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  #161  
Old 06-03-2009
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Diesel/Electric Locomotives have 8 sets of wheels with 8 traction motors (sometimes 6). The big advantage is the instant torque availble from an electric motor right from start at low rpms. Lots of startup grunt.

Now, how about a single diesel gen and 4 electric driven props on a boat.
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  #162  
Old 12-09-2009
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Auxilary Sailboat vs. Motorsailor

I stumbled onto this thread via google while researching the SolidNav unit.

Not sure if any of the participants are still reading, but felt compelled to respond.

First, I am a separate human being from the CEO of SolidNav and his various friends, split personalities, etc.. :-)

Second, I was pretty interested in the SolidNav unit, but that single post by their CEO really put me off -- I'll now be looking at Electric Yacht, Re-E-Power, etc.

Third, to Rockter and ChucklesR, I respectfully submit that whether or not an electric motor makes sense depends on whether one is a sailor, an auxiliary sailor, or a motorsailor.

My current boats (Ingrid 38 -- Rockter: sounds similar to your double-ender and Santana 22) are engineless. If the wind dies, we break out the oars (sweeps for the little boat, sculling oar for the big.) The standard question at this point is "Well, what if you have to row upwind in chop?" This is not the response of a sailor. If there is wind, sail. Period. Rowing is for absolute calms, when you need to get in or out of a tight spot. Sailing engineless (especially in a big boat) can be boring, nerve wracking, hard, but possible. Our sailing forefathers got all over the place without engines in boats that were much less handy in stays than most modern boats. Hardy folks like the Pardeys, the Hiscocks, Don Street, etc. etc. prove that it is still possible today. The key is that your boat must be set up to sail really well, especially upwind.

Which leads to the auxiliary sailboat philosophy. Frankly, rowing gets pretty old pretty quick! If we accept that a sailboat engine is there for convenience not safety (motorsailors will disagree -- see paragraph below), then there is a place for small auxiliary kickers to move sailboats in a dead calm. The old rule of thumb used to be 1 horsepower per ton. Again, for the auxiliary sailor there is no question of motoring at hullspeed for days. If you want to cross oceans, hoist your sails.

chucklesR: I sail a lot on a buddy's Gemini 105MC. Great boat -- being a monohull guy my only complaint is like most cats it lacks helm feel. One of the things I like about my friend's Gemini is it's light, fast, has easily driven hulls, and only draws 18" with daggerboards up. My buddy recently upgraded from a 1.5HP electric trolling motor to a 5HP electric outboard. Yeah, you read that right. :-) The motor is only for moving the boat at a slow walking speed while docking. The only reason he has an engine at all is that he has an upwind slip with a crazy, narrow, dog-leg final approach. He's a great sailor and he makes it work. I think for auxiliary sailors where you motor out of a tight spot for an hour, cross a bay (or an ocean) then motor into a tight spot, there just might be a place for an electric motor. (And again, I'm a neutral potential consumer here, not some wild eyed devotee or company shill.)

Finally, there is the motorsailor philosophy. Rockter, if you're talking about motoring for 8 hours at a stretch, this sounds like the camp you're in. No shame in that I guess, but let's be honest and say that on your boat, it sounds like it's the sail rig that is auxiliary... :-)

- Ari

Last edited by Aroostifer; 12-09-2009 at 05:53 PM.
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  #163  
Old 12-09-2009
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This is an interesting thread,
Ari thank you for bringing it back to the light.
If you are rowing an engineless Ingrid 38, then
you are certainly pretty far from the mainstream,
but I identify with several points in your post.
Firstly I concur that many people these days use
their boats like powerboats with auxiliary sails.
This is in part because many modern production
boats really only sail well in ideal conditions, ie. reaching
in 15 knots TWS. They have poor sailing characteristics
in light air due to the excessive weight and wetted surface
of their voluminous hulls. Many do not sail to weather well.
Back on topic, I realise that electric propulsion is not the
right solution for everyone but it appears to be ideal for the
way I and many other people use their boats.
It is very common for people to only use the their engine
for a few minutes at low rpm to get out of or into the slip.
This is the worst possible application for a diesel engine, which
wants to be run under a load. The electric does not need to be
started or warmed up at idle, just put it in drive. This is a handy
feature you blow a tack and find yourself drifting into a jetty.
I can not wait to ditch my diesel and clean out the oily mess
beneath it and install a quiet and clean golf cart motor in its place.
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  #164  
Old 12-09-2009
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Rowing

Cool,

I try not row my sailboats at all. That's the point... :-)

- Ari
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Old 12-09-2009
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Quote:
Originally Posted by Aroostifer View Post
Cool,

I try not row my sailboats at all. That's the point... :-)

- Ari
Understood. I am very patient, and 95% of the time
I find that I can get where I am going under sail, eventually.
Light airs do not deter me, the only time propulsion is needed
is when the wind is up and blowing straight down the fairway
to my slip which is too narrow to short tack in.
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  #166  
Old 12-11-2009
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Quite the thread we have here. Who would have thought that a topic could cause more angry than anchor choice.

I've been interested in electric propultion for quite some time, but as Cam and others have pointed out several times in this thread it is not more efficient pound for pound, dollar for dollar, or by most other measures. I won't argue with the disadvantages, as they've been well explored on this thread and are quite valid. What I feel is lacking from the particular discussion is the other aspects that electric and electric/hybrid have over conventional diesel.

What attracts ME to electric/hybrid systems is similar to what has attracted me to hydraulic systems in the past. Here is what I like:

1: Silent motoring (or nearly with a very well insulated genset)
2: Easier to mount a dual prop setup (still only one diesel generator) for better maneuvering and redundancy.
3: Lots of options for motorsailing.
4: Instant availability of power from the electrics in case of sail failure or diesel genset failure.
5: The possibility of sitting at anchor and slowly augmenting your fuel supply by generating power.
6: The possibility of creeping home (albet slowly) after diesel failure on a windless day.

Allow me to flesh out each of these advantages a little:

1: For starters I LOVE the idea of silent motoring. Yes I know sails are silent and that's why I use them when I can but the fact is that in the PNW with the type of cruising I do I motor about 50% of the time. I have seen many a small genset so well insulated that you can't even tell it's on dockside. Literally a whisper. I guess you "could" sound insulate your main motor this well, but I've never seen it done. It also appears that you can use a much smaller diesel for your genset (than you would for your main engine) and insulate it more easily with off the shelf technologies. If my motor were quiet I'd hate motoring less.

2: I'm getting better at docking, and less stressed as I practice, but I own a heavy full-keeled boat with a unidirectional wind powered bow thruster (large bowsprit). My maneuverability in harbor SUCKS. A dual prop setup of high torque electric motors would be a HUGE advantage in close quarters maneuvering. I would go out more often having confidence in a setup like this. I also recently had a large rug wrap itself around my prop on a windless day. If I had two props, it wouldn't have been an issue. Mounting one genset and two pods is possible, mounting two engines, transmissions, etc is just not possible for me.

3: The owner with the E-pod gemini (that Chuckles mentioned) talks at length about the options he has for motorsailing. I'm one of those sailors that doesn't mind using the nylon sails and drifting along all day. Problem is that drifting at 2 knots sometimes means having to use the engine at the end of the day to beat darkness or make a slack tide appointment. I would much prefer to SAIL all day with a couple amp hour push from the silent motors helping me along. Apparently they don't use much power in this role. I am much more likely to use this setup instead of fire up, warm up, and engage the rattlebanger. Once again, another advantage that would allow me to sail more.

4: Instant availability of power would help keep the stomach ulcers away. I try and maintain my diesel so that it won't suddenly die, but they all do sometimes. With my big heavy ketch I can't set my sails quick enough and short tack in a marina to keep off the breakwater. I keep my anchor at the ready, but an electric system that will continue to run if the diesel genset dies would eliminate this problem. Also if sailing and lines foul and suddenly I'm headed for a lee shore I have electric backup again in case the diesel doesn't want to start. It's a safety and stress-relieving feature. A safety feature I do without today, as when my motor dies I have exactly zero engine motoring time in reserve, but it would be "nice to have" even that 1 or 2 hours of motoring time in your batteries for after your diesel engine (genset in this case) fails.

5. Sitting at anchor topping up your tanks. This is more of a sate of mind really than a real savings. I compare it to the smirk of superiority that I see on trucks with biodiesel bumper stickers. It would take far too much to fill up an empty tank, even with a week at anchor in a windy sunny spot. But you could add some, especially with a nice windy night, and the though of it is nice.

6. We all know that mechanical things like diesel engines have two states of being: 1. Broken. 2. waiting to break. I've had my diesel die while out cruising and I've usually managed to creatively fix it at anchor. It would be nice though to have the option of crawling home at 2 or 3 knots using your battery bank if your diesel genset dies. Can the electric setup fail? Of course, but it's another tier of redundancy, much like an outboard to back up your main inboard. Recently when the rug wrapped itself around my prop and we had EXACTLY 0 wind I had to call buddies at my marina to come fetch us in outboard powered tenders. Had we even 1 knot of wind I could have sailed most of the way home. I still would have been screwed trying to dock with nylon sails in a close marina in 1 knot. With the electric setup I could have limped home at 2 knots using low amps from the remaining motor and even docked myself. I've also had the engine die in wind. We sailed into anchor but sailing into anchor would be easier with a little electric backup even if only for the final maneuvering in the (hopefully) wind-protected anchorage. I love redundancy and self sufficiency and this would add another step.

The technologies are not mature right now. I thought E-pods were a good bet until I saw the photos of the rusted out ones and the stories of poor service. Other companies have hot-headed CEOs. So for now they're not good enough for me to fork over more than the cost of a regular repower but hopefully soon they'll get more reliable, cheaper and hopefully batteries will get better as well.

Here is a link to the gentleman with the dual E-pod gemini. He has some really good real world data (including real amperage usage vs speed graphs) on his setup as well as a good explanation of some of the advantages that aren't normally listed when people compare the technologies side by side.

Epods in Use
speed vs. amperage From the link to this page:"(update: the epods actually take half the power indicated on the chart to reach the speed),"

Regards,

Medsailor (not affiliated with anything electric or diesel)
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Last edited by MedSailor; 12-11-2009 at 04:17 PM.
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  #167  
Old 12-12-2009
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Wow! I have just read this thread from beginning to here and when you take out the irrelevant comments about business practices and Giu's 4 strange posts you're left with this:
If you want more than an hour or so of electric power you have to have a generator or a hell of a lot of batteries. If you have to have a generator, why not just have an engine? Why buy an electric motor, controller, and lot of batteries and still have to have an engine?
The E-Pod example I've seen on this site E-POD 3000+ - Petaris' Photos
ends up leaking and corroded in a short time. To me the only configuration that makes sense is to use the boat's original shaft and a suitable propeller - moving to a vulnerable saildrive type unit like the E-Pod is a step backward.
If you daysail and plug in at the dock, maybe it would work. But the references to moving through the doldrums and plugging in at dockside at your destination for a long term cruiser just don't make sense. Any cruiser I know that heads offshore seldom ties to a dock as there are very few in many places and where they exist doesn't want to tie to them anyway. Better peace and quiet and breezes at anchor. So that theory doesn't work either.
In my local cruising area motoring is very common in the summer months. We have narrow channels, light winds or no wind and tidal currents of 7 to 10 knots in some passes (actually higher is a few places) and when slack water arrives you don't drift through at 1 knot with bare steerage way, you use the engine to get through quickly and efficiently - no matter how much of a purist you'd like to be. The engine has to be relied on and for more than 1 hour. When you get to your desired destination you don't plug in to charge as in the nicest places to cruise to (Desolation Sound being the best example) there's nowhere to plug in - just like the best foreign destinations you anchor because that's all there is. Maybe in Southern California you can go from dock to dock but we can't here (and don't want to anyway).
Battery charging as has been posted is best reserved for house batteries for the boat's systems (lights, refrigeration, etc) and unless you want to look like a floating solar panel store the power you generate has to go to this instead of the propulsion system.
No, until battery technology reaches the point when you can continually drain your batteries below 50% charge (way below) and recharge them quickly it's a no go in my opinion. At this stage electric propulsion for everyman is in the Model T era (if that advanced) and most of us are going to stick to our horses until it makes a leap or two in technology.

ps
Our friend SolidNav gave the link to his facts page in one of his first posts and everybody seems to have missed a fairly critical point about his numbers. His range figures are all hours to 80% depth of discharge for the batteries in his example. While it makes the numbers look better the batteries aren't long for this world with that kind of use. see below.
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  #168  
Old 12-12-2009
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Hi Mitiempo,

I'm not going to read through all the posts but I thought at some point I posted my real-life performance in this thread.

I have motored for seven hours at 4 knots and did not use half of my battery reserve, SolidNav Explorer with 200 amp hours in two banks.

It is a lot of batteries (8) but the boat (Ericson 27) doesn't seem to mind.

If you moor your boat you would have to get creative with charging. Around here Monterey Bay/San Francisco Bay the vast majority of boats are in a slip with shore power.

It's a shame that people with no hands on experience with a new technology will dismiss it as inferior. My electric motor suits me fine and is superior in every way from previous motor.

It sounds like electric propulsion isn't for you but I'm guessing it is a viable (superior) option for 80% of the sailboat public.
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Old 12-12-2009
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Mark
I too tie to a dock with shorepower (the one in my avatar), but in B.C. the normal summer holiday for many is to cruise up the coast to Desolation Sound which is one of the largest pristine marine parks in the world - no docks, so no shorepower and many other B.C. cruising areas are also barren of ac power. Sometimes you might tie up to a log boom in a bay but mostly anchor for the night. This is what makes it a great cruising area and if you're more adventurous and have more than 2 weeks you can go farther north where there is even less civilization. While in a 2 week trip I guess you could tie to a dock every night if you planned it carefully most don't want to. When I think of the times I have tied to docks over the years it has often been rafted on the outside of a fishing boat with few amenities. So no. it wouldn't work for me or a lot of the people in this area. And we wouldn't want it any other way. At the risk of making it even more popular I'll post a couple of pics.

I have a few questions for you though. How deep do you discharge your batteries? Do you have a battery monitor to see state of charge? What is your top speed? How large are the battery banks? What propeller are you using? What was the cost all in for the change to electric? What was the engine on your boat before the change?

ps Your profile shows you have a 1969 Ericson 23
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  #170  
Old 12-12-2009
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I spent way too many hours last evening reading this thread, looking for information and to answer my questions concerning the prospects of electric for my boat, a Bristol Corsair. Outside of adulation for Giu's incredible boat, I came away with the distinct impression that the technology isn't quite 'there' yet for most applications.
My boat uses an outboard configuration (in a well), and I did note that there was a report of success using a trolling motor in an application similar to mine. So I'm debating going down that road. There is a saltwater fishing boat application called a "trim and troll" that uses twin motors that seems like a good prospect. For my application, the saltwater electric trolling motors by Torquedo and Minnkota seem like a decent enough choice, and with only a few exceptional instances, I don't intend to 'need' to motor for any distance, and solar panels should recharge my bank until the next time out. I can scull pretty well, but I don't know about sculling my little tub effectively. It's certainly not set up for rowing.
And when it comes time to navigate the Cape Cod Canal or the ICW, then all bets are off.
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