Rodman 41with IPS.

[ari]

Doubt the Phantom 46 has any more windage or the Turbo 36 but both have the engines in the middle of the boat not towards the aft end.

I doubt it does either, I'm talking about modern boats, you know, designed in this century!!

Good grief.

 

[ari]

So on a more serious note , here’s a mate of mine in his Porto 47 .This was designed for twin shafts , but around 2008 ish with IPS all the “sales “rage S/Sker did what MapishM is saying they took a nice fairly balanced hull cog and installed IPS .
I think at the time MBM did a back to back review of a shafts + IPS , the fuel burn was better at low planing , but equalled the shafty at high .
His sold it btw , one season after buying .
Cruising in Co was a pain as he would come over on the VHF as ask me drop the rpm s .
24 knots and he got alarms + the ride suffered because it was soooo far bow high due to the changed cog .Even with full flaps , here we are at 22 knots ( his request ) .
The AoA is far too high he has to pop his head out over the screen .
Too much weight at the back .

Except it's not conventional shaft drive is it? It's vee drives. So the engines would already be at the back and therefore centre of gravity will barely have moved - might even have moved forward a tad.

 

[MapisM]

I'm not familiar with that boat and if/how she was affected by the propulsion choice.
But her attitude in the pic that PF posted is indeed beyond a joke, also because the pic is deceiving - just look at the horizon.
The second below is more like it, and boys, ain't that awful!?!

 

[BruceK]

Impossible it would defy the laws of physics.

Wonders never cease

Maybe not quite as bad but they could all do with a periscope

 

[Portofino]

Except it's not conventional shaft drive is it? It's vee drives. So the engines would already be at the back and therefore centre of gravity will barely have moved - might even have moved forward a tad.

Inside the ER of the IPS pods + engines connected were tight against the inside of the transom .The tank was athwart ship up fwd against the aft cabin BH There was about 1 m gap between the tank and engines , a sort of checker plated storage area .
Batts one side of the D6 , geny outboard on the other both back .
Plus a hi lo bathing platform hanging off the whole lot .

The 48 was the true Mid cabin version , The 47 still had the 2 nd guest under the cockpit .
As said total re hash with the San Remo 48 IPS .
Flair prin seeker are light on IPS , Infact only S/Sker dabbled with arguably little commercial success , in terms of % ot TO ? or meter age sold , which ever way you attempt to jiggle the figures
Ferretti Group absented too , with year on growth in TO and meter age .
So where does IPS sit In the European market ?
Full credit to volvo P for market alacrity, but IPS is just an evolution of the outdrive , with all the inherent issues of separating the oily bits from the sea. There’s an inevitability.

 

[BruceK]

Wonders never cease

Maybe not quite as bad but they could all do with a periscope

Now I'm not saying it's down to shaft drives and massive degrees of deadrise but I gotta wonder because here we have a flatassed stern drive with all the gubbins on the back and the helmsman can sit and puff contentedly on a fag while reclining in his comfy chair.

 

[Portofino]

Wonders never cease

Maybe not quite as bad but they could all do with a periscope

They all fly a bit over waves and momentarily rise a bit while popping out .
You can do the flying thing over other folks wake s no need to ease back .

This threads about ( if understood it correctly) trying to make sense of a forumites recents IPS ride .
We are erring on the Cog shift ( which makes fantastic mid cabins ) and the hull attenuation , moving away from deadrise .

 

[Portofino]

Ah you have added a pic of your boat dead flat after I posted ^^^
.We are talking IPS handling .
Can you trim a IPS pod ....move it ?
I understand from being in the ‘ outdrive club “ you can trim them in .Correct .

Aside you are going fast in a dead calm .This can too .

 

[BruceK]

Is this the same Porto speaking or a new Porto?

Anyway. Here is flatass the sterndrive over some swells

flying flat I think.

 

[BruceK]

I mean seeing as we're talking complete bollox I could post some vids too. You could post your mates one again. That's always good for another laugh

 

[Portofino]

Why are you hijacking this with Images your flat bottomed rear weight adjustable trim sterndrive boat in pancake flat seas ?
Connect up the line of thought ps .

 

[BruceK]

This thread right from the OP's post is a hijack and of course we got to hear the usual rubbish from the usual suspects poo-pooing other people boats and it's a shame really because they have such conviction they are right it's just too easy to rock their self belief. Do you have any idea how such sweeping generalisations come across? I'm happy to be the clown, I'm just chuffed to have found playmates

 

[Portofino]

@ Bruce you get understand, vectoring pods with a joystick on an incline plane deep V for seakeeping at speed ,means in the dock some of that inclined plane effect ( 23 degrees in by boat ) would translate into severe rocking , tilting of the hull .
The higher the free board the worse the swing gonna look verging on clashing neighbours.
The rearward weight upsets the CoG so lift has to added .
Flattening the rear areas ( MapisM s ) pic over comes both problems .
1- less adverse roll / tilt vector on the jot stick vectoring .
2- enhanced rear stern lift .


The out drive rear weight bias , loss of CoG in relation to CoL can be corrected by flattening the rear and trimming .
With out drive high speed deep v the extra lift is proved by lifting strips and a wider chine , north of 30:knots ..Huntons Cigarettes etc . But and it’s a big but ...the ability to trim them unlike IPS .

Are there any fast IPS boats ? They all seem to be floating caravans .

 

[Portofino]

Return from East Coast back to civilization in the Medway.
Brisk winds against tide providing a short steep chop all the way.
80 miles 4 hours .
2500 RPM gave around 20 -21 knot cruise.
On last leg gave it some welly, not my fuel.
Short spell @ WOT gave 3000 on one engine and 3200 on the other. Max 30-31 knots.
Tanks about 60 % and water half full.
3 crew.
About right ? or .......mucky bottom perhaps.
Observations from one very short trip......................
Will we be rushing out to buy a boat with IPS. Judging by what you gain, basically bit of extra maneuverability as opposed to inevitable expence of extra maintaince and repairs. Err........probably not.
Cheaper and better to learn how to handle your boat.

Where the hijack Bruce ?

 

[Portofino]

To some extent it is, because even if the main IPS raison d'être are the ones I mentioned in post #16, it's undeniable that it also has the side advantage of requiring a bit less e/r space, AOTBE. And less e/r space means more space elsewhere, which is obviously another selling point, particularly with newcomers which surely don't buy boats based on e/r accessibility.

But actually, interior spaces and windows aside, whose obsessive search obviously affect any boat regardless of their propulsion, the choice of IPS affects seakeeping and comfort more than any other systems regardless.
In fact, as I already mentioned, pods require a rather peculiar hull shape, which no naval architect would even remotely consider for a planing hull, if it weren't for the need to mitigate undesired side effects of pods.
And since one pic is worth a thousand words, here's one example of a hull specifically designed from scratch with IPS propulsion in mind, and strictly optimized for it.
If this isn't enough to remind of Heath Robinson, I don't know what else is...

Careful once you start looking at Hull form .......you know where it’s gonna lead
Forum pariah.

 

[ari]

I'm not familiar with that boat and if/how she was affected by the propulsion choice.
But her attitude in the pic that PF posted is indeed beyond a joke, also because the pic is deceiving - just look at the horizon.
The second below is more like it, and boys, ain't that awful!?!
View attachment 98593

Completely impossible to tell from a single photo. That's coming off a slight swell, the next photo 1/2 second later would show it with the bows well buried.

Search Google images for Sunseeker Portofino 47 - NONE of them are running like that because that's not how they run.

Still, this thread (like so many) seems to have degenerated into the usual suspects 'proving' themselves 'right' rather than containing many actual facts.

Pity.

 

[BruceK]

I refuse to believe that Volvo and all the industry heavy weights in boat building colluded together and said hey, lets make something absolutely horrific and unseaworthy because then we can sell more of them and make more bucks.
Too many donuts in the boardroom perhaps?

 

[Portofino]

Completely impossible to tell from a single photo. That's coming off a slight swell, the next photo 1/2 second later would show it with the bows well buried.

Search Google images for Sunseeker Portofino 47 - NONE of them are running like that because that's not how they run.

Still, this thread (like so many) seems to have degenerated into the usual suspects 'proving' themselves 'right' rather than containing many actual facts.

Pity.

Ok Ari bear with me i will have to u tube the vid then post .
Expect a full apology if my IT skills in the marina are up to it .

 

[Portofino]

ari are you as smart as MapishM? Ps level up the horizon.

 

[BruceK]

Well while you are doing that lets have another look at Itama's

Awful

This one looks like it's in danger of rolling back into it's own hole. Talk about inefficient use of power

Does this one have IPS?

Love the way this one slices through the wake like a hot knife through butter

Porto is back. Hiya