supercavitating hull ?, is it possible ?, SES ?

i am constrained by length and horsepower due to fisheries regulations, so i have come up with an advanced concept vessel design that incorporates hydrodynamic lift and air lubrication, but it is not designed to be a rigid wall hovercraft or a WIG. but more of a surface skimmer , SES., or CAB.

i was just wondering does a vessel of this design sound feasible ?,

the boat when viewed from the surface would just look like a very wide deep displacement commercial fishing / lobsterboat style,but it is in reality a catamaran or semi trimaran design below the surface,the sponsons and the single engine/jet pod would be underwater when vessel is at rest, (you would not be able to see daylight under the hull when looking at the bow) although there would be 4 wide but shallow air spaces under the hull, it has a length to width ratio of only 2 to 1 (40' length X 20' width), it is designed to be a large capacity displacement boat that would also be able to bring itself onto a plane without using an overly large horpower eng. ( it's a tall order i know).

in order to achieve this and to overcome some of the adverse effects of a flat wide bottom, i have incorporated four shallow air cavity chambers, the air spaces that are brokenup into quadrents under the hull,they narrow out at the stern in ordrer to minimize squat. these also create an air lubricated/cusioned ride on a plane and it also creates a stabilizing effect when operated in the displacement and planeing mode's in addition these air pockets would help to avoid the pounding and slamming of flat bottomed designs, also these air cavities can be pressurized with water or air jets,in order to negate some of the effects of suction,
i have done much research but i have only been able to come up with very minimal info about boat designs that may be similar/?, they usually are catagorized as CAB.~captured air bubble vessels, or SES.~surface effect ships. but they never show the underside of the hulls. so i do not know if this design is similar or has been attempted before.

any info or input that you could provide on vessels that may be of a similar design to this would be greatly appreciated, thanks.

Patrick M.

 

Hello, im in a bit of a situation...I'm choosing majors for college, so i thought id go into engineering. but that has nothing to do with boats....how can i get involved with boats in college, what major is this?? i live on a lake, and own a boat...I love it. I also own 2 remote controlled boats. I was just wondering how the heck some of you guys are so knowledgable on these topics....how can i become like you..lol...my goal is to make a prototype of a boat...but i need knowledge to do this, and that is what i lack...Please help...any advice is greatly appreciated

Brian

 

Hello brian,you may want to narrow it down a little and then post this question for all to see. as there are far to many different types of work in the marine industries as well as in the engineering field to recommend anything in particular, but have you checked out Mass maritime acadamy they are near you and offer some short + inexpensive certificate courses that may be used to boost your college credits or they may be able to help in other ways, or possibly try a web search on marine engineering.
good luck, Patrick M.

 

i've been looking into ses ships also but dont fully understand what you aim for. got any schetches on your design? there is the fast ventilating hickman sled and stepped hull designs to get air lubrication. on the other hand there are allready flatbottom captured air bubble big fraighters sailing the river rhine here ive been reading about. also did see some cab bottom foto's of other boats and its certainly a interesting concept! for myself i'm back into designing a swath; with legs and pods folded in it can look and behave like a inconspicious houseboat, folded out i think it may just be the ultimate economic fast and comfortable passagemaker.

 

thanks for the reply....i havent checked mass maritime out yet, i did send in a card requesting more info....im only a jr. but id like to have a decent idea....
also, i think i may be doing a science fair project and hopefully get an engineering award or somthing....i will be making a model of a prototype....it cant be too big (2 ft at most) ....can you help, or give some advice..how do i make the hull...should i just use wood and carve it....i think ill be testing by the use of drag....so ill probably be making a boat that has a very low drag, and also, maybe something to do with its planing...i think i might have to make a testing tank, using a pump, fish tank, a rope, and a measuring spring....if i can find a real testing place, then i might do something on its stability with the combo of speed and waves....any help is welcomed....thanks again Brian

 

YIPSTER- i am attempting to design a vessel that is not a compromise between a displacement or a planing hull, but one that fully takes advantage of the positive features of both types. while at the same time trying to obtain all of the attributes that any mariner would desire such as safety,speed,stability,fuel economy,endurance,large load capacity,etc.etc., but being a commercial fisherman ( lobsterman ) i feel that a large open deck space is very important,also i don't have a need for all of the creature comforts that are aboard most recreational vessels, i don't even have a seat aboard my vessels,if friends or crew get tired they can sit on the rail or use the bunks down below. i guess i'm attempting to design a small high speed sea barge / ?, the closest thing i've been able to find on the web that might look similar is at ( www.mangiaonda.com it would probably resemble there MO-65 cargo ship ),i do not have anthing that can be put on the computer yet as all of my designs are in notebooks and i don't have a scanner not to mention the fact that i'm technologically illiterate :~), i'm lucky if i can get a connection speed thats fast enough to view most websites. my current boat is a 30' SISU lobsterboat with a 175 hp. Lugger, shes certainly no speed demon , but i'm am more concerned with seaworthyness. i'm not slow but i'm not fast either, i guess i'm just halfast .
your swath houseboat idea sounds intriguing, i've been toying with the idea of building some type of floating cottage to use as a rental unit. is it in the netherlands where they have canal boats that are converted into house boats ?, i've seen some nice looking one's but they are very narrow.

BRIAN- i think your best material to build your prototype out of would be foam, it can be easily cut, shaved, sanded, glued, painted, altered,etc., it is very forgiving. i think a good idea for yor project might be the study of the metacentric center of gravity (metacenter) and its effect on the stability of a vessel


thanks for the replies and input, i appreciate it, have a great day, thanks.

Patrick M.

 

Patrick, thanks for the advice....unfortuantely, if i have to do it home-style, then im not sure foam will have enough resistance to even calculate the drag
This could be a serious flaw...I could weight it...Im not sure, still toying with the idea....What kind of hull do u think i should build?? mono-v? ....no matter what i build it out of, what do u think i should measure...drag, stability speed....again, i might have to test all of this in a fish tank with a pump and a measured spring.... so baisically, how would u approach this project?? thanks

 

forget trying to calculate drag in a fish tank, it just wont happen, but if you read what you just wrote, you will realize that a light had gone on over your head when you thought about adding keel weight, your study should focus on bouyancy and stability. on the subject of hull styles i'd opt for a barge it is more stable and easier to build, but you don't even need a model boat to demontrate the principle, float a small plastic bowl put a paper cup upside down in it,then start stacking half dollar coins on top of it, now dry everyting off and try it without the paper cup ( now go get more change ) :~> , or you could try it using lead weights on top of different size blocks of wood as your boats such as a 2"x4"x8" compared to a 2"x8"x8" Pat

 

thanks for the advice, but with the fish tank, the water will be moving; propelled by a pool pump....but ill def need to calculate the amount of weight to add to the hull, and im not just looking to demonstrate the principles of boyancy, im a jr, doing this to get an engineering award, or scholarship to a school or something....i dont need to do it, but id like to do it, cause i find it interesting, and i want to work on a complex project....maybe in the long run, this will help me out getting a job for a boat design place...(do u know of any in RI??? or new england) needless to say, i want to make it good, and really interesting...no offense, but im a little more sophisticated than bowls and change...lol....im lookin more at say, a V hull, with and with out planin strakes, then add a few of my ideas to the hull and see what i come up with
ill be measruing drag by a sensative mesaured spring....we use them in physics classroom, to measure the drag on X surface, and the amount of force used to pull it,.... Have any ideas on the above?? thanks for everything so far...especially foam idea, that was good.....thanks Brian

 

Pat, i go for that bowl with money anytime, as i would for a floating cottage!

the small rebuild canal boats you refer to are probably from the UK. here its square concreet houseboats or older rebuild river fraighters. for my swat idea lichtweight is better, i'm even thinking of a big camper rebuild...

took pic below from the site you mentioned hoping some others want to express their ideas on air incapsulation hullbottoms


that MO65 cargo is big and different again, loaded i wonder about seakeeping and stability.

just got this newsletter in from kinetix:

you may write them, they do know quit a bit on strange hulls, are interested and a NA will (try to) answer your questions, frendly people!

 

thanks, i checked out that site it's interesting, i'd love to get the type of help that they could possibly provide but unfortunatly i'm in no financial position now to get involved into a project like that, and i could never afford the time or resources that the project would deserve, i am now in the process of patenting an invention that benefits both the enviroment and the commercial fishermen (i can't say much more about it at the moment) other than i had recieved a couple grants for market research and development of it, but then the company that had helped me obtain the grants they took the money and ran, now i'm left holding the bag. i got screwed again :^( .

it's kind of funny i was wondering if you'd notice that very picture, with that pic i can explain my design a little better to you. if you imagine that the bulk of the bouyancy be transfered the outside hulls, while the center hull and keel that would house the single engine and jet or prop drive would be aft of amidships,but it would flare all the way up to the bow merely for the pourpose of seperating the four air chambers which are made with 3 transverse planeing / lifting wedges at the.. bow, midships and stern, similar to what is visible in the stern section of the pic. only with steep angles and sharp or squared trailing edges to create a high pressure zones behind themselves as well as to cause cavitation to provide air lubrication.
i'm sorry, but i've got to go, i'm falling asleep at the computer. Pat M.