Electric Main Drive(s)

[planetoftheapes]

Found this and wanted to share with other 420ers.
Maybe a possibility here. http://www.powerstream.com/dcdc.htm Very inexpensive 75 to 12 volt converter 9 amp.

This opens the possibility of eliminating the house bank, save a couple hundred pounds, run the house 12 volt fom the propulsion bank. You could probably use these to run a 12 volt inverter off that bank and save the expense of the 72 volt inverter ($8000).

Use solar panels in series @ 72 volts to trickle charge to the propulsion bank. You could even add the house batteries to the propulsion bank and extend range although replacing the weight with the larger genset is probably a better option.

Apes

[planetoftheapes]

http://www.trcelectronics.com/Meanwell/sd-350d-12.shtml Here is a better 72 to 12 volt converter that is 30 amp, 350 watts and $150.00.
Got rough estimate for carbon mast from GMT. About 32K to save 160 lbs aloft. Wow!
West marine now sells PBO synthetic shrouds (similar used by Fastcat, Gunboat and Farrier) 1/4 weight of stainless. http://www.sailinganarchy.com/ADs/we...ITE%20FAQs.pdfHuge weight off the boat.
Most cruiser use woven dacron polyester sails. This must be the stock sail animal. New laminate cruising sails weight 30% less hold shape longer.
Just a guess, 600lbs or more off the boat, and a better sailor. All this to counteract to heavy batteries.

Apes

[Jeff]

FastCats are optionally using Lithium. Announcement here:

http://www.africancats.com/resources...ELEKTR_ENG.pdf

Originally Posted by planetoftheapes

This is the quote they gave me?

U24 100Ah battery (Group 24 size) cost $2030 each.

Technology Comparison U1 U-Charge® System Performance Standard Lead-acid Saphion® Technology Improvement Operating Voltage 12V 12V Equivalent Capacity (Ah@ C/5) 45 27.2 65% Nominal Energy (Wh) 584 326 79% Cycle Life (80% DOD) 2000 300 666% Dimensions U1 U1 Equivalent Nominal Weight (kg) 7 11 36% Cost of Ownership 3.3 7.5 56%
Look at the cost of ownership. If ths is correct, these would be a far better choice given the weight savings and increased life.

Get rid of the generator. Replace its weight (and price) with additional Li batts, large bank of solars and two large wind generators. No maintanence, no fuel, maybe 20 hrs of motoring time. All at less total weight. That's for me!

You could have a small 6 hp diesel gen as emergency back-up!

Anyone know the total amp-hrs and peak current draw of standard battery banks?

[Intentional Drifter]

I've corresponded with the African Cats people. I like several things about their designs. Their focus is definitely on performance and keeping the weight down. If you asked them to send you a pricing sheet, one of the things they also include is the weight + or -, for each option selected! They offer an "extreme light weight" package that shaves off 1150kg, as well as many carbon fiber options. If you're looking for a bleeding edge cruising cat, I think they deserve your serious consideration.

ID

[planetoftheapes]

I've finally got some rest and crunched numbers myself. Disappointment! This is much more of a diesel than an electric boat when used as long range cruiser (LRC).

Observations:

1. The propulsion batteries contribute little to the picture as an LRC. At 50% DOD - One hour motoring at 8KW, 45 min motoring at 10 KW motor power. Often cruising one must motor for days. Estimate 50% of the time motoring.

2. If the genset starts every time you hit 20% DOD it will basically always be running while motoring. For the LRC, life would change little if you removed much of the propulsion bank.

3. The 13.5 Genset will provide full power with battery help for 2 hours only. Enough said.

4. If you accept the limited role of the propulsion batteries, then valence Li ions 40 Ah U1-12XP will provide the same genset free cruising range (equal to 20% DOD of regular bank) 48 min at 6 Kw and save 1100 lbs, cost $12000 for 2000 cycles (bulk price reduction?). Good weight reduction/cost ratio. I may do this if there are no re-charging issues but see 6.

5. If you plan to deep cycle the lead-acids to 60-70%, Li batteries make no sense at all from a cost/cycle standpoint. Might as well build the hull in carbon and saved the weight permanently. Cost $30K for 130 Ah and does not have the Ah capacity of the wet cell banks at 70% DOD. Still deep cycling will not get you far and you will need to run the generator anyway if there is no wind.

6. Lead acid batts have an amazing cost advantage. If you willing to accept a two year battery life span with a 70%-80% DOD, you can cut the size of the banks to 100 Ah, save 670 lbs and just spend $1200 every two years for new batts. No significant performance difference if you are going to run the Genset at 20% DOD anyway. I believe this was mentioned before on this board.

7. This whole green cruiser thing only works if you motor for a couple of hours a run, like a charter boat. You can see better economy only if you can combined energy produced green with a smaller diesel. Not for LRC. It stiil has wonderful advantages though especially recharge while sailing but any water generator could do that.

8 Something no one has mentioned. Why the hell are the Batts in the transoms? My God, you could put them anywhere in the boat if properly vented or use AGMs. Can you imagine the reduction in pitching. Gee 1200 unnecessary lbs in the sterns. Maybe designed to float with a sail drive repalcement?

9. The Fastcat 435 has the interior space of a modern 38 foot cat. It's ugly and boxy, looks home built. Angelo Lavranos has no sense of style. They will fail.

10. I don't consider carbon spars or PBO rigging all that bleeding edge at this point. The round the world sailors have proven it more reliable than stainless. The PBO is so light, you could keep spares onboard without sinking. Many production boats come standard with carbon spars.

11. My summary: Forget the batteries they are not worth the weight for LRC. Have a propulsion bank large enough to have some back-up if the generator fails and to use as a big house bank. You could eliminate the wind gen and solars-not worth a gallon or two of diesel a week- and just full chage once a week off the gen or when running AC or sailing. 100 Ah at 72 V = 7200 Ah at 12 volts. Go with 40-65 Ah Li or 60-100 Ah acids both 70-80% DOD.
Get the batts out of the transoms. If you can trade-in the stock rig and sails, it won't cost all that much to upgrade to carbon spars and light sails/stand rigging. My 420 will sail well indeed. I will install my own AC and water maker (thanks Richard) and use the savings to upgrade as above if I have her delivered. No way around the big genset and extra fuel capacity.

As usual, I hope you will share your thoughts. Don't be kind. I want to cure my delusions not promote/propagate them. Thanks again Richard!

[planetoftheapes]

oops, I should proof better- 100 Ah @ 72 vols = 600 Ah at 12 volts x 2 for both banks = 1200 Ah. 1200 x 80% DOD = 960 AH available at anchor from small propulsion banks - sorry

[Jeff]

Originally Posted by planetoftheapes

I've finally got some rest and crunched numbers myself. Disappointment! This is much more of a diesel than an electric boat when used as long range cruiser (LRC).

...

As usual, I hope you will share your thoughts. Don't be kind. I want to cure my delusions not promote/propagate them. Thanks again Richard!

Richard,

on the LRC theme, did you calculations broach the subject of range? What is your best guess at the range of 420 with 79 (US) Gallon tank?

j

PS Totally agree that the Fast Cat 435 is fugly! It did get an excellent review in Multihulls World (issue 86) where they state "I must admit, it is always a pleasure to find a good looking boat"

[Intentional Drifter]

I didn't say you would like how it looks! But if it sails like they say, the only thing anyone else will see is the stern, anyway!

Its great seeing people think about how to make a better cat. Certainly things like carbon spars will cut weight, but speaking just for myself, I don't think I want the cost associated with buying them. Although I have no personal experience with them, from my reading they can be tricky beasts. Also, while I would hope to never be struck by lightning in any boat, for lots of reasons, a carbon spar is going to be reduced to ash. While an aluminum masted boat would likely still have lots of other problems after a strike, they seem to retain the mast.

RE: batteries. It is my understanding that they are distributed in two places. The propulsion batts at the aft crossbeam in each hull; the house bank under the cockpit sole, pretty much in the middle of the bridgedeck. (I have no doubt, though, that the engineers thought quite carefully in optimizing the weight distribution and sailing characteristics. Over the last several models, the Lagoon design team has done remarkably well at coming up with big boats that sail pretty well. Look at the ARC results.)

RE: range. Trying to estimate that gets complicated. How fast? Is it only motoring? Running other electricity consumers? Really, to get to a common denominator, one must look at the electricity produced by the genset, regardless of how you're using it. Once you have that, you can estimate how you're going to use it. There is a related problem, too: We still have not heard, for sure, about the size of the motors. Some of the literature on the 420 says "8KW", other says "10KW". Which is it?

Anyway, to get to the question, I pulled the literature from Onan on the fuel consumption stats for the two gensets. The standard genset is the Onan MDKAZ and produces 11.0 KW at 220V/50Hz and 13.5 KW at 110V/60Hz. The optional genset is the Onan MDKBE and produces 17.5 KW at 220V/50Hz and 21.5 KW at 110V/60Hz.

Important point: Lagoon says that when recharging propulsion batteries, it will always do so at 60Hz, since this is more efficient. So, all of the estimates given below will for 110V/60Hz.

The fuel consumption stats indicate that the smaller genset will be more fuel efficient when producing electricity up to about 11KW, which is of course, almost at the maximum capability. When producing 10KW (which is estimated to give you a 5kt motoring speed using both motors) the respective consumption will be .9gph vs. 1.05 gph (for the 21.5 genset).

So, standard fuel tank is 86 gallons divided by .9, times 5 kts = 478 nm range on the smaller genset vs. 86 divided by 1.05 times 5 kts = 410 nm range on the larger genset.

This is an attempt to maintain some constants for comparison purposes. Of course, it doesn't reflect actual use.

Personally, I'm leaning toward the larger genset, even with the added weight. You can always have a bigger genset produce less power, but you can't do the opposite.

There's lots yet to learn, folks. We'll see how the boats actually look and perform over the next several months. I'd expect we'll start hearing about actual experiences come Sept/Oct.

ID

[planetoftheapes]

http://www.cata-lagoon.com/pdf/Lagoo...ochure2006.pdf

Regarding the propulsion bank placement. I hope ID is correct, but if you look at the above brochure from Lagoon, the batteries sit at the rear cross-beam a few feet from the end of the transoms. I believe the center of buoyancy is nearer the mast.

There are three reasons I can think of for this:

1) The hulls are designed to take the weight of diesel sail drives in the sterns and need the weight there to float to the water line. If all else fails they start selling the diesel only 420s without significant hull modification.

2) The wire gage for the large current draw at 72 volts is too heavy to make a long run.

3) They felt many out-gassing batteries in the living quarters were unsafe.

This is no small issue. The designers of the cats that sail well go the great lengths to keep the ends light (Gunboat). If you moved the banks, I don't know how you would get the boat to float level?
This is a palce where I believe the design team really did not fully commit to the electric hybrid only theme.

For what it is worth from the Carbon Fiber mast Co:

"We continue to be excited by the results of our efforts; carbon spars make dramatic improvements in safety, comfort, motion, heel and speed. All are improvements that cannot be easily achieved by any other means.



Safety and comfort at sea begin with stability. Simply stated, there's no better way to gain stability than to reduce weight aloft. Carbon offers the best value in terms of weight reduction and performance gain without compromise to safety or longevity. This weight savings translates into added sail carrying power and the ability to drive through waves with considerably less pitching. The bottom line is improved performance and comfort on every point of sail. This was borne out fifteen years ago when The Hinckley Company conducted a test between two of their 59 ft. sloops. One was equipped with a standard aluminum rig and the other was fitted with a GMT carbon furling spar. In 15-20 knots of breeze, the carbon sparred boat was significantly faster, pitched less, heeled less and sailed through the lee of the aluminum sparred boat.





Designed to match the strength of the standard alloy mast, the mast we propose for the Lagoon 420 will save about 160 lbs. aloft, while increasing stability. While this weight savings equates to strong performance gains, the benefits of carbon spars don't end there.



Carbon masts and booms are also much more rugged than aluminum. Virtually all competitors sailing in round the world races are equipped with carbon spars for their superior durability. Skippers frequently credit their carbon spars with preventing a dismasting when shroud and gear failures occur. Returning from an Antarctic expedition, the Apogee 50 WESTRI survived a near rollover in gale conditions due in large part to the strength of her GMT carbon spar.



These spars are as beautiful as they are strong, and will stay looking good longer as carbon doesn't corrode and paint adheres to it better than it does to aluminum."

Lighting is an issue that can be compensated for. Cost is a big issue.


I realize all this is a waste of time, for the most part, but I still need to check the boxes on the options sheet, spending up to 125K. I want to have the illusion that I know what I'm doing. At least I tried.

If I pick her up in France, I won't modify anything. Just get in and Go.

[dana-tenacity]

Must take issue with POA"s allowance for 50% motoring for a cruiser, my experience was nothing like that, in fact so small as to be negligible.

[planetoftheapes]

DT,

I have read this estimate of 50% repeatedly. I have lived it, even though I promised myself I would motor as little as possible. If your experience is different, I would wager you are the exception rather than the rule. If you are coastal cruising, that is a different animal.

Everyone gets ready for heavy weather, but we see mostly light wind while while world cruising. If you cruise the Mediterranian you will likely motor more than this, if in the trades less (down wind of course). It is easy to tell yourself that you have a sailboat and won't motor but when you and your crew is damp and tired, when not making the next land fall before dark means spending another night at sea, when the anxiety of being becalmed sets in, when the wine is gone, people that can motor, motor. If your wife is aboard, chances are, the shorter the passage the happier the spouse. Heavy cruisers don't sail well in light air generally.
If you are like the Pardey's, and go sans engine, more power to you. Lin Pardey, in her book, sounded miserable in the Med. Too much wind or none at all.

Possible exception - the Fastcat is so light you may be able to keep moving in very light air. As long as you are moving alittle, people won't have a psychological meltdown. Just use electric for harbor/marina. I would give up AC and DVD's not to have diesel aboard but the boat is so ugly and has tiny accommadations. Even then,it's still tempting.
Just trying to be realistic. Can the Fastcat people build a 9000lb version of the 420 for me - all electric of course?

[henryv]

Hey guys - while the Fast Cat may not be the prettiest cat I've seen I'm not sure it qualifies as ugly - beauty is in the eye of the beholder - keep in mind that most monohullers think all cats are ugly - I've never been a fan of the Lagoon style - what the admiral refers to as "the tug boat look" -- but to each his own.

Back on the original topic - Nigel Calder did a good article on diesel electric drives in Sail Mag recently - he does not favour large battery banks as he feels the system offers many benefits without using the batteries as a drive source - he quoted some very impressive fuel efficiency gains being obtained by hybrids. He is having a new boat built with a hybrid drive for his own use.

[dana-tenacity]

I haven't kept track of my motoring % , but I have covered over 150,000 miles, mostly cruising plus the odd race or delivery, and off the top of my head 10% or less. I remember filling my 20 gallon tank in Ft Lauderdale and being about one third full when I arrived in NZ.

[Brent Swain]

I've often seen times with no wind and solid overcast for a month or more. You need some kind of generator.
Building your rig so light that it will break is no guarantee of safety whatever your righting moment. To a point, the lighter your rig the greater your likelihood of capsize.The price of carbon fibre makes it impractical for most cruisers. It will improve safety at sea by insuring that you will be far les likely to be able to afford to spend as much time cruising. However that will mean more time ashore in dangerous traffic ,breathing toxic gasses, raising your blood pressure ,and stressing out, trying to get to work to pay for them ,so you will actually reduce your safety and life expectancy, overall. The sea on any well built yacht is still the safest place on the planet to be, no carbon fibre needed.
Brent

[planetoftheapes]

DT,

I think the point of 50% motoring estimate is not that of all the miles you travel, half of them will be under power, but that there is a high probability you encounter periods where you will need (want?) to motor half the time or more. I can make the decision to sail only, but only if I want to induce my family to mutiny. So, you are preparing for these times. I'm sure one can sail thousands of miles without aux power. It has been done for thousands of years.
LR-Price is a reasonable argument against carbon but strength is not. This is now mature technology. Just imagine removing 160lbs aloft on a 40 ft boat! I have read the paper on heavy mast increasing initial stability (moment of inertia) in contex of wave inpact, but this seems far less applicable to a light multihull. The weight issue is important to reduce wetted surface which increases light air preformance, making an engineless ship more practical.
I agree the non-fossil fuel cruiser is rather impractical. The Baja bash would be hell.
Battery tech may increase to the point that in 10 years we will be able to motor under batteries for 24 hours before recharge. You could do it now if you spent $200K on lithium batteries.
I definitely agree with less work more cruising!
-Apes