Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 24-08-2010, 09:15   #31
Registered User
 
mbianka's Avatar

Join Date: Mar 2008
Posts: 2,125
Images: 1
Pelagic:

Interesting ship. Especially love the waterfall option. Thanks for the link. I just love it when companies in the oil rich mideast start being concerned about fuel efficency and start using electric propulsion in their mega yachts.

Capt. Mike
THE BIANKA LOG BLOG
__________________

__________________
Capt. Mike
mbianka is offline   Reply With Quote
Old 24-08-2010, 09:36   #32
Registered User

Join Date: Jul 2010
Location: Austin, TX
Boat: Hobie, Wave Cat 16ft - "Bum Soaked"
Posts: 10
Images: 1
Quote:
Originally Posted by Curmudgeon View Post
Because the electric motors available today do not have nearly the range of a diesel.
Why is the range of today’s electric motors a problem? How often do you really need extended use of your motor as a cruiser if you also have solar and wind power generation capabilities? Basically, I’m thinking the motors are really needed for canal passage, traversing up rivers and safe maneuvering in/out of port, right?

So why isn't an electric motor sufficient? It may require more planning but it seems sufficient to me. You’ll just pretty much be under sail most places you go except where impossible or unadvisable
__________________

__________________
maisis00 is offline   Reply With Quote
Old 24-08-2010, 09:46   #33
Registered User

Join Date: Jul 2008
Location: Boston, MA
Boat: Bristol 38.8
Posts: 1,625
Suppose you are dismasted, or your mainsail blows out? Suppose the nearest safe haven from a storm is dead to windward? Suppose you have to go backwards, such as to get off a shoal after you have run aground? I can back the mainsail and sail backwards in a dinghy, but I'd hesitate to try it with a 40 fooot cruising boat.
__________________
Curmudgeon is offline   Reply With Quote
Old 24-08-2010, 09:51   #34
Registered User

Join Date: Jul 2010
Location: Austin, TX
Boat: Hobie, Wave Cat 16ft - "Bum Soaked"
Posts: 10
Images: 1
Quote:
Originally Posted by Curmudgeon View Post
Suppose you are dismasted, or your mainsail blows out? Suppose the nearest safe haven from a storm is dead to windward? Suppose you have to go backwards, such as to get off a shoal after you have run aground? I can back the mainsail and sail backwards in a dinghy, but I'd hesitate to try it with a 40 fooot cruising boat.
Alright, alright... if your going to be all logical and try to use reasonable arguments on me then fine. I'll just shut up and eat my popcorn.
__________________
maisis00 is offline   Reply With Quote
Old 24-08-2010, 09:52   #35
Registered User
 
mbianka's Avatar

Join Date: Mar 2008
Posts: 2,125
Images: 1
Quote:
Originally Posted by Curmudgeon View Post
A diesel with plenty of tankage is not just a convenience issue, it's a safety issue.
Huh? I carry less fuel now than when I had a diesel because as So it Goes pointed out the Honda generator needs less fuel to operate and don't need as much for a safety range. As far as tankage being a safety issue with diesel. Well yes. More diesel fuel in storage means more chance of it going bad and preventing the diesel engine from starting when you need it most. Back in the Diesel days I was coming into Boston Harbor for the first time at sundown when my engine sputtered and died. I restarted and it ran for a few minutes and died again. Then I could not get it started. Luckily, I had recently dropped the sail and was able to raise it quickly and sailed up to a mooring in Portugese Cove. The fuel filter had clogged even though I changed it religiously at the begining of every season. If the same thing had happened with my Honda generator my battery bank would have taken over and I would not have had to scramble to get the sail up. It's one of the nice things about being able to operate with a Honda generator in an electric propulsion hybrid operation is that there is an automatic redundency.
__________________
Capt. Mike
mbianka is offline   Reply With Quote
Old 24-08-2010, 10:01   #36
Senior Cruiser
 
Sailmonkey's Avatar

Cruisers Forum Supporter

Join Date: Sep 2009
Location: Houston
Boat: '76 Allied Seawind II, 32'
Posts: 5,772
Quote:
Originally Posted by Curmudgeon View Post
Suppose you are dismasted, or your mainsail blows out? .
Jury rig or headsail hoisted in place of main

Quote:
Originally Posted by Curmudgeon View Post
Suppose the nearest safe haven from a storm is dead to windward? .
Ummmm........tack
There are well known cruisers who sail without engines, and even non-stop circumnavigators who removed the engines to go around.

Quote:
Originally Posted by Curmudgeon View Post
Suppose you have to go backwards, such as to get off a shoal after you have run aground? I can back the mainsail and sail backwards in a dinghy, but I'd hesitate to try it with a 40 fooot cruising boat.
The electrics will go backwards better than a diesel running through a reversing gear.........and have more power available since there's no reduction loss.
__________________
Sailmonkey is offline   Reply With Quote
Old 24-08-2010, 10:02   #37
Registered User
 
fishwife's Avatar

Join Date: Aug 2009
Location: South coast of England, moving around a bit.
Boat: Long range motor cruiser
Posts: 750
A question, am I wrong in thinking that there is a minimum speed on the Panama Canal?

P.
__________________
The message is the journey, we are sure the answer lies in the destination. But in reality, there is no station, no place to arrive at once and for all. The joy of life is the trip, and the station is a dream that constantly out distances us”. Robert Hastings, The Station
fishwife is offline   Reply With Quote
Old 24-08-2010, 10:17   #38
Registered User

Join Date: May 2010
Location: Where the boat is (currently Caribbean)
Boat: CA 34
Posts: 30
Minimum speed for a Panama Canal transit is 4 knots
__________________
Bob
http://boatbits.blogspot.com/
SoItGoes is offline   Reply With Quote
Old 24-08-2010, 10:31   #39
Registered User
 
mbianka's Avatar

Join Date: Mar 2008
Posts: 2,125
Images: 1
Quote:
Originally Posted by Curmudgeon View Post
Suppose you are dismasted, or your mainsail blows out? Suppose the nearest safe haven from a storm is dead to windward? Suppose you have to go backwards, such as to get off a shoal after you have run aground? I can back the mainsail and sail backwards in a dinghy, but I'd hesitate to try it with a 40 fooot cruising boat.
Crumudge:
That's a lot of 'what ifs". What if the bugs if your diesel fuel tank get stirred up and clog your fuel filter. Have fun changing the filter down below in pitching seas. What if your starter motor/connection fails? What if your fuel pump fails. What if one of you hoses fails? What if your raw water intake gets clogged? Got more "what ifs" if you want.
Not sure where you get the idea that an electric boat can not get you off a shoal, motor into the wind or move in reverse. I assure you it can. But, going electric does not allow one to stop being a "prudent mariner" either. Just like one should not think that their diesel engine will always be avalible and trouble free when needed. Guess how I know?
__________________
Capt. Mike
mbianka is offline   Reply With Quote
Old 24-08-2010, 10:34   #40
Registered User
 
Astrid's Avatar

Join Date: Oct 2008
Location: Northern British Columbia, part of the time in Prince Rupert and part of the time on Moresby Island.
Boat: 50-ft steel Ketch
Posts: 1,885
Send a message via MSN to Astrid Send a message via Yahoo to Astrid
Personally, I think it is marvelous idea, Mike. I haven't seen your figures for the Honda's electrical out put compared to the electrical motor's requirements at various speeds, but if out put at least equals or exceeds your total electrical needs, and given that you will be under sail most of the time, I really don't see a problem. I realize you dislike diesel for various reasons, but the only thing I would prefer would be a small diesel genset simply for the sake of keeping petrol off my boat. As long as you have adequate forced ventilation, though, it would be reasonably safe.
__________________
'Tis evening on the moorland free,The starlit wave is still: Home is the sailor from the sea, The hunter from the hill.
Astrid is offline   Reply With Quote
Old 24-08-2010, 10:44   #41
Registered User

Join Date: Oct 2005
Posts: 341
Send a message via Skype™ to gosstyla
Quote:
Originally Posted by SoItGoes View Post
Minimum speed for a Panama Canal transit is 4 knots
I believe Noonsite's statement is more accurate:
"The optimum minimum speed to transit the Canal, is 8 knots. The Canal Authority may deny transit if a handline vessel (i.e. a yacht) cannot maintain a minimum speed of 5 knots. However, a vessel may be towed through the Canal by another handline vessel if it can tow her at 5 or more knots, or make arrangements to be towed, at their own expense, by a Panama Canal Authority launch."

Going North if can't make the transit in one day you will be charged extra for delay of transit.
__________________
gosstyla is offline   Reply With Quote
Old 24-08-2010, 11:38   #42
Registered User
 
capn_billl's Avatar

Join Date: Aug 2010
Location: Houston,Tx
Boat: Maxum 37'
Posts: 1,587
Right now an electric system can be designed so efficiency is at least even with a straight diesel. The efficiency gain you get from running the electric motor straight to the prop offsets the efficiency loss from the double conversion of power. Add the gains from being able to add electricity cheaply when at port and you get a net gain. I have converted a car to electric and have first hand experience on the pros and cons. I have worked out a design for electric boat I am just waiting for the right hull to become available. (I bought a 28' with no engine and was purchasing the parts for the conversion when Ike came through, as the boat had no power I was unable to move it and it ended up in the freeway,...in pieces). Range is a problem, you can go far, or fast, but not both. A pure hybrid system is scalable to about 45' under that the room for a backup engine plus batteries make things tight. The systems I looked at give a net efficiency gain comparable to hybrid cars, plus several hours of silent operation on electric alone. If you have never driven a pure electric vehicle try it, (it's scary quiet). Instant power no hesitation like IC engines, flat power curve. Smaller boats can use a modified system with some compromises. I had worked out a 15KW system with a 8KW generator and 2KW Solar, daytime operation I calculated would be 3-4kts for 6-7 hours with full pack and full sun. Up to 8 kts with generator. For a sailboat that only needed engine for docking, electric makes perfect sense.
__________________
capn_billl is offline   Reply With Quote
Old 24-08-2010, 12:28   #43
Registered User

Join Date: Apr 2007
Location: Centreville, VA
Boat: Lagoon 410 ELECTRIC!
Posts: 361
There are a couple of places you can improve efficiency and therefore fuel consumption.

First of all, an electric motor can be directly coupled to the propeller shaft, eliminating drive train friction.
My System Solomons Drives (2) with a cruising range of 3 hours at 5 knots. Then Sail and regen from the props.
A generator can run the engine at the speed that represents the best fuel economy for power generated. By contrast a normal marine engine has to run over a wide range of RPMs and will not always be used at the most fuel efficiency speed.
Exactly! I have a 16 KW genset with 120 gal of diesel. I just filled the tanks up after 18 months, using the boat on weekends (approx. 15). A sister cat just did Florida to Mass. mostly ICW over the last couple of months with a family of 4.

You can run a much much more efficient propeller. I have read that up to 50% of your engine power is actually turned to thrust. The rest is lost.
Generally a larger, slower spinning propeller is more efficient. A normal engine only develops usable power over a certain range of RPMs.

I have 2 18" props.
An electric motor runs at a lower RPM and can use a more efficient prop. It can also provide full and efficient power over the full RPM range of the motor.

Nothing beats leaving the gas dock on Saturday and the attendant saying (note not yelling) "that's the coolest thing NO NOISE!" Not fully true, the damn noisy cooling fan is the only way I can tell if the motors are switched on!

We've done overnighters and run 2 days with sail and battery power, no genset. I can run as long as a diesel using the genset. I've returned to the dock with the batteries fully charged from the props only. You have to be aware of the usage but I think we all are when it comes to power wasted on a boat. IF I get in trouble and need extended power I can start the genset and run the tanks dry. It's not perfect and I've still got a lot to learn but I'm perfectly happy with a Hybrid.

Steve in Solomons MD
__________________
Hyprdrv is offline   Reply With Quote
Old 24-08-2010, 13:00   #44
Registered User
 
Astrid's Avatar

Join Date: Oct 2008
Location: Northern British Columbia, part of the time in Prince Rupert and part of the time on Moresby Island.
Boat: 50-ft steel Ketch
Posts: 1,885
Send a message via MSN to Astrid Send a message via Yahoo to Astrid
Steve, how long does it take to recharge batteries under sail and using the props to recharge as they turn on their own. And as something of a probably academic question, since you have two motors, is it feasible to cruise on one motor while letting the other motor 'windmill' as you move forward and thereby produce current (I do realize the output is probably not equal to what the on line motor is using)?
__________________
'Tis evening on the moorland free,The starlit wave is still: Home is the sailor from the sea, The hunter from the hill.
Astrid is offline   Reply With Quote
Old 24-08-2010, 13:09   #45
Registered User

Join Date: Apr 2007
Location: Centreville, VA
Boat: Lagoon 410 ELECTRIC!
Posts: 361
Astrid,
The recharge rate is dependent on a lot of factors and probably imposable to answer without a set of conditions like how fast your going along with the usage rate, how many amps you burning. I can tell you that the first 410 that came across the Atlantic had an issue with overcharging.

Electric drive for Lagoon catamarans

First Electric Lagoon Crosses Atlantic to Annapolis...Then Heads to Tortola

As for the second part the answer is Yes.

Steve in Solomons MD
__________________

__________________
Hyprdrv is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Electric or Diesel, That is the question Hyprdrv Electrical: Batteries, Generators & Solar 9 02-03-2009 12:38
Electric Diesel bleed pump advice... Christian Van H Engines and Propulsion Systems 18 09-12-2008 05:32
Electric and Diesel comparison Whimsical Multihull Sailboats 90 04-08-2008 16:38
diesel/electric hybrid sailorboy1 Electrical: Batteries, Generators & Solar 91 18-06-2008 19:03
420: Lagoon Diesel-Electric Problems PeterL Lagoon Catamarans 13 12-06-2007 07:28



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 20:09.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.