Characteristics of a Circumnavigating Cat

[Therapy]

Originally Posted by deckofficer

Experts, please chime in. What is your take on a 1985 Catalac 12 meter? I know it is heavy, but that is a plus for me as I plan to pull the diesels, fuel tanks, and replace with electric drive which means a lot of heavy batteries. But overall, with the rather low price, it is what I'm leaning towards, but am looking forward to all of your input.

Even the big guys that have tried to remove diesels and replace with electric have gone back to the drawing board (or thrown it out ).

Do you think you can do better than them?

I truly hope you do though as I have no ability to figure it out.

[deckofficer]

I was hoping for feedback on the choice of a 26 year old Catalac 12M for this thread. My converting over to electric drives is for another topic header. I have a lot of experience with electric drives, own a truck, car, and scooter that I have converted to electric. Also plan on a fully electric galley and even an electric cat dingy. Will be running a 96 volt battery bank made up of (48) 2 volt AGM 700 a/hr batteries for a total storage of 67 kw/hr.

[Lodesman]

Originally Posted by SettingSail2009

Forward facing props are (according to the builder) 15% more efficient.

They are more efficient - not sure 15% more, but that can be measured. When I recommended it to Gideon, he didn't seem so keen on the idea: http://www.cruisersforum.com/forums/...n-10261-2.html

[44'cruisingcat]

Originally Posted by deckofficer

I was hoping for feedback on the choice of a 26 year old Catalac 12M for this thread. My converting over to electric drives is for another topic header. I have a lot of experience with electric drives, own a truck, car, and scooter that I have converted to electric. Also plan on a fully electric galley and even an electric cat dingy. Will be running a 96 volt battery bank made up of (48) 2 volt AGM 700 a/hr batteries for a total storage of 67 kw/hr.

Any idea how much those batteries will weigh?

[Stella Polaris]

Originally Posted by deckofficer

I was hoping for feedback on the choice of a 26 year old Catalac 12M for this thread.

Hopefully someone that owns a Catalac will chime in, but my gut reaction is: Are you sure you want to use a heavy boat?
If you're doing it to make an electric boat, then you can do it on any boat, but since you're doing it on a sailboat, I'm assuming you also want to sail. The most important thing then is to look at load carrying ability. Since I'm not familiar with the Catalac, I don't know how they are, but there are several forum members that own them. If none of them write anything here, try to contact them.

Originally Posted by Lodesman

They are more efficient - not sure 15% more, but that can be measured. When I recommended it to Gideon, he didn't seem so keen on the idea: http://www.cruisersforum.com/forums/...n-10261-2.html

Gideon obviously had a big change of heart, because now he's all thumbs up about it.

[deckofficer]

Originally Posted by 44'cruisingcat

Any idea how much those batteries will weigh?

4800 lbs. As the cost of Li Po batteries drop, I get more interested. To put together a Thunder Sky Li Po of 76.8 Kwh (a bit larger), current cost $30K, weight 1845 lbs.

[DotDun]

Originally Posted by deckofficer

4800 lbs. As the cost of Li Po batteries drop, I get more interested. To put together a Thunder Sky Li Po of 76.8 Kwh (a bit larger), current cost $30K, weight 1845 lbs.

I hope you made a mistake and didn't really mean four thousand eight hundred pounds of batteries you are going to try and put in a 1985 Catalac 12 meter. I would guess there isn't enough payload left for anything else.

[deckofficer]

4800 lbs is not a mistake but is too heavy. I'm a single-hander, so save weight there. Also with a water maker, no need for full water tanks. No diesels or their tanks, but could go down to 500 a/hr 2 volts batteries if LiPo are still too expensive. I would prefer the 1845 lbs of the LiPo batteries, but not too fond of a $30K price tag. I'll bet when the time comes, they will have dropped in price again as they have for the 10 years I have racing electric vehicles.

[44'cruisingcat]

Originally Posted by deckofficer

4800 lbs. As the cost of Li Po batteries drop, I get more interested. To put together a Thunder Sky Li Po of 76.8 Kwh (a bit larger), current cost $30K, weight 1845 lbs.

With LiPO batteries you could use a smaller bank. LiPO's can be discharged to around 80% and still give a good cycle life, whereas lead batteries should be cycled around 50%. Given the greaer cycle life of Lipo's as well, they would likely be a cheaper option for your use. Certainly much lighter.

Prices have fallen dramatically in the last couple of years.

[deckofficer]

Originally Posted by 44'cruisingcat

With LiPO batteries you could use a smaller bank. LiPO's can be discharged to around 80% and still give a good cycle life, whereas lead batteries should be cycled around 50%. Given the greaer cycle life of Lipo's as well, they would likely be a cheaper option for your use. Certainly much lighter.

Prices have fallen dramatically in the last couple of years.

I know, and hope they will continue to drop in price. I'm ready to bite the bullet on the dinghy and buy LiPo for it at the current price. Will be a cheaper way of determining proof of concept. It will have a 96 volt 160 a/hr bank.

[brettnkay]

Andreas
How about bridge deck clearance? What was it on the fast cat and is it something you'll consider on the new boat?

Also, one conflict I see is that most/all of the famous builders you mention are now putting 4 heads in their boats above 44 feet, I suppose to accommodate the charter trade. Any thoughts about how to get around that?

Brett

[Stella Polaris]

Originally Posted by brettnkay

How about bridge deck clearance? What was it on the fast cat and is it something you'll consider on the new boat?

Hey Brett,

Bridgedeck clearance is a tough topic, because it's not as easy as some people want to make it. As a general rule, higher bridge deck clearance can be better with regards to slamming, but there are many factors that come into play. The shape of the hulls, where the actual bridgedeck starts, how it is shaped, how far back it goes, how heavily you're loaded, which direction waves are hitting you, etc. There are a ton of things that matter. The higher the bridgedeck clearance, the higher your windage as well, which brings different challenges. Keeping weight out of the ends of your cat will usually help a lot (keeping weight off your cat, period, helps even more).

On the FastCat I had no problems with bridgedeck slamming. Sure a wave could hit every now and then, but that would happen almost no matter how high your clearance is. If you asked the people that sailed with me what bridgedeck slamming is, they would probably look at you with a questionmark in their eyes.

Would I think about this on my next cat? ... Yes. Without a question. If I a cat has a very low bridgedeck clearance, like a few Broadblues and Leopards I've seen, then it will definitely give me pause for thought (and reconsideration).

Originally Posted by brettnkay

Also, one conflict I see is that most/all of the famous builders you mention are now putting 4 heads in their boats above 44 feet, I suppose to accommodate the charter trade. Any thoughts about how to get around that?

It's a tough one, unless you look at older boats. The manufacturers haven't added 4 heads to all their boats, so there is still hope. If I buy one with 4 heads, then I will probably convert 2 of them into wet lockers or storage. I'd try not to do something too drastic, so that when I sold it, the new owner could use 4 heads, if he so chose.

[Stella Polaris]

The boat I picked through this thread and sailed with for 2.5 years is for sale from the guy that bought her from me a year ago: Used Fastcat 435 70k Refit 2011 for Sale | Yachts For Sale | Yachthub

[geoleo]

Originally Posted by SettingSail2009

What exactly rules out the African cats? (I forgot to ask you this question when you posted). Are you thinking about a maker in particular (e.g. Leopard) or SA makers in general?

Why is it that a lot of people seem to distrust the typical charter cats: Lagoon, Leopard and Fountaine-Pajot?

I think the Fountaine-Pajot cats have some appealing features: they are light (so they should sail well), have a high bridgedeck clearance and good lay-outs ... In many ways they seem like good cats for circumnavigating, but a lot of people slam them for inferior quality, so that's kind of put me off.

In general I get the feeling that people bad-mouth the typical charter cats as being "fat and slow", on top of seeming flimsy and not made for "proper use". Proper use being voyaging and not chartering. Since I'm looking for a good design for a circumnavigation, I'm very interested in this.

When I look at their designs on paper and pictures, they look very nice (anything can look nice on paper), but in real life it could definitely be something else, especially when you start looking at the fine details that will make sailing it practical, safe and enjoyable.

Charter CAts seem to have cheap "guts" and low cost sails---you might think of adding a requirement to have effective "Rub Rails" to your list.

[geoleo]

Your not going anywhere much upwind without daggerboards or engines on in the typical Charter oriented Condomarans offered these days.....