass layout was just fantastic.
Just an idea: what about adding one / two underwater lights in place of original center engine? 🙂
❤❤❤
you spoke about redundancy with the engines, and it's mostly correct. Have you ever tried to dock a catamaran with only one engine? 🙂 it's basically a matter of luck with the space, wind direction, help you get etc. Also, you only get a single chance – usually there is now way to try again, because you can turn only to one side until you gain speed.
It's interesting that you chose that – I wish you you never have to find out the downsides of this system 🙂
Better people than you have come to grief, so not having a back up isn’t smart
🤔 Jimmy Cornel tried the zero fossil fuel concept on his Garcia Exploration 45. The marine architects admonished Jimmy to carry a small generator as an ultimate back-up, but Jimmy was adamant about carrying no fossil fuel. He started his circumnavigation demonstration but lost his battery capacity in the high latitudes (little wind, low clouds, little sun elevation) , necessitating being rescued & towed (if memory serves).
The problem Jimmy encountered was that during high latitude sailing the longer nights and low sun elevation angle prevented keeping Garcia Exploration 45’s battery from becoming depleted.
Likewise, the renowned Rodger Taylor who made four trips to Greenland in Ming Ming 1&2 had a different situation. Rodger carried no engine, just a skulling oar. His defense was to remain far at sea to prevent being “blown onto a lee shore”.
Most know that the North Atlantic is known for its violent storms. What is less known is that also has long periods of being becalmed with a glass like surface and there little to no wind …… which Rodger experienced (do you remember the sea state when the Titanic sank?). Rodger’s solution was to add large light fabric to his lower junk rig panels to allow Ming Ming II to “ghost along” in very light winds.
The lesson for Uma is that in these conditions there is no regeneration from boat motion, no generation from wind, and very limited PV input.
A secondary high latitude issue is how to heat the SV. Insulation reduces heat loss, but one still needs a heat source. Resistance heat is a very large load on the battery.
Wind generation and main motor regeneration or Watt-n-Sea type generators can replenish the battery, but only if there is wind to move the boat and turn the impellers.
The only other charging possibility I can envision is the rare instance of being in an area which has strong tidal currents, fast thermal currents like the Gulf Stream, or fast effluent flow from river mouths combined with relatively shallow water.
In this scenario the SV could anchor when becalmed in a high current area and allow the ambient current to turn the regeneration props.
I spent six years on submarines and 34 years in commercial nuclear power and have knowledge of power redundancy for critical infrastructure like hospitals, military operations, and data centers. All employ multiple redundant power sources should normal power be lost. All employ batteries and UPS to supply instantaneous emergency power in the event of a loss of normal power as a bridge to power restoration. In all cases fossil fuel supplied generators are known as “The ultimate on-site redundant power supply.”, normally an EDG.
While DG’s are normally only 30-40% efficient. Nigel Caulder did extensive research on diesel electric hybrid propulsion. The electric side is normally about 90% efficient and can deliver full power at zero RPM. The diesel side efficiency however varies with its power curve, being least efficient at low RPM/power and most efficient at high load.
Nigel correctly reasoned (ie demonstrated) that the most efficient use of the BTU’s in the diesel fuel was to use the diesel at whatever was the required shaft RPM, but to then use the electric side to charge the battery, supply excess electric loads, or even power the drive motors. This increased the load on the diesel to its most efficient power band, while also keeping the battery topped off. This concept also provides instant propulsion redundancy should the diesel be lost (clogged FO strainer, MT supply tank, clogged RW strainer, etc).
I apologize for this long post. A parallel diesel electric hybrid makes the most sense for redundancy, safety and fuel efficiency. The disadvantages of PDEH of course is complexity and increased cost.
I share your desire to be an all electric SV, as Jimmy Cornel did. The most prudent approach however with regard to diesel is to employ a philosophy of ALARA (As Low As Reasonably Achievable) coupled with “AEARA” (As Efficient As Reasonably Achievable).
There is a huge difference between an “All Electric” coastal cruising SV where help is close by and a Blue Water Hybrid where rescue may be thousands of miles and many days away. In this case rescue may be possible but the SV will in all likelihood have to be abandoned (The Coast Guard rescues people, not remote boats).
Dan & Kika, I’m a fan of your philosophy and wish you both great success. We stand on the shoulders of giants. 👍😎
Germany has been dismantling its nuclear power stations and has been going totally regenerative… well not so successfully so far. But maybe you can get one of our nuclear reactors from the scrapyard for cheap?
Sailing Uma: We're going back to all electric!
Also Sailing Uma: We've got this massive 15Kw PROPANE heater.
I physically felt mother Earth take a sharp intake of breath.
Redundancy is always best. You never go wrong with a backup of just about everything.
Cooking using electric only? Hope you like salads.
10:30 I dont understand, I see 3 holes, 1 in the middle, 2 on both sides next to them. The left and the middle you closed…
The right one, is that one for the propulsion? Why not a center hole for that? 🤔❓❓
10:47 wait, two holes remaining, but how? Are you installing dual propulsion and dual rudders? Why?
11:51 ah, explanation afterwards, that's not what I am used of you 😁
Glad the fibre glass worked this time!
Sea water batteries?
Do not get rid of the log burner. A Cubic Mini provides solid heat, and you will never get the same heat from electric heating. Then, look at the flames with a glass of wine in your hand; it makes it all worthwhile.
What punishment do we the viewers get when you inevitably need to use either diesel or petrol? I think you should create a poll for this! Each of you has to wear a Care Bear full body suite for 1 week 24/7? Must eat slop for a month? What do the other viewers think???
Fyi you can just use infrared heaters on the inside of the boat if you can get the section of the haul to 68F it will cure fine
After researching the potentially fatal results of losing propulsion, I am concerned about NOT having at least a suitcase generator for the rare but inevitable worst case scenario, for example several cloudy windless days in a row. Its small, light and potentially life saving.
In a maritime environment, the redundancy of a double prop system is by far the largest advantage. Happy for you getting the other advantages as well. Hello from Finland.