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Old 08-14-2009, 01:24 PM   #1
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What makes a good cruising Multihull ? The topic title qualifies the question by including 'cruising'.

and cruising in this forum's terms includes offshore crossing oceans
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Old 08-20-2009, 11:44 AM   #2
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# The Ability to beach without worrying about hull stress or damage to rudders or props.

# The design Payload should be such that it does not effect average SOG

# External dagger boards to improve windward ability

# Standing rigging to be oversize by at least 20 %

# Cockpit seating for 16

# LOA no greater than 12 metres or 39ft 5in

# Beam no greater than 8 metres or 26ft 4in

# Draft no greater than 1 metre or 3ft 3in.

# Single naturally aspirated 80hp engine on aft duckboard driving a hydraulic pump system,

which in turn drives an hydraulic motor drive in each hull.

Plus hydraulically driven anchor windlass & generator.

# Galley up

# Helm to be operated from remote position in addition to bulkhead helm

What else ????
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Old 08-20-2009, 03:28 PM   #3
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# The Ability to beach without worrying about hull stress or damage to rudders or props.

Agree and most important for maintenance

# The design Payload should be such that it does not effect average SOG

Ditto to this

# External dagger boards to improve windward ability

I have to disagree here, I am not in love with dagger boards on a cruiser, sure you will sail closer to the wind but you are cruising and going trans ocean which lot of cruisers do I see little gain, rather I would prefer to sail abeam or a close reach or god forbid close hauled in a cat, the 5% closer to the wind a dagger board gives me is offset by having to clean them and get them up in an emergency after sailing with them down for 3 weeks and being stuck up with barnacles and such. Daggerboards tend to get scraped and scratched lifting and lowering them as a result seldom are they barnacle free.

# Standing rigging to be oversize by at least 20 %

15% for me but close enough

# Cockpit seating for 16

Which has open access to the saloon so that the person cooking can communicate with the rest of the folks on board. A window or hatch system similar to the one on the lagoon 38 or Leopard 40



# LOA no greater than 12 metres or 39ft 5in

Again, for me whatever makes you comfortable that you and your mate can sail easily on your own. I prefer 40 to 44 ft, for me it is a matter of being comfortable and at ease. I know couples that happily sail 50 footers on their own and others that happiest with 36 ft. Simply put what size cork are you happy bobbing around the ocean in/ on.

# Beam no greater than 8 metres or 26ft 4in

Pretty beamy for a 39 footer. Admiral 38 has 23ft beam and the Leopard 40 has a just over 20 ft (20'1") I believe. Too beamy makes a cat more prone to pitch poling.



# Draft no greater than 1 meter or 3ft 3in.

No argument here ...

# Single naturally aspirated 80hp engine on aft duckboard driving a hydraulic pump system,

which in turn drives an hydraulic motor drive in each hull.

Plus hydraulically driven anchor windlass & generator.

For me 2 is always better than one, and the hydraulic system that you propose is cool, but the motor dies and you have no power. For me on a 39 - 40 footer twin 30hp naturally aspirated diesels do it for me. 7 to 8 knots out of my diesels is plenty, now if I want to outrun pirates then 2 80hps may do the trick

# Galley up

Why would you ever want it any other way...

# Helm to be operated from remote position in addition to bulkhead helm

What else ????

How about a asymmetric on a furler for downwind surfing err sailing ....

Additional hanging space, not one of the Cats that I have seen (barring a custom Admiral) has enough space for hanging clothes. When I was younger I lived in shorts, swimsuits and t-shirts, as I age I find a need to cover up more, or is it more to cover up???


Additional seating space on the foredeck between the cabin and trampolines (as per the Lagoon 44)

Hardtop Bimini (great for protection and mounting solar panels which to me is a must as well)

Safety / access hatches in each hull, it may be upside down, but it is still floating and I need to either get in and get food and supplies or get out and wait for rescuers.

Gavin
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Old 08-21-2009, 12:19 AM   #4
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Note Quote has new response replies inserted :-



Quote:
Originally Posted by gslabbert5119 View Post
# The Ability to beach without worrying about hull stress or damage to rudders or props.

Agree and most important for maintenance

# The design Payload should be such that it does not effect average SOG

Ditto to this

# External dagger boards to improve windward ability

I have to disagree here, I am not in love with dagger boards on a cruiser, sure you will sail closer to the wind but you are cruising and going trans ocean which lot of cruisers do I see little gain, rather I would prefer to sail abeam or a close reach or god forbid close hauled in a cat, the 5% closer to the wind a dagger board gives me is offset by having to clean them and get them up in an emergency after sailing with them down for 3 weeks and being stuck up with barnacles and such. Daggerboards tend to get scraped and scratched lifting and lowering them as a result seldom are they barnacle free.

True, BUT dagger boards in this design are External the cases of which terminate just above the water line = no barnicles and easy to clean. Besides improving the ability to point,

much easier to tack, helps not being set down. Nearly all the best designs coming out of Australia have dagger boards. Elsewhere the accountants in production line companies have out-designed the DBs to add bottomline profit.


# Standing rigging to be oversize by at least 20 %

15% for me but close enough

# Cockpit seating for 16

Which has open access to the saloon so that the person cooking can communicate with the rest of the folks on board. A window or hatch system similar to the one on the lagoon 38 or Leopard 40



# LOA no greater than 12 metres or 39ft 5in

Again, for me whatever makes you comfortable that you and your mate can sail easily on your own. I prefer 40 to 44 ft, for me it is a matter of being comfortable and at ease. I know couples that happily sail 50 footers on their own and others that happiest with 36 ft. Simply put what size cork are you happy bobbing around the ocean in/ on.

The 7 inches short of 40ft may save a lot of money in marinas, lift outs, taxes, insurance etc because the boat is not in the 40ft plus category.



# Beam no greater than 8 metres or 26ft 4in

Pretty beamy for a 39 footer. Admiral 38 has 23ft beam and the Leopard 40 has a just over 20 ft (20'1") I believe. Too beamy makes a cat more prone to pitch poling.



Meet you half way 24ft (7.3 metres)

# Draft no greater than 1 meter or 3ft 3in.

No argument here ...

# Single naturally aspirated 80hp engine on aft duckboard driving a hydraulic pump system,

which in turn drives an hydraulic motor drive in each hull.

Plus hydraulically driven anchor windlass & generator.

For me 2 is always better than one, and the hydraulic system that you propose is cool, but the motor dies and you have no power. For me on a 39 - 40 footer twin 30hp naturally aspirated diesels do it for me. 7 to 8 knots out of my diesels is plenty, now if I want to outrun pirates then 2 80hps may do the trick

True 2 is better than 1 - however 1 is all that is found in the vast majority of sailboats cruising the ocean. The design plunked for above provided very very easy access to all parts of the engine so that scheduled maintenance did not have to be carried out in a confined engine compartment.



# Galley up

Why would you ever want it any other way...

# Helm to be operated from remote position in addition to bulkhead helm

What else ????

How about a asymmetric on a furler for downwind surfing err sailing ....

Additional hanging space, not one of the Cats that I have seen (barring a custom Admiral) has enough space for hanging clothes. When I was younger I lived in shorts, swimsuits and t-shirts, as I age I find a need to cover up more, or is it more to cover up???


Agreed - Absolutely

Additional seating space on the foredeck between the cabin and trampolines (as per the Lagoon 44)

Would this mean cutting down the space in the Saloon?

Hardtop Bimini (great for protection and mounting solar panels which to me is a must as well)

A must have

Safety / access hatches in each hull, it may be upside down, but it is still floating and I need to either get in and get food and supplies or get out and wait for rescuers.

It depends where they situated - will they let water in ?

Gavin
Richard

PS:- Rudders would be retractable
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Old 08-21-2009, 12:43 PM   #5
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Note Quote has new response replies inserted :-

# The Ability to beach without worrying about hull stress or damage to rudders or props.

Agree and most important for maintenance

# The design Payload should be such that it does not effect average SOG

Ditto to this

# External dagger boards to improve windward ability

I have to disagree here, I am not in love with dagger boards on a cruiser, sure you will sail closer to the wind but you are cruising and going trans ocean which lot of cruisers do I see little gain, rather I would prefer to sail abeam or a close reach or god forbid close hauled in a cat, the 5% closer to the wind a dagger board gives me is offset by having to clean them and get them up in an emergency after sailing with them down for 3 weeks and being stuck up with barnacles and such. Daggerboards tend to get scraped and scratched lifting and lowering them as a result seldom are they barnacle free.

True, BUT dagger boards in this design are External the cases of which terminate just above the water line = no barnicles and easy to clean. Besides improving the ability to point,

much easier to tack, helps not being set down. Nearly all the best designs coming out of Australia have dagger boards. Elsewhere the accountants in production line companies have out-designed the DBs to add bottomline profit.


From a technical prospective daggerboards are an excellent idea I still see little use for them cruising, racing and day sailing or even weekenders and you will get little argument from me. Though I may simply be an arm chair critic here as I have never cruised the oceans but from what I have read and in the discussions I have had with cruisers I am told that they sail in one direction for days at a time only really needing to tack on the rarest occasion.

Still from a performance prospective daggerboards do the job.



# Standing rigging to be oversize by at least 20 %

15% for me but close enough

# Cockpit seating for 16

Which has open access to the saloon so that the person cooking can communicate with the rest of the folks on board.

A window or hatch system similar to the one on the lagoon 38 or Leopard 40

# LOA no greater than 12 metres or 39ft 5in

Again, for me whatever makes you comfortable that you and your mate can sail easily on your own. I prefer 40 to 44 ft, for me it is a matter of being comfortable and at ease. I know couples that happily sail 50 footers on their own and others that happiest with 36 ft. Simply put what size cork are you happy bobbing around the ocean in/ on.

The 7 inches short of 40ft may save a lot of money in marinas, lift outs, taxes, insurance etc because the boat is not in the 40ft plus category.

Ahh but we are not discussing finances here, simply the best / ideal Multihull cruisers

# Beam no greater than 8 metres or 26ft 4in

Pretty beamy for a 39 footer. Admiral 38 has 23ft beam and the Leopard 40 has a just over 20 ft (20'1") I believe. Too beamy makes a cat more prone to pitch poling.

Meet you half way 24ft (7.3 metres)

How about 23ft which is the maximum width of the 100 ton hoist, over that and you have to go to the 300 ton. Just been down this road when attempting to survey Highland Odyssey which was bought out from under my nose... DAMN

# Draft no greater than 1 meter or 3ft 3in.

No argument here ...

# Single naturally aspirated 80hp engine on aft duckboard driving a hydraulic pump system,

which in turn drives an hydraulic motor drive in each hull.

Plus hydraulically driven anchor windlass & generator.

For me 2 is always better than one, and the hydraulic system that you propose is cool, but the motor dies and you have no power. For me on a 39 - 40 footer twin 30hp naturally aspirated diesels do it for me. 7 to 8 knots out of my diesels is plenty, now if I want to outrun pirates then 2 80hps may do the trick


True 2 is better than 1 - however 1 is all that is found in the vast majority of sailboats cruising the ocean. The design plunked for above provided very very easy access to all parts of the engine so that scheduled maintenance did not have to be carried out in a confined engine compartment.

The vast majority of sailboats cruising the ocean are mono-hulls and in many cases there is hardly room for 1 engine, let alone 2. I like the improved access you design / suggestion implies, which for me is key, but where I come from you were not allowed to sea with 1 engine if you were a fishing vessel, yachts back in the day did not have any engines so we may both be correct. I come from a fishing vessel background.

# Galley up

Why would you ever want it any other way...

# Helm to be operated from remote position in addition to bulkhead helm

Without question an essential, you need to be able to operate the vessel in bad weather and lightening storms, though many an old salt will tell you that you are a wuss(sp) if you are not out in the elements. Given the choice I like the idea of not being washed overboard and getting soaked for days on end, but again there are times when that is enjoyable and gets the juices flowing.

What else ????

How about a asymmetric on a furler for downwind surfing err sailing ....

Additional hanging space, not one of the Cats that I have seen (barring a custom Admiral) has enough space for hanging clothes. When I was younger I lived in shorts, swimsuits and t-shirts, as I age I find a need to cover up more, or is it more to cover up???


Agreed - Absolutely

Additional seating space on the foredeck between the cabin and trampolines (as per the Lagoon 44)

Would this mean cutting down the space in the Saloon?

Nope, I would not trade saloon space for anything, shorten/make smaller the trampolin area still leaving sufficient trampoline to allow it to function as designed. An additional feature would be additional structural integrity though in many designs it is not needed.

Hardtop Bimini (great for protection and mounting solar panels which to me is a must as well)

A must have

Safety / access hatches in each hull, it may be upside down, but it is still floating and I need to either get in and get food and supplies or get out and wait for rescuers.

It depends where they situated - will they let water in ?

Nope, look at the locations of the hatches on the FP, well pretty much all the French yachts, and the Knysna 44. Now absolutely they will let water in if left open but they are designed not to leak (is there such a thing on the water) and the glass is reinforced.

1. more thought, additional bridge deck clearance, to reduce slapping and improve the ride. I do not have a number in mind as each design is different. I will say that the French Cats have better bridgedeck clearance than most of the SA yachts, and I have little experience with the Australian / New Zealand vessels

2. For cruising a water maker, water is scarce in places and pretty bad in others

Gavin
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Old 08-21-2009, 01:37 PM   #6
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Thanks Gavin,

And we have only scratched the surface (or Gelcoat)

What about sleeping accommodation ??

and Tender ? and Outboard ?

Richard
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Old 08-21-2009, 03:54 PM   #7
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Quote:
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Thanks Gavin,

And we have only scratched the surface (or Gelcoat)

What about sleeping accommodation ??

and Tender ? and Outboard ?

Richard
Who needs a tender when you can swim, and if you had a tender why add a motor when you have oars and need the exercise .... didn't someone say that rowing your sweetheart was romantic

Seriously though I will add to this a little later as I find it really interesting, too busy packing for Alaska.
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Old 11-30-2009, 11:25 PM   #8
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I will add, a forward boarding ladder for beaching.

High bridgedeck clearance. (Most of these productions cats these days don't have it)

Ground tackle setup where the anchor nestles up somewhere under the mast, keeping the weight off the bows and allowing it's windlass to double as the main halyard winch.

Daggerboards are the way to go. Angled inwards. This keeps the trunk up against the outboard side of the hull, increasing interior room, and also allows the board to produce lift not only to windward but upward. Huge performance increase.

Dual steering stations port and starboard.

One setup I would like to see but never do: Heads in the bow. In a multihull you want to keep the bows empty and light. Put a head with shower up in each bow, make it HUGE and empty. This is a personal quirk of mine. I don't know about you guys, but I spend about two percent of my time in the head, therefore I do not see the rationale of making heads take up fifty percent of the interior. All the boats now have "en suite" heads in each stateroom. I don't know about you, but I really don't want a stinky marine toilet right next to my bed. Maybe I'm weird.

This single engine running hydraulics, I like the sound of that. Never seen that type of setup but it intrigues me...
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Old 12-26-2009, 02:12 PM   #9
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By any chance could we add one of those little Margarita machines???
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Old 01-08-2010, 11:38 PM   #10
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Gunboat works for me... 48, 62, 80... all good.
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Old 01-09-2010, 06:53 PM   #11
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Hi totemthepole,

My 10.2m x 6.2m cat has most of the attributes you mention - enough bridgedeck clearance, ground tackle at the main crossbeam, daggerboards, dual steering, head up front, single 36hp Lombardini diesel coupeld to twin hydraulic drives with folding props.

She is a one-off Dutch built catamaran designed by Bob Oldenziel and built in wrc epoxy.

Roger
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Old 01-17-2010, 07:12 PM   #12
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I have decided to use the advantage of a single engine installation on my cat in the following way:

The aft port cabin will be converted into a double-function area:

- when needed it will function as a double berth, sideways sleeping cabin

- when no guests are aboard (which will be most of the time) this area will be converted and function into the inside dining area for four, located adjacent to the galley. The conversion in fact will entail pushing the berth support board sideways to be stored under the mattress and moving the mattress section. The seats and table will thus be located underneath the mattress support.
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Old 01-18-2010, 12:27 PM   #13
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Single 36hp Lombardini diesel coupled to twin hydraulic drives with folding props.

Roger
Hi Roger, where was the engine mounted ? What Hydraulic Pump and motors were used ?

How were the pump and motors connected ? how much noise is generated by the hydraulics?

Richard
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Old 01-18-2010, 06:32 PM   #14
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Hi Roger, where was the engine mounted ? What Hydraulic Pump and motors were used ?

How were the pump and motors connected ? how much noise is generated by the hydraulics?

Richard
Hi Richard.

The engine in mounted in the starboard hull, below the aft double berth. The front of the engine is approx. 3.2m from the stern, with the whole installation being about 2m long. The pump and hydraulic fluid tank are behind the engine with access through a deck hatch. Though not being perfectly insulated (still work to do) the engine noise is not loud, when you are in the port aft cabin the hydraulic turning the prop shaft produces a humming noise.

Can't tell you much more currently, as the boat is 10,000km away and the previous owner had all the units installed professionally, everything is very sturdy looking.
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Old 01-19-2010, 09:48 AM   #15
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Hi Roger,

I am very interested in your setup - my own experience of installing a similar system on a catamaran drew lots of criticism at the period when the usual comment regarding multihulls was

"of course they capsize, they can't go to windward etcc. In addition to having hydraulic motors I also had an hydraulic windlass.

Richard
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Old 01-10-2011, 10:44 AM   #16
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Diesel electric drives are inefficient and complicated and diesel Hydraulic drives are even more so. Invest in the best diesel engine you can afford and couple it as simply as possible to the best prop for application. The biggest container ships in the world have one large diesel midships and a shaft that runs for 100s of metres and this is still much more efficient than diesel electric drives. When you think about it logically you don't get anything for nothing otherwise all we would need to do is get a large flywheel build it up to speed and connect this to a prop and it would never stop in the same sense when we change one form of energy to another we lose energy/ efficiency and are making the whole thing more complicated and expensive. I have seen some very slick sculptural but not practical French Cats trying to promote their diesel electric drives they crap on about the fact that the engine revs don't have to fluctuate hence better fuel consumption, how often when crusing for economy do you change the revs of your engines.
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Old 01-10-2011, 11:32 AM   #17
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Diesel electric drives are inefficient and complicated and diesel Hydraulic drives are even more so.
Up and Away

Agree that Electrically Driven drives in the marine environment which have to be powered by combustion engines are not living up to the Hype - however they are very successfully used in a rail environment.

As for Diesel Hydraulic drives being MORE inefficient and complicated - this combination is very successfully utilized in the Earth Moving and Mining Industry and by the Commercial fishing fleets. My own experience using a Yanmar diesel engine driving a Cessna pump in turn driving 2 Cessna motors driving the Cat's 2 propellers is very positive.
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Old 01-10-2011, 07:17 PM   #18
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The "weak link" of a traditional diesel propulsion system in a yacht is really the transmission, IMHO. When folks get around this matter by using electric drive or hydraulic drive, I believe they have the right idea. In a multi-hull, it is really a great idea to employ electric drive or hydraulic.

In today's marketplace, vendors are trying to tout electric drive/hybrid as something really hi-tech; the hype is crazy and sadly, these systems are often overpriced and poorly engineered. That need not be the case. We have an old, old, old monohull boat that originally had a hybrid gas genset/electric drive propulsion system--installed way back in 1931 when the boat was new! Our boat, the owner, and that system were much written about in the 1930's Yachting magazines as it was the "first" gas-electric drive hybrid private yacht known. The drive system employed two 10 kW gas generators and one 25 kW electric drive motor. It worked wonderfully to propel the boat at 60% hull speed with one generator running and zero float on the batteries and 72% of hull speed with both generators running and zero float on the batteries. The owner loved it and only stated that he never used the system on batteries alone, thus should have not put in such a big battery bank. When he sold the boat in the late 30's the next owner removed the electric drive/generator system and put in a huge single gas motor. Each owner since has re-powered with a regular diesel (not gas) powerplant. We considered going back to electric drive with two diesel (not gas) gensets, but the owner previous to us had purchased a brand new diesel engine for install and that came with the boat. We just couldn't justify the cost of ignoring that new engine and getting set up with proper electric drive. However, we will someday do it to restore the boat to her original power configuration and because we think it makes good sense. Similarly, diesel/hydraulic drive is also very sensible.

Fair winds,
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Old 01-22-2011, 08:44 AM   #19
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[QUOTE=redbopeep;1294687035]

The "weak link" of a traditional diesel propulsion system in a yacht is really the transmission, IMHO. When folks get around this matter by using electric drive or hydraulic drive, I believe they have the right idea. In a multi-hull, it is really a great idea to employ electric drive or hydraulic.

In today's marketplace, vendors are trying to tout electric drive/hybrid as something really hi-tech; the hype is crazy and sadly, these systems are often overpriced and poorly engineered. That need not be the case. We have an old, old, old monohull boat that originally had a hybrid gas genset/electric drive propulsion system--installed way back in 1931 when the boat was new! Our boat, the owner, and that system were much written about in the 1930's Yachting magazines as it was the "first" gas-electric drive hybrid private yacht known. The drive system employed two 10 kW gas generators and one 25 kW electric drive motor. It worked wonderfully to propel the boat at 60% hull speed with one generator running and zero float on the batteries and 72% of hull speed with both generators running and zero float on the batteries. The owner loved it and only stated that he never used the system on batteries alone, thus should have not put in such a big battery bank. When he sold the boat in the late 30's the next owner removed the electric drive/generator system and put in a huge single gas motor. Each owner since has re-powered with a regular diesel (not gas) powerplant. We considered going back to electric drive with two diesel (not gas) gensets, but the owner previous to us had purchased a brand new diesel engine for install and that came with the boat. We just couldn't justify the cost of ignoring that new engine and getting set up with proper electric drive. However, we will someday do it to restore the boat to her original power configuration and because we think it makes good sense. Similarly, diesel/hydraulic drive is also very sensible. Fair winds,

G'day you two & 'Mahdee'. I think I here your tone of voice, bit lower than Brenda's. Re: Multihull propulsion; What is wrong with a new approach, like a high performance, efficient, fuel thrifty & smooth running motor coupled with a 'water-jet'. These, modern 'water-jets coupled to a suitable motor are EXTREMELY efficient. They have 'little' to no drag (very low profile appendages) & also are great for steering. Can't think of why people have not thought of this very efficient method. A very important factor - is the whole system is 'low profile' within the hulls & does NOT weigh very much at all. As I'm only slightly over the hill, 71 in Feb. - I may well be missing the point totally. A water-jet is extra efficient when moving a vessel over the water more so when that vessel doesn't weigh very much compared to a monohull such as yours where I'm sure it would not be applicable. Please straighten me out (not tied to a pole in an ants nest). Thanks, 'JJ-geri-hat-trick'
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Old 01-22-2011, 04:06 PM   #20
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Hey there Silver Raven, it was actually me, Brenda, commenting. David seldom joins us here on CL. I just asked him about what he thinks of water jets and he says--great regarding places where there are lots of swimmers, obstacles, ice, etc in the water. Things that would hurt a prop or be hurt by a prop.

The ducting size requirements for a large heavy displacement vessel might be a bit much whereas a lightweight vessel, good. L ets see--big holes through the timbers... you get the drift.

Well, gotta go now, have a great time with this topic--I hope someone else comments on the water jet prop idea for cats.
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