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Post by mbw9494 on Mar 30, 2015 10:33:41 GMT
Hello, can you help me calculate the diesel consumption on my Jeanneau SO 39i with 40hp Yanmar. I am crossing Biscay from Plymouth to Bayona as one leg, and want enough fuel to motor there if I had too. My fuel tank holds 130 litres and I carry two cans of 20litres each. Your comments would be much appreciated. Regards Malcolm |
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Post by rockstar on Mar 30, 2015 11:39:21 GMT
Hi Malcolm,
Thats a very hard one to answer but as you are a sailing boat hopefully you will not have to motor all the way. If you have to motor in a flat sea the revs down to give 4.5 to 5 kns I think you could get about 475 miles a bit more at 4kns.
Best of luck
Francis.
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Post by JEF on Mar 30, 2015 11:58:07 GMT
Malcolm
So many influential factors when mapping passage fuel usage trends .. Prop std or otherwise / Hull clean or fouled / Weather / Tides / Engine Revs ... you can go on ... so IMO you need to work out you own current usage averages plus build in a small percentage allowing for a fuel safety margin.
Starting point ...
1. Reference the Yanmar website and get the manufactures Ltr / Hour map for your engine type
2. Do your own fuel tank top up / neck test and collate data. ie Start with Full tank note actual engine hours then passage for more than 3 hours min in various conditions if possible at your prefered cruising revs, When back on berth top up tank again noting the amount the fuel to refill tank and the engine hours run.
3. Map out Ltr / hour and build in a percentage that you are happy with on top of this figure to ensure you are always on the safe side.
I personally log all fuel usage on passage and never let my fuel tank go any lower than 2/3rds empty that way I have always a min of 1/3rd of fuel in the tank at any one time which covers for safe running in a very heavy seas etc. In my case I carry approx 1/3rd of a tank in reserve containers on most of my longer yacht passages which safely cover most eventualities.
Hope this helps ....
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Post by MalcolmP on Mar 30, 2015 12:10:11 GMT
Interesting one - on our 39i with the same 39hp I normally assume around 2.5l /h @ 6knts but that is maybe a bit cautious. Agree that you should be able to presume sailing quite a lot of it - Looks like 550nm so that could be as many as 110 hours motoring if you cant sail so you would be short even with 170l and obviously best not to scrape the bottom of the tank if you can avoid it. Although for the saildrive version this has the "official" consumption figures various revs so might be helpful www.forkedrivermarinas.com/yanmar/pdfs/jh/3JH4E_TechData.pdfPresume you will have a clean bottom and prop before you start as well - makes a massive difference Not really relevant but yesterday I was chatting to a Norwegian owner of a 39i that he had just bought out of the Sunsail Carribean charter fleet and had refreshed in Port Solent - new grey graphics and canvas work made the boat look stunning. he was waiting for weather window but was planning to plug directly up the North Sea to Norway |
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Post by Damir on Mar 30, 2015 12:25:26 GMT
To cross the Bay of Biscay check that weather conditions are good. I've passed many times and many times it was terrible for large vessels. Attach all well on board which can be moved because when boiling sea no chance to fix, can only get hurt and help is far away.
Have a calm sea
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Post by vasko on Mar 30, 2015 17:57:04 GMT
Seems a long passage on one go.. about 3-5 days - will be difficult to predict the exact weather for such a long period in the Biscay - if I'm on your place I will plane a refuelling stop at Lorient or La Rochelle ... I guess will be better if you can refill with fresh water too ...
Have a calm sea
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Post by dublin on Mar 30, 2015 21:28:06 GMT
Same engine, 39DS
We average 2.5lt per hour on motored passage, moderate conditions and average 6 kts boat speed
Can't motor all way across Biscay and very unlikely to have need to do so.
Prevailing wind is SW. Very little likelihood of no wind. Strong winds create huge seas due to structure of continental shelf. Saw swell rising over the edge of the shelf creates huge seas.
Real issue is too much wi JD - we had 40kts gusting to 55 for almost two days from SW. Luckily we were headed north.
Plan a passage of at least 2 dayes longer than direct course and be prepared to heave to for a period
Will never cross direct again. Will do last 300 miles in jump from France to Northern Spain
But of course there are people who had a beautiful sail all the way.
That's nature
But bottom line is our boats do not carry enough fuel to motor that distance and refuelling from cans is not really practical in big rolling seas
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Post by sailbleu on Mar 31, 2015 5:36:31 GMT
Hello, can you help me calculate the diesel consumption on my Jeanneau SO 39i with 40hp Yanmar. I am crossing Biscay from Plymouth to Bayona as one leg, and want enough fuel to motor there if I had too. My fuel tank holds 130 litres and I carry two cans of 20litres each. Your comments would be much appreciated. Regards Malcolm More than enough. First of all you will - no doubt about it - be timing the start of the crossing using a good weather window. That will get you going ( sailing) for at least two days. From where you start it takes 4 days ( average) to get to La Coruna or Cap Finisterre , mind you if the weather turns bad , and that can happen out of the blue , it would be very hard to take Cap Finisterre . From the 3 times I made the crossing ( from France 3 days each time ) I had to shelter and wait a few days before being able to take the Cap. from the Cap to Bayone another day sailing , but that could also turn into a nightmare because the classic North usually starts from Portugal Hard to tell how many depressions will hit the bay this year , but the last few years were terrible. Biscay has a reputation and it' s well deserved. Good luck |
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Post by ianpowolny on Mar 31, 2015 11:01:44 GMT
This won't answer your question on fuel requirements but may get you thinking. My wife and I spent last summer sailing to NW Spain. Looking back we're glad we didn't miss out all the ports we arrived at along the French Coast but you may have been to these already. We finally arrived in Spain at Getox and visited Bilbao. We then traveled along the north coast of Spain and laid up for the winter at Viviero. What a great journey it was. I would advise one of these for topping up your fuel tank at sea: www.force4.co.uk/force-4-superpump-syphon-pump.html#.VRp-PvnF-Sowww.facebook.com/yachtaffinity?ref=bookmarks |
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Post by MalcolmP on Mar 31, 2015 11:38:05 GMT
MBW9494 is in the ARC Portugal - so will be crossing with a fleet Regarding filling from Jerry cans - try one of these - bought one at the last boat show - very clever indeed www.superspout.com/ |
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Post by ianpowolny on Mar 31, 2015 14:43:01 GMT
That looks like a good idea.
We went for a siphon tube, as advised by a friendly lady sailing school owner, as our fuel filler is outboard of the safety rail and lifting and balancing a 20kg fuel can is difficult enough in a marina but at sea it becomes a real chore. We also bought 10ltr cans not 20ltr to reduce the weight.
If you have easy access to the fuel filler then a siphon tube and small cans are unnecessary. Ian
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Post by Deleted on Mar 31, 2015 15:18:32 GMT
Malcolm - your fuel reserves should be fine.
For an idea of what you might expect with careful weather planning, copying below the Sailblog from our last crossing.
The GRIB wind forecasts were spot on!
Jeanneau 36i ‘SUNSET’ delivery: Chichester – Gibraltar SEPT 10 – 19 2013
Chichester - Ushant: 215nm: 34 hours: 6kts
With new owner Geoff, we sailed from Chichester at 0340 on Tuesday Sept 10 with winds at NW 10 - 15 for a fast reach to the Fromveur Channel to transit Ushant.
Ushant - Cabo Villano: 375nm: 61 hours: 6.2kts
Into Biscay with those lovely north westerlies for 24 hours, veering N to NE to run wing & wing with the genoa poled to starboard & assymetric spinnaker flown to port - magic.
Cabo Villano - Cape St Vincent: 375nm: 63hours: 6.2kts
The NW corner of Spain did not disappoint - solid NW 20-25 kts to run fast down the Iberian Peninsular.
Cape St Vincent - Gibraltar: 200nm: 32 hours: 6.2kts
We rounded the great Cape of Sao Vicente in NW 25kts; superb sailing.
Winds then backed to SW 12-15 kts for a broad reach to Gibraltar.
Then the big mistake - to enter the Bay of Gibraltar at 0200 on a pitch black night, to be confronted with lights everywhere, huge ships anchored all over the place, great walls of steel under way steaming in all directions - stuff of nightmares for a tired skipper.
Very grateful to berth safely in Marina Bay and a large tot of rum!
One great final sail - 1165 nm averaging over 6 knots - thank you SUNSET and fair winds in the future.
So its all about getting a feel for the Biscay weather for your start; GRIB files are a great asset today.
Hopefully the ARC will not commit you to a fixed start date?
Above was our 7th Biscay crossing; apart from a few short lived squalls we have enjoyed good sailing.
That said, I retain great respect for La Biscay.
Enjoy!
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Post by hoppy on Mar 31, 2015 16:31:16 GMT
I did a test to see the speed at a given revs between 2000 & 3000 rpm and added the consumption figures from the Yanmar manual. Plugged it all into a spreadsheet and made a pretty graph  All it really told me was that the faster I go, the less distance I cover ;-) |
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Post by hoppy on Mar 31, 2015 16:34:06 GMT
MBW9494 is in the ARC Portugal - so will be crossing with a fleet Regarding filling from Jerry cans - try one of these - bought one at the last boat show - very clever indeed www.superspout.com/Wouldn't a siphon be better for filling up at sea? |
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Post by sunnydayz on Mar 31, 2015 17:14:04 GMT
Hi Malcolm,
A very good good question and some really great advice.
For my two pennies we have crossed Biscay twice. The first time in 2012 on our much loved 42 DS which has a similar fuel size fuel tank, and that was with the Rally Portugal. Just for interest your question prompted me to check our log books, and they show that in 2012 we motored for 50 hours and a carried 60 litres in Jerry cans.
The last crossing we did was in 2014 also in June on our new to us Jeanneau 45, and the log book shows 68 engine hours.
As weather and sea conditions are the main factors, my information is somewhat academic, but thought I would share it anyway.
Just copy and paste scarletladysodyssey into Google to see our experience in 2012.
Our advice would be if you can make room for another can or two it could be worthwhile for your peace of mind. If you get the chance to top the main tank on route up make sure this is done on a calm day if possible, we use a jiggle siphon.
Last year we had friends on the ARC Portugal who had used a fair bit of fuel in the first few days calm days only to find themselves in horrible conditions after that. Two yachts that I know of had engine issues because the rough seas has stirred up muck in the dwindling fuel tank, which made for interesting moments! Both managed to clear the blockages and re start engines. Both had loads of fuel in Jerry cans which with hindsight, would have been better in the main tank when they had the opportunity but that is just my opinion.
Now the next question will be how much fuel do I need for crossing the Atlantic later this year!
Good luck Malcolm, we had tremendous fun with the Rally, wonderful memories and friendships that have lasted well beyond the end of the event.
Keep a look out for Aztec Dream if you have AIS when you get to the Algarve, as we may pass at some point, and if possible would be great to meet up.
All the best
Steve
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Post by mbw9494 on Apr 3, 2015 8:34:54 GMT
Hello, to everyone who has been kind enough to provide really helpful advice.
From the information you have provided:-
I will take an additional 50litres of fuel to be on the safe side. Buy a fuel pump to fill from tank to tank direct to avoid spillage. Seriously look at breaking up the trip and not sailing direct to Baiona, which I will need as a Plan B. in any event. I agree about the comment, that of course over a few days passage, weather can change a lot, particularly in Biscay.
The ARC Portugal has around 10 boats in the fleet so far and leaves Plymouth on Sunday May 31st and we don't leave Baiona until 9th June. So there is plenty of time for the 550 NM. trip. After leaving Baiona the legs to Lagos are between 15 to 75 NM. These are the legs I am looking forward to. Thanks again to you all for such good and comforting advice. Regards MBW
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Post by ianpowolny on Apr 3, 2015 23:27:52 GMT
MBW, keep in touch. Your friends leave us at Baiona on the 25 May and we"ll tootal down the Portugese Coast after that. We transmit AIS so check for us as you go. Ian
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Post by mbw9494 on Apr 4, 2015 14:39:27 GMT
Hi Ian, yes will stay in touch and thanks again for your advice. Regards, MBW/ Malcolm |
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Post by ianpowolny on Jun 12, 2015 12:24:12 GMT
That looks like a good idea. We went for a siphon tube, as advised by a friendly lady sailing school owner, as our fuel filler is outboard of the safety rail and lifting and balancing a 20kg fuel can is difficult enough in a marina but at sea it becomes a real chore. We also bought 10ltr cans not 20ltr to reduce the weight. If you have easy access to the fuel filler then a siphon tube and small cans are unnecessary. Ian I used our siphon tube today to add 60lts of fuel to the tank. We were in a marina but could easily do this at sea. It took less than 3mins to empty a 10ltr fuel can and was easy to use. Need a bucket to collect the diesel drips. Ian |
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Post by mbw9494 on Jul 5, 2015 9:11:39 GMT
Hello, can you help me calculate the diesel consumption on my Jeanneau SO 39i with 40hp Yanmar. I am crossing Biscay from Plymouth to Bayona as one leg, and want enough fuel to motor there if I had too. My fuel tank holds 130 litres and I carry two cans of 20litres each. Your comments would be much appreciated. Regards Malcolm |
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Post by mbw9494 on Jul 5, 2015 9:18:17 GMT
Hello all.
I finally calculated that my diesel fuel consumption was 2.85 ltr. per hour, av. speed about 5.6 knots for 30 plus hours. Passage was meant to be Plymouth Bayona, but we had to divert to Brest due to a sick crew. Weather mixed and some strong tides. So in future i am working on 3 ltr per hour. I hope that helps others.
Fair Winds
MBW
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Post by ForGrinsToo on Jul 13, 2015 21:05:48 GMT
Over 400 nm in the last three weeks, our 36i averaged 6.0 kts at 2100 rpm (we sailed for about 70% of the trip)consuming 1.84 L/hr, which is about 15% more than Yanmar shows for the the 3YM30 specific fuel consumption. Yes, the bottom could be cleaner.
Geoff
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Post by ForGrinsToo on Jul 14, 2015 19:12:41 GMT
The point I was trying to make: my measured fuel consumption was 15 - 20% more than Yanmar predicted. That's not surprising for a number of reasons. But it tells me my range is 300nm, not 400, in relatively flat seas (and leaving a few gallons as reserve).
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Post by sitara on Jul 14, 2015 22:17:44 GMT
Hi ForGrinsToo,
What prop do you have on the boat?
Rob
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Post by ForGrinsToo on Jul 15, 2015 16:23:54 GMT
Hi Rob,
Standard 3-blade supplied by Jeanneau for a US-built boat. I've never checked the pitch or diameter (and haven't found it on-line), but will as I am considering a folding prop upgrade.
Geoff
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