Catamaran Evolution

only ment that area and under there to be able to fill with water from a following wave
so that volume temperoraly be weighted with water running out slowly while the wave passes fwd.
it would keep the rudder down in waves as well tho. now you got me curious what you see to check cutting steps

here a pencil sketch of a possible kick up spade rudder cutting only a part out of the hull without taking the whole stern up
any thoughts? you could say KISS ( Keep It Simple Stupid )

 

Good Morning and Happy Holidays to all

Yipster...that drawing of the rudder is almost the same idea that I did a CAD sketch to visualize. I think that if it was to happen...it could be the best one to choose from. Trying to set up the bearing to be stiff enough and swing on axis when kicked up could be a bit more difficult, but not impossible.

The trunk would cause some flow disturbance and ventilation, but my initial thought was to set up a thin fiberglass plate that effectively closes up the hole and will just crumple when the rudder kicks up. If a grounding is never sustained, then it will just remain as part of the hull.

The transom steps did cause me some concern because it is a lot of volume that can get heavy fast and at that distance from the CB...well you know. I was going to chop out the inboard panels and wrap the steps back to the aft beam, but... it added weight, looked horrible, took away from the longitudinal clearance I want to have and, although it would allow immediate evacuation of a boarding wave, it also increased volume that a wave can board...so no chopping it out.

I did modify the transom steps so that water evacuates quicker by way of scuppers on the second steps and more slope to the steps. Also, I reduced the volume by something like 28%. As already stated, a strongly battened heavy canvas will be designed to cover the transom steps while under way. I'll attach a couple of pics so you can compare the difference.

Did some work and I'm going to try and post the results to get some final suggestions on my next post.

Thanks
J

 

Hello all...

Here it is, but I have to point some things out. This will be the last major design changes before final stage where I will just trim her up and make final minor changes.
I was supposed to do this:

1. Reduce final weights.
2. Establish Racing Trim Weights and CG.
3. Optimize Lead for Boards.
4. Finalize Board design.
5. Optimize Waterline Length.
6. Finalize and Optimize Sail Area.
7. Design Rudders

Everything is done except #2...which I plan to do at the final stage.
I tried to complete #5, but the work involved (basically changing every damn thing) to get the extra .4 feet of LWL was just not worth it.
I looked at #7 and it is still a toss, but I am definitely going to give serious thought to the kick-back design if they are not fixed. Swing back has been ruled out.

The spreadsheet I have been using to update the group has significantly more information than before because I incorporated all the seperate sheets into one spread. Take your time and if there is anything that requires more explanation, then please ask. The final spread will only compare the base design, and the final modification. At this stage, the overall design improvement from the base design is 91.43%. This is strictly numerically speaking. I'm certain that the design would have been over 100% improved if I would have considered the optimized canoe hull from Rick.

All comments and suggestions are requested at this point since the next stage is final before I take the whole design to AutoCad for final detailed plans.

Thanks
J

 

I really like the way you are progressing with this design and I know you will get great satisfaction when it is built and sailing like a dream (as I'm sure it will).
I know that's not very helpful....but I just wanted to say it.

- Richard

 

Okay...that did it. New Zealand will have to be on the cruisers itinerary for places to visit so I can show her off. Then again...it could be Los Angeles!

The design is untested but if all these calculations mean anything then I believe that she is going to be a very safe and lively all around racer/cruiser.

Final update coming soon...with secret weapon #2.

Thanks
J

 

Green Lantern

Happy holidays to all...

Well...here is the Green Lantern in all of its glory.
I did an incredible amount of work and feel burned out. Lots of things to offer.

The design was completed and the spreadsheet has been updated. All my research is in the spreadsheets and I think that most will find it useful for many purposes and not just because it is part of the Green Lantern.

Close attention may want to be given to the material and cost sheets. They took a lot of research but I believe that it is probably the most up to date and comprehensive study on pricing out and comparing costs for foam core with glass skins. I hope it proves useful to someone. If there is any clarity needed on the spread just ask and I'll try to explaint it.

Secret weapon number two incorporated into the Green Lantern is daggerboards that don't extend beyond the hull windage while raised and are raised and lowered with motors. I'm not eeven going to ask about them because I am using them!

I also completed a study plan for the Green Lantern. It is attached. I would appreciate any comments on the study plan about layout and content and if systematically and methodically well written or not. Depending on response, I may post it somewhere else because I really want opinions on it.

Break Time

Thanks
J

 

Whoops...here it is.

J

 

Had a quick look still looks good. Most cats have a bridle, to take the load when anchored bow to the breeze, so that whilst at anchor sits steady instead of yawing about.

 

hi JDC, cool never finished tho
i was recently looking over some profesional design briefs and requetted saying above i was on a break
we got to work harder, producing more complete and better work as i noticed it can always be better

to compare the green lantarn (why not green sporter or so) you can do the same, hold it next to some well known designers
i dont think it would have done bad in the recent "design your ideal cruising boat" competition eighter
homebuild one off vacuum sandwich bagging those hulls is not that easy i think but maybe i'm missing something
personally i like a guy in the drawings and found the floorplans a bit poorly, and would have gone for a rotating mast
also personal i dont really like "this is the ultimate" sort of copywriting many designers use, you use "it could be" terminology also
so i guess its allright after enthousiasticly designing a good looking and sound hearing cat in short time but keep going

 

Hello Masalai...

The Green lantern will also have a bridle. It will be attached to u bolts connected to the beam.

Thanks
J

 

Hello Yipster...

I stopped working harder and started working smarter 45 years ago. Got used to it and I don't want to go back. This is as far as she will go in FreeShip and I'll move on to CAD which I am more confident to work with. FreeShip was indispensible. Top of the line in my opinion.

Nope. The name will remain THE GREEN LANTERN, and I'm not sure that I want to try to hold her up against any well known designers or anyone else for fear that I will be crushed. I have huge respect for everyone's work...even when I don't like it. However, I feel confident that the GL is everything I set her out to be even if she is better or worse than other designs. I couldn't honestly do that anyway because she is the product of many even if it was my mind that caused my hand to draft it.

I read the competition thread. Hmmm, it appears that there might have been some favoritism and funny business that went on in there. This observation may very well be my own misconception, but I think there should have been full disclosure about all entries and competitors after the results, but thanks for saying that I may have done well. Personally, I would like to get a hold of some of their numbers and see how they compare to the GL's performance and design.

Vacuum bagging is becoming more and more commonplace. I don't think that the GL will be extremely difficult for the construction method. In fact, I think she is well suited because of her radial geometries. It won't be easy, as if anything ever is, but it won't be as hard as say strip plank where fairing and sanding will be a killer and messy at best.

Tell me how to put some people in there and I'll do it. The floor plans are linear and symmetrical and they provide excellent accommodations for the "racer" part of the design although a bit standard for the cruiser. Okay...I respect that you found the layout poor because the design is for me, but how would you envision laying it out?

Rotating mast is nice and I gave it some serious thought. I excluded wingmasts based on cost alone and I wasn't sure if her performance would have increased substantially based on her section if a rotating mast had been incorporated. I suppose that if interest is found it could be done but if it came to that, then it may as well go to wingmast and forget about the cost.

I'm not sure what you refer to regarding designers using "this is the ultimate" in their designs and it is pretty critical reading as far as I'm concerned...but I like the observation and candor. I believe that it is called boasting. One infamous boast by a famous designer "The Titanic is unsinkable" is a good example and look at what happened. I went back and read through the study plan and all I found along those lines is:

"The sailor racing inshore with a team will find that the ride will be the ultimate chemical imbalance."

If this is the reference to which you allude...yes, it is boasting, but it will also be true. Brain synaptics firing off; adrenaline in abundant amounts; confused hormones; high emotions; high testosterone production; facial muscle contortions resembling smiles; brain farts when the windward hull flies, etc. etc., will find the team in a state of "ultimate chemical imbalance". Well, right now that is how I envision it based on the data.

Enthusiastic yes, but brother it was not in a short amount of time. Trust me on that one. The part time hours add up to years of full time work. Have you looked at the spread? Did you find any of the sheets useful? What about the formulas used for calculations? I'm particularly interested in the sheet for estimating costs. I was considering separating all of them and producing them for the community to test and use.

Thanks

J

 

no thanks JDC. me? i'm older but no wiser
still have a sharp eye and pencil tho, like you do too
right, cant be said enough, free delftship is a fine tool
green lantern associates with an old inn not a racer in my mind
or the officers rear section of an old line ship somehow
you ask for reactions so i speak what comes to mind okay?
at the end of that cruising competition thread are some cat nr's
something i only poorly did in my entree and later left out alltogether
i looked but did not compare or checked your exell files
thinking about having to make them too, cost estimates, details etc
while the only reaction i had was for freely develloping sheetmetal
for twice the size ladybird without wings, but ok thats still a compliment
anyway, you did them and it is important, so call me late or lazy
for a acad humanoid look in my gallery and when not mistaken a fbm here
floor lay outs like here or even hehehe in walkthrue 3d
masts, you said it and may like to check cris whites book above on it again
have my compliments and ah, dinner cold, see, i'm older, but not wiser ;-)

 

Hi JCD. I think it's good that Yipster speaks his mind. I will give you my opinion.
I have always liked the name "The Green Lantern" from the time you first mentioned it. I never invisioned an old ship because your design looks so modern. The name has a modest charm which makes the boat sound 'intelligent' and not cheap or corny. I don't see the merit in giving it a sporty name. Racers will like the name if it performs well. (just my opinion).

I did find your study plan to be quite 'passionate'.....but it made me think that the designer is very proud of his design....so I like the enthusiasm but I would probably prefer the text to be a bit more compact. But I have more faith in a designer who takes pride in his work.....so take my comment with a pinch of salt.

When you mentioned 'study plans' I was looking forward to seeing detailed sketches of the interior, and like Yipster, I like to see little people in there. Helps me to imagine. But as you say....this is just what you can do so far with Freeship, so I look forward to seeing your CAD presentations.

What's it like sleeping at the bow in a choppy sea? How many people do you expect to be able to sleep comfortably?

I still love the huge cabin space, and I think it has all the hallmarks of a popular design.

Those are my thoughts

- Richard

 

Hello Yipster...

Thanks for the response. On the above, I wouldn't expect it to be any other way. I don't sensor thought or opinion.

I got your blue man figurines and I want to thank you for them. You will not believe how helpful. I was using little crosses and had a hard time feeling the space in 3D. Do you have any that sit.? Good job on them. Also...I like what you're doing with that fbm...I failed to ever really work hard enough to put out nice sails like that, but I'll have to work on it.

Having being able to close the "3D" gap, I have to retract a former statement of mine from a prior post which is below:

"The floor plans are linear and symmetrical and they provide excellent accommodations for the "racer" part of the design although a bit standard for the cruiser."

I was wrong. There is plenty of space for the cruiser. There is a huge amount of minimum volume and I don't consider it "standard". The accommodations are excellent for both. Take a look below and visualize only 2 to 4 people in any one place and there is lots of room and privacy or space for being in close proximity. I didn't put one in the head or bathroom because that's usually in and out, but it is still huge.

Let Me know what you think.

Thank's

J

 

Yipster

Here are a couple more on a color scheme I was looking at.

J