Boat Designers

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Originally Posted by RANCHI OTTO

The design is very nice, I like it.
Perhaps a problem would be the inclination of the exhaust, what about side water intake by strong wind...
Not bad perhaps 2 wing shaped exhausts on side deck.

RANCHI Otto

This Air Induct design be used on Class 1 racers that runs 300Km/h....
Ok, Wings could even be nice

[RANCHI OTTO]

In the offshore the air intake are ok... no discussion.
The dimensions of these air intake are for lamborghini engines, I think that for gas-turbine they must have more intake surface...
I was meaning about the gas exhaust curved outside and placed in low position.
The offshore has their gas exhaust in transom, well protected.

RANCHI Otto

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Originally Posted by RANCHI OTTO

In the offshore the air intake are ok... no discussion.
The dimensions of these air intake are for lamborghini engines, I think that for gas-turbine they must have more intake surface...
I was meaning about the gas exhaust curved outside and placed in low position.
The offshore has their gas exhaust in transom, well protected.

RANCHI Otto

Its all about "Extravaganza" design

You do not buy a Ferrari for its practical advantages....

[RANCHI OTTO]

For this reason I buy PORSCHE.....never a ferrari !

RANCHI Otto

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Originally Posted by RANCHI OTTO

For this reason I buy PORSCHE.....never a ferrari !

RANCHI Otto

Ok, I understand you
Or something like this...
by www.viztech.se

[RANCHI OTTO]

Nice, nice but.......

RANCHI Otto

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VERY nice autobahn missile...
Now we talking Turboz.....

www.turbinetecsystems.de

2200 HP - 285kg

[RANCHI OTTO]

Beautiful, only you have to added the gear box weight, double fuel (oil + avio) and a 3rd engine for the low speeds.

In any way it is my opinion that even with 2 x turbine + 1 central engine you have the best ratio btw. weight and power concerning the propulsion plant.

To reach 100 knots with 2 x 2200 bhp and piercing propellers you will need 15 t abt. displacement....

Exciting project.

RANCHI Otto

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What about a leight weight 250 bhp 6-cyl Steyr turbo diesel coupled via axel to a water jet as 3trd. and a bowtruster for easy manouverability in harbours?

100 knots+ , fast but not impossible

[RANCHI OTTO]

Diesel engine of 250 bhp is ok for low range speed up to 15 knots.
The maker is only question of weight, spare parts and price.

Waterjet + gas turbine is a good choiche.
With a waterjet you will have a very good manoeuvrability in harbor.

Look the exhaust size for 1 gas turbine engine...
It is placed straight in high position because the high temperature of the gas... very dangerous if you place 2 exhaust at side.

The speed of 100 knots is not a dream but a question of weight.

I've employed my "rule of thumb" for estimate speed based on several results from sea tests for boats over 40 knots, i.e. :

Vk = (KR - 11.4) * 3.9697 + 30

KR = (BHP^0.551/Displ.^0.476)

where:
Vk > speed in knots
BHP > metric brake horspower
Displ. > displacement in metric ton

RANCHI Otto

[D'ARTOIS]

Waterjet propulsion in the case of MS will not function at high speeds; the waterinlet will be too far forward and therefore will run dry at high speeds;

The exhaustpipes of the gasturbines can be placed horizontally aft; they are of the watercooled kind and therefore will cause no heating problems - second to that the proposed building material of MS will not transfer heat as any other material will do and will be resistant against extreme high temperatures;

To reach a top speed of 100 knots plus is not a matter of mathematical calculation but of a reinement of the hull and a suppression of weight.

Where are the 15 t overall weight coming from?

Can you give me specific examples of weight of drive train, engines/reduction boxes, interior and hull? Save for the tankage?

[RANCHI OTTO]

The waterjet is installed only for the low speed and manoeuvring in harbor not for added power of the propulsion plant.

Perhaps you know how much is the expulsion speed of the gas and the temperature ?
Are you sure that it is possible and reccomanded to have wet exhaust ?

!00 knots is the relationship btw power and displacement for normal hulls.
If in the formula you have less displacement the speed is increasing, is not the same as what you say...?

15 tons is the estimated displacement to reach with the power indicated the 100 knots.

I see such craft built in aluminum...

Last points, I'm sorry but I don't understand the questions...

RANCHI Otto

[D'ARTOIS]

I appreciate your kind approach of this matter, however I have a very close relationship with high speed craft and therefore I might be a bit more at ease in this particular matter.

The two gasturbines can give about 1750 hp each; the drive train's weight will be approx 900 kgs in total including the trimax; Hull weight will be approx 2500 kgs or less; interior will be 800 kgs or less - the tankage can be designed at will - speeds of 100 knots will cause not a singular problem.

I received from John Arruda two pictures of such a drive train.

You will see that this is a state of the art kind of engineering and the results of this company are widely recognised.
www.turbinemarine.com

[RANCHI OTTO]

Thank you for the web...very interesting!
Why Trimax...? Rudder at 100 knots? Not possibility to trim while running....
Better Arneson, ZF or SDS....
If you visite my web I'm very closed to high speed craft too ..until yet up to 86 knots. Not enough, I hope to reach the 100 knots in short time.

RANCHI Otto

[D'ARTOIS]

Yes, personally I would opt too for those applications. Probably you are familiar with Paul Bezzi's SDS - I worked closely with his comapny in 1995/6 when I was designing a 63 mtr motoryacht with a triple SDS drivetrain - later on this configuration had been used on "Golden Eye" and unfortunately the naval architect of that particular boat errored gravely in the weight calculation so this drive failed to reach it's supposed target.

The main disadvantage of such a configuration is the very poor manoeuvrability at low speeds. For the rest: there is almost no better propulsion thinkable.
A side problem is the difficulty of trimming during driving the boat at it's top speed. Driving an SDS means that you start with lowering the shafts and gradually bring them up till the engines reach their max rpm.
At speeds lower, much lower than 80 mph it is quite possible, but not for the every day's amateur.
At higher speeds, you have to be a proficient driver, almost equalling a F1 driver so, the complex system might be a bit too much for the everyday's boater.
But technically spoken, yes I agree, an SDS or ZF system would be much preferrable.