Ok, Now What...?

[tom28571]

Mike,

I don't think it is possible for you to "lose" the argument since we are really just tossing ideas at each other. Naturally these ideas reflect each persons bias and preferences. If everyone agrees with me, then I don't learn anything.

Reading about your proposed cruise, I understand what you want in a boat although I did not view that as our intended scenario. I have not been in the north Baja area but in the area between Santa Rosalia and Loreto we had no problem finding drinking water in gallons and tank quantity. A lot cheaper than in the US too. Even ice was readily available. The road along northeast Baja is dirt and pretty rough so we avoided it. I hope you intend to go in the winter since summers can be brutal there. Mexican officialdom can sometimes be overbearing also. It's a beautiful cruising area though and certainly not crowded.

[ErikG]

I haven't been that unvolved in the O1 so far, much to much sailing to take care of . Now I've started working again, so here's my first sketch.

It's just a computer sketch nothing fancy. Interior pic speaks for itself except the helm seat, it can fold up to make space for a standing stearing position.

One could use a top like on Tom's "Liz" but that depends on what look we want O1 to have, I like Tom's distinctive "retro" styling. But I think this project should be "sellable" to normal people and not just to us, so I think a more modern styling would "sell" better.

I have included a large galley because it's nice to be able to cook properly.

I still thinks it looks way to much like a rocket! But I don't think theres to much one could do while being legally trailerable.


Aaaahhh, I can't wait 'til I hear thoose "zzzzziiiinnnggg" sounds with the occasional "Ouch - aim at the drawing will ya".

Erik

[b_rodwell]

Could the hull form be changed slightly?

I don't have a lot of experience with motor boat hull forms. However.....

Will's shape looks fine except for building it in flat sheet construction. The horizontal flat next to the chine would add to the complexity of construction in flat sheet. This would translate to extra time, cost and probably slightly more weight. Would there be a lot lost if this flat was taken out.

One other question - are all the surfaces developable?


________________
Brian

[Portager]

OK Tom I try this one more time.

First, my purpose in mentioning the conditions in Mexico was to point out that not all people share your or my needs and requirements. Most are probable somewhere in the middle. I think the intent of O1 should be to satisfy the middle part of the bell curve of those requirements, thus satisfying the maximum number of potential users. If we design for either end of the bell curve we will satisfy a very small group. Now all that being said the real problem is finding the middle of a curve we can't see.

Now to address the waterplane area to displacement ratio. My understanding is that through years of experience Naval Architects have determined that people find excessive heave to be uncomfortable. Heave is defined as the rate of change, or the derivative of acceleration, or the third derivative of position, the first derivative being velocity and the second being acceleration. In boats heave is primarily in the vertical direction and worst on the fore deck. Acceleration is equal to force/mass and assuming constant mass, heave is equal to the rate of change of the pitching force. The rate of change of the pitch force is a function of the slope of the waves, the relative speed of the wave relative to the boat and the change in waterplane area versus depth. If all this is too complex, go to http://pws.prserv.net/fmyers/HCFactor.html and use the Heave/Comfort factor calculator. Put in 28' to 31' ft length and 8.2' beam and adjust height until you get a comfort factor of 64. Now ask yourself if you want a boat that is comfortable on the road or comfortable on the water.

Will;
Slowing down and going over the waves sounds good but what about when the waves are coming at you fasted than you want to go over them? Or what do you do at anchor when the local ferry hits you with a wake?

There is no substitute for mass to make a boat comfortable on the water. A light weight boat is fine for small lakes, rivers and shelter harbors and water ways, but for comfortable ocean cruising you just can't cut corners.

The best news is we have gotten some more contributors. Maybe we should argue more.

Cheers;
Mike Schooley

[8knots]

Just a quick note. I plan to have the 2 hour sketch by the weekend. so get em honed. Mooooore great sketchers out there I see. Great work. Mike...do you have a job or are you retired? It would take me days to compile all the great info and stats you provide! 8Kts

[8knots]

Hey
What construction method did you all decide on?
FRP or ALUMINUM or does it matter at this stage in the game?
8Kts

[Willallison]

Will's shape looks fine except for building it in flat sheet construction. The horizontal flat next to the chine would add to the complexity of construction in flat sheet. This would translate to extra time, cost and probably slightly more weight. Would there be a lot lost if this flat was taken out.

One other question - are all the surfaces developable?

Brian - all the surfaces are developable, so all can be produced from flat sheets. It's true that the chine adds a little complexity to the construction - though not really any more than any of the other sheets and yes it adds greatly to the design - stability, efficiency, spray deflection etc etc. You only have to take a look in any marine - there ain't too many planing hulls that don't incorporate chines.....

What construction method did you all decide on?

I plan to have the 2 hour sketch by the weekend. so get em honed.

We decided on flat panel construction - leaving the material up to the builder (at this stage anyway).
I spent all day sharpening my darts, so I look forward to your post.....

First, my purpose in mentioning the conditions in Mexico was to point out that not all people share your or my needs and requirements. Most are probable somewhere in the middle. I think the intent of O1 should be to satisfy the middle part of the bell curve of those requirements, thus satisfying the maximum number of potential users. If we design for either end of the bell curve we will satisfy a very small group. Now all that being said the real problem is finding the middle of a curve we can't see.

I think you have hit the nail on the head Mike - this is what I have been saying - and hello! - I am the middle of the bell curve!

Slowing down and going over the waves sounds good but what about when the waves are coming at you fasted than you want to go over them?

Leave the boat on the trailer.

Or what do you do at anchor when the local ferry hits you with a wake?

Pick a better anchorage.

There is no substitute for mass to make a boat comfortable on the water. A light weight boat is fine for small lakes, rivers and shelter harbors and water ways, but for comfortable ocean cruising you just can't cut corners.

In the end, this is true. But life - especially on boats is all about compromise. And O-1's primary design considerations included economy to build and operate and easily trailerable - not ocean crossings. With a boat like this you go where you want, when you can - not where you want, when you want.

I think we probably need to define our "one week cruise" a little more definitely. To me it means cruising mostly in 'sheltered' waters, coastal hopping and occaisional trip in exposed waters when conditions permit.

Tom,

OK here is the boat that I now use. It's been on the forum since before the O1 project started. Why do I reintroduce it? Because all in all, I don't want to add very much to meet the O1 goals, at least to my satisfaction. It has all we need now and with minor modifications meets all but high speed in rough water.

I don't actually recall a decision requiring high-speed rough water operation. My desire to increase fwd deadrise is simply to improve all round rough water performance.

None of us would argue the success of "Liz" - she has obviously met all of your design considerations, so could not be considered otherwise. And as I've stated any number of times I admire your single-minded pursuit of lightweight and simplicity. But, given that O-1 is not a design based around any one person's requirements (as Liz and Portager both are) she must satisfy the needs of a greater market. I believe that market would want a little 'more' in their boat.
I think the raised pilothouse concept goes too far, and Liz doesn't go quite far enough - the compromise (there's our favourite word again!) is to be found somewhere in the middle. (And I still think that both my original "express cruiser" and "extended cab" concepts lie in that middle ground {water?})


Erik,
Welcome to the dart board!!
With a little imagination, your boat is very similar to the hard-top version of my original "express cruiser" concept. I agree that we should consider more modern styling - it's very much a matter of taste - but I don't know if you've noticed, but all these other blokes like the older tubs....
You might want to raise your chine up forward of about amidships. As you've drawn her, your boat would slam shockingly in rough water.

[Willallison]

Just had a thought.
Once we've finished O-1 (in 2020 ) perhaps we could move on to some other projects - we could stick our beaks into 'Portager' and give Mike some much needed assistance . Or perhaps we could work on 'Big Liz' for Tom, maybe a wooden masterpiece for Gary to carve out, or a triple engined super-peedster for Jeff (am I the only one who's noticed his obsession for all things big, fast and thirsty?!?

[tom28571]

OK Mike,

I ran that heave calculation and found that I could make "Liz" into a nice riding boat by increasing the displacement to 7800 lbs or by reducing the waterline beam to 2 ft 4 inches. Neither is acceptable.

Having spent almost three years on a Gearing class Navy destroyer, I expect I know what the term heave means. It means leaving your stomach about 30 feet above your head and losing your dinner over the side.

I have driven "Liz" into waves coming faster than I wanted to go and can readily agree that it's tough and would take Will's advice and stay in port unless I just gotta go. A 35kt northeaster in water only 15 to 19 feet deep with the crests confused, very close together, very steepfaced and moving at over 10kts at me. Such conditions keep any sane person in any boat in port but we were trying to get back to homeport and crossed a piece of water recognized as one of the worse on the east coast that we could have waited out in a sheltered anchorage. This is pilot error not equipment or design error.

You are right about the comfort zone though, even if the formula is too simple minded to actually use without already understanding the process.

I know that my boat is not acceptable to the mass of boat buyers but, thinking back, that is exactly why it was designed and built in the first place. There are no boats like it on the market so I clearly am missing the center of the bell curve or even high up on the side of the bell. A sucessful boat dealer tells me that you can not make a boat too fast or too powerful or have too much stuff on it or make it look too spacey to appeal to the the mass buyer. Will, that IS the center of the bell curve.

[Portager]

OK, as long as we all understand that O1 is intended to be an economical boat intended for sheltered water and/or fair seas.

Originally posted by Willallison

"O-1 is UNLIKE any other express cruiser on the market. She (Loyds may have dropped the title, but buggered if I'm going to! ) is a lightweight, comfortable mini-cruiser: home buildable and legally trailerable world-wide - by design, O-1 will be economical to build, own and operate."

I guess comfortable here was referring to the accommodations and not sea keeping? In my way of thinking lightweight and comfortable don't really go together.

I think we need to start defining a weight budget for O1. It is all pie in the sky until you start adding up pounds and dollars and then reality starts sinking in (O, bad wording).

By the way "Portager" with half full tanks rates a perfect 64 on the heave comfort calculator. That is what Portager is all about. I like to think lots of people would appreciate Portager if they could afford it. Since I can afford it why should I compromise? I was asked once what boat I would get if I won the lottery. I have given that much thought and I decided I would get Portager. It can go anywhere I want to go and portage around where I don't want to go. One more thing. I would appreciate into on Portager (although I won't loose any votes on Portager) but I hope to have many miles on her before 2020.

Cheers;
Mike Schooley

[Willallison]

I know that my boat is not acceptable to the mass of boat buyers but, thinking back, that is exactly why it was designed and built in the first place. There are no boats like it on the market so I clearly am missing the center of the bell curve or even high up on the side of the bell. A sucessful boat dealer tells me that you can not make a boat too fast or too powerful or have too much stuff on it or make it look too spacey to appeal to the the mass buyer. Will, that IS the center of the bell curve.

As is so oft the case, I sadly must agree with you Tom - I say sadly because that is the centre of the bell curve. There is no doubt that we should be aiming O-1 at a niche market. You can't compete with the likes of the Brunswick corporation who build for just that buyer.
And there is definitely a niche for boats like 'Liz' - but I think there is a bigger niche for a slightly up-specced and up-sized 'Liz', which is where I think we should be aiming. By necessity, that would result in a slightly different and marginally heavier boat.

I think a target displacement is a good idea - even if it just a ball park figure to more accurately define the design.
Once more, I suggest 1800kg - 820 lbs

[Portager]

Originally posted by Willallison
And there is definitely a niche for boats like 'Liz' - but I think there is a bigger niche for a slightly up-specced and up-sized 'Liz', which is where I think we should be aiming.

I agree, Will.

It occurred to me that the market niche for Portager is probable smaller than the market for 'Liz' or should I say 'BlueJacket'?

I think a target displacement is a good idea - even if it just a ball park figure to more accurately define the design. Once more, I suggest 1800kg - 820 lbs

I think you divided when you should have multiplied. 1800 kg should be 3960 lbs. Is this fully loaded or empty? If the fuel capacity is 80 gallons that is 480 lbs. 60 gallons of water would also be another 480 lbs. I don't know if these quantities are correct but if it adds then the fully loaded weight is ~5,000, if it subtracts the empty weight would be ~3,000. I can agree with the 4,000 lbs empty and 5,000 lbs fully loaded, but I think 4,000 lbs fully loaded and 3,000 lbs empty would be too low to meet our stated objectives.

Cheers;
Mike Schooley

[Portager]

Erik;

I appreciate your participation. The more participants the better.

I really don't want to "zzzzziiiinnnggg" you, but I am concerned with the headroom in the shower. I thought one of our objectives was a standing headroom shower.

Originally posted by 8knots
Just a quick note. I plan to have the 2 hour sketch by the weekend. so get em honed. Mooooore great sketchers out there I see. Great work. Mike...do you have a job or are you retired? It would take me days to compile all the great info and stats you provide! 8Kts

You smooth talker, you don't need to worry about my darts. The tips are all bent from hitting my hide. Appreciate the compliment. I do have a job. I am a full time engineer. I am just very experienced at using search engines.

Originally posted by tom28571
I ran that heave calculation and found that I could make "Liz" into a nice riding boat by increasing the displacement to 7800 lbs or by reducing the waterline beam to 2 ft 4 inches. Neither is acceptable.

The 7,800 lbs sounds OK to me. If you restrict it to displacement speed it wouldn't take much power or fuel, just a lot of time. If I were retired, I'd find it acceptable.

Cheers;
Mike Schooley

[duluthboats]

“Will's shape looks fine except for building it in flat sheet construction. The horizontal flat next to the chine would add to the complexity of construction in flat sheet. This would translate to extra time, cost and probably slightly more weight. Would there be a lot lost if this flat was taken out.”

b_rodwell

Well we all know I don’t know a thing about planning hulls but this is my take on the small horizontal flat. With out this O-1 would have trouble planning at slower speeds. It will not increase the difficulty of construction and will act as a stringer down the side, increasing the stiffness of the hull.


Gary

[8knots]

The two hour sketch
O.K. here we go…. This is the first attempt at 01 for me in quite a while. I will post and leave you to critique her as you all see fit. I must admit I have not done any real math or numbers games on her YET! I am waiting for the reaction of you all before wasting any time on that sort of fun.
PARTICULARS are as follows
LOA 33’5”
LWL 29’3”
BEAM 8’2” (really needs to be about 10’3” or so)
DRAFT 1’6” (drive up)
DISP ???????? we will wait and see I haven’t even done the body plan yet!

NOTES:
I have read a few articles on OB’s and I feel this boat would meet the speed requirements with a Yamaha 225hp some numbers that I have run across state 8.1GPH @3500RPM
And 24.9 @WOT @ 5500RPM Seems to be plenty of power and at about $15.000.00 within the budget of 01 Of course there is room for a twin of said engine. If at a later date or her owner has deep pockets!
I will need to revise the fore-ward cabin arrangement I can see that there is not the width required for the berth as drawn in relation to the sweep of the chine at the stem.