New style Harryproa cruiser

[44'cruisingcat]

A fairly substantial fraction.

[44'cruisingcat]

Originally Posted by lucdekeyser

- the sea keeping qualities of a 60 footer
- the airy space of a 40 foot catamaran
- at the price of a 30 foot catamaran
- the sailing simplicity of a proa with double rudders/schooner unstayed masts

I don't see it having:

- the sea keeping qualities of a 60 footer
- the airy space of a 40 foot catamaran
- at the price of a 30 foot catamaran

And do some research. I've heard of some difficulties with proa steering systems.

[rob denney]

Lots of interesting feedback. Thanks.

The Cruiser 18 has 2 queen size double cabins, each with it's own ensuite toilet and shower and 2 single cabins with a shared toilet and shower. The first one will have a bath. The saloon is 5.4m x 3.2m/16' x 10' and has fixed seating for 8, with temporary seating for another 8. Outside, there is seating for >20. It is not so much the total space available, but how it is used.

The steering position can be inside the cabin, fully sheltered with the lee facing door open or shut, or outside. Both use the same steering wheel, which pivots on it's lower cog.
Extra sun protection can be added, but is a trade off with being able to see the sails and the horizon. On the Cruiser, you can see everything, while still being sheltered. And you are not isolated from the rest of the crew, sitting uncomfortably or getting a stiff neck.

Helm balance is not a problem. The 2 rudders are mounted fore and aft and the front one can be lifted to improve balance. On the bigger harrys, no one bothers. The Melbourne proa has a lot of windage on the ww hull, smaller than normal rudders and a large, roachy main. This combination makes the boat want to round up in very light air. It is not a problem on any of the others. The recent boats are schooner rigged to give more space in the lee hull. A side effect of this is to give easier balance options than lifting the rudders.
Proa steering is an ongoing process that has involved some failures and dead ends. It is easy to do it using standard steering set ups, but these are not ideal. The requirement is for rudders that 1) can be lifted for shallow water sailing, sitting out storms or balance 2) kick up in a collision or grounding and can be quickly and easily returned to sailing position 3) have no holes below the waterline 4) are big enough to eliminate the need for daggerboards, their cases and holes in the hull and 5) work in both directions. This has been achieved on the Cruiser, at the expense of aesthetics and a little more drag, although this is disputable.

All the boats sailing have the motion and speed expected of the longer lee hull. The motion upwind in waves is much nicer than in a cat as both bows hit the waves at the same time, so you don't corkscrew over them.

Unknown quantity? The boat in the video at

https://www.youtube.com/watch?v=8chR6DAFjGA

is sailing at 10 knots in 10 knots windspeed under main and jib. In the second half they are doing 15 in 15. The crew are totally relaxed, the steering balance perfect. There are not many videos of cruising cats doing this. With the helm locked, this boat steers itself for long periods upwind and reaching. Later designs have finer bows and less exposed rudders.
An overloaded 12m/40'ter Harry | crossed the Tasman, including a decent gale. They broke a ring frame which should have been a bulkhead, but otherwise no problems.
A 7.5m/25'ter solo cruised extensively up and down the windy, exposed south and west Australian coasts, with no boat related problems.
I have been sailing my 25'ter for 10 years experimenting with rigs, rudders and hull spacings. Currently it is a foiling (almost) kite boat. There are not many mistakes I haven't made, nor options I haven't tried. These (and the steering developments) are all discussed on the web page or in the harryproa chat group.

Why a proa instead of a cat? Cheaper, easier, safer, faster. See "why a harryproa" in the News section of www.harryproa.com for explanations of each. Some of them would apply to a cat with unstayed rigs, but given how few of these there are, I think the comparisons are relevant.

The big difference with the Cruiser is not so much that it is a proa, but the build method. We have just finished the lee hull plans. Everything, (doors, hatches, bunks, shelves, bulkheads, hull, decks, local strengthening) is infused, except the 300mm collision pieces on the hull ends which are polystyrene with a layer of glass over them.
The bulkheads, frames, shelves, sink unit, steps and lockers glue in to slots which are included in the hull infusion. A tailored joint allows the 2 half hulls to also be glued together.
There is no sanding, grinding, filling, fairing, wet laminating, bogging, filletting, polishing or cutting of cured glass apart from the end pieces. All exposed edges are glassed and hatches and doors are made as part of the panel in which they will fit. Rebates and holes for windows, taps and sinks are included, along with hidden conduits for wiring and plumbing.
The glue is applied with a mixing head dispenser, the only contact with sticky stuff is scraping off any excess which is squeezed out of the joins and bulk mixing for the infusions.
The finished product is ready for undercoat, inside and out.

The set up time for the laminate is also much quicker as all the location measurements are made on the flat. There are no in hull measurements, aligning of bulkheads or making them vertical.

The savings in materials and build time are huge and the building is all done without sticky mess or dust. This is significantly different to the method used on the Kelsall proa that Ballotta launched last week. It should also be significantly cheaper, and lighter.

Doing something a second time is quicker than the first, for sure. And reusing a mould/strongback etc is quicker than making a new one. But this build method is quick enough that the differences in actual time are relatively small and more than offset by the materials saved in the shorter hull, and the extra space possible in a hull that sees no sailing loads or equipment (masts, rudders) and is never to leeward so does not have to be as sleek.

I don't know what a conventionally built 30' cat would cost, but if you look at a detailed build blog for a cruising cat and eliminate all the work and materials outlined above, the build cost of the Cruiser 18 will be comparatively low.

Unlike many designers, I really appreciate interaction with forums as they draw on a very wide base of experience. However, unsubstantiated statements are pretty pointless. If you disagree with what is said and expect an informed answer, then please give reasons, facts, experience, numbers, calculations, theories, etc. Thanks.

Any other questions, please ask.

rob denney
www.harryproa.com

[Seaslug Caravan]

Originally Posted by lucdekeyser

Whatever the build method, my focus is on the cost of ownership over 5 to 10 years. The sail away price is only a fraction of that.

You may find the resale value at the end of ownership is also a tiny fraction of the
original cost.

Pretty good optics may be required if you want to focus on what remains of your initial investment .

[lucdekeyser]

I have done my homework. Thank you for the exam questions.

The sea keeping qualities derive from a driving hull that is 60 feet long. It is a full fledged schooner in its own right. Instead of a keel the RM is provided by the other hull. I feel no need to add to the discussion mono vs multi.

The open airy space of a 40 foot catamaran is more easily appreciated when one rotates the living spaces of the HP Cruiser one quarter over the hulls and compare it with the layout of a KSS 39. Pretty much the same difference.

The price of a 30 foot catamaran: Design simplicity, build method and weight reduction spiral look promising, at least on paper and heretofore in smaller scale. This needs to be confirmed by a hard quote. The sail away price is an appreciable part of the cost of ownership. I expect to have a head start with a low purchase price, relatively speaking, without risk of losing this advantage with higher recurrent costs. The resale value is indeed an issue in general. What would it be compared to a KSS 39 ?

I have read about steering and other issues more than I cared for. Almost all the "literature" out there is of little relevance as it pertains to much smaller craft. There are four cruisers of similar size: a Dutch, a French, an Australian and a Portuguese one. It looks like the only feature these proa's share is the congeniality of their owners. The first three have been sailing for years. Two have made some modifications to their rudder/boards since launch. None report steering issues since. The last one will hit the water this summer. The setup is very similar to the HP cruiser. It should quickly become clear how this performs. This is exhibit A for plan A. The scheme for a plan B is being installed in another somewhat smaller but still sizable proa. It would require no fundamental structural modifications. It also should have results by this summer. Remark, I have no interest to add complexity for the sake of squeezing performance out of very light wind conditions; I have a motor to handle those.

[44'cruisingcat]

Originally Posted by rob denney

Unknown quantity? The boat in the video at

is sailing at 10 knots in 10 knots windspeed under main and jib. In the second half they are doing 15 in 15. rob denney
www.harryproa.com

I didn't see any GPS or speed logs, or wind speed indicators....

Certainly the bows needed fining up, that's an amazing amount of spray for 10-15 knots. Makes it look fast though.

[Mitchell87]

Originally Posted by rob denney

is never to leeward so does not have to be as sleek.

Can you elaborate on this statement. I don't know know anything about proas so forgive my ignorance, but are you saying these are only meant to be sailed on a stbd tack?

[lucdekeyser]

proa's shunt

short clip of small proa

longer clip of larger proa

[lucdekeyser]

Originally Posted by 44'cruisingcat

Certainly the bows needed fining up, that's an amazing amount of spray for 10-15 knots. Makes it look fast though.

Probably so, but the bows are only half the height of that of a catamaran. Less windage, more volume down below where it matters most. So the wave spills off the top faster. That less weight to carry in the bow wave.

[lucdekeyser]

Originally Posted by 44'cruisingcat

I didn't see any GPS or speed logs, or wind speed indicators....

That would be useful. However, I am beyond race talk. What is of interest to me is to how close I come in maximum avg distance per day that my wife still finds comfortable given the sea state and the angle to the wind. Maybe we could call these psypolars ;-)

[valhalla360]

You can make a 60' cat for the 30' cat price (at least pretty close). Extending the hulls out to 60' doesn't cost much if you don't put anything in them and keep the living space equivalent to a 30' and sail plan of the 30' boat.


In fact it will likely be a fast easily driven design as you can keep the hull length to beam ratio very high.


It appears this is the basic idea being used here, except only on one hull. (I understand the differences of a proa)


I expect just like with cats most cruisers can't resist the space the longer length provides if they go longer and if they get the space of a 30' they want the slip and haul out costs of a 30' boat.

[nimblemotors]

Indeed, one can make a 60ft catamaran that is not expensive,
is lightweight, has fine hulls and sails very fast.
If you have one hull 60ft, why would you not want the second hull also 60ft.
In fact, why not 65ft.

[lucdekeyser]

Originally Posted by valhalla360

You can make a 60' cat for the 30' cat price (at least pretty close)....

I expect just like with cats most cruisers can't resist the space the longer length provides if they go longer and if they get the space of a 30' they want the slip and haul out costs of a 30' boat.

The scheme consists of the sea keeping qualities of a 60 foot with the space of a 40 foot for the price of a 30 foot catamaran.
One could extend the hulls of a 40 foot cat to 60 foot and pay some fraction more than for a 40 foot cat. The "secret" however is how can this be done for the price of a 30 foot cat? This is the result of the downward design spiral: more simplicity, less parts, less structure, less weight.
1. a stayed mast in the center of the catamaran is triangulated "in the air" needing beefing up the beams and the hulls to handle the tensions; the unstayed mast for the proa sticks firmly in the hull from top to bottom and needs almost only the beefing up of the mast itself, not the whole structure of the boat.
2. the mainsail only rig eliminates the need for high bows, the whole cross beam structure necessary to keep the tensions on the foresails and the associated stanchions to keep the crew on board.
3. the daggerboards in hull require a strong trunk to protect from accidental water ingress - on the HP the rudder/daggerboard combination hang "outside" and do not endanger the integrity of the hull
4. a cat generally needs two helm stations with associated linkages - a proa just one
5. a cat needs two long hulls - the proa just one and still sails at least as efficient
6. both hulls of the cat are "active" hydrodynamically requiring the beefing up of the beams and bulkheads to stiffen up the boat to sustain tension and compression load differences; with the proa only the lee hull is "active" with the hull structure itself absorbing most loads and with the windward hull just hanging in there rather passively, lowering loads on the beams.
7. the proa requires no large cross hull bulk heads beyond the simple beams.
8. the proa hulls are specialized: one is optimized for the technical; the other one for accommodations; In a cat the mix in both hulls requires more complex compromises in space and form.

A closer comparison would be with a cat with unstayed biplane mainsail only rigs. The advantages of the schooner proa are still obvious: the masts stay out of living spaces and are only in one hull; no blanketing out the wind between the sails; points 3-8 remain relevant;

But yes the cost of slip and haul out of a 60 footer for the space of a 40 footer (not 30 as you mentioned) remains a potential draw back. That is why cost of ownership and operation is important too. Much will depend on the price of the "real estate" of the regions navigated to judge if this is worth the increased performance and safety of the length. My admiral says it is no matter where. And there is a higher chance that the neighbors will appreciate the same high quality tea and light refreshments;-)

[valhalla360]

Originally Posted by lucdekeyser

The scheme consists of the sea keeping qualities of a 60 foot with the space of a 40 foot for the price of a 30 foot catamaran.
One could extend the hulls of a 40 foot cat to 60 foot and pay some fraction more than for a 40 foot cat. The "secret" however is how can this be done for the price of a 30 foot cat? This is the result of the downward design spiral: more simplicity, less parts, less structure, less weight.
1. a stayed mast in the center of the catamaran is triangulated "in the air" needing beefing up the beams and the hulls to handle the tensions; the unstayed mast for the proa sticks firmly in the hull from top to bottom and needs almost only the beefing up of the mast itself, not the whole structure of the boat.
2. the mainsail only rig eliminates the need for high bows, the whole cross beam structure necessary to keep the tensions on the foresails and the associated stanchions to keep the crew on board.
3. the daggerboards in hull require a strong trunk to protect from accidental water ingress - on the HP the rudder/daggerboard combination hang "outside" and do not endanger the integrity of the hull
4. a cat generally needs two helm stations with associated linkages - a proa just one
5. a cat needs two long hulls - the proa just one and still sails at least as efficient
6. both hulls of the cat are "active" hydrodynamically requiring the beefing up of the beams and bulkheads to stiffen up the boat to sustain tension and compression load differences; with the proa only the lee hull is "active" with the hull structure itself absorbing most loads and with the windward hull just hanging in there rather passively, lowering loads on the beams.
7. the proa requires no large cross hull bulk heads beyond the simple beams.
8. the proa hulls are specialized: one is optimized for the technical; the other one for accommodations; In a cat the mix in both hulls requires more complex compromises in space and form.

A closer comparison would be with a cat with unstayed biplane mainsail only rigs. The advantages of the schooner proa are still obvious: the masts stay out of living spaces and are only in one hull; no blanketing out the wind between the sails; points 3-8 remain relevant;

But yes the cost of slip and haul out of a 60 footer for the space of a 40 footer (not 30 as you mentioned) remains a potential draw back. That is why cost of ownership and operation is important too. Much will depend on the price of the "real estate" of the regions navigated to judge if this is worth the increased performance and safety of the length. My admiral says it is no matter where. And there is a higher chance that the neighbors will appreciate the same high quality tea and light refreshments;-)

1. Unstayed masts tend to be more expensive as they have to be built heavier.
2. Many of the newer cats, are mostly mainsail driven with just a small jib.
3. You can add lee boards to cats. Most use fixed keels which are simple and cheap.
4. One vs two helms is a coin toss. Of course, they don't need rudders on both ends of the hulls with associated linkages to disengage the rudders.
5. The original point was it costs very little to extend the hulls. If you can use the same mold, there is likely an overall cost savings.
6. Sounds great...until a wave hits and it's not.
7. Those bulk heads typically form the walls that are going to be there regardless to form the interior spaces.
8. Symmetrical hulls make the design simpler.

We can play around the edges (nebulous definitions of cost of a 30'er vs space of a 40'er) but the point still stands, you can build a much longer cat with much less accommodation for a low price which is largely what is being proposed.

I like the Proa idea. I have a partially built proa dingy. I just don't think it makes much sense for a large cruising boat when there are other options.

[lucdekeyser]

Originally Posted by nimblemotors

Indeed, one can make a 60ft catamaran that is not expensive,
is lightweight, has fine hulls and sails very fast.
If you have one hull 60ft, why would you not want the second hull also 60ft.
In fact, why not 65ft.

look-ma-no-rocker-x-john-hitch.jpg

The upward design spiral is always tempting.
The art is sliding down the design spiral to find the sweet spot for your SOR's.
Hitch's boat is an original and very interesting compromise. It does not fit my SOR's though.