Kurt Jon Ulmer wrote:

Gary King wrote:

Kurt Jon Ulmer wrote:

We might resurrect the well idea, and put one into mehitabel yet, if we decide to go through Panama, or other canals, or somewhere difficult. Buying, using and selling an outboard once in a while shouldn't be too much trouble, if we do.

Cheers,

Kurt

I would have thought your plan for a Honda generator would solve range issues.

Re: Yamaha T9.9 

I never noticed they pack such a huge prop, dont think my well would take it, it was modelled on standard 8" models.

But where either the current or the Panama Canal Authority enforce minimum speed limits, the power of a 9.9HP outboard added to the electric drive would give confidence. 

Cheers,

Kurt

For the Panama Canal, you have to sign a piece of paper that says you can keep up a speed of 8 knots. As long as you sign, and say nothing, it's fine if you can keep up 5 knots. If you don't sign, they charge you a lot more. If you do sign, 5 knots is enough to keep to schedule, but any less, and you may get your "Advisor" ( the sort-of-pilot-cum-link-to-the-canal-authorities that you have to carry) asking you to hurry it up. Going east to west, you have a tailwind, and I asked if we could sail across Gatun Lake. "Not really allowed, but OK, then". Our Advisor was quite pleased with the way we could go faster, in silence, and watch the wildlife without disturbing it. Going west to east, it will be upwind, and more power will be needed to keep to schedule.

Lesley Verbrugge wrote:I reckon your maths is faultless, Annie, just the unit is wrong?

The way I read it was 30 nm per 12L at 4 knots = 2.5nm per litre at 4 knots

Ah yes, silly me.  All these isocyanates and epoxy fumes, I guess.

For the sake of comparison, I would expect to get a little over 4 nm to the litre at 4 knots, assuming calm conditions.

While cruising Easy Go in the Canadian Great Lakes we used a 9.9 HP Honda 4 stroke mounted on at bulkhead over the port side. While good for the rivers and lakes we abandoned the setup for ocean travel. This setup easily cruised at 4 to 4.5 knots and at full throttle pushed us along in excess of 6 knots, the speed we needed to transit the St Lawrence Seaway. I'm sure a similar motor mounted in a well would give similar performance.

Thanks for all the interest from everyone in the outboard option. Having owned several cruising yachts with 'good enough' (to quote one our well respected members) deisel engines, I have, as stated elswhere, a gut feeling that the 9.9hp Yamaha high thrust gives about the same performance as say a 20hp deisel would. Certainly since I upgraded to the 9.9 from the 8hp I now have reasonable motoring speed in calm to moderate conditions which for me is between 4 and 5 knots, and with the high thrust prop enough manouvering capability in all wind conditions I have encountered. The nice thing about the outboard is it's lower cost and simplicity of installation, apart from the complexity of the outboard well. Certainly I think that with the stage of development that at least the Yamaha outboards are at they are now a realistic option to a diesel motor provided it is the right configuration of boat. 

I am about to head off tomorrow evening for the 100 nautical mile passage to the Bay of Islands and as there is not a lot of wind forecast I may have a bit more to report next week about the long range performance of the outboard. Hopefully there will be at least enough wind for my new camber panel sail to push me along at something approaching motoring speed and I will arrive in the BOI with most of the 44 litres of fuel onboard still in the fuel tanks.

                                                                  Stavanger, Monday

Motors are intersting stuff. One thing which is often overlooked is the efficiency of the propeller - or lack of it.

When the Norwegian fishing fleet replaced propulsion by sail and oars early in the 20th century, they skipped the steam engines and went right onto the 1-2 cylinder 2-stroke semidiesel engines. These dominated until after WW2. Their output was low compared to their weight, but fuel economy was good. My point is that all these slow-running engines could swing huge 2-blade propellers with variable pitch. These propellers had a very high efficiency, resulting in a good mileage per gallon

The videos below shows a little Stavanger ship of some 50-60t displacement. Her 50hp 1-Cyl. Wichmann (‘Rubb’, built in 1937) is able to propel her at about 7kts

link 1

link2　

These days the best outboard engines with high-thrust propellers have become terribly effective, compared to those in the 1960s. My 3-ton Johanna has been tested to go at 5.8kts on 0.50litre/NM (Top speed =6.3kts). The engine is a 9.9hp Yamaha 4-stroke outboard with 3:1 gear and swinging an 11 3/4 " propeller.

Many of today’s folding propellers, used on sailboats, are miserably inefficient. In many cases it would be much smarter to keep the engine and replace the folding propeller with a big, nice 3-blade Kiwi-propeller and play around with its adjustable pitch until one gets it right. Personally I’ll stick to the outboard as it gives such super manoeuvrability in harbour - especially welcome in a blow. I don’t spend much over 10litre per summer so investing in a diesel would simply not make sense. OK then, maybe a Torqeedo electric outboard when the Yamaha one day says farewell.

Cheers, Arne