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Thread: I have just been handed a boat design challenge

  1. #71
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    Default Re: I have just been handed a boat design challenge

    This is so cool, the idea, the boat, and the thread. Thank you so much for sharing this, Michael.

    Mickey Lake
    'A disciple of the Norse god of aesthetically pleasing boats, Johan Anker'

  2. #72
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    Default Re: I have just been handed a boat design challenge

    I am pleased that folks are enjoying this. I suppose that I should mention that I reserve the right to pull the thread, and delete all of it, if the builder or client objects to it. It happened once before when I was project manager of the build of the Portland fire boat and was posting pics from the shop. The shipyard was OK with it initially, but got cold feet and told me to cease & desist. I don't think that there will be any such issues with this builder or client, but just in case there is, you've be warned... <grin>
    Hope for the best, but plan for the worst.

  3. #73
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    Default Re: I have just been handed a boat design challenge

    Thank you for the time you took to respond. 50k is indeed a powerfull argument, no question about it. I did not think it would be that much, and I understand now why things are done that way. Local market conditions rule.

    I have not tought about warranty on the generator since it's no problem here, I can easily spec a PTO on gensets over 8kW as a factory option, for example from https://www.whisperpower.com/4/6/44/...rator-pto.html (they fit Kubota and Mitsubishi engines but do not seem to have a dealer in Canada, only the USA). It's not a real problem for most other companies either, just a question of asking and money. In case such a setup is not available, I would prefer an external powerpack for the hydraulics and a backup generator for the electrics.

    Just a few clarifications to my previous post. When I said the finish is compromised I did not mean the worked on area would be visible, rather that the splices need grinding and refinishing by hand wich to my mind looses the main advantage of using a female mold (not having to fair and paint the surface). Of course depending on how much slicing is done and where, it can still save a lot of finshing over a male form.
    The other thing is CAM temporary molds. I am not talking about milling foam as normally done for tooling. I would build a temporary female mold by milling frames out of MDF put in some battens and clad with spiled sheet material. A spray of Duratec and quick sand over the joints and you have a practical one use mold with decent (but not yacht quality) finish. Frames and cladding can be cut on a 5 axis CNC designed for standard sheet dimensions. The economics of the thing of course depend on local conditions, if slicing and dicing is cheaper and produces good enough hulls then it makes no sense.

  4. #74
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    Default Re: I have just been handed a boat design challenge

    Rumars, I am advocating the installation of a back-up hydraulic power-pack to run the hydraulic seawater pumps for the live wells in case of emergency; the builder is leaning towards electric pumps and a genset that would be too large for normal house loads in any other condition besides main engine shut-down (the primary hydraulic pump will be driven off the main's crankshaft). I might be speaking out of my ass about running a hydraulic pump off the genset, as I have not asked that question for about ten years. In any case, I will be compiling data on the the possible solutions and creating an evaluation algorithm to determine which is the best solution that accounts for cost, operational parameters, and intangibles such as warranties.

    I will poke two holes in your argument for a temporary female mold: First, building said mold would require staff whom are reasonably competent with building boat-shaped wooden structures. Those creatures are fairly rare around here. We have wood-butchers, at best. I have supervised a crew of 'glass builders in building a plug for a mold, and I don't think that I have the intestinal fortitude to do it again. I know people whom I could hire-in for the job, but that is another large expense. I will work with the tools at hand, in a manner in which they are used to being used. The builder & I have had discussions about, "If we were to create a whole new hull form...", but that dream is for a later time. Second, as the methods described are common hereabouts, it will be the simplest way to get the job done in a reasonable amount of time.
    Last edited by mmd; 09-02-2020 at 07:46 PM.
    Hope for the best, but plan for the worst.

  5. #75
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    Default Re: I have just been handed a boat design challenge

    I find myself really appreciating your ability to differentiate between "want to do", "could do", should do", & what is reasonable to expect - combined with willingness to think outside the box & listen to armchair quarterbacks (though many are obviously knowledgeable). It shows a deep understanding of the people you are working with and an ability to see what's best for the client.

    That's a rare talent!
    "If it ain't broke, you're not trying." - Red Green

  6. #76
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    Default Re: I have just been handed a boat design challenge

    Well, I looked for you, at least Nothern Lights offers the optional PTO for hydraulics. https://www.northern-lights.com/opti...-863f4ed9-7779
    I say ask your favorite genset supplier about it, see if it is an option and how much it costs. Whatever the final solution, you should at least know of all the options.

    As I said, local conditions rule, if you don't have local knowledge available at competitive prices there is no point to trying since the economics will not work. In the Netherlands for example metal would certainly be an option, but you don't build there. I totally understand that.
    But just to poke the dung a little more, a 5 axis CNC allows the frame bevels to be cut by the machine. Plus the NA gets to bill more hours because he has to design a jig that only goes togheter one way to keep the frames aligned properly so the wood-butchers can not mess it up. If you want to keep the glass builders happy look at C-flex construction, they will have hours of fairing to bill. But I know it is all theory without a client willing to front the money and a builder willing to do something new, and those are rare birds indeed. Sometimes one gets lucky tough, and I wish they come your way.

  7. #77
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    Default Re: I have just been handed a boat design challenge

    Quote Originally Posted by mmd View Post
    I am pleased that folks are enjoying this. I suppose that I should mention that I reserve the right to pull the thread, and delete all of it, if the builder or client objects to it. It happened once before when I was project manager of the build of the Portland fire boat and was posting pics from the shop. The shipyard was OK with it initially, but got cold feet and told me to cease & desist. I don't think that there will be any such issues with this builder or client, but just in case there is, you've be warned... <grin>
    Thanks again Michael. I'm going to enjoy it for however long it lasts. It's been quite an education already!
    - Chris

    Life is short. Go boating now!

  8. #78
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    Default Re: I have just been handed a boat design challenge

    Quote Originally Posted by mmd View Post
    Lugalong, before I reply directly to your post above, allow me to describe my thought processes in evaluating a new idea - mine included (especially mine): Whenever I am presented with the 'next great idea', I attack it from every angle I can think of to try to find its weak point(s). Often, I will invite others whom have experience in the subject to attack it, too. IF it can survive this withering attack, it is probably a good idea; if a crack is found, then the idea needs to be either re-thunk, or trash-canned. So please do not take any criticisms I may put forth as anything personal - it is just the way I go about such things. Now to your proposal:

    Your proposal is intriguing, but I see a few issues that might arise in my application. Firstly, how is this fundamentally different from the method of running a loop of pipe longitudinally along the hull, tucked up under the turn of the skeg/hull intersection as is normally done around here? It seems that your proposal is the same concept, but in a different location. Second, the local method places the pipes on the opposite side of the skeg from the side of the boat that pots are hauled from, thereby removing them from possible harm from the hydraulically-propelled sixty-kilo pot; if I understand your description correctly, your proposal would put the cooling pipe in harm's way at the edge of the keel/skeg (you would not believe the scarring on the stbd keel side from ropes being hauled across it). Third, as we operate in a region with tides in the range of six to ten metres, the boats quite often ground out at low tide att heir home wharf - how would your method stand up to being repeatedly buried in the mud and then lifted out by irresistible forces, or being crushed by the boat drying out on a gravel bottom against a wharf and leaning into the wharf by ten degrees or so? Finally, and again if I understand you correctly, I think that the reduction in drag would be minimal, as the primary source of drag would be skin friction along the length of the semi-open piping, not appendage drag from the frontal area of the pipe/tray combination.
    No offence taken, and if it is normal/usual to carry coolant pipes externally, without them being damaged, I misunderstood the need for a box cooler. Admittedly, the protector cowl that I had envisioned, would need to be fastened to flanges, enabling removal for cleaning and antifouling, so getting by with exposed pipes is obviously more practical on that count and surface drag is inconsequential, making the regular system A OK.

  9. #79
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    Default Re: I have just been handed a boat design challenge

    Quote Originally Posted by Rumars View Post
    Well, I looked for you, at least Nothern Lights offers the optional PTO for hydraulics. https://www.northern-lights.com/opti...-863f4ed9-7779
    I say ask your favorite genset supplier about it, see if it is an option and how much it costs. Whatever the final solution, you should at least know of all the options.

    As I said, local conditions rule, if you don't have local knowledge available at competitive prices there is no point to trying since the economics will not work. In the Netherlands for example metal would certainly be an option, but you don't build there. I totally understand that.
    But just to poke the dung a little more, a 5 axis CNC allows the frame bevels to be cut by the machine. Plus the NA gets to bill more hours because he has to design a jig that only goes togheter one way to keep the frames aligned properly so the wood-butchers can not mess it up. If you want to keep the glass builders happy look at C-flex construction, they will have hours of fairing to bill. But I know it is all theory without a client willing to front the money and a builder willing to do something new, and those are rare birds indeed. Sometimes one gets lucky tough, and I wish they come your way.
    Thanks for the update on gensets with PTO's; if the client has not finalized the engine package yet I will look into the possibility.

    Metal would be an option, albeit at an premium, but there is also resistance from the owners whom have had nothing but FRP for the past thirty to forty years, and with no great culture of hull maintenance in the fishery rust would be an issue with steel, and with horror stories ringing in their ears about stray current corrosion destroying aluminum, getting a fisherman to buy a metal boat would be a tall task.

    As I stated at the outset, this boat will look like all the other local boats, but we will strive to make it better, at more or less the same cost.
    Hope for the best, but plan for the worst.

  10. #80
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    Default Re: I have just been handed a boat design challenge

    What are your thoughts on CPP, can the boat benefit from it if the owners can be convinced to use one?

  11. #81
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    Default Re: I have just been handed a boat design challenge

    I like controllable-pitch propellers generally, but with the caveat that they are not needed in all circumstances. If they do not address a real need, then they are an unnecessary (large) expense. In the type of vessel being discussed herein, the operational range of the prop is rather limited, making a CPP a bit of a luxury. Speed-wise, the boat is run pretty much as if the throttle was an on-off switch; it runs either at idle or full wail. The boat has a pretty small variance between running light and running at full load (the difference between running light and running at normal load is about 20% of lightship displacement), except for a couple days per year when is carries a heavy deck load of traps (about 60% of lightship). Admittedly, being able to change pitch when running heavy would be good, but when you consider that the requirement for a lower pitch prop occurs only about 6 - 7% of the total time at sea, it is a significant expense for so little time used. That, and the increase in mechanical complexity and loss of "real estate" in the already-crowded skeg area are compelling arguments to dispense with their use.
    Hope for the best, but plan for the worst.

  12. #82
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    Default Re: I have just been handed a boat design challenge

    Thanks, CPP does not seem to make sense.
    Could you share what the fishermen think is the best engine for such a boat (power and brand) and if you agree with them or if there is room for improvement? I suppose the engines have to have "prime mover" ratings?

  13. #83
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    Default Re: I have just been handed a boat design challenge

    One last question and then I'll stop for good, what do you think are the areas the most improvement is possible, given the limitations you have to work with.

  14. #84
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    Default Re: I have just been handed a boat design challenge

    Quote Originally Posted by Rumars View Post
    One last question and then I'll stop for good, what do you think are the areas the most improvement is possible, given the limitations you have to work with.
    Oh, gosh no! Keep asking questions - it keeps me focused and often opens up trains of thought that I hadn't considered. I get frustrated at answering questions that have been asked and answered (read through the thread, folks!), but that hasn't been a problem yet, especially with your queries.

    The most popular engines for primary propulsion and hydraulics (hyd pump is almost exclusively driven off the main engine crankshaft) are, in order of popularity) Cummins, Caterpillar, and Mitsubishi, usually in the 450 to 650 hp range, although 800 and 900 hp is not uncommon. It is mostly dick-wagging ("I got a bigger engine than you do, nyaa, nyaaa...") because the boats have grown so fat and blunt that achieving anything over hull speed is pretty much impossible, even though the hulls look like the semi-planing types that they evolved from. All have their good and bad points. I like Cats because the tech staff at the regional dealer are easy to work with and free with tech info and CAD drawings, which makes my job a lot easier. The drawback of Cats are that they are big and heavy. Cummins are small, but tech info is sometimes difficult to get. Mitsu's are good engines, but they are a pain to get CAD drawings for. All three have good parts & service availability in the region. All engines must (should) have 'heavy-duty' or 'continuous duty' rating and be Tier II or Tier III emissions compliance. One of the down-sides of Tier III compliance is that the engine management system - fuel rate, horsepower, etc. - is microprocessor controlled, so horsepower upgrades are able to be done in a half-an-hour by the service mechanic. More than a few fishermen install engines de-rated to below 1,000 hp (Canadian gov't regulations require a licensed marine engineer to be aboard any vessel with more than 1,000 hp) and as soon as the Transport Canada inspector signs off on the new boat and gives the owner his compliance certificate, the fisherman calls the mechanic to come and swap the EM chipset and boost horsepower to as much as 1300 hp. This, I feel, will reach up out of the engine room and bite the fisherman in the butt because the drivetrain components are usually all sized for the lower horsepower.

    The primary ambition with this boat will be to maintain the appearance and functional layout of the boat to that of the current fleet, but to do improvements in some systems to make the boat faster, more efficient, safer, and able to deliver the catch in a superior condition. We're going to remove all wood used in the construction of the boat and switch to foam-core construction to save weight, improve the live well water flow and aeration, remove as much drag-inducing bits from the hull as we can, improve flow to the propeller, swap out the old-style plate rudder for a proper NACA-foil type, rationalize the hydraulics system and create redundancies for critical components, improve the down-time environment for the engine room and wheelhouse (primarily arrange for heat in these areas so that cold starts in -20 deg. C weather is faster, easier on the mechanicals and electronics, and more comfortable for the crew), and improve cargo -handling for ease of use and safety.
    Hope for the best, but plan for the worst.

  15. #85
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    Default Re: I have just been handed a boat design challenge

    Is there any way to introduce a bulbous bow without exceeding max length?

    Would it even help?

    (I don't remember this being asked or suggested yet. I might be being bad. That's a specialty of mine, just ask Lovey.)
    Last edited by Gib Etheridge; 09-03-2020 at 12:17 PM.

  16. #86
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    Default Re: I have just been handed a boat design challenge

    I would love to introduce a bulbous bow to the hull, Gib, but with the combination of pretty-much plumb stem and LOA restrictions, and the need to push the engine room and crew accommodations as far forward in the bow as possible to maximize hold volume, it is just not do-able in this hull form.
    Hope for the best, but plan for the worst.

  17. #87
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    Default Re: I have just been handed a boat design challenge

    What would happen Michael if you just applied 1/2 of it to each side with it's forward end extending only as far as the existing LOA? Would it not help even though it's held back like that?

    Is this the sort of thing you can draw up on the computer and have tested in a virtual test tank?

    Is there such a thing as a virtual test tank?

  18. #88
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    Default Re: I have just been handed a boat design challenge

    I don't think that 'side bulbs' would help hydrodynamics all that much on this type of hull, Gib. the artificial bow wave created by a bulb needs to be generated in front of the actual hull to lower hull drag. They do improve bow flotation and decrease plunging, if those things happen to be a problem. These boats are so blunt and fat that those problems are not problems.

    Hydrodynamics prediction via computer is getting better all the time, but still not quite as good as real tank testing (or so I am led to believe by the reading I do). As with most things, the more precision you want, the more powerful the computer you need and the more expensive the programming is. I am scared to look at what might be available, because I am still choking on the fact that the desirable go-to stability program that would be so nice to have in my office is about thirty thousand dollars.
    Hope for the best, but plan for the worst.

  19. #89
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    Default Re: I have just been handed a boat design challenge

    Sigh...

  20. #90
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    Default Re: I have just been handed a boat design challenge

    It should be beaten into the owners that chip tuning is stupid. They should be made to handwrite "maximum continuous rating is king" 100 000 times before they get a licence and every time they buy a boat or engine. Want more HP, pony up and buy more liters.

    We have here (and I am convinced it's available in Canada) a polypropylene honeycomb with fused glasfibre/polypropylene sides. Comes painted or translucent, can be riveted, screwd, glued and welded. It is used heavily in the truck body industry since it is cheaper per square meter than foam cored panels. For furniture building there are systems of Al profiles, just slide in and pop rivet. Not even the wood butchers can mess that up.
    Whatever you end up using, it normally pays to buy sandwich panels with factory finish.

    For cold starting, can you specify electric block heaters for the engine and generator (I suppose power is available at the dock)? With simple automation (wi-fi enabled relay for example) the engine can be warm when the crew arrives. If you add an auxiliary electric pump on the heating circuit the whole boat is warm. The captain just has to remember to swich on the heat from his smartphone when he wakes up.

    For the hydraulics, is it possible to run a big pipe centrally under the whole lenght of the deck to serve as accumulator and central distribution spine? That keeps branches short but requires electrically actuated valves. Running wires is a lot easier than plumbing.

    Is this an AC or DC boat?

  21. #91
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    Default Re: I have just been handed a boat design challenge

    Quote Originally Posted by Rumars View Post
    It should be beaten into the owners that chip tuning is stupid. They should be made to handwrite "maximum continuous rating is king" 100 000 times before they get a licence and every time they buy a boat or engine. Want more HP, pony up and buy more liters.

    We have here (and I am convinced it's available in Canada) a polypropylene honeycomb with fused glasfibre/polypropylene sides. Comes painted or translucent, can be riveted, screwd, glued and welded. It is used heavily in the truck body industry since it is cheaper per square meter than foam cored panels. For furniture building there are systems of Al profiles, just slide in and pop rivet. Not even the wood butchers can mess that up.
    Whatever you end up using, it normally pays to buy sandwich panels with factory finish.

    For cold starting, can you specify electric block heaters for the engine and generator (I suppose power is available at the dock)? With simple automation (wi-fi enabled relay for example) the engine can be warm when the crew arrives. If you add an auxiliary electric pump on the heating circuit the whole boat is warm. The captain just has to remember to swich on the heat from his smartphone when he wakes up.

    For the hydraulics, is it possible to run a big pipe centrally under the whole lenght of the deck to serve as accumulator and central distribution spine? That keeps branches short but requires electrically actuated valves. Running wires is a lot easier than plumbing.

    Is this an AC or DC boat?
    I have no issues with 'chip tuning' - the engines are designed for that amount of horsepower, hence the dealer mechanic supplying and installing them. The issue is that the drive train after the gearbox (and sometimes the gearbox, too) is often not sized for the increased horsepower. That, plus the fact that all the extra horsepower won't gain much more than a quarter- or half-knot of speed.

    I know of the polyprop honeycomb panels (I taught a course in advanced composites construction at a local Community College for a while, mostly targeted at the aerospace industry, so I still get all kinds of info from composites materials suppliers), but I don't think that they are approved by Transport Canada yet for use as structural bulkheads for marine use.

    Electric block heaters are probably the way we will go, and will introduce an external loop with circulating pump and fan-forced cabin heaters in the engine room, wheelhouse and accommodations, all run via the shore power system. Remote dial-up is not necessary - when it is cold, they will be on all the time that the boat is at the wharf. There are a couple of boats in the region that use an oil-fired furnace hooked into the cabin heater system, so we will have a look at that, too, but there is an insurance premium to be paid if there is an active flame-fired heat source on board when the boat is unmanned.

    I have though about a central distribution line for hydraulics, but the majority of the hydraulically activated components are within five meters of the hydraulic pump, so it is probably adding complexity to an already complex (for a small boat) hydraulic system. Have a look at the GA in my OP and you will see what I mean.

    The boat will be both AC and DC. Most are.
    Hope for the best, but plan for the worst.

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    Default Re: I have just been handed a boat design challenge

    I was thinking at the polyprop panels for everything that is not structural, mainly because they are cheaper (at least here) then foam cored ones (even the PU cored panels, not to mention more structural foams). For structure (bulkheads, tanks, etc.) of course only approved foams with the requisite skin thickness. You mentioned the boats are overbuildt so I take it you don't need tabbed in structural furniture to stiffen the hull.

    Electrically, I expect all instruments and automation (if any) on 24V with engine alternator, and all hotel loads on AC (including cooking)? With inverter and DC transformer for backup when on generator/alternator alone? Plus of course whatever UPS battery is necessary by law for nav lights and instruments?

  23. #93
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    Default Re: I have just been handed a boat design challenge

    The amount of non-structural bulkheads - approximately 30 sq meters - is such a small percentage of the total amount of cored laminations that need to be made up that the difference in material costs is negligible in the grand scheme of things, plus it just adds to the inventory that the builder has to administer and store. Nice thought, but I will concentrate on the bigger fish to fry for now.

    Standard electrical installations on there boats are 24v & 12v DC for electronics, navigation & emergency lighting, and control actuators; 120vAC for hotel services including galley stove, microwave, coffee machine (boats run on diesel and fishermen run on coffee, right?), refrigerator, entertainment equipment (TV, stereo, and even game consoles), and general lighting. AC is via generator and shore power and occasionally an inverter, and DC power is via main engine alternator and battery banks. I haven't been able to convince anybody yet to install solar panels to aid in battery charging.
    Hope for the best, but plan for the worst.

  24. #94
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    Default Re: I have just been handed a boat design challenge

    This is currently my favourite thread on the forum.Hoping to understand a lot more of the reasoning behind the design choices and I hope it moves the quality of the designs in the fishery ahead a bit.I wonder whether there will be any consideration given to reducing the aerodynamic drag by using larger corner radii on the wheelhouse and other deck structures.It might be worth a little when running into a headwind.

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    Default Re: I have just been handed a boat design challenge

    I am not expecting a 'break-through' boat, John; just baby steps towards a greater end. As for understanding, ask questions. If I don't know or can't say, I'll tell you that, too.

    Aerodynamics probably does add some drag, but I'm not sure if streamlining the superstructure will have enough of an effect to warrant the extra work. There is probably more windage drag in the antenna platform, boom, rigging, and sundry bits on the wheelhouse roof than on the wheelhouse itself. There is also the aesthetics to consider - fishermen are notoriously loathe to have a boat that looks 'different'.
    Hope for the best, but plan for the worst.

  26. #96
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    Default Re: I have just been handed a boat design challenge

    I have to agree with Michael on chips. Generally, if you can tune an engine with factory chips to 1300HP, it means it's designed for that. IOW - 900HP from that same engine is just detuned. Of course there are aftermarket chips that'll go higher for many engines, but they also void warranties.

    The points on transmission & shafting are entirely valid though.
    "If it ain't broke, you're not trying." - Red Green

  27. #97
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    Default Re: I have just been handed a boat design challenge

    Why the 12V? What is not available in native 24V? Even if something is significantly cheaper in 12V like the VHF, a local 30W step down converter is cheap and has the added benefit of supplying a rock steady voltage.

  28. #98
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    Default Re: I have just been handed a boat design challenge

    There is always equipment that is 12v, Rumars. Not to plan for it is a dereliction of duty. The 12vDC distribution panel draws power from the 24vDC panel through a converter, but is is essentially a stand-alone system otherwise. The 24vDC panel draws power from house battery bank or the emergency battery bank, which are both charged by the main engine alternator. In a recent lobster boat that I worked on the following items were 12vDC:

    * 3x 12vDC outlets ('cigarette'-type receptacles to plug in hand-held spotlights, charge hand-held radios and charge cellphones, etc.)
    * fuel pump for the diesel stove in the crew accommodations
    * a computer monitor for a laptop
    * the CCTV system
    * the blower motor for the diesel stove in the crew accommodations
    * the security alarm system
    * VHF radio
    * VHF radio/loudhailer
    * stereo in the mess
    * water temperature monitor
    Hope for the best, but plan for the worst.

  29. #99
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    Default Re: I have just been handed a boat design challenge

    Yes there is, and that's exactly why I am against it. If you provide a 12V distribution panel people will start adding more cheap automotive stuff to it until something fails. At least with the 24V stuff they are forced to think twice before they grab something at the discount table.

    I also dont like chip tuning. The manufacturer has only one MCR for a given engine because the limiting factor is usually the ability to take heat away in a given time and that's hardware limited. You want more power it's OK, the engine can take it, but not continuously. A fishing boat on a return run, fully loaded and running flat out because they want to sell fresh fish, is a bad place to have your engine set up so that full throttle is way above MCR. Even if you get away with it for a few times, engine lifespan is greatly reduced. The engine should have an MCR that allows the boat to run full speed for days on end while fully loaded and in a normally expected sea state. This ensures healthy engine life and good fuel economy.

  30. #100

    Default Re: I have just been handed a boat design challenge

    is this any help


    http://thistlegroup.co.uk/

  31. #101
    Join Date
    Jun 2000
    Location
    Pleasant Valley NS Canada
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    21,075

    Default Re: I have just been handed a boat design challenge

    Rumars, we're going to have to disagree on your last post. To whit:

    If "people ... start adding more cheap automotive stuff to it until something fails", it will be the breaker in the 12v panel that trips, ergo, no failure. That is why there is a breaker panel installed between the converter and the powered devices.

    You can dislike chip tuning for whatever reasons that you wish, but the engines are designed for the higher horsepower ratings and de-tuned with the chipset to the lower horsepower output. As long as you install factory-supplied chipsets to raise the power output within the designated rating, you can't run the engine at a power output greater than what it was designed for. The engines in the local lobster boats are rated for continuous/intermittent running, meaning that they will reliably run - for weeks on end - with the rpms being run up and down as the boat works its gear, at the highest end of its power output at its rated use. You can have the same engine, with a different chipset, run continuously but at lower power output, which takes care of the heating issues.

    For example, consider the Cummins QSK19 marine engine: It is rated at EPA Tier II and III and at Continuous rating it can be controlled to output between 500 and 660 BHP, at Heavy Duty rating can produce between 750 and 800 BHP, and rated at Medium/Continuous it can produce 800 hp at either EPA Tier II or Tier III. Same block, same fuel system, same everything except the engine management chipsets.
    Hope for the best, but plan for the worst.

  32. #102
    Join Date
    Jun 2000
    Location
    Pleasant Valley NS Canada
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    Default Re: I have just been handed a boat design challenge

    Quote Originally Posted by peter radclyffe View Post
    Lovely stuff for sure, but importing and parts & service would be an issue. North American suppliers - or EU firms with a strong North American presence - can usually provide P&S overnight. Hiab and Palfinger, for example, have technicians right here in Yarmouth, and parts depots three hours distant by road.
    Hope for the best, but plan for the worst.

  33. #103
    Join Date
    Dec 2009
    Location
    Vancouver Island
    Posts
    2,102

    Default Re: I have just been handed a boat design challenge

    "What would happen Michael if you just applied 1/2 of it to each side with it's forward end extending only as far as the existing LOA? Would it not help even though it's held back like that?"

    Gib, these guys seem to be giving your concept a go, after a fashion. / Jim


  34. #104
    Join Date
    Mar 2007
    Location
    East Quogue,NY
    Posts
    20,666

    Default Re: I have just been handed a boat design challenge

    Michael, for the 12-volt receptacles, consider adding some USB receptacles, as most phones and devices will charge with USB. Maybe on deck use the cigarette lighter type and for inside, spec the USB?

    This way separate adapters ( which go missing) will not be needed to charge phones. And, you can plug two into each receptacle.

    EX:

    Screen Shot 2020-09-04 at 12.22.34 PM.jpg

    or

    Screen Shot 2020-09-04 at 12.25.06 PM.jpg


    Kevin
    There are two kinds of boaters: those who have run aground, and those who lie about it.

  35. #105
    Join Date
    Jun 2000
    Location
    Pleasant Valley NS Canada
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    21,075

    Default Re: I have just been handed a boat design challenge

    Chas - Much bigger boat, though; able to absorb the loss of interior volume in the bow without penalty to the crew accommodations.

    Kevin - good idea; I will present this to the owners.
    Hope for the best, but plan for the worst.

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