Displacement speed Qs

[vas]

Not sure that I need to disengage the gearbox during electric operation. I guess, it can just be in neutral provided that a separate pump lubricates/cools it.

check it out carefully, depends on the box and on principle I'd try to find a way to avoid it.

sure, not reinventing the wheel, but interesting nontheless.

Maybe someone can do the maths easily from fuel consumption and speed. That should be the only two things you need, speed for the revs and consumption to calculate through the calorific value the energy and then convert to an el.motor. Calcs not for me!

cheers

V.

 

[Hardmy]

If/when you do give me a shout as I think Pagasitikos bay and the n. sporades are definitely worth a visit, or even a stop over for a year. Not sure you'll have too many things to do in Chalkidiki, only visited from land, must be rather crowded.
Not sure though you can lift your stabbed boat on the trolleys we have in the local yards, but any patents or machinist work you want, you can definitely do it on the cheap down here.

Yes your home waters would be definitively on my list! But the place became slightly less practicable since RyanScare discontinued their HHN-VOL connection one or two years ago. The Chalkidiki is not on the flotillas track and is supposed not to be as crowded as the Ionian? There is also the excellent Manitsas yard in the area and lots of flights to SKG. Then, would be a nice trip down to the Dodecanese, we’ll see how things evolve in the area.
Re your yard in Volos, I never tried such a trailer and I am a bit scared about it (BTW, my boat has no stabs, so it would certainly work). A pity that there is no travel-lift far and wide from you. How many tons is Pefkakia able to handle?

 

[vas]

Yes your home waters would be definitively on my list! But the place became slightly less practicable since RyanScare discontinued their HHN-VOL connection one or two years ago. The Chalkidiki is not on the flotillas track and is supposed not to be as crowded as the Ionian? There is also the excellent Manitsas yard in the area and lots of flights to SKG. Then, would be a nice trip down to the Dodecanese, we’ll see how things evolve in the area.
Re your yard in Volos, I never tried such a trailer and I am a bit scared about it (BTW, my boat has no stabs, so it would certainly work). A pity that there is no travel-lift far and wide from you. How many tons is Pefkakia able to handle?

Yes, no floatillas and should be quieter than then Ionian.
Cannot comment on the flights, the only thing I know is that at a prefecture level they are working hard to get the Almyros (or Volos as it's called outside Greece) airport running with regular service and we should have news on that soon.
Bear in mind that my colleagues at the Uni are doing the feasibility study for a large "proper" marina within the bay will all proper amenities and that at a higher level this has already been accepted.
OK, this is Greece so don't hold your breath, but we may manage to get a decent marina in the end. I'm personally not moving as boat is halfway between home and work (400metres each side...) but others and ppl from abroad will definitely appreciate that.
You should definitely pass by and explore the area though!

Edited to add that pefkakia trolleys regularly haul 50+ and up to 60ft grp mobos and up to 30tons (or maybe 40 don't remember, can ask if you want)

cheers

V.

 

[Sandmartin]

There is confusion between hull speed and displacement speed.
To start with there is hull speed, this is normaly 1 x the square root of warer line length. this is where the hull divides the water and it flows around the hull. an example is a narrow boat doing 4 knots on a 5hp engine. this is normaly 1 x the square root of the waterline lengh.
Next is displacemnt speed, normaly about 1.4 x the square root of the waterline length. At displacent speed the bow is no longer dividing the waterand and starts pushing it away and starts a bow wave. At this point the bows start to lift and you start waisting fuel.
As you incease speed you will create a bow wave. The dip
wave after your bow wave will slowly move aft as you increase speed. Eventualy the dip from your bow wave will reach the stern. When the dip in the wave reaches the stern the stern will drop. To ride up the bow wave with the dropped stern will need more power, you are now semi displacement.
A great increase in power is now required to push the boat up onto its bow wave and start to plane.
My boat does 9 mpg at 4 knots 8 mpg at 5 knots 5mpg at 6 knots 3mpg at 7 knots 2mpg at 8 knots 1mpg at 10 knots