I'm running a derated MAN 4 liter 90/44hp 3000/1500rpm, 3/1 reduction 34inch 3blade, runs at 7.11kts at 1200 rpm gets 5.4mpg over 120,000 logged miles. 46,000pounds, 45/13/4.5, Anyhow the John Deeres 4045s seem a good replacement with peak torque curves in the 1400-1600rpm range these are also almost optimum fuel use parameters, Matching cruising speed, to optimum fuel use and maximum torque, is a question of gear reduction and finially prop choice.hydrodynamics being whatever they are my pc is .55. Point being, My boat wont plane no mater how much Hp is injected into it all it does is 7 knots, anything more that 28hp is extra, Question is,do you need to be operating at other than optimum fuel burn, passagemaking-under-power-request@lists.samurai.com wrote: Send Passagemaking-Under-Power mailing list submissions to passagemaking-under-power@lists.samurai.com To subscribe or unsubscribe via the World Wide Web, visit http://lists.samurai.com/mailman/listinfo/passagemaking-under-power or, via email, send a message with subject or body 'help' to passagemaking-under-power-request@lists.samurai.com You can reach the person managing the list at passagemaking-under-power-owner@lists.samurai.com When replying, please edit your Subject line so it is more specific than "Re: Contents of Passagemaking-Under-Power digest..." Today's Topics: 1. Done Dreamin' 08/27/06: A troublesome leak develops (by way of Georgs Kolesnikovs) 2. Swan Song roll tank design (bob) 3. Re: FW: Swan Song in Venezuela (Carl H. Martin) 4. Re: FW: Swan Song in Venezuela (Steven Dubnoff) 5. Re: Unsailboat fuel consumption (Mark Richter) 6. Re: Unsailboat fuel consumption (Dave Cooper) 7. Re: FW: Swan Song in Venezuela (Dave Cooper) 8. Re: Over propping (Mark) 9. Re: Unsailboat fuel consumption (Ron Rogers) 10. Re: Unsailboat fuel consumption (John Harris) 11. Re: Unsailboat fuel consumption (Ron Rogers) 12. Re: FW: Swan Song in Venezuela (Carl H. Martin) 13. Re: Unsailboat fuel consumption (Hal Wyman) ---------------------------------------------------------------------- Message: 1 Date: Wed, 30 Aug 2006 07:54:36 -0400 From: poohwen@comcast.net (by way of Georgs Kolesnikovs) Subject: [PUP] Done Dreamin' 08/27/06: A troublesome leak develops To: Passagemaking Under Power List Message-ID: Content-Type: text/plain; charset="iso-8859-1" ; format="flowed" #115 NOW August 27, 2006 1415 (UTC -11 hours Samoa Standard Time) S13049.8 W171045.8 Anchored in Apia Harbour, Temp 91 with gusty winds Good Afternoon, We made good time between Tonga and Western Samoa. It was necessary to slow down a bit, so that our arrival would be in daylight. Entering Apia is not difficult, which has excellent range markers and a well-lit harbour, but daylight is always more comfortable. We pulled up to the shipping wharf and called the Port Captain at 8:15 am to set the wheels in motion for our clearance into the country. The last time I was here, it took 24 hours before we could get anyone to come out to the boat. So with as much authority as I could muster in a polite way I tried to impress upon them that we would really like to see there fair city today. By 11:00 am, customs, quarantine, health officials, and the port authority had visited us. The later charges $50 US to use the harbour for an indefinite period. The only thing left was immigration. I came up with the brilliant idea of calling them direct and asking if we could come downtown to the immigration office thus saving them a trip out to the harbour. They agreed that this was a wonderful idea and we hailed a taxi and soon had the necessary stamps in our passport. Now for a big problem that has developed. About two days out of Apia, we began to smell diesel fuel coming from the engine room. I looked around and found one hose that was damp and thought that might be the problem. However, by the time we got to Apia, the bilge had considerable fuel in it and some was being pumped overboard by the bilge pump. Upon closer examination, I discovered that the seam on the backside of the supply reservoir (a one-gallon tank that distributes fuel to all the systems) was leaking from about half way up the tank. This is not good! The tank, which has seven connections to it, will be a major undertaking to remove. I am not a fan of patching things, but in this case, I thought I would try some liquid steel along the seam and see if that will stop it. Right now, it is curing and I should know in a few hours. >From every bad situation, some good can be found. The good news is that I will be in Apia for a while and since the winter festival starts on Friday, I should have a good time enjoying the colorful events scheduled to take place. Planned activities include war canoe races, parades, games, even a beauty pageant. So, what is the rush? My only requirement is to be out of the southern hemisphere before cyclone season starts in October. My bread maker came to a noisy halt the other day. I have enjoyed may loafs of wonderful homemade bread over the past couple of years, and its demise would be a real loss. Prior to sending it to the bottom of the ocean, I thought I had better look at the innards and see if there was anything I could fix. Sure enough, the problem was the belt had come off the pulley and was making a terrible racket. This was a simple fix and right now, we have a fresh loaf of bread on the way. So, this important piece of equipment has a renewed life and hopefully will produce many more loaves of mouth-watering fresh bread. Rainer has left to go back to New Zealand. I certainly appreciated his help and cheerful attitude. Kirk has been a great help and a surprisingly good cook. The later skill being something I consider most desirable, which compliments my eating skills. Thus, life goes on with problems to challenge and special things to enjoy. Life is a Cruise, Larry and Kirk -- Larry Rick Done Dreamin' Nordhavn 40 #33 Site: http://gricknet.homedns.org/Dads%20Web/doneDreamnHome.htm ------------------------------ Message: 2 Date: Wed, 30 Aug 2006 08:01:38 -0400 From: "bob" Subject: [PUP] Swan Song roll tank design To: "'Passagemaking Under Power List'" Message-ID: <001a01c6cc2c$10b65550$660fa8c0@BOB> Content-Type: text/plain; charset="us-ascii" Hi Dave, These roll tanks fascinate me. Who did the design on yours? Cost of design? Tank install cost? Anything else you can share? Many thanks. Bob Frenier ------------------------------ Message: 3 Date: Wed, 30 Aug 2006 12:08:23 -0400 From: "Carl H. Martin" Subject: Re: [PUP] FW: Swan Song in Venezuela To: "Passagemaking Under Power List" Message-ID: <007201c6cc4e$85741310$6601a8c0@carl> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Very interesting post. I've never heard of the stability tank. How would I get ahold of the software to design one or have one designed for me? Also, this would be an interesting post on the T&T website. Carl Martin Scout 30 Hudson Beach, FL ----- Original Message ----- From: "Dave Cooper" To: "'Passagemaking Under Power List'" Sent: Tuesday, August 29, 2006 9:13 PM Subject: [PUP] FW: Swan Song in Venezuela > Greetings all, just a quick note to let you know we arrived safely in PLC, > Venezuela on Thursday AM logging 616.5 nm which included about 30 during > our > sea trials. We made one stop in St Martin for supplies. > > Fuel used was 433 gals and the genset was running 90% of the time (200 > hrs) > for our air conditioning. Also the main engine alternator was not hooked > up > yet so the genset was our sole source of AC and DC. > > We had two issues on the trip: > 1. Lost the dinghy when the tow line parted. Found it and replaced the tow > line with a new one and had no further problems in the 600 miles. > 2. A fitting on the steering ram bypass valve failed and dumped all the > hydraulic fluid. A bit tricky putting in a hose to bypass the bypass and > then filling and bleeding the system while beam-to in 8-10' seas but > doable > thanks to the roll tank which stabilizes Swan Song. > > I guess we can take the cover off the top of our pilothouse now and let > everyone see why Swan Song doesn't roll. > We have a tank engineered with baffles that keep 200 gals of water 180 > degrees out of sync with the roll period of the boat. The net result is > that > Swan Song doesn't roll enough to notice whether moving, at the dock or at > anchor. When other boats a rolling and bobbing about she just sits there. > Amazing! > It does nothing for pitch so we still go up and down but very, very little > roll. > The tank is 12 ft long, 4' wide and 16" high and is firmly attached to the > boat. Roughly 1500 lbs of water sloshing back and forth out of sync with > the > boat. > > We have a solid state gyro with a DAC which feeds our laptop. Prior to > filling the tank you could get Swan Song rolling at the dock 10-15 degrees > by synchronously stepping on the side. You can do this with most boats. > Some > will roll more some will roll less but all will roll..even a catamaran. > After filling the tank you can't even get the rolling to start! > > Timing 10 of these rolls will give you the roll period of you boat. In > Swan > Song's case it was 4.1 seconds per roll. This goes into the formula that > helps define the tank. > > The second item is the stiffness of the vessel. For this you need to do an > inclination test. Putting weights on one side then the other and > accurately > measuring the heel angle in calm water. In Swan Song's case we got 500 lbs > per degree to about 5 degrees and then it goes to 600 lb/degree and is > 1000 > lb/degree at 10 degrees static heel. > > So 1500 lbs of water on the top of the pilothouse stacked at one end > (which > is impossible as the tank is only 16" high) would result in a worst case > added heel angle of 3 degree. The conclusion is that the boat has plenty > of > reserve stability for the roll tank. > > The last part of the input is the hull lines. In our case there were none > so > we measured the hull at 15 stations in one foot depth increments. From > this > a wire frame computer model was generated and input into the software. > > The output is a set of parameters that allow one to design a tank with > fixed > baffles that will delay the free surface effect of the water such that it > becomes an advantage to you vs. a detriment. No power, no pumps, no > valves, > no maintenance, no drag, no deployment/retrieval effort, no nothing. It > just > sits up there and works 100% of the time. > > We expect over time that we will find that adjusting the amount of water > in > the tank in various wave heights will improve it even more. The trip down > was 350 miles of beam sea ranging from 5 to 12' and except for the > occasional "drop thru a wave" we were very comfortable. With an eye height > of 12' in our seat looking out the Port side window and up at the wave > tops > on occasion did get that knee jerk reaction but it never was required. > > Our new Fly By Wire system performed flawlessly. We have zero mechanical > controls...no steering nor engine controls. Interesting it was the > steering > ram bypass valve that failed. If we' had a conventional system and lost > all > the hydraulic fluid I doubt we could have repaired it at sea in 2 hours if > at all. > > A great trip down, the Marina folks are great and the officials are very > polite. There is a very visible show of various law enforcement people. > Sort > of like the local police, the state police, the harbor patrol, the coast > guard and the Navy all keeping an eye on a parade in Boston Harbor. > > Is there crime here? Is there crime in New York? You better believe it. > Same > thing. > > More reports, etc. as we get settled in. My work list is ten pages long > and > the "honey do" list is even longer. Sure hope the hurricane season ends > quickly so I can get out of the marina ;-) > > Dave & Nancy > Swan Song > 1974 Roughwater 58 > Caribbean Tour 2006 > _______________________________________________ > Passagemaking-Under-Power Mailing List ------------------------------ Message: 4 Date: Wed, 30 Aug 2006 12:15:56 -0700 From: Steven Dubnoff Subject: Re: [PUP] FW: Swan Song in Venezuela To: Passagemaking Under Power List Message-ID: <7.0.1.0.2.20060830121225.10716c68@circlesys.com> Content-Type: text/plain; charset="us-ascii"; format=flowed At 09:08 AM 8/30/2006, you wrote: >Very interesting post. I've never heard of the stability tank. How would I >get ahold of the software to design one or have one designed for me? This is, I think, a job for a professional, as poorly designed roll tanks can easily decrease stability. Michael Kasten has a discussion of roll--reduction strategies here: http://www.kastenmarine.com/roll_attenuation.htm Best, Steve Steve Dubnoff 1966 Willard Pilothouse www.mvnereid.com sdubnoff@circlesys.com ------------------------------ Message: 5 Date: Wed, 30 Aug 2006 12:52:07 -0700 (PDT) From: Mark Richter Subject: Re: [PUP] Unsailboat fuel consumption To: passagemaking-under-power@lists.samurai.com Message-ID: <20060830195207.91774.qmail@web51915.mail.yahoo.com> Content-Type: text/plain; charset=iso-8859-1 < narrow boats, but perhaps not, because of the increasing difficulty of finding dockage and the increasing cost of dockage.>> Perhaps there is a market for narrow boats for those who own their own docks. Dockage expense has never been a concern of mine, since at first I cruised full time and anchored out, rarely setting foot on a marina dock. Two years ago, We bought a home on the Okeechobee Waterway canal with 98' of dockage, and now cruise half the year, using marina docks only about one day in 3 months. At 46' long and 15' beam, Pooh isn't particularly narrow, but his sailboat shape is sliprier than most trawler hulls at below hull speed; and having only 80 diesel HP for 16 tons of boat allows pretty good mileage. We typically burn 1.3-1.4 GPH with a cruise speed of 7-7.5 kts. (that's statute gallons and knotical knots) We should do better on the way home now, since it's all down hill from here. Mark Richter, m/v Winnie the Pooh, Ortona, FL presently at the free town dock in Mechanicville, NY ------------------------------ Message: 6 Date: Wed, 30 Aug 2006 17:28:17 -0400 From: "Dave Cooper" Subject: Re: [PUP] Unsailboat fuel consumption To: "'Passagemaking Under Power List'" Message-ID: <006701c6cc7b$356b0e50$5602000a@Dell> Content-Type: text/plain; charset="us-ascii" I guess we must qualify as a "narrow boat" at 63' overall and 12'10" of beam. At 92,000 lbs as weighed on the travel lift when we left the BVI I guess we are "heavy & narrow". Our mileage wasn't spectacular at ~ 1.6nm then again the seas and wind weren't too kind either ;-) So I think you need to be long, narrow and "light" to achieve the higher fuel numbers we see from the unsailboat and others who get or claim higher NM/G. Perhaps a better metric is tons/waterline, aka length/displacement. We're 52' WL so we're .88 tons/ft. Mark, I expect is 42' on the waterline at 16 tons. This is .38 or so tons/ft The unsailboat is 80' waterline and if memory serves me about 30 tons all up. I may be wrong on this please correct me if you know what it actually weighs. If correct then she's .37 tons/ft. Again very light, IMO. So maybe we can compile a list here from real numbers that we know from our own performance of our boats. I could be a bit eye opening as I think it is the weight i.e. tons/ft, not the beam that uses the fuel ;-) YMMV Cheers Dave & Nancy Swan Song 1974 Roughwater 58 Caribbean Cruise 2006 ------------------------------ Message: 7 Date: Wed, 30 Aug 2006 17:28:17 -0400 From: "Dave Cooper" Subject: Re: [PUP] FW: Swan Song in Venezuela To: "'Passagemaking Under Power List'" Message-ID: <006601c6cc7b$35573830$5602000a@Dell> Content-Type: text/plain; charset="us-ascii" I wasn't suggesting that someone toss a tank on their boat, fill it with water and go to sea. Bad karma ;-) The designer of our tank is a professor and has many of these tanks designed and in place on boats. Mostly commercial ones. There is, to my knowledge, very few persons (one that I know of) who can do this and have the experience. I suspect that most marine architects would get there tanks designed from this same source. Also to my knowledge there is no one doing this on a commercial basis. That is someone whom you can go to, give $$$ to and end up with a properly designed tank installed on your boat. In other words it is not a product ready for the "public". However for those who wish a very inexpensive alternative to other roll reduction options and have the time and expertise to implement one they are the best. On Swan Song I priced everything as a complete system to reduce the roll on our narrow, heavy, full displacement boat. MHI gyros: $145,000. Two gyros required, a dedicated 16KW genset and 1 16K BTU Air Conditioner to cool the space as they put out lots of heat! Active fins: $45,000 and up. Swan Song again is narrow, heavy and for fins slow. SO we would need large fins and all the attendant hydraulic systems to support them Trim Tab stabilizers: These are really not suitable for slow boats as they need at least 12-15 kts before they can be effective. They also are not cheap at $100K or so. Paravanes: $25-30K. Given the hull wasn't suitable for them as built we would need major structural changes to support the loads generated. Roll Tank: $11K. Design cost; $4,500. Materials $2500, Labor to build $2500, Cost to install on the pilothouse deck $1,500. Cost to fill $25.00 So, we didn't enter into this lightly and we knew we wanted a system that works full time whether the boat is moving or not. It is possible it could have all just gone bust but the designer has a good track record and we had faith. We also had been aboard Bob Phillips' Another Asylum and were very impressed with the results he achieved. Many of the Canadian fishing boats up in the Newfoundland to Cape Sable area are using then in lieu of paravanes now. It had to take some convincing arguments to get them to change ;-) So, as Steve says, these are not for everyone and there is a very small knowledge base out there in using them on small boats. I'm not sure who's tank design Mike Kasten was using for his comparison of roll reduction but in reading the article it seems it hadn't been explored in depth, IMO. Cheers Dave & Nancy Swan Song 787 990-6064 Sat 954 252-3830 fax -----Original Message----- From: passagemaking-under-power-bounces@lists.samurai.com [mailto:passagemaking-under-power-bounces@lists.samurai.com] On Behalf Of Steven Dubnoff Sent: Wednesday, August 30, 2006 3:16 PM To: Passagemaking Under Power List Subject: Re: [PUP] FW: Swan Song in Venezuela At 09:08 AM 8/30/2006, you wrote: >Very interesting post. I've never heard of the stability tank. How would I >get ahold of the software to design one or have one designed for me? This is, I think, a job for a professional, as poorly designed roll tanks can easily decrease stability. Michael Kasten has a discussion of roll--reduction strategies here: http://www.kastenmarine.com/roll_attenuation.htm Best, Steve Steve Dubnoff 1966 Willard Pilothouse www.mvnereid.com sdubnoff@circlesys.com _______________________________________________ Passagemaking-Under-Power Mailing List ------------------------------ Message: 8 Date: Wed, 30 Aug 2006 14:43:24 -0700 (PDT) From: Mark Subject: Re: [PUP] Over propping To: passagemaking-under-power@lists.samurai.com Message-ID: <20060830214324.24226.qmail@web31806.mail.mud.yahoo.com> Content-Type: text/plain; charset="us-ascii" Bob, help me understand why this is the case. As I read the engine and prop curves on: http://www.ossapowerlite.com/tech_library/fuel_efficiency/fuel_efficiency.htm they say: "It turns out that by shifting our propeller curve upward, we operate in the peak efficiency range of the engine over a much greater power range. Comparing the new prop to the original one, we see that the fuel economy of the engine would improve by an average of 13% in the low and middle speed ranges." He does go on to say that there is a problem that you can damage the engine by exceeding the point at which you overload the engine. However if one is willing to give up some high RPM operation for increased efficiency in the range in which the engine is used most often (or use a VPP) that seems reasonable, no? I think Beowulf used a VPP and they dialed up the prop until the exhaust temp indicated that the engine was properly loaded. === message truncated === --------------------------------- All-new Yahoo! 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