Oceanvolt Hybrid Motor

[44'cruisingcat]

Originally Posted by Claude-D

And yes, I am involved with Oceanvolt.

And used to be involved with Torqueedo?

[BigBeakie]

Originally Posted by cwjohm

This would have to be your 4th go at redefining the performance of Kato. I think you just make up stuff to suit your argument when someone takes a contrarian point of view.

Discussion is pointless when the response to any argument is to simply move the goal posts. I think I will join the others in not pursuing this with you any further.

Would that be a duck and weave move you just attempted?
Nice try. So, you are questioning my integrity, and implying I'm lying? That's an old tactic the ad hominem, used by those who have little else.

Call Julian, Chris. Tomorrow morning, and ask him. Ask Tony. Ask Claude,
he was on the boat all during trials. Claude I believe even has hard data, Chris. Would that do? Maybe he has video of WOT.

Oh, and by the way, it is also found in the write up in Australian Multihull World this month.

If they confirm what I've just said, I expect you to come back here and own up.

But just humour me for the moment, and assume I'm correct. Kato II does 10 knots at WOT with the new prop. What say you then my friend?

[cwjohm]

Rob

From the article you reference

"We motored to the Gold Coast once the wind died out, under dark rainy skies. We used 3L of fuel per hour at a steady speed of 6kts.". I deduce from the fact that they were using fuel that this was generator driven.

BTW the generator is rated to 11Kw - not 8Kw.

But you will believe what you will believe. Even on the Oceanvolt site that Claude references when one compares the EP motors to standard diesel motors the ratio of KW to HP is not 3 times as you maintain.

I can mount a technical argument but I cannot change your religious view on this matter, and like most posters here I should have given it up long ago.

[valhalla360]

Originally Posted by ranchero76

We come back to the point that this is not for everyone. It's for big cats, like that Kato, which has ability to carry these retractable panels. I'm throwing very rough numbers, precise calculating of particular boat needs will give better idea. Maybe 8-10 kW will be enough, which will take way less space.


.

The problem with saying it's for bigger cats means while you can fit more panels, you also have higher electrical demands, so the net effect is it's still impractical.

[Claude-D]

Originally Posted by cwjohm

Rob

From the article you reference

"We motored to the Gold Coast once the wind died out, under dark rainy skies. We used 3L of fuel per hour at a steady speed of 6kts.". I deduce from the fact that they were using fuel that this was generator driven.

BTW the generator is rated to 11Kw - not 8Kw.

But you will believe what you will believe. Even on the Oceanvolt site that Claude references when one compares the EP motors to standard diesel motors the ratio of KW to HP is not 3 times as you maintain.

I can mount a technical argument but I cannot change your religious view on this matter, and like most posters here I should have given it up long ago.

This is exhausting.... Do you guys argue non-stop on this forum....

Anyway, yes Rob is right the data that he quoted for Kato is correct.

So, firstly yes the genset is 11kW, but we only get 8.4kW from it. I have pictures of the display if you do not believe me. The electrician was also on board on this first trip. Maybe I can arrange for a stat declaration from him about the genset output.

The average on that trip was 6 knots. But this was with the initial 16.5 X 11 Gori propellers, Now that we fitted the Gori 16.5 X 13 the speed at 8.4 kW as increased from 6 to 7 knots.

Also, the max speed has increased from 9.2 to 10knots with the new propellers. But this was done in shallow water. In which, Tony claim that the old Kato was always a couple of knots slower... Still, I am happy with the 10 knots maximum. And so is Tony.

[valhalla360]

Originally Posted by Claude-D

This is exhausting.... Do you guys argue non-stop on this forum....

This isn't the OV website and we haven't hacked it to post questions about how OV is able to violate the laws of physics. It's a forum intended for discussion.

Post crazy explanations of physics at your own peril.

[BigBeakie]

Originally Posted by Claude-D

This is exhausting.... Do you guys argue non-stop on this forum....

Anyway, yes Rob is right the data that he quoted for Kato is correct.

So, firstly yes the genset is 11kW, but we only get 8.4kW from it. I have pictures of the display if you do not believe me. The electrician was also on board on this first trip. Maybe I can arrange for a stat declaration from him about the genset output.

The average on that trip was 6 knots. But this was with the initial 16.5 X 11 Gori propellers, Now that we fitted the Gori 16.5 X 13 the speed at 8.4 kW as increased from 6 to 7 knots.

Also, the max speed has increased from 9.2 to 10knots with the new propellers. But this was done in shallow water. In which, Tony claim that the old Kato was always a couple of knots slower... Still, I am happy with the 10 knots maximum. And so is Tony.

Thanks Claude.

So Chris, I'm waiting for a mea culpa. I have offered them before on CF when I have been wrong. I'm interested in getting at the truth, not adopting a religious faith based determination of reality. Unlike you, I have cold hard cash at stake here, not just some verbal gymnastics.

By all means, validate what I have said about Kato II performance in any manner that you choose.

When you've sorted it out, I'll be waiting....

[44'cruisingcat]

Originally Posted by Claude-D

This is exhausting.... Do you guys argue non-stop on this forum....

Anyway, yes Rob is right the data that he quoted for Kato is correct.

So, firstly yes the genset is 11kW, but we only get 8.4kW from it. I have pictures of the display if you do not believe me. The electrician was also on board on this first trip. Maybe I can arrange for a stat declaration from him about the genset output.

The average on that trip was 6 knots. But this was with the initial 16.5 X 11 Gori propellers, Now that we fitted the Gori 16.5 X 13 the speed at 8.4 kW as increased from 6 to 7 knots.

Also, the max speed has increased from 9.2 to 10knots with the new propellers. But this was done in shallow water. In which, Tony claim that the old Kato was always a couple of knots slower... Still, I am happy with the 10 knots maximum. And so is Tony.

Was this the trip from Mooloolaba to Coomera?
Before the rig was stepped?

[Factor]

Originally Posted by 44'cruisingcat

This system will be viable on Kato, principally for one reason: that boat is a superb sailing machine. It's not going to motor much.

QFT
also contrary to what Chris (cwjohm) thinks, it is sailed by a highly experienced and extremely competent sailor

[cwjohm]

Making up stories again Andrew - I never made a claim otherwise.

[cwjohm]

This isn't the OV website and we haven't hacked it to post questions about how OV is able to violate the laws of physics. It's a forum intended for discussion.

Post crazy explanations of physics at your own peril.

I do not necessarily think that the laws of physics are violated. I think it is simply testament to the incredible job that Julien has done in building this boat. I think it is entirely possible that this performance is generated by as little as 25Hp equivalent propulsive force from the motors. I would be interested in a comparison of 44Cs boat to Kato in terms of ratios of Kg/m and motor HP.

[ranchero76]

Originally Posted by valhalla360

The problem with saying it's for bigger cats means while you can fit more panels, you also have higher electrical demands, so the net effect is it's still impractical.

Really? Well, of course, people will use all that extra power while on hook - why not??? But before and during passage power consumption should be and can be limited to EP and very important things which also should be used carefully (fridge, fresh water, autopilot, cooking, and such). Arrive to next destination - and you have plenty of power for pleasure use, once batteries are charged. Sounds like good plan to me.

[ranchero76]

Originally Posted by Claude-D

This is exhausting.... Do you guys argue non-stop on this forum...

Videos, videos and more videos. That's what will shut (some) opponents up.

[DotDun]

Originally Posted by ranchero76

It's not that far, Kato is real, so are few other boats.



I've missed that - how much battery storage on Kato? I've mentioned above - there's Sunreef 62 on the market which has 68 kWh of Li-Po batteries and that boat is capable to run AC overnight. That amount of storage seems somewhat adequate, unless something with even more efficiency will show up on the market.

Hmm, at DIY pricing of $5/AH, $25k that's for batteries. And then the 17000watts of solar required to recharge won't fit on most boats.

Up charge for going "house green":

$22k for extra battery
$13k for extra solar

Do you know how many years that $35k will support a generator and diesel???

I realize this is an extreme example, but going green, at some point, has to have an ROI associated with it.

[Just Another Sa]

Originally Posted by BigBeakie

But to my specific statement re 15kW OV SD15 & 45HP Beta Turbo, I spoke directly to the technical director of Beta Marine in the UK and asked what is the thrust expressed in kgf of his Beta 45 Turbo. He knew that figure ( I was impressed) at is is 320 kgf at full throttle, and that is with a 3 bladed fixed prop.

Wrong question. The technical director of Beta Marine did not answer your wrong question, he was trying to be helpful and answered what you should have asked. And it seems you never understood that was the case.
In the real world 45HP Beta Turbo produces no thrust at all. It does produce torque if it's running. The 3 bladed fixed prop provides all the thrust regardless if it's rotated by Beta turbo, some other diesel or gasoline engine, or an electric motor.
Please try to learn the difference how engine or motors work vs how a prop work. And never to mix them up again.

Originally Posted by BigBeakie

So, I hear you ask, what is the relationship between static bollard pull force and actual propulsive thrust that pushes your boat against wind & waves?
Good question, and I sought that answer from multiple sources such as propeller design engineers, diesel technical resources and the technical papers written that form the basis of ship propulsion system design. I did not understand the math or even tried to, I just wanted the answer. It is about 0.9 , i.e. the static bollard value is 10% less than the propulsive thrust.

It is unfortunately dramatically wrong. The static bollard value is typically 10%...150% more than the propulsive thrust. But it's not always in the typical range. In practice the static value is less only when pitch/diameter ratio is so high (well above 1.5), that flow is stalled (and therefore separated) in static thrust test. For example only 12 inch diameter and 26 inch pitch, something suitable for a fast high powered powerboat.