Single Engine... vs more

NYCAP123... if I took overnighter holiday to Amsterdam to have a late night talk the lady of the house might be insisting on an early mourning confessional because she might think I was not just talking boating... a language she understands not at all.

Olderboater... you are right we are all wanting it all. Like I said if we had a magic power source that did everything, never broke down, needed no maintenance and turned on and off with a switch on the helm there would be no discussion. But I think this could be gone about differently.

The subject of this thread is single engine vs. more... now conventionally that is one propulsion engine vs two or more. But to me it also has the meaning of ONE ENGINE.

I am not talking about new technology but new way of configuring current technology. Why not have one engine to power the boat... both propulsion and otherwise. Why not have another technology such as a modern storage battery system as back up. If the power plant fails the batteries make for a back up.
This could be taken further if fuel cells become more common.

Submarines use one power source... and a second power storage system by tradition. Diesel electric boats have batteries in addition to the diesel power... and a few have fuel cells too for a total of three independent and different power supplies. Nuclear have batteries and emergency generators (this last for reactor protective functions) besides the nuclear plant.

Why cannot a yacht have on power source that is a diesel engine powered and backup of a second like batteries or something else. Most sail boats now days have sails and a diesel so there are two sources... thought to sail one still needs power to supply the sail handling equipment too.

So why cannot a yacht have one engine either directly driving the shaft with a generator/motor in series where the diesel can be operate either the generator and shaft or shaft or generator only. Then have batteries for back up.

Or why cannot a yacht have the diesel driving a generator only with batteries for backup and the propulsion and other loads electrically driven.

Yachts seldom operate at top speed and for only brief periods... so they are over powered... you could have a smaller diesel being used and use the batteries for the peak load.

This is all standard stuff but not applied to yachting because of convention. But it would make yachts more roomy... likely more reliable and safer... have lower operating costs... have less space devoted to the machinery... require fewer crew... and be less expensive to operate or build.

The J boat Rainbow recreation faced the problem as there was limited space available but the owner wanted it all. Now they did not go as far as I have suggested but came closer.

This subject came up when I was thinking about another boat and replacing two engines with four. The lady of the house... who is truly always right on everything... though I am too stubborn to generally admit it... she said one word... POURQUOI !

At first I was thinking she meant 'why get the boat'... which she did... then I thought she meant 'why replace the two with the four'... which she did... but it really took me back when she said, "Pourquoi avez-vous besoin plusieurs ... que l'on est assez pour une voiture." Basically... "why do you need many... when one is enough for a car".

BUT like everyone else I found this IS HORRIFYING TO CONTEMPLATE... I think because we are creatures of habit and cultural convention.

Thanks everyone for the suggestions and comments.

I suppose it is one of my fanciful ideas to have "one power source" or lets call that one fuel powered power source and battery backups as a hybrid even.

And, I accept that at least two power sources are vital... and probably should leave design issues to the experts.

This is especially true for a sail yacht of a size other than something you would class a daysailer. Why the term especially is I cannot image sail handling totally manually now-a-days on any larger boat. And, if the power system goes out you may be stuck worse than on any power boat. And, it is true for motor yachts too... leave it to the experts.

But... I really like the idea of an all electric boat... but you have to produce the power somehow. Of course a sail boat has the sails as primary or backup as you please... and the world has been sailed by many with only sails and maybe human powered oars as backup. Now when I was young my ideal was something about 36 to 40 feet or 9-10m and that I though could take me anywhere I wanted. The power sail handling was not something even considered. However, the auxiliary and electric power for lights and some modest hotel loads was. In those days 50 years ago the solution was to have the engine generator do everything... with battery storage. Of course, I thought a windmill or waterwheel electric generator would be the ultimate as I could 'save on fuel costs'. I tried a couple set ups but they were only really suitable for topping up batteries... something today I suppose could be done with properly placed and thought out solar panels. That could have been done in those days too but the panels would have cost what the boat cost so were impractical. And that size boat is way too small... now.

Now I have to admit when I was 21 I crossed the English Channel in October in very rough weather 3-4m seas maybe a little more... wasn't that bad when I left... after starting off in a few hours it poured rain the whole rest of the way... I suppose a trip in a fold-up kayak might have been a lot more trouble than I thought because of the weather situation... it took about 2 days. Actually seas and weather picked up not long after I started so I wasn't so foolish... except for not checking weather forecast. Arrived in France on the blackest overcast nasty day you could imagine... unless you live in Brittany. Arriving I was so cold, wet, and exhausted I actually lost memory for awhile. Now I was the only power source running on a few chocolate bars and bananas. I sometimes think of doing it again for nostalga but that is only thinking and not doing... but I would be missed and cause some heartache!

Now it's hard to imagine a boat without power assist for everything. Its unimaginable now to consider a 9-10m other than a day sailor... a kayak is a toy for warm tropical days. But then... now I am spoiled... boats are bigger and it is not so simple.

Belle... I think your idea of using a wind generator.... or large air propeller as a propulsion and energy production means has huge merit... and have seen a couple experimental yachts like this on YouTube.

The drag of the propeller proves sail like propulsion by direct wind to push on the hull.

The energy generated by the propeller spinning produces energy for hotel and/or motor based propulsion via electric drive.

Its not only possible it has been done.... and may be the best of all worlds... though has huge market resistance due to not being "like" something conventional... people get believe what they commonly see is right and are resistive to new ideas... so is the story of technology.

My brother sent me this link today.
http://news.yahoo.com/virtually-perfect-plane-231500844--politics.html

Its about the 777 Boeing aircraft's reliability record. Actually this is partly why I have been thinking of less is more for a new boat. Certainly Flt 370 might cause one to rethink but it did fly until it ran out of fuel from the reports coming together.

That article makes the point I have been trying to make with this post and back up my thinking. I have been thinking for some time only one power source needs to be in operation at any one time on a yacht. Certainly a redundant second is important but really most of the time one is all that would be used at a time.

Now I agree probably ONE ENGINE is not enough. Using two is a better situation. But in my mind the thinking is on a motor yacht is eliminate all the generators and just have one or TWO diesel electric drives with battery parallel hybrid electric drive/power system... as the only power source. Two large generators... running one most of the time underway at cruise to provide the entire power needs of the boat. But that basically means ONE engine running most of the time with the other in backup for emergency or for high speed runs that is seldom used or needed. At anchor the batteries would suffice except for one or two charge cycles of an hour or two a day one one of the primary generator sets.

Now many would argue with a diesel electric more generator sets is preferable due to loading variances. But on a yacht those are less than on a cruise ship. Also, having variable speed generators with conditioned power would allow the output to be tailored to the need.

Maybe this should be in the diesel electric thread or a new thread (and I might repost in the diesel thread for that reason) but the idea behind this thread was this line of thought!