tuning tips for multihulls

[David M]

Originally Posted by fastcat435

Yes you are right they have lost one engine but How come the 420 weights well over 13.000 kilo,s and even misses one engine ?
They have gone wrong somewhere Just do not know where.
It is by far the heaviest 42 footer around !!!

Could it be that now with an electric drive one has to have an oversized generator, plus the engines have been replaced not with nothing but with a relatively heavy electric motor?...in addition to more batteries to power those drives when you don't want to have to use your oversized generator.

[gramos]

hi , Keegan how does the Dolphin sail ? i am sure theres lots of multihullers would like to know ?

[philip van praag]

Originally Posted by fastcat435

We at African Cats build in 4 separate tanks all positioned on either side of the mast.
For shorter cruises the 2 inner tanks are filled and optionally we can open valves to increase tankage to 180 US gallons.
the left or right tank can be used and the back flow of diesel is also directed to the tank where the flow is set from.
In the save weight department we have made drastical effort to get the weight down from the original 9000 kilo,s or 20.000 lbs to the 5000 kilo (11000 LBS )that the last boat came out at.
Some of the weight saving where simple , taking the 50 meters of 10 mm galvanized
and change it for 25 meters of Duplex 8 mm chain and 25 meters of weighted line.
Just this change saved over 100 kilo or 220 LBS. chaging from glass windows to Lexan marguard saved another 115 kilo or 255 Lbs
The biggest single weight saver was taking the lead acid batteries out and putting in Lithium Ion Phosphate. this saved over 200 kilo,s or 440 LBS
All cabinets and locker spaces are build within 10 ft or 3 meters of the centre of gravity. the anchor chain locker is under the mast step together with the winch.
The generator and the batteries are mounted under the nav station and seatin area right on the centre of gravity.
We changed from Lewmar winches to Harken and Meissner winches and this was also a good one , 40 kilo,s ( 88 LBS ) less on the scale .
Are cats are build on 4 load cells so during the building time we can measure all weights coming on board and we can keep the weights at the right locations .
Another weight saver is chaging the porcelin Toilets most of you use to the RM 69 Plastic toilet, a weight saver of 25 k. or 55 LBS per toilet.
Changing from a normal powr distribution system to a Buss system saved 128 kilo,s or 280 LBS.
For the Rigid inflatable we changed from a 85 kilo Caribe to a self build carbon fiber and Hypalon Rigid inflatable in the same size but a weight of only 28 kilo.
Because of this change we could reduce the size and strenght of the davits for a weight saving of 85 kilo.The ouitboard became smaller in the process, before it was a 10 HP Suzuki 4 cycle long leg with a weight of 39 kilo,s excluding the tank and now we use a 6 HP Tohatsu 4 Cycle with a weight of 19,6 kilo with a build in tank.
All control lines where changed from normal polyester to Dyneema 36 kilo.
The side stays where changed from 12 mm Dyform to Dyneema side stays . 66 Kilo,s
The roof originally constructed with glass and foam is now constructed with Carbon Fiber 110 kilo.We left out the Gell and flow Coat and now use Spray paint the boat with Awl Grip.This saved 850 Kilo,s. Optionally we install a carbon fiber mast and Boom for 185 kilos of weight saved.
We left out all inner linings originally made in Fiberglass/Epoxy 225 Kilos
etc.etc.

Greetings
FastCat435

after reading this post we have undertaken to go through the hole boat and revew all our stuff and get some weight of. its amazing how mutch stuff you acumalate liveing onboard.
well we have managed to get about 1000kg of without missing anything.
and 40mm on the waterline.

i am curently replacing some of our sheets and halayards with dynema.
i was wondering
fastcat do you use lightweight blocks there seem to be some around that replace the metal parts with dynema
can you recomend.
also do you use dynema for the gard rails, and how mutch weight does this save?

we cant aford a fastcat but are going to try and replace thing with a lighter option when they need replacing.

[2Hulls]

Originally Posted by philip van praag

i am curently replacing some of our sheets and halayards with dynema.

also do you use dynema for the gard rails, and how mutch weight does this save?

When you switch to high tech lines, make sure rope clutches (if you use them) still work they way you expect them to. An acquaintence is currently grapling with a spinlock that won't hold a new main halyard made from Paraloc. A combination of smaller diameter line, a worm spinlock cam, and slippery covering on the line made his spinlock useless.

I am replacing my (typical) SS life lines with something, but not dynema. I don't think the extra expense of dynema vs some other slightly less sexy, but very strong line is worth the small weight savings. JMHO.

Dave

[philip van praag]

Originally Posted by 2Hulls

When you switch to high tech lines, make sure rope clutches (if you use them) still work they way you expect them to. An acquaintence is currently grapling with a spinlock that won't hold a new main halyard made from Paraloc. A combination of smaller diameter line, a worm spinlock cam, and slippery covering on the line made his spinlock useless.

I am replacing my (typical) SS life lines with something, but not dynema. I don't think the extra expense of dynema vs some other slightly less sexy, but very strong line is worth the small weight savings. JMHO.

Dave

i see what you are saying but by the time i remove all the bottle screws and shackles and the fact that our gard rails are plastic coated i think there will be a reasonable weight saving, plus less maintance.
also the amount needed to replace all the lines and the safty lines means it worth me buying a drum of line and that means i can get a good price!!
have checked our clutches and they take the smaller lines
if you look at every thing on its own the weight saving seem not worth the efort, but if you can do a lot in a short space of time as we have done it amazing what a diferance it makes.
so i am now on a mission.

[GordMay]

Dave:
Which “Paraloc” product is your acquaintance using (slips in SpinLok)?
mamutec - Paraloc-Technology - Swiss innovation

[pilot]

Gideon, a little off topic, but nevertheless how reliable are the new developed Lithium Ion batteries?
Read an article in automotive industry, that introduction to the Car market will take some more time.
Germany for example is trailing in the this research area.

[2Hulls]

Originally Posted by GordMay

Dave:
Which “Paraloc” product is your acquaintance using (slips in SpinLok)?
mamutec - Paraloc-Technology - Swiss innovation

I do not know exactly. I had never heard of it until he started seeking help among other Catana owners. He replaced his 12mm main halyard, probably of some low stretch variety line, with 11mm Paraloc and immediately had problems. Of course, both Paraloc and spinlock are pointing at the other guy.

I doubt this is wholly a Paraloc or spinlock or worn cam or smaller diameter line problem - rather, it's probably "tolerance stack up" of all these variables.

The point I was offering is that unintended consequences may reveal themselves when switching lines - not the least of which may be worn cams in rope clutches which would eventually manifest themselves even if new lines aren't being used! I'll be checking mine at the first opportunity!

edit: his fix is replacing the cam. Running the halyard thru an adjacent spinlock temporarily solved his problem.

Dave

[fastcat435]

Hallo Philip instead of shacles we use rope connections 20 % of the weight
and stronger and no noise.
All our blocks are the carbo 75 blocks from Harken reasonable in weight and very strong.
We will start using dyneema for our guard rails on hull number 6 where we have also replaced the stainless stanchoins with basalt fiber stanchions .

Greetings

Gideon

p.s. I am glad not every body can afford a FastCat it would leave me no time to sail

[fastcat435]

Originally Posted by pilot

Gideon, a little off topic, but nevertheless how reliable are the new developed Lithium Ion batteries?
Read an article in automotive industry, that introduction to the Car market will take some more time.
Germany for example is trailing in the this research area.

They are very reliable , actually more so than the Lead acid or AGM units they replace.
The advantage of a Lithium Ion battery is that the batteries are connected in strigns to make the 12.8 volts there are at least 48 strings in one battery , if one string fails that still leaves you with 97 % of your original power.
A strange thing also occurs with these batteries, the more often we load them the more energy they accept , so far 5 % over the original load
Greetings

Gideon

[SailFastTri]

Defender now carries weighted lead-core anchor line in the US. Go to Discount Marine and Boat Supplies - Inflatable Sales - Defender and search for "robline" anchor line or "FSE".

BTW I have no affiliation with them except as a customer.

[SailFastTri]

Originally Posted by 2Hulls

When ever (if ever) I need to replace the main I plan on discussing a square top with the candidate sailmakers. I don't see this as a useless advantage on an otherwise performance oriented cruising cat. It can't be THAT much more expensive. For a non-performance oriented cat, it would probably look like a spoiler on a Winnebago. JMHO

Dave

Hey Dave --
Wouldn't a square top create issues with stowing the lowered sail on the boom? That's the reason I never went that route - was advised against it for that reason.

Larry

[fastcat435]

Originally Posted by SailFastTri

Hey Dave --
Wouldn't a square top create issues with stowing the lowered sail on the boom? That's the reason I never went that route - was advised against it for that reason.

Larry

There is no reason for not using a squire topped sail the extra batten should fold needly if the sail is well designed.
Greetings

[fastcat435]

Originally Posted by SailFastTri

Defender now carries weighted lead-core anchor line in the US. Go to Discount Marine and Boat Supplies - Inflatable Sales - Defender and search for "robline" anchor line or "FSE".

BTW I have no affiliation with them except as a customer.

A Breaking load for a 40 ft cat of 5200 lbs is not enough and for that reason we had these weighted lines made for 10000 Lbs working load.
There are many weighted anchor line manufacturers but mostly up to 5000 lbs breaking load and 100 ft mostly.
The line we had manufactured is 163 ft and 15000 breaking and 10000 working load .
Greetings
Gideon

[2Hulls]

Originally Posted by SailFastTri

Hey Dave --
Wouldn't a square top create issues with stowing the lowered sail on the boom? That's the reason I never went that route - was advised against it for that reason.

Larry

Hi Larry - nice to see you here.

To be honest, I hadn't thought of that potential problem. On my rig I have lazy jacks and a boom bag which probably has enough room. But this may not be the case for everyone and your point should not be overlooked. I'm probably a loooooooong way off from making this move. Hope I don't forget this when the time comes.

Dave