|
PDQ 39' sailing catamaran FOR SALE
|
PDQ 39' sailing catamaran FOR SALE
On Mon, 06 Jul 2009 23:11:05 -0400, Wayne.B
wrote: On Sun, 05 Jul 2009 09:07:00 -0400, wrote: Most of Wayne's arguments center around his personal need to isolate himself from his surroundings. That is an assumption that does not wash. One of our favorite cruising activities is to go out in the dinghy, explore the boondocks, go into town, meet the locals, try their food, see the sights, etc. For most people, including us, that's what cruising is all about. *All* of my arguments center around what I consider to be necessary for reasonable comfort and safety on an extended cruise - one where supplies are not located on every corner, and a high degree of reliability and self sufficiency are very desirable. Of course everyone has different ideas about what that means, and there are always budget constraints for everyone - that's why I don't have a fully crewed mega yacht capable of crossing oceans in style. :-) This all started of course when I expressed the opinion that ouboard propulsion is not a very good option for long range cruising. No offense intended toward anyone, I just happen to think it's true for a number of good reasons and some personal experiences. Some interesting discussion points were brought out in any case. It might be interesting to start another thread on what people consider to be essential or highly desirable on cruising boats, perhaps broken out by three or more size ranges: Under 30 feet; 30 to 40; 40 and up, for example. I'd suggest that we should consider what it would take for your wife to agree to a 3 month cruise on the boat. :-) My wife has already set the ground rules for that day, which will come. She wants an Island Packet 370. She prefers it to the bigger models. Until we are BOTH ready to actually stop working, we have no need of that boat, and she loves our present boat for what we do now. For you guys who aren't married, you'll just have to use your imagination. Some possible discussion items: - Type of dinghy, dinghy power, dinghy storage. Portabote, oars, sails and 3.5 outboard. Folds up and gets lashed to the lifelines lke a surfboard. When we get a bigger boat, I'll probably get the next size up Portaboat from what we have now. I have had enough RIBs to know I never want another one. - Water tankage and/or water maker?. Watermaker? Your list is already getting funny. Do you also grow all your own food? - Pressure water?, hot water?, shower?, number and type of heads. - Number and type of anchors, length/type of rode, windlass?, etc - Galley equipment, stove type, refrigeration type, microwave?, blender?, toaster?, freezer? - Safety equipment, liferaft?, EPIRB?, SSB radio?, Sat Phone? - Aux power, none?, outboard?, inboard gas?, inboard diesel?, tankage/range?, fuel filtration and polishing?, oil change system? - Electrical system, none?, basic 12 volt?, house bank/size?, recharging capability?, inverter/type/size/switching?, generator type/size/switching? - Self steering?, autopilot?, wind vane? - Electronics, GPS plotter/features, radar/features, depth sounder, AIS?, DSC VHF?, handhelds?, entertainment systems?, etc. and so on.... Actually, I look forward to reading whatever this generates. Thanks for keeping the conversation going, Wayne. |
PDQ 39' sailing catamaran FOR SALE
On Mon, 06 Jul 2009 23:11:05 -0400, Wayne.B
wrote: On Sun, 05 Jul 2009 09:07:00 -0400, wrote: Most of Wayne's arguments center around his personal need to isolate himself from his surroundings. That is an assumption that does not wash. One of our favorite cruising activities is to go out in the dinghy, explore the boondocks, go into town, meet the locals, try their food, see the sights, etc. For most people, including us, that's what cruising is all about. *All* of my arguments center around what I consider to be necessary for reasonable comfort and safety on an extended cruise - one where supplies are not located on every corner, and a high degree of reliability and self sufficiency are very desirable. Of course everyone has different ideas about what that means, and there are always budget constraints for everyone - that's why I don't have a fully crewed mega yacht capable of crossing oceans in style. :-) This all started of course when I expressed the opinion that ouboard propulsion is not a very good option for long range cruising. No offense intended toward anyone, I just happen to think it's true for a number of good reasons and some personal experiences. Some interesting discussion points were brought out in any case. It might be interesting to start another thread on what people consider to be essential or highly desirable on cruising boats, perhaps broken out by three or more size ranges: Under 30 feet; 30 to 40; 40 and up, for example. I'd suggest that we should consider what it would take for your wife to agree to a 3 month cruise on the boat. :-) For you guys who aren't married, you'll just have to use your imagination. Some possible discussion items: - Type of dinghy, dinghy power, dinghy storage. - Water tankage and/or water maker?. - Pressure water?, hot water?, shower?, number and type of heads. - Number and type of anchors, length/type of rode, windlass?, etc - Galley equipment, stove type, refrigeration type, microwave?, blender?, toaster?, freezer? - Safety equipment, liferaft?, EPIRB?, SSB radio?, Sat Phone? - Aux power, none?, outboard?, inboard gas?, inboard diesel?, tankage/range?, fuel filtration and polishing?, oil change system? - Electrical system, none?, basic 12 volt?, house bank/size?, recharging capability?, inverter/type/size/switching?, generator type/size/switching? - Self steering?, autopilot?, wind vane? - Electronics, GPS plotter/features, radar/features, depth sounder, AIS?, DSC VHF?, handhelds?, entertainment systems?, etc. and so on.... I suggest a criteria for the type of cruising. Maybe, day sailing up the coast where one stops every evening and spares and supplies are available. Travel to foreign or remote areas where you are pretty much on your own for several weeks at a time. I find storage as being the most important factor in determining boat size. If "provisions" consists of a loaf of bread and a bottle of jelly for tomorrow's breakfast and peanut butter and saltine crackers for lunch because we will stop at "hole in the wall" where they have that darling little restaurant for supper, it is one thing. If you aren't going to see land for three weeks it is quite another. Boat size, depending on use but for a couple my opinion is 35 ft. minimum and 40 ft. makes a more pleasant living space. Fridge - Damned nice if you are cruising in tropical areas. On the other hand I would be reluctant to depend on it for long trips as a failure could be life threatening. Water maker - Allows you to sail a lighter boat but failure could be life threatening. Probably a good idea for long distance but should be combined with a sensible fresh water management system. In any event you want fairly large water tanks to allow a water management system to function. Water system - for long distance cruising a manual pump system. If you can build a automatic pressure system for marina use and a manual pump for off shore you have the best of two worlds. Stove - LPG. You can get it anywhere, a couple of 9 Kg. tanks lasts for months. It is easy to light and it cooks good. Microwave, etc. For marina use only. Autopilot/wind vane steering - YES! A must have item. the vane steering works only under sail and the Autopilot works both under power and sail. I see more and more people using autopilots but I'd prefer both as many autopilots use too much power for reliable use in long sailing passages. Battery bank - House and start batteries that are separate. Size depends on use. Auxiliary power - Diesel inboard! Shaft drive with no sail drive or Vee or Zee drives. I suggest a Baja Filter. I don't have one but I normally refuel from jerry cans and let them settle before transferring to the tanks. Fuel Polishing - I consider a system to "polish" the fuel probably unreliable however a system to cycle the fuel through a water catcher is not a bad idea. I have gotten water from both shore tanks and fuel barges. Fuel tankage - A minimum of several days steaming. If you undertake a circumnavigation it is likely you will, sooner or later, encounter extended periods with either adverse wind or no wind. Communication - VHF for inshore and a Amateur Band SSB with a modem to be able to use SailMail during cruises. More and more Cell Phone is used to communicate with marina's so a multi band phone with a system for the areas you are visiting is nice. EPIRB is probably a must although in much of Asia it is going to be several days before anyone goes looking for you. Dinghy - Probably the most useful dinghy is an inflatable however if cruising in tropical climates it should be Hypalon as other material fails quickly in tropical sun light. A dinghy cover is also a good idea. With the usual inflatable a 5 HP engine is useful. Finally; lets change the subject name if this thread is going to continue. Cheers, Bruce (bruceinbangkokatgmaildotcom) |
PDQ 39' sailing catamaran FOR SALE
|
PDQ 39' sailing catamaran FOR SALE
On Mon, 06 Jul 2009 23:11:05 -0400, Wayne.B
wrote: Some possible discussion items: First, let me state that MY WAY is the RIGHT and ONLY WAY... For me. YOUR WAY is the RIGHT and ONLY WAY.... For you. Of course MY WAY and YOUR WAY have to be almost endlessly modified for an almost endless number of reasons: Money, ability, your/my boat setup and capacities, etc., etc., etc. For a bit over 2 years we are a live-aboard, full timer cruiser couple. The boat is a Pearson Rhodes 41. Not a real roomy 41, she's long and lean and FAST. I've lived-aboard and/or extended cruised off and on for a total of about 8 years. Having said all that.... - Type of dinghy, dinghy power, dinghy storage. I much prefer a hard dinghy. We have a Sandpiper 8. Power is usually a small trolling motor or oars. I just got a 2 HP outboard and will use it for those longer and hurrier trips. Most of the time it's rowed, except for those places we have to anchor more than about a tenth of a mile out. When not used it's on davits. I tried a Porta-Boat and found it much more trouble than it was worth. I wound up giving it away. I've had inflatables and my only grip is they really don't row too well and can be pretty wet in a chop. We're thinking of getting a WaterTender 9.4. I tried one out and it has the stability and room of an inflatable, but rows well. - Water tankage and/or water maker? 70 gallons in 2 tanks. That's what the boat came with and there's really no way to add more. PUR 80E 3.4 GPH watermaker. I wouldn't even consider not having one. Our cruising is extended stays in out of the way places. I would not have one if we took occasional weeks or months cruises. - Pressure water?, hot water?, shower?, number and type of heads. Yes for pressure water, hot water and shower-for-two. We have a manual pump in the galley but it doesn't work. One can conserve with pressure water. If you can't bring yourself to do it, buy a "water saver" for each faucet. It screws on in place of the aerator and has a little rod. You leave the faucet on and when you move the rod water comes out. We also have a pressure raw water system plumbed to separate faucets. One head with a Jabsco toilet going to a Lectra/San. A lot of folks, including the Princess of Poop, Peggie Hall, bad mouths the Jabscos, but it's been used ever day for 2 years and another like it was used every day for 3 years. Never had a problem nor had to rebuild. - Number and type of anchors, length/type of rode, windlass?, etc 4 anchors: 45 lb Bruce, 45 lb CQR, 35 lb (I think) Danforth and same size aluminum Danforth (I think it's 11 lb). The Bruce is the main one. I swear that thing has a "bottom magnet". We use a dedicated GPS as an anchor alarm and the Bruce has never dragged. Note too that the aluminum Danforth sets faster and holds better than the "iron" one. I don't know why and I suppose it doesn't make sense, but that's the way it is. Main anchor rode is 130 ft of chain plus 250 ft. 3/4" line. Secondary is 40 ft. chain plus 250 ft of 3/4" line. Simpson Laurence 2-speed manual windless. The gypsy will take any size chain. In fact the main rode is 30 ft. of 5/16 chain coupled to 100 ft of 3/8 chain. I think that's the sizes. - Galley equipment, stove type, refrigeration type, microwave?, blender?, toaster?, freezer? 4 burner w/ oven gimbled propane stove, Norcold 110/12 Volt icebox conversion in re-insulated built in icebox. I would NOT recommend the Norcold. It doesn't come close to the Adler/Barber I had before. 1,000 Watt compact mirowave, toaster, 110V Haier 1.3 cu. ft. freezer with decicated inverter. - Safety equipment, liferaft?, EPIRB?, SSB radio?, Sat Phone? Spot, Ham/SSB radio with modem. - Aux power, none?, outboard?, inboard gas?, inboard diesel?, tankage/range?, fuel filtration and polishing?, oil change system? Perkins 4-107 inboard diesel. 40 gallon tank, again that's what the boat came with and no place to add tankage. We usually carry 20 gallons in jerry cans on deck (I HATE that!). Range is 300 nautical miles at 6.3 kts to 480 nautical miles at 5 kts, including the jerry cans. Standard Racor and inline filters. No polishing system. Oil change is locking ball valve on oil pan with hose to drop in gallon jug. To address the ongoing war about diesel inboard vs. outboard: I think either are fine. An outboard will burn more fuel, but is a lot cheaper to buy and/or replace. It would take a lot of running to make up the difference. Some, maybe most, boats would have the problem of the prop coming out of the water in rough conditions. A longer shaft should take care of most of this. An old outboard dealer told me one can just order shaft and foot extensions and put as many together as needed, so a 4 or 5 or 6 or even 10 foot shaft is not unreasonable. I had a Morgan 27 with an Atomic 4 inboard. The clutch developed a problem. I had a 15 HP outboard so fabricated a mount for it. To my surprise the outboard reached hull speed at about half throttle and burned the same amount of fuel per hours as the Atomic 4. I eventually repaired the clutch, but kept the outboard handy in case. I had decided to sell the boat, but before that decision I thought seriously about removing the Atomic 4 and going with the outboard. I would consider a 4-cycle outboard if the Perkins died, but we have too much overhang, plus the dinghy/davits would have to go. Here goes another discussion maybe... If the Perkins dies, I plan on replacing it with a DC electric motor and diesel generator. The motor would probably mostly be run from the house bank for short periods and calmer conditions. - Electrical system, none?, basic 12 volt?, house bank/size?, recharging capability?, inverter/type/size/switching?, generator type/size/switching? House bank: 4 golf cart batteris plus 1 deep cycle marine (this was my trolling motor battery I replaced with a smaller one). 500 Amp Hour total. I'd like to add 2 more golf cart batteries, but the problem is room. Engine bank is 2 group 24 marine starting in parallel, with a 10 W solar trickle panel. Recharging: 600 Watts of solar panels with a Blue Sky MPPT controller; Air Marine 450 Watt wind generator; 100 Amp Baldor alternator on engine; Freedom 10 50 Amp charger/ 1,000 Watt inverter. Inverters: Vector 2,500 Watt, 750 Watt, 450 Watt. The 450 is used for the flat screen TV and DVD recorder. The 750 is dedicated to the freezer. The 2,500 is used for the microwave and coffee pot. Note that the coffee pot takes 70 Amps from the battery, but only takes 5 minutes for a total of 6 Amp Hours. Generator: 3.5 KW gasoline on cabin top. Yeah, I know. I hate the thing and always refused to have one. But I bought it last summer so we could run the marine A/C for my wife. And me too, I have to admit. It was HOT and this summer seems to be the same. At least it's pretty quiet. Halfway thinking about getting a Next Gen diesel... - Self steering?, autopilot?, wind vane? Raymarine S1 Wheel Pilot with an old Simrad wheel pilot for a spare. Wouldn't be without one! I do like the idea of a wind vane, but I'd prefer to have my dinghy on davits. - Electronics, GPS plotter/features, radar/features, depth sounder, AIS?, DSC VHF?, handhelds?, entertainment systems?, etc. 2 Garmin GPS color plotter/sounders, 1 old B&W Garmin chartplotter for anchor drag alarm, wired to LOUD piezo buzzer, Garmin handheld GPS, Garmin StreetPilot GPS (which works with nautical charts), Navetec GPS sleeve for one of the Compaq IPaq pocket computers, Delorme serial output GPS. 4 laptop computers, 3 Compaq/HP pocket computers, all with Nav software. DSC VHF down below, VHF at steering station, handheld VHF. SPOT Satellite Messenger. 19" flat HD TV, antenna on mizzen, DVD recorder with digital conveter, auto type AM/FM radio with 5 CD changer. Would like to have AIS, at least receive only, but too durn expen$ive!! and so on.... OGM LED Tricolor/Anchor light and mostly LED interior lights. No one should criticize another for his/her choices. We're all different. I've cruised aboard different sized and equipped sailboats over the last 47 years, and a few powerboats. My first was a 16 ft Petral with a gasoline camp stove and D-cell running, anchor and interior lights. The engine was an old 5 HP outboard. I was 16 at the time and it was a most pleasurable few months. Could I do it now at age 63? Certainly! Would I? No, I don't think so. Rick |
PDQ 39' sailing catamaran FOR SALE
I'm curious about the S1. Raymarine says it is rated to 16,500 lbs but
I would guess the Rhodes 41 loaded probably exceeds that by a bit. So how much time/miles do you have on it and how is the performance in the slop? Thanks G - Self steering?, autopilot?, wind vane? Raymarine S1 Wheel Pilot with an old Simrad wheel pilot for a spare. Wouldn't be without one! I do like the idea of a wind vane, but I'd prefer to have my dinghy on davits. |
PDQ 39' sailing catamaran FOR SALE
On Tue, 07 Jul 2009 12:36:06 -0700, Gordon wrote:
I'm curious about the S1. Raymarine says it is rated to 16,500 lbs but I would guess the Rhodes 41 loaded probably exceeds that by a bit. So how much time/miles do you have on it and how is the performance in the slop? Thanks G By quite a bit, displacement is 24,000 lbs. I really don't understand that displacement rating. I always go with if a human can steer it, an autopilot can. I had a 4000+ on a Coranado 35 and it steered over 12,000 nautical miles with no problems, including 15 ft folowing seas. A friend put one on his 40,000 lb trawler and it worked fine. Only a couple thousand miles on the Rhodes, but it's done fine on all points of sail and under power. Twice the S1 turned off with a "locked" error. Both times under power while pushing through mud. Under those conditions it's all I can do to budge the wheel with both hands. Rick |
PDQ 39' sailing catamaran FOR SALE
On Tue, 07 Jul 2009 13:02:30 -0500, Rick Morel
wrote: For a bit over 2 years we are a live-aboard, full timer cruiser couple. The boat is a Pearson Rhodes 41. Not a real roomy 41, she's long and lean and FAST. Classic good old boat ! Looks like you've got it nicely equipped also. I just realized today that you are also a member of the "Liveaboard List". I've been on there a long time but mostly lurk. We have met some of the other denizens at various times however including the famous "Norm and Jan" duo from Bandersnatch. |
PDQ 39' sailing catamaran FOR SALE
On Tue, 07 Jul 2009 12:05:08 -0400, wrote:
On Tue, 07 Jul 2009 11:47:51 -0400, Wayne.B wrote: On Tue, 07 Jul 2009 06:40:29 -0400, wrote: Watermaker? Your list is already getting funny. Do you also grow all your own food? No, but there are many places in the world where good potable water is impossible to obtain at any price. You cruise in the Sahara desert? LOL Most marinas in the Bahamas, a very real cruising destination for us North American types, are already charging 50 cents a gallon for dock water, and the price keeps going up. For people making long passages, water capacity is always an issue, and it's really nice to get one or two good showers a day without worrying about draining the tank. You'd probably be surprised at the number of long range cruisers who are already equipped with water makers for exactly these reasons. There are other ways to supplement fresh water without adding the expense and problems of a high maintenence watermaker. I'm not surprised by the number of cruisers who think they can't live without a watermaker and hot showers. For fully half the year in the monsoon areas there is little or no rain. You replenish water supplies by either going ashore and toting it back to the boat or a watermaker :-) Cheers, Bruce (bruceinbangkokatgmaildotcom) |
PDQ 39' sailing catamaran FOR SALE
Wayne.B wrote:
You and your wife can cruise without showers if you want but not with us. :-) How much water does it take to shower you, Wayne? We are doing ot on 1.5 Gallons for the both of us and having fun doing it (!). |
PDQ 39' sailing catamaran FOR SALE
Rick Morel wrote:
No one should criticize another for his/her choices. We're all different. I've cruised aboard different sized and equipped sailboats over the last 47 years, and a few powerboats. My first was a 16 ft Petral with a gasoline camp stove and D-cell running, anchor and interior lights. The engine was an old 5 HP outboard. I was 16 at the time and it was a most pleasurable few months. Could I do it now at age 63? Certainly! Would I? No, I don't think so. Rick That was a breath of fresh air. Thanks Rick. Post more - please! Richard |
PDQ 39' sailing catamaran FOR SALE
On Tue, 07 Jul 2009 21:56:49 -0500, cavelamb
wrote: Wayne.B wrote: You and your wife can cruise without showers if you want but not with us. :-) How much water does it take to shower you, Wayne? Don't know but more than it used to. We are doing ot on 1.5 Gallons for the both of us and having fun doing it (!). Yes, I can remember the old sun shower on a halyard days. I thought they held more like 2 gallons though. We used to cheat and heat ours up with water from the tea kettle, faster that way. Those days are over, now it's a 20 gallon electric heater. You need that with a washer/dryer on board and 2 heads. :-) |
PDQ 39' sailing catamaran FOR SALE
On Tue, 07 Jul 2009 20:07:21 -0400, Wayne.B
wrote: Classic good old boat ! Looks like you've got it nicely equipped also. I just realized today that you are also a member of the "Liveaboard List". I've been on there a long time but mostly lurk. We have met some of the other denizens at various times however including the famous "Norm and Jan" duo from Bandersnatch. Thanks Wayne. Yes, I've been on the Liveaboard List a long time. I used to post quite a lot but not too much now. Norm and I have gone round and round in the past, but we mostly agree :-) I was thinking you were familiar. Rick |
PDQ 39' sailing catamaran FOR SALE
On Wed, 08 Jul 2009 07:45:39 +0700, Bruce In Bangkok
wrote: On Tue, 07 Jul 2009 12:05:08 -0400, wrote: On Tue, 07 Jul 2009 11:47:51 -0400, Wayne.B wrote: On Tue, 07 Jul 2009 06:40:29 -0400, wrote: Watermaker? Your list is already getting funny. Do you also grow all your own food? No, but there are many places in the world where good potable water is impossible to obtain at any price. You cruise in the Sahara desert? LOL Most marinas in the Bahamas, a very real cruising destination for us North American types, are already charging 50 cents a gallon for dock water, and the price keeps going up. For people making long passages, water capacity is always an issue, and it's really nice to get one or two good showers a day without worrying about draining the tank. You'd probably be surprised at the number of long range cruisers who are already equipped with water makers for exactly these reasons. There are other ways to supplement fresh water without adding the expense and problems of a high maintenence watermaker. I'm not surprised by the number of cruisers who think they can't live without a watermaker and hot showers. For fully half the year in the monsoon areas there is little or no rain. You replenish water supplies by either going ashore and toting it back to the boat or a watermaker :-) A cruiser with half a brain would take the hint and go elsewhere. I realize you don't have that option and must do without water for 6 months at a time. Surely you don't walk down the dock and go ASHORE to get water! What watermaker do you have on board? How often does it require maintenance? How much water does it provide daily? What powers it? Oh... you don't need rain to collect water. Probably not enough to take long showers, but enough to support life. |
PDQ 39' sailing catamaran FOR SALE
|
PDQ 39' sailing catamaran FOR SALE
On Tue, 07 Jul 2009 13:02:30 -0500, Rick Morel
wrote: On Mon, 06 Jul 2009 23:11:05 -0400, Wayne.B wrote: Much snipped I would consider a 4-cycle outboard if the Perkins died, but we have too much overhang, plus the dinghy/davits would have to go. Here goes another discussion maybe... If the Perkins dies, I plan on replacing it with a DC electric motor and diesel generator. The motor would probably mostly be run from the house bank for short periods and calmer conditions. Your preliminary comments are correct :-) I'm interested in your reasoning for the electric drive as it seems to present no advantages to have a diesel fueled generator which charge a set of batteries to provide power to an electric motor to turn a propeller. Given that any mechanical or electrical device will have some losses it would seem that there will be less efficiency then a system that connects the diesel engine directly to the propeller rather then going all round Robin Hood's barn, as it were. Rick Cheers, Bruce (bruceinbangkokatgmaildotcom) |
PDQ 39' sailing catamaran FOR SALE
|
PDQ 39' sailing catamaran FOR SALE
On Wed, 08 Jul 2009 08:33:05 -0400, wrote:
Diesel/Electric has been used on trains for a very long time. There must be some advantages. I guess one would be full power available at low speeds, and another would be the elimination of need for a transmission. Correct on both points, those are the only real advantages, much more applicable to trains than boats. |
PDQ 39' sailing catamaran FOR SALE
On Wed, 08 Jul 2009 07:32:24 -0500, Rick Morel
wrote: I've heard the excuse, "It's too much trouble." I don't buy that. The daily routine is a lot less trouble and effort than raising or dousing the mainsail! Come on, flip the switch, make a glass of water and test (taste test is best, TDS meter okay), grab a gallon jug, fill the jug, If you are using it for an hour a day is it still necessary to do the daily water test and discard the first gallon? Does it have a UV sterilizer to kill viruses, etc. ? |
PDQ 39' sailing catamaran FOR SALE
|
PDQ 39' sailing catamaran FOR SALE
On Wed, 08 Jul 2009 19:22:34 +0700, Bruce In Bangkok
wrote: Your preliminary comments are correct :-) I'm interested in your reasoning for the electric drive as it seems to present no advantages to have a diesel fueled generator which charge a set of batteries to provide power to an electric motor to turn a propeller. Given that any mechanical or electrical device will have some losses it would seem that there will be less efficiency then a system that connects the diesel engine directly to the propeller rather then going all round Robin Hood's barn, as it were. Cheers, Bruce Be glad to explain my reasoning. First, you are correct in that is is less efficient, maybe by as much as 15%. Don't forget though, that the clutch is going to give some losses, more so with a hydralic one. But. In my case at least I think overall it would be better. Not a major thing, but it would give me a bit more of stowage space because the generator would be moved back from where the engine is and the electric motor would take little room and be back where the clutch is now. I've built a couple electric cars, bikes and trikes and a motorcycle so I'm quite familiar with the beast :-) The electric on battery only would give 3.5 to 4 kts for several hours, assuming I don't add any batteries. It would be used mostly for less than an hour at a time, probably more like a few minutes to 15 or 20 minutes. The solar/wind should be able to put this back in a day or two or three in most cases. If not, there's the generator. Assuming the generator is not needed, a plus is no heat to make its way into the cabin. Efficiency is really not a factor. You might as well say it's infinity percent or totally free sine the solar/wind is eventually putting it all back. For longer runs, which do happen occasionally, the electric motor would be run directly off the generator, like a train diesel locomotive or hybrid car. This would give 5 to 6 kts, depending on generator size, for as long as there's fuel. This mode would be where the efficiency loss comes into play, but I feel it would be worth it for the other battery mode. Again, this would be a fairly small part of "normal" operation. So there would be two motor circuits - one for pure battery and one for generator. The pure battery would be simple, just inexpensive "continuous duty solenoids" and maybe a couple big diodes for a "rectactor" controller to series/parellel the batteries for 2 speeds. You don't really need a "throttle" type controller for these lower powers. The generator ciruit would be simpler and cheaper as well. Instead of a complex DC controller, SCR's can be used on the AC output, then rectifiers to convert to pulsating DC for a true variable "throttle". The trick is to match the prop to the motor. It would probably be better to gear down to turn the prop slower. This could be a fairly simple chain or notched belt drive. So... Mode 1, battery only, would be simple to use. No warming up the engine, moving, cooling down and stopping the engine. Just flip a switch and go. Most of the time the energy gets put back "free". Mode 2, generator only, would be pretty much like now except burning a little more fuel. Maybe. Maybe not. There are factors that could make that up. Clutch efficiency on a "straight engine drive" and the higher torque of an electic motor come to mind. Okay, there's got to be some loss overall, but again I think it would be worth it having Mode 1. The above is my opinion based on the calculations. It would work for my cruising style, but maybe not for yours. Rick |
PDQ 39' sailing catamaran FOR SALE
On Wed, 08 Jul 2009 09:31:42 -0400, Wayne.B
wrote: If you are using it for an hour a day is it still necessary to do the daily water test and discard the first gallon? Does it have a UV sterilizer to kill viruses, etc. ? Maybe I wasn't clear on that "first gallon". It's not discarded, it's used to "flush" the sal****er out of the system. Worth it to keep the membrane happy! The first 5 minutes is discarded, as per instructions. This can (notice CAN) contain byproducts of bacterial decomposition small enough to make it through, such as Hydrogen Sulfide, the "rotten egg" smell stuff. It won't really hurt you, but yuck. That's a good "proof" of the value of the flush. Don't flush, just turn off, then the next day sniff the first water coming out. Yes, the water should be tested after that 5-minute discard, mainly because a cracked membrane will let stuff though. I occasionally use a TDS meter, but usually just put the hose in a cup for a bit and have a drink. The "taste test" is recommended over TDS meter by the manufacturer. I guess if one is a bit on the overcautious side one could use the meter first. No UV steriizer. I feel that's a waste of power. All viruses, bacteria, cysts, etc. are supposed to be unable to pass through the membrane. I've been flamed before about this, but the fact remains that we've drunk literally thousands of gallons of RO water with no ill effects. Now I do chlorinate the water in the tanks occasionally. BTW, chlorine and oil will quickly DESTROY the membrane. That's why I use that jug for collecting the flush water. Rick |
PDQ 39' sailing catamaran FOR SALE
On Wed, 08 Jul 2009 10:05:13 -0400, wrote:
I wouldn't be so quick to make that call, Wayne. Those advantages might be big ones for a displacement hulled boat, especially if you supplement the diesel with PV and wind generation charging a battery bank. We need somewhere between 150 and 200 horsepower to run at about hull speed. That's a *lot* of kilowatts, PV or otherwise. I don't believe there have been any successful implementations of diesel-electric on mid-sized full displacement yachts. Nordhavn was supposedly going to offer it as an option on their passage makers but dropped the project because of costs. http://lists.samurai.com/pipermail/passagemaking-under-power/2008-February/004081.html or http://tinyurl.com/nd39po Incidently that's the same John Marshall that used to be the head of North Sails and also managed a few America's Cup campaigns. He's a trawler owner now, currently cruising Glacier Bay, Alaska. |
PDQ 39' sailing catamaran FOR SALE
|
PDQ 39' sailing catamaran FOR SALE
On Wed, 08 Jul 2009 09:22:39 -0400, Wayne.B
wrote: On Wed, 08 Jul 2009 08:33:05 -0400, wrote: Diesel/Electric has been used on trains for a very long time. There must be some advantages. I guess one would be full power available at low speeds, and another would be the elimination of need for a transmission. Correct on both points, those are the only real advantages, much more applicable to trains than boats. Ahem. Perhaps neither of you are aware of the progress being made in seawater batteries. Seawater is usually not available to power trains, but vessels at sea are a different matter. This link may discuss "state of the art" or there might be more recent news on this exciting front in the battle for free locomotion. http://blog.modernmechanix.com/2009/...-on-sea-water/ --Vic |
PDQ 39' sailing catamaran FOR SALE
On Wed, 08 Jul 2009 09:09:30 -0500, Rick Morel
wrote: On Wed, 08 Jul 2009 19:22:34 +0700, Bruce In Bangkok wrote: Your preliminary comments are correct :-) I'm interested in your reasoning for the electric drive as it seems to present no advantages to have a diesel fueled generator which charge a set of batteries to provide power to an electric motor to turn a propeller. Given that any mechanical or electrical device will have some losses it would seem that there will be less efficiency then a system that connects the diesel engine directly to the propeller rather then going all round Robin Hood's barn, as it were. Cheers, Bruce Be glad to explain my reasoning. First, you are correct in that is is less efficient, maybe by as much as 15%. Don't forget though, that the clutch is going to give some losses, more so with a hydralic one. But. In my case at least I think overall it would be better. Not a major thing, but it would give me a bit more of stowage space because the generator would be moved back from where the engine is and the electric motor would take little room and be back where the clutch is now. I've built a couple electric cars, bikes and trikes and a motorcycle so I'm quite familiar with the beast :-) The electric on battery only would give 3.5 to 4 kts for several hours, assuming I don't add any batteries. It would be used mostly for less than an hour at a time, probably more like a few minutes to 15 or 20 minutes. The solar/wind should be able to put this back in a day or two or three in most cases. If not, there's the generator. Assuming the generator is not needed, a plus is no heat to make its way into the cabin. Efficiency is really not a factor. You might as well say it's infinity percent or totally free sine the solar/wind is eventually putting it all back. For longer runs, which do happen occasionally, the electric motor would be run directly off the generator, like a train diesel locomotive or hybrid car. This would give 5 to 6 kts, depending on generator size, for as long as there's fuel. This mode would be where the efficiency loss comes into play, but I feel it would be worth it for the other battery mode. Again, this would be a fairly small part of "normal" operation. So there would be two motor circuits - one for pure battery and one for generator. The pure battery would be simple, just inexpensive "continuous duty solenoids" and maybe a couple big diodes for a "rectactor" controller to series/parellel the batteries for 2 speeds. You don't really need a "throttle" type controller for these lower powers. The generator ciruit would be simpler and cheaper as well. Instead of a complex DC controller, SCR's can be used on the AC output, then rectifiers to convert to pulsating DC for a true variable "throttle". The trick is to match the prop to the motor. It would probably be better to gear down to turn the prop slower. This could be a fairly simple chain or notched belt drive. So... Mode 1, battery only, would be simple to use. No warming up the engine, moving, cooling down and stopping the engine. Just flip a switch and go. Most of the time the energy gets put back "free". Mode 2, generator only, would be pretty much like now except burning a little more fuel. Maybe. Maybe not. There are factors that could make that up. Clutch efficiency on a "straight engine drive" and the higher torque of an electic motor come to mind. Okay, there's got to be some loss overall, but again I think it would be worth it having Mode 1. The above is my opinion based on the calculations. It would work for my cruising style, but maybe not for yours. Rick I can see what you are doing but I still don't see an advantage - this is not to say that "I wanna do it that way" is not a valid reason. But it seems to me: I don't know what sort of electric motor you plan on using but the one boat installation I saw used raw water cooled motors. There was a fairly extensive cooling system with at least one over temp warning system per motor. The one or two water cooled generators I have seen exhibited severe corrosion in only a few years of use. will water cooled motors have the same service life and a low speed, small, diesel engine? I wonder about the high power/low power control systems. What is the advantage of this? with the diesel auxiliary I might use idle to back out of a slip or to creep up on the anchor rode but that is generally a very small percent of the engine's operating time. In addition, especially inside a marina, I have frequently seen a need for almost full power in maneuvering, particularly when the current is running 3 or 4 knts through the marina. It seems to me that saving space is the biggest advantage of a diesel-electric drive. You do get rid of the gearbox but do you need a speed change between the motor and the propeller? In short, is there a distinct advantage in the diesel-electric drive? I'm not trying to start an argument here, I know what the advantages are for a diesel-electric drilling rig, for example, and I'm trying to figure out if there is one for a small engined sailing boat. Cheers, Bruce (bruceinbangkokatgmaildotcom) |
PDQ 39' sailing catamaran FOR SALE
On Wed, 08 Jul 2009 20:28:18 -0500, Vic Smith
wrote: On Wed, 08 Jul 2009 09:22:39 -0400, Wayne.B wrote: On Wed, 08 Jul 2009 08:33:05 -0400, wrote: Diesel/Electric has been used on trains for a very long time. There must be some advantages. I guess one would be full power available at low speeds, and another would be the elimination of need for a transmission. Correct on both points, those are the only real advantages, much more applicable to trains than boats. Ahem. Perhaps neither of you are aware of the progress being made in seawater batteries. Seawater is usually not available to power trains, but vessels at sea are a different matter. This link may discuss "state of the art" or there might be more recent news on this exciting front in the battle for free locomotion. http://blog.modernmechanix.com/2009/...-on-sea-water/ --Vic The marvels of electrolyses. You can do the same thing with a lemon, a galvanized screw and a piece of copper wire. Cheers, Bruce (bruceinbangkokatgmaildotcom) |
PDQ 39' sailing catamaran FOR SALE
On Thu, 09 Jul 2009 20:14:54 +0700, Bruce In Bangkok
wrote: The marvels of electrolyses. You can do the same thing with a lemon, a galvanized screw and a piece of copper wire. Yes, it is easy to make a battery out of a lemon. It's not a very good battery however. That's because it was designed to be a lemon, not a battery, same problem with a sea water battery. It's interesting to see guys working on things like that, and every once in a while something useful comes out of it. |
PDQ 39' sailing catamaran FOR SALE
On Thu, 09 Jul 2009 19:13:59 +0700, Bruce In Bangkok
wrote: I can see what you are doing but I still don't see an advantage - this is not to say that "I wanna do it that way" is not a valid reason. But it seems to me: I don't know what sort of electric motor you plan on using but the one boat installation I saw used raw water cooled motors. There was a fairly extensive cooling system with at least one over temp warning system per motor. The one or two water cooled generators I have seen exhibited severe corrosion in only a few years of use. will water cooled motors have the same service life and a low speed, small, diesel engine? Yes, I guess "I wanna do it that way" is a valid reason. Hadn't thought about it, but that is part of it. The plan is to use a fork lift raise/lower motor. This is the exact same motor as used in electric cars, but with a much heavier case. It will develop 35 HP at 120 VDC and about 8 HP at 24 VDC. No need for water cooling. Oh, a extra plus is the motor, like all DC motors, will work in "reverse" as a generator under sail. Not sure what you mean about the severe corrosion you've seen in water cooled generators. I've seen a bunch of marine generators over 30 years old still running and looking good. I wonder about the high power/low power control systems. What is the advantage of this? with the diesel auxiliary I might use idle to back out of a slip or to creep up on the anchor rode but that is generally a very small percent of the engine's operating time. In addition, especially inside a marina, I have frequently seen a need for almost full power in maneuvering, particularly when the current is running 3 or 4 knts through the marina. First, with those kinds of currents you mention it would definitely be a situation to use the high power mode!! :-) Low power mode would not be like idle. It would be closer to the way it seems some manufacturers, particularly Hunter, put small engines in, like a 10 HP diesel in a Hunter 33 a friend had. Or, if you prefer, it would be like a max range power setting. Remember we're talking 3.5 to 4 kts on battery only. A couple more batteries and it could be 4.5 to 5 kts, probably with about the same "range" with the added Amp Hours. Remember, battery only is for short time use. Max range would probably be 4 to 8 miles, but you really wouldn't want to do that because you'd have to use the generator to recharge. Better to go into high power mode. Okay, let's look at how low power, battery only, would be used. As I had mentioned, right now we're at a marina in Slidell, LA due to a care-giver situation. It's about 2 miles to the lake. We could use battery only to get to the lake, sail about, etc., then maybe low power back. In a way it does make sense because when we get back we'll plug in and recharge "free" (fixed rate electricity). If we moved to a nearby marina, our trip to the lake would be about 1/4 mile. Now this would make more sense to use low power. Someone not cruising, day sailing or overnight weekending, in this situation could use electric only and recharge when they got back. There'd be no need for anything else unless they take occasional cruises. Our normal sailing mode is cruising and anchoring out, with occasional marina stays. There are times when we travel some in canals, so the high power generator mode is needed. IOW, there are times when we need to play motorboat for hours, days or maybe even weeks at a time. Low power battery mode: Yes, we know how to drop and weigh anchor under sail, but sometimes there's little or no margin for error. Easier and safer to douse the sails and flip a switch. Getting in and out of "port" when needed for supplies, clearing in/out, etc. Ever try to creep though reefs visually under sail? Rather than go on, just look back how you use your engine. If it's say less than a 1/2 hour a day if cruising or less than an hour day-sailing, pure electric would work for you. Think about how nice it would be to flip a switch and have instant power for whatever reason. Maybe the winds are light and you want to come about and your boat is one of those that's reluctant or very slow to do so in light conditions. Hard over, flip the switch, come about, flip the switch off. The 110 VAC generator gives another plus of power for A/C if you want to burn the fuel, fast charging with a large charger, etc. Heck, I might pull the propane stove and put in an electric one. I wonder how that would compare to "cooking with gas", fuel and cost wise? It seems to me that saving space is the biggest advantage of a diesel-electric drive. You do get rid of the gearbox but do you need a speed change between the motor and the propeller? As I had mentioned, it would take a recduction for much better propellor efficiency. A chain drive would be cheapest, but a bit noisy. Notched belt would be much ore expensive, but quiet. One could maybe find a "gearbox" surplus or junked or... The motor brushes can be electricly swapped for reverse. In short, is there a distinct advantage in the diesel-electric drive? I don't think there is a "distinct" advantage and in some cases a disadvantage. It depends on one's boating style. Our case I feel there is an advantage. Wayne had mentioned his trawler - in his case I would say big disadvantage. As mentioned before, I've had lots of experience with electric power and with "green" power - solar and wind. Whenever you use those you have to look at your needs and wants and decide if it's for you. You can't just turn on stuff or jump into your electric car and drive it like a combustion one. You have to do a bit of "resouce management". Most folks want "energy on demand" and are unwilling to put up with the "work" to use or the waiting sometimes. I'm not trying to start an argument here, I know what the advantages are for a diesel-electric drilling rig, for example, and I'm trying to figure out if there is one for a small engined sailing boat. No argumant, Bruce :-) I know where you're coming from. It's a complex subject with all kinds of "gotcha's". I wish it were like in the movies, where they have a 2 X 2 ft. solar panel on a 20 passenger electric transport and it runs it at 90 MPH all day and even all night (from starlight???). It just doesn't work that way in the real world. Other than a dinghy, I wouldn't even consider an electric power boat. Well, maybe a slow 'African Queen' type on a lake or bayou for short weekend use. Rick |
PDQ 39' sailing catamaran FOR SALE
On Thu, 09 Jul 2009 09:04:26 -0500, Rick Morel
wrote: The plan is to use a fork lift raise/lower motor. This is the exact same motor as used in electric cars, but with a much heavier case. It will develop 35 HP at 120 VDC 20 golf cart batts and you're there ! You also get 1100 pounds of extra internal ballast and one heck of a house bank as part of the deal. :-) |
PDQ 39' sailing catamaran FOR SALE
On Thu, 09 Jul 2009 10:44:59 -0400, Wayne.B
wrote: On Thu, 09 Jul 2009 09:04:26 -0500, Rick Morel wrote: The plan is to use a fork lift raise/lower motor. This is the exact same motor as used in electric cars, but with a much heavier case. It will develop 35 HP at 120 VDC 20 golf cart batts and you're there ! You also get 1100 pounds of extra internal ballast and one heck of a house bank as part of the deal. :-) Yeah you rite, Wayne! Actually, that's what's used in electric cars - 20 golf cart batteries. Energy equivalent of 1-1/2 gallons of gasoline! Actually, I figure on running the motor on 36V for low mode and direct off the generator for high mode. Won't get full power though unless I put in a 30KW generator (YOW!). Figure on getting about 20 HP. Rick |
PDQ 39' sailing catamaran FOR SALE
On Thu, 09 Jul 2009 10:20:57 -0500, Rick Morel
wrote: Won't get full power though unless I put in a 30KW generator (YOW!). Figure on getting about 20 HP. I've got a 20kw Kohler in a sound shield. It's about 800 pounds but might make an attractive dining table in the middle of the main cabin. http://tinyurl.com/kvadvo http://www.kohlerpower.com/onlinecatalog/pdf/g2087.pdf |
PDQ 39' sailing catamaran FOR SALE
"Rick Morel" wrote in message ... On Thu, 09 Jul 2009 19:13:59 +0700, Bruce In Bangkok wrote: I can see what you are doing but I still don't see an advantage - this is not to say that "I wanna do it that way" is not a valid reason. But it seems to me: I don't know what sort of electric motor you plan on using but the one boat installation I saw used raw water cooled motors. There was a fairly extensive cooling system with at least one over temp warning system per motor. The one or two water cooled generators I have seen exhibited severe corrosion in only a few years of use. will water cooled motors have the same service life and a low speed, small, diesel engine? Yes, I guess "I wanna do it that way" is a valid reason. Hadn't thought about it, but that is part of it. The plan is to use a fork lift raise/lower motor. This is the exact same motor as used in electric cars, but with a much heavier case. It will develop 35 HP at 120 VDC and about 8 HP at 24 VDC. No need for water cooling. Oh, a extra plus is the motor, like all DC motors, will work in "reverse" as a generator under sail. Not sure what you mean about the severe corrosion you've seen in water cooled generators. I've seen a bunch of marine generators over 30 years old still running and looking good. I wonder about the high power/low power control systems. What is the advantage of this? with the diesel auxiliary I might use idle to back out of a slip or to creep up on the anchor rode but that is generally a very small percent of the engine's operating time. In addition, especially inside a marina, I have frequently seen a need for almost full power in maneuvering, particularly when the current is running 3 or 4 knts through the marina. First, with those kinds of currents you mention it would definitely be a situation to use the high power mode!! :-) Low power mode would not be like idle. It would be closer to the way it seems some manufacturers, particularly Hunter, put small engines in, like a 10 HP diesel in a Hunter 33 a friend had. Or, if you prefer, it would be like a max range power setting. Remember we're talking 3.5 to 4 kts on battery only. A couple more batteries and it could be 4.5 to 5 kts, probably with about the same "range" with the added Amp Hours. Remember, battery only is for short time use. Max range would probably be 4 to 8 miles, but you really wouldn't want to do that because you'd have to use the generator to recharge. Better to go into high power mode. Okay, let's look at how low power, battery only, would be used. As I had mentioned, right now we're at a marina in Slidell, LA due to a care-giver situation. It's about 2 miles to the lake. We could use battery only to get to the lake, sail about, etc., then maybe low power back. In a way it does make sense because when we get back we'll plug in and recharge "free" (fixed rate electricity). If we moved to a nearby marina, our trip to the lake would be about 1/4 mile. Now this would make more sense to use low power. Someone not cruising, day sailing or overnight weekending, in this situation could use electric only and recharge when they got back. There'd be no need for anything else unless they take occasional cruises. Our normal sailing mode is cruising and anchoring out, with occasional marina stays. There are times when we travel some in canals, so the high power generator mode is needed. IOW, there are times when we need to play motorboat for hours, days or maybe even weeks at a time. Low power battery mode: Yes, we know how to drop and weigh anchor under sail, but sometimes there's little or no margin for error. Easier and safer to douse the sails and flip a switch. Getting in and out of "port" when needed for supplies, clearing in/out, etc. Ever try to creep though reefs visually under sail? Rather than go on, just look back how you use your engine. If it's say less than a 1/2 hour a day if cruising or less than an hour day-sailing, pure electric would work for you. Think about how nice it would be to flip a switch and have instant power for whatever reason. Maybe the winds are light and you want to come about and your boat is one of those that's reluctant or very slow to do so in light conditions. Hard over, flip the switch, come about, flip the switch off. The 110 VAC generator gives another plus of power for A/C if you want to burn the fuel, fast charging with a large charger, etc. Heck, I might pull the propane stove and put in an electric one. I wonder how that would compare to "cooking with gas", fuel and cost wise? It seems to me that saving space is the biggest advantage of a diesel-electric drive. You do get rid of the gearbox but do you need a speed change between the motor and the propeller? As I had mentioned, it would take a recduction for much better propellor efficiency. A chain drive would be cheapest, but a bit noisy. Notched belt would be much ore expensive, but quiet. One could maybe find a "gearbox" surplus or junked or... The motor brushes can be electricly swapped for reverse. In short, is there a distinct advantage in the diesel-electric drive? I don't think there is a "distinct" advantage and in some cases a disadvantage. It depends on one's boating style. Our case I feel there is an advantage. Wayne had mentioned his trawler - in his case I would say big disadvantage. As mentioned before, I've had lots of experience with electric power and with "green" power - solar and wind. Whenever you use those you have to look at your needs and wants and decide if it's for you. You can't just turn on stuff or jump into your electric car and drive it like a combustion one. You have to do a bit of "resouce management". Most folks want "energy on demand" and are unwilling to put up with the "work" to use or the waiting sometimes. I'm not trying to start an argument here, I know what the advantages are for a diesel-electric drilling rig, for example, and I'm trying to figure out if there is one for a small engined sailing boat. No argumant, Bruce :-) I know where you're coming from. It's a complex subject with all kinds of "gotcha's". I wish it were like in the movies, where they have a 2 X 2 ft. solar panel on a 20 passenger electric transport and it runs it at 90 MPH all day and even all night (from starlight???). It just doesn't work that way in the real world. Other than a dinghy, I wouldn't even consider an electric power boat. Well, maybe a slow 'African Queen' type on a lake or bayou for short weekend use. Rick I encourage those of you discussing the efeiency of electric propulsion to read the following artical. http://www.cruisingworld.com/how-to/...ion-36169.html Newly built cruise liners use electric power as their main engines located under the hull on swiveling pods thus eliminating the drag of the rudders. Regards, JR |
PDQ 39' sailing catamaran FOR SALE
On Thu, 09 Jul 2009 09:48:37 -0400, Wayne.B
wrote: On Thu, 09 Jul 2009 20:14:54 +0700, Bruce In Bangkok wrote: The marvels of electrolyses. You can do the same thing with a lemon, a galvanized screw and a piece of copper wire. Yes, it is easy to make a battery out of a lemon. It's not a very good battery however. That's because it was designed to be a lemon, not a battery, same problem with a sea water battery. It's interesting to see guys working on things like that, and every once in a while something useful comes out of it. You did notice that his experiments were all with little model boats. when he get something 15 feet long that does 15 miles an hour it will be far more worthy of notice. Cheers, Bruce (bruceinbangkokatgmaildotcom) |
PDQ 39' sailing catamaran FOR SALE
On Thu, 09 Jul 2009 09:04:26 -0500, Rick Morel
wrote: On Thu, 09 Jul 2009 19:13:59 +0700, Bruce In Bangkok wrote: I can see what you are doing but I still don't see an advantage - this is not to say that "I wanna do it that way" is not a valid reason. But it seems to me: I don't know what sort of electric motor you plan on using but the one boat installation I saw used raw water cooled motors. There was a fairly extensive cooling system with at least one over temp warning system per motor. The one or two water cooled generators I have seen exhibited severe corrosion in only a few years of use. will water cooled motors have the same service life and a low speed, small, diesel engine? Yes, I guess "I wanna do it that way" is a valid reason. Hadn't thought about it, but that is part of it. The plan is to use a fork lift raise/lower motor. This is the exact same motor as used in electric cars, but with a much heavier case. It will develop 35 HP at 120 VDC and about 8 HP at 24 VDC. No need for water cooling. Oh, a extra plus is the motor, like all DC motors, will work in "reverse" as a generator under sail. My thinking was along these lines: In this part of the world we have two seasons, the S.W. Monsoons when it rains a lot and we get a lot of squalls, sort of lousy weather, with quite a bit of wind; and the N.E. Monsoons when we get no rain, beautiful sunny days, and not much wind. If you are going anywhere in the N.Easterlies you will probably have to motor about half of each day. In the case of my boat (40 ft. sloop with 4-107 engine) I would be motoring at about 2,000 RPM, and probably about 25 - 30H.P driving the prop. Can you run your electric motor tucked down there in the bilges for, say 5 hours continuously, producing, say 25 HP, with no cooling? Not sure what you mean about the severe corrosion you've seen in water cooled generators. I've seen a bunch of marine generators over 30 years old still running and looking good. Granted I haven made a study of auxiliary generators (not having one) but I have seen a couple of water cooled generators (the electric making part) that used see water flowing through passages in the frame for cooling - I assume in order to build a smaller device - and there was severe corrosion in and around these cooling passages. Sufficient that I didn't think that one of them should be returned to service. I wonder about the high power/low power control systems. What is the advantage of this? with the diesel auxiliary I might use idle to back out of a slip or to creep up on the anchor rode but that is generally a very small percent of the engine's operating time. In addition, especially inside a marina, I have frequently seen a need for almost full power in maneuvering, particularly when the current is running 3 or 4 knts through the marina. First, with those kinds of currents you mention it would definitely be a situation to use the high power mode!! :-) Low power mode would not be like idle. It would be closer to the way it seems some manufacturers, particularly Hunter, put small engines in, like a 10 HP diesel in a Hunter 33 a friend had. Or, if you prefer, it would be like a max range power setting. Remember we're talking 3.5 to 4 kts on battery only. A couple more batteries and it could be 4.5 to 5 kts, probably with about the same "range" with the added Amp Hours. Remember, battery only is for short time use. Max range would probably be 4 to 8 miles, but you really wouldn't want to do that because you'd have to use the generator to recharge. Better to go into high power mode. Okay, let's look at how low power, battery only, would be used. As I had mentioned, right now we're at a marina in Slidell, LA due to a care-giver situation. It's about 2 miles to the lake. We could use battery only to get to the lake, sail about, etc., then maybe low power back. In a way it does make sense because when we get back we'll plug in and recharge "free" (fixed rate electricity). What is the advantage of low power mode? Simple avoiding the loss through the SCR system? If we moved to a nearby marina, our trip to the lake would be about 1/4 mile. Now this would make more sense to use low power. Someone not cruising, day sailing or overnight weekending, in this situation could use electric only and recharge when they got back. There'd be no need for anything else unless they take occasional cruises. Our normal sailing mode is cruising and anchoring out, with occasional marina stays. There are times when we travel some in canals, so the high power generator mode is needed. IOW, there are times when we need to play motorboat for hours, days or maybe even weeks at a time. Low power battery mode: Yes, we know how to drop and weigh anchor under sail, but sometimes there's little or no margin for error. Easier and safer to douse the sails and flip a switch. Getting in and out of "port" when needed for supplies, clearing in/out, etc. Ever try to creep though reefs visually under sail? Rather than go on, just look back how you use your engine. If it's say less than a 1/2 hour a day if cruising or less than an hour day-sailing, pure electric would work for you. Think about how nice it would be to flip a switch and have instant power for whatever reason. Maybe the winds are light and you want to come about and your boat is one of those that's reluctant or very slow to do so in light conditions. Hard over, flip the switch, come about, flip the switch off. But nearly all of my sailing now is just going somewhere so it is turn on the autopilot or adjust the wind vane and that is it until we find a hiddy hole for the evening :-) None of this frantic "Helm alee" stuff. The 110 VAC generator gives another plus of power for A/C if you want to burn the fuel, fast charging with a large charger, etc. Heck, I might pull the propane stove and put in an electric one. I wonder how that would compare to "cooking with gas", fuel and cost wise? My major complaint about electric stoves is that when you want a cup of coffee you need to start the generator. The gas you flip a switch and turn a know and you got heat. It seems to me that saving space is the biggest advantage of a diesel-electric drive. You do get rid of the gearbox but do you need a speed change between the motor and the propeller? As I had mentioned, it would take a recduction for much better propellor efficiency. A chain drive would be cheapest, but a bit noisy. Notched belt would be much ore expensive, but quiet. One could maybe find a "gearbox" surplus or junked or... The motor brushes can be electricly swapped for reverse. In short, is there a distinct advantage in the diesel-electric drive? I don't think there is a "distinct" advantage and in some cases a disadvantage. It depends on one's boating style. Our case I feel there is an advantage. Wayne had mentioned his trawler - in his case I would say big disadvantage. As mentioned before, I've had lots of experience with electric power and with "green" power - solar and wind. Whenever you use those you have to look at your needs and wants and decide if it's for you. You can't just turn on stuff or jump into your electric car and drive it like a combustion one. You have to do a bit of "resouce management". Most folks want "energy on demand" and are unwilling to put up with the "work" to use or the waiting sometimes. I'm still a skeptic. I think I'll do a little research and see what the calcs show. I would take as parameters something similar to what I have now - absolute maximum power - 40 H.P. Range - dependant on fuel carried. Max continuous, say 30 HP. Not equal to the diesel I have now but probably pretty much the way I actually use the engine. I'm not trying to start an argument here, I know what the advantages are for a diesel-electric drilling rig, for example, and I'm trying to figure out if there is one for a small engined sailing boat. No argumant, Bruce :-) I know where you're coming from. It's a complex subject with all kinds of "gotcha's". I wish it were like in the movies, where they have a 2 X 2 ft. solar panel on a 20 passenger electric transport and it runs it at 90 MPH all day and even all night (from starlight???). It just doesn't work that way in the real world. Other than a dinghy, I wouldn't even consider an electric power boat. Well, maybe a slow 'African Queen' type on a lake or bayou for short weekend use. Rick Cheers, Bruce (bruceinbangkokatgmaildotcom) |
PDQ 39' sailing catamaran FOR SALE
On Fri, 10 Jul 2009 12:20:46 +0700, Bruce In Bangkok
wrote: His main claim to fame seems to be that he wants to designs and manufacturers a motor to meet the exact requirement of hull and propeller which means that he is going to either design and stock a large number of different size and capacity motors or do exactly what he complains the big companies do - have a few standard sizes and pick the closest. A custom designed motor is going to cost several multiples of what an off the shelf motor does. My neighbor has a racing parts shop with a complete of NC machine tools. He could do one custom prop as cheaply as a hundred. Casady |
| All times are GMT +1. The time now is 02:29 AM. |
Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 BoatBanter.com