Help with college project

Jabor,

im making an actual physical model. ive made a few, weather its Class 1 Powerboat, ACC, S/F x2, i feel it gives u a bit more on top of a 3D render. like drawing the boat, but better.
also i know this is a design comp, but i think there really looking for how green the boat can be or the reuse of wasted energy aswell. so i wouldnt go down that path of safety regulations to far, only whats required. well thats my plan of attack anyway.

the hydrostatics i'll do - center of buoyancy, center of gravity, displacement, prismatic/waterplane/midship coefficients, displacement/length ratio, curve of areas (which is one they will have a good look at i think). it gives them a graph representation of the underbody volume... or how well the boat will go through the water. intact/damaged stability, i might get a hand with that.

also K1W1 is on the money in regards to doing a N/A course, it will allow u to know if the design is going to work. u do get to a stage where all u have to do is look at a few features of a boat to see weather it will work in the real world or not. ive been boating my whole life weather its on the family cruiser, sailing the 49er, or skippering a powercat 3000 while the owners get on the turps. but doing a course, well it just allows u to know why a boat is designed the way it is.

CODOG, why inside out? wouldnt u get a lot of conflicts when doing the exterior detailing? sounds interesting.

any takers on the engine issue? or should i send an email off to MTU to see what the deal is?

far

Hi,

84FAR- What is your engine question?

K1W1,

well ive just found half the question i was after, but the second part is - does MTU do the installing of the electric motors or is there a separate company that does it?
its seems to be a bit hush hush where ever i look.

far

Hi,

Is it the drive motors you are asking about or the electrical generating end ( The Alternator if it's AC) of the Genset?

There is nothing "hush hush" about this stuff. Unless you provided a lot more information or actually asked a question you probably haven't got much of a response because no one can figure out what you are asking and they realise it's probably not worth investing time and precious office resources in what is obviously not going to happen.

How can you spec equipment and ask for installation information without telling anyone what you want to do? The more informed you are about what you want to do, the better information you can get from the suppliers.

You will get conflicts aplenty, which ever way you go about it. However, as you are a one man band for this project, you only need be in conflict with yourself, not several other departments not necessarily singing from the same sheet. You have to start somewhere, and if my opinion was asked for, I'd suggest starting with the internal spaces then work up the exterior to suit...not the other way around. Obviously changes of direction will happen constantly during the process, conflicts as you call them, opportunities as I call them, but that process is less painful IMO if you start with the package that your exterior will be packaging.
If on the other hand you (like my son did) are starting off with a pre-determined sized hull and pre-determined exterior profile and then fill it with 'stuff' that fills the space, then fair enough.
What I meant (in blatantly generalised style) was to work out a rough accommodation plan, machinery spaces, tenders and toys first (having made a brief for yourself first), giving you a good feel for length required between the forward collision bulkhead and the transom, a good feel for overall height required above the lower accommodation deck (assume this is on or near to the waterline to start with), and by then a decent feel for relative deck levels and access between them for both guests and crew. Add a decent amount fwd of the collision bulkhead for anchoring gear and preferred bow style, and whatever you deem necessary for transom platform etc. The hull length therefore suits the pre-determined package, rather than the package having to be adapted to a pre-determined hull length. The exterior above the lower accommodation deck / approx waterline will also therefore need to evolve around the number of decks, relative deck levels and lines of sight....an opportunity to explore different exterior styles, rather than forcing the interior package to fit within a pre-ordained exterior profile etc.
As far as a yacht design concept goes, all the above can be roughed out before you need to worry about whats under the water...by this I mean that in generalised terms the same conceptual 'above water' package and profile could sit just as well on a planing hull, semi-displacement or full displacement hull. Assuming you have already decided what hull form you want to use and what performance criteria you want already, planning the interior package up front will also give you a head start on the weight estimate, which in turn can be juggled with fuel / water / other fluid weights and hence all-up displacement / LCG / VCG which you need to develop the underwater hull form further.
In summary, IMO its easier to design a hull to match a target layout, displacement, LCG, performance vs installed power requirement etc, rather than start with a hull design with pre-set characteristics and try to design the internal package to suit.
Starting from the inside out helps you initially determine those targets, and helps give you a known set of variables that can be adjusted to chase those targets.

CODOG,

that was some pretty good design advise there. and yes ive taken it all on board. i have pretty much finished the design, and at the moment just fitting in the tender bay/anchor system/wind generator up front. your advise will forsure get put to the test next time round.

K1W1,

ive been trying to get what your after. i was doing some seaching on the net about the MOCHI 23, they did one system in-house (i think), and couldnt find it at first, but i did find it in a old magazine. so its running a 17kw and 13kw generators that supply a battery bank that then power the 70kw electric motors (when not operating the MAN 800hpx2). which is the system ill be after (hope that made sence). but if your running a boat like Feadship Predator, u would have to double the sizes at the least, right?

but having said all that theres not many pros to this system (so i could tell on the MOCHI). your still either burning your fuel or charging from the shore power which is coming from the power stations... comments?

Marmot,

as the title surgests jabor and myself are after 'help'. which means we ask, and yes sometimes silly questions. so when someone on here does help with the question jabor and myself are for one very greatful, and two, can then go ahead and ask the right questions to whoever it may relate to, and thus dont waste there time.

Cheers

far

Hi,

70 ekW ain't going to push your 23m boat at any great rate of knots.

I have experience where a 70m displacement yacht can be pushed at 4.5 kts just with it's Stern Thruster which has a Power of 250 ekW. The same boat needs nearly 12 times that power to go 4 times faster.

Are you looking to do a full electric drive project or do you want to have conventional drive and an additional electric motor driving a prop?

In either the drive equipment would normally be installed by the builder working to the manufacturers installation instructions.

If you had asked a "silly question" that would be one thing, you would probably have had an answer and an explanation as to why it might seem "silly" and gone from there to receive good info. The point I was attempting to make is that you didn't ask a question regarding propulsion or machinery.

Post #11, a passing reference to diesel electric
Post #35, MTU or CAT and "throw on" an electric motor ... was that a question?
Post #41, "any takers" to the engine question ... what was the question?
Post #42, K1W1, arguably one of the best people on this forum to answer a question about yacht propulsion asked you "what is the question?"
Post #44, K1W1 again asked what is the question?
Post #45, I tried to explain why you haven't received any information because it appears that you still haven't asked a question. You have not described a system or the system you have in mind, the only question you have asked is who installs the machinery. There is no "hush hush" you have to be very clear about what you want to do before asking propulsion system suppliers if they can deliver such a system or if it is feasible.
Post #47, you finally provided a small piece of information about what you are thinking about doing, it appears to be a hybrid of some sort with small gensets in addition to main propulsion engines ... there is still a great deal of information missing if you wish to begin a dialogue with a manufacturer or system integrator.

As I wrote a couple of lines back, be clear about what you want, that doesn't necessarly have to be a technical description and you don't even have to know if it is possible, it is a statement of your goal or objective and provides something on which the rest of us who do have the relevant background to help can base a response. If you were to get a stylist's answer to the questions you actually asked, it would have to be "mauve." So install a mauve powerplant with soothing curves and fitted with electrochromic variable transmissivity glass between the control room and engine room to enhance the engineer's onboard experience.

K1W1,

i was wanting to have a conventional drive unit and an additional electric motor driving the props. but i might just leave it there for the time and reseach this a bit more.

thanks for your efforts aswell.

far