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  1. #71
    Boomshanka's Avatar
    Boomshanka is offline Registered User
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    Here's a guy who converted the bottom half of an outboard leg to make an electric saildrive:



    More info here: http://www.glen-l.com/designs/specia...tricdrive.html

    Step-by-step guide: http://www.glen-l.com/designs/special/elecdr1.html
    Are we there yet?

  2. #72
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    Sorry to discover, that I have myself, run clean out of irony...but was that remark from PRV deliberately sceptical? Was there really a fuel-cell salesman here? Oh! PRV, you have a future in music hall! At least, more of a future than music hall has.

    The point, lest you needed telling, is surely that until the new, mind-blowingly clever stuff is here, I recognise that it's natural to be cynical. It may even be shrewd, if you're the type who 'costs' his days and nights out in advance. But, it isn't very enviable.

    I just don't look at life that way myself, or think wistfully of when I might begin to. I'm not young, but some of you ladies and gentlemen have a way of making me feel younger! I ought to be grateful to you, really.

    It's so true, it scarcely needs saying: electricity aboard yachts is not yet established. I know that, so please don't feel it bears repeating.

    But don't close the curtains on the idea. If you do, for sure, you'll be the ones left in the dark.

    PS. Thanks Boomshanka, nice pic.
    Last edited by dancrane; 04-04-11 at 22:58.

  3. #73
    prv is offline Registered User
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    Quote Originally Posted by dancrane View Post
    Was there really a fuel-cell salesman here?
    Either here or Scuttlebutt, yes. It was just after the London boat show finished; he'd been manning a stand there and wanted to know what we thought of his products. Wasn't a sales pitch as such, in fact the thread as a whole was a surprisingly mature exchange of questions, answers, and discussion.

    Big problems were that the kit didn't last all that long (5 years or so?), was very expensive to buy, and required fuel in plug-in cartridges that were expensive and also not widely available. But as I said, I'm sure those will be overcome in time.

    Pete

  4. #74
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    Quote Originally Posted by dancrane View Post
    Avocet, you're the practical, living spirit of imagination! Name a charity, I'll drop them £10 in the morning.

    You're an educated blend of intelligent thinking - about what might be possible, plus what we know we can rely on.

    I think I'll try to think as you do, if I can.
    You're very kind sir! It will come as no surprise, I'm sure, to learn that I have a soft spot for the RNLI...!

    I've had a few dealings with electric vehicles (I come across them in my day job) and so far, it seems that the motors (60kW) are absolutely bomb proof. The control systems, however, seem less so, and the battery management systems can have their moments. If you want to have a go, PM me and I can send you a few links. I wouldn't bother with lead-acid, to be honest. Li-ion are much better for deep discharge. You might even be able to find a crashed Toyota Prius (NiMh batteries I think) and cannibalise that, but I think they run at pretty high voltages - which you might not want to do with water nearby...

    Last time I looked, fuel cells worked out at about £1000 per kW, so probably not quite there yet. We do, however, need the really rich (which might not be yourgoodself, of course!) to become "early adopters" of new technology. They can afford to spend a fortune on stuff that goes wrong and thereby bring the cost down and help develop the product for the rest of us. The whole history of automotive development has been largely along those lines.

    Good luck!

  5. #75
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    Red face

    Pete! My apologies. I was so sarcastic, a while back. I thought you were taking the mickey from my own earlier post.

    I had no idea that some loony had seriously tried to market fuel cells, here; but surely they must still be at the very outer-margins of practicality. Although as you say, and I'd echo, their time will come. And, probably sooner than predictable.

    Glad your diesel's doing as it's told. Mine needs a swift kick, but my boots aren't up to it...

  6. #76
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    Avocet, sir, you're so charming, I'll make it £20 for the lifeboaters. I probably owe them lots more than that. But anyway, I'm at least that flattered, to be mistaken for a wealthy twit!

    I only wish I had £20,000 or ten times that, to throw at hybrid systems. As a poor fellow, I have a profligate instinct that makes my relatives and SWMBO, wince. Well, they would wince, if I had anything to lose.

    Did you ever hear of the very wealthy 19th century chap, who offered an early, experimental railway operator the full cost for a length of track, plus two complete locomotives, provided he could watch them crash into each other at full whack? Barmy. But, I admire his deranged sense of fun.

    £1000 per kw certainly is a trifle rich. But I'll go through all you've written at length, in dawn's sober light.

    Yours, with respect,

    DC

  7. #77
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    Quote Originally Posted by michaelchapman View Post
    I think it is worthwhile to spend some time looking up diesel electric submarines. They are still made.

    The best performances I have seen from a modern one are a submerged range of 350 miles at 8 knots. The batteries they use are typically 134 cells or more, each cell weights between 500 and 700 kgs. I also saw one which can do 25 knots under water - but has a maximum endurance of 90 minutes.

    The best world war two peformances I found were 48 hours at 2 knots.
    Pity you did not check out AIP as well, using either fuel cells or stirling engines many modern submarines have far greater endurance. Battery size does vary so suggesting typical sizes is perhaps misleading. In my last boat we had some 440 cells of some 7500Ah capacity. We could flatten the box in some 30 minutes but equally with care we could run much longer between snorts.

    DE drive is well proven and using storage batteries can allow minimising the time the generator part is run but the use of fuel cells or stirlng engines to give normal cruising power with the battery doing any full power surges.

    Electric drive is good for manoeuvring as it is both quickly reversed and gives rapid power application.
    Peter

  8. #78
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    Quote Originally Posted by dancrane View Post
    Total respect for Ubergeekian's outlook. I especially approve of the oars.

    But, if I had to motor such a distance before I could set sail, I'd relocate. That said, I don't know the Crinan Canal area. I'm sure its beauty makes a distance under power well worth any small inconvenience.
    The Crinan Canal is a) beautiful and b) under some circumstances a useful route from the Clyde to the Hebrides. It cannot be traversed under sail; the 15 locks make it impractical, and it is too narrow for most cruising yachts to tack in.

    Basically, it isn't comparing like with like. An electrical system is NOT a replacement for an internal combustion engine; there is no way, with current battery technology, that the energy storage of an electrical system could come anywhere near that of a tankful of diesel or petrol; as someone else computed, the energy storage of a tank of diesel is equivalent to hundreds of standard 110Ah batteries. Electrical propulsion simply can't provide the range or versatility of a diesel engine, unless you have the battery capacity (and charging capability) of a submarine.

    However, if you genuinely NEVER need to be able to rely on doing 100 nm in a day come what may, and are happy to be unable to make passages that require you to be through a tidal gate by a specific time (that would bar a lot of the West Coast of Scotland), or passages that must be undertaken under engine (e.g. the canals), then electrical power as you describe it has a lot to offer.

  9. #79
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    Smile A short bedtime read...

    Thank you, AntarcticPilot...although...you haven't told me anything I didn't already know.

    Use of my own diesel auxilliary has certainly made me into a better sailor, because it is irrecoverably far past its prime, and can no longer be relied upon, so in consequence, I don't rely on it.

    Sailors many decades ago were glad to benefit from their engine when it worked; but I've no doubt they were more exasperated than amazed or alarmed, if it didn't...because at that time, plenty of large vessels still had no means of propulsion at all, other than sail.

    When the 'little donkey' was being mule-headed, they'd consider how to modify their plans. If there was only one possible course across the sea and no wind to push them there, they'd be used to that, and one presumes they'd developed patience to cope in the motionless silence.

    That approach to sailing really isn't so bad!

    I accept that it's completely out of fashion. But I never gave a damn for trends and I'd be sorry to think like the herd. Most yachtsmen today don't have the time simply to sail, nor any inclination to go sailing without getting somewhere in the predetermined period, after which they must hurry back to home or work.

    I'm delighted that well-tended diesel engines allow those who don't have time to kill, still to get what they want out of being afloat.

    But I see it this way: I'd rather spend eight hours cycling on quiet country roads, than the use the same time to drive five times the distance, on motorways. I wouldn't get nearly as far, but the time would have been much more enjoyably spent. And critically, I'm not in a hurry.

    Running a part-renewable/part-hybrid electric auxilliary system, will undoubtedly restrict the vessel's short-term range, and will require me to think and plan ahead and anticipate, in ways that diesel had almost trained me never to think about.

    I'm not, and I never was, kidding myself that electric power on board represents an instant replacement for diesel...

    ...it's vastly more than that.

  10. #80
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    Quote Originally Posted by dancrane View Post
    Avocet, sir, you're so charming, I'll make it £20 for the lifeboaters. I probably owe them lots more than that. But anyway, I'm at least that flattered, to be mistaken for a wealthy twit!

    I only wish I had £20,000 or ten times that, to throw at hybrid systems. As a poor fellow, I have a profligate instinct that makes my relatives and SWMBO, wince. Well, they would wince, if I had anything to lose.

    Did you ever hear of the very wealthy 19th century chap, who offered an early, experimental railway operator the full cost for a length of track, plus two complete locomotives, provided he could watch them crash into each other at full whack? Barmy. But, I admire his deranged sense of fun.

    £1000 per kw certainly is a trifle rich. But I'll go through all you've written at length, in dawn's sober light.

    Yours, with respect,

    DC
    Most kind! I had heard stories of late 19th & early 20th century entrepreneurs buying up scrap railway engines, putting down a mile or so of track and charging people to come and watch the spectacle of them hitting each other head-on!

    http://www.youtube.com/watch?v=yUc3w...eature=related

    I've nothing against people wealthy enough to be able to afford to loose money on new technologies (quite envious, in fact!) but unfortunately, I ain't one of them either. All my stuff is pretty Heath Robinson. I'd love to have a go, but I know that I probably won't. I think we also need to be ruthlessly analytical about the benefits. I for one, am all too prone to falling into the "clever-for clever's sake" trap and finding that while I've got something really cool, it doesn't actually deliver that much real benefit over what it replaces. Alan17's suggestion that all your diesel would be used for battery charging (thus attracting a lower rate of duty!) was one of the most appealing advantages - to me at least!

    Do let us know how you get on if you decide to go ahead. I'd be fascinated by such an experiment!

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