Why Gasturbine? This boat is why...

[GasTurbine]

People keep asking me about my handle, but I was never in the navy, however, have been building performance boats since the '60s. My handle comes from one of those project...a 1999 20' Rogers Bonneville with a 1350 hp Lycoming T-53 Gas Turbine stuffed in it. Drive is a Arnesen Surface unit swinging a 24x29 screw.

Top speed is about 145 mph, and can get from 0 to 100 in about 7 seconds because we put a disc brake on the output shaft which allows us to load the turbine up, then release the brake allowing tremendous hole shots.

Power is delivered through a Casale 1:.83 over-drive v-drive, which has forward, reverse, and neutral.

The boat is turn key, reliable, and built right. We can build piston engines that make this HP, but the rebuild schedule would be high, and any "sustained" runs could result in grenading the engine. Thats the nice thing about turbines...they are right at home running 100%...all day long. In fact, they tend to run cooler at speed.

The downsides are noise and fuel consumption. The thing is loud, real loud. We wear helicopter noise-cancelling intercom headsets when in operation and fuel consumption is 100 GPH at speed. It was not uncommon to drop $200-$400 in fuel costs for a short afternoon of fun.

Hers are some pix and a crappy video...

http://www.n8wct.com/web/mvc-913f.jpg

http://www.n8wct.com/web/mvc-914f.jpg

http://www.n8wct.com/web/mvc-915f.jpg

http://www.n8wct.com/web/mvc-916f.jpg

http://www.n8wct.com/web/mvc-917f.jpg

[GasTurbine]

http://www.n8wct.com/web/mvc-918f.jpg

http://www.n8wct.com/web/mvc-919f.jpg

http://www.n8wct.com/web/mvc-920f.jpg

http://www.n8wct.com/web/mvc-921f.jpg

[Atlas]

:thumbsup:

[Wax_job]

That thin is tearin' ass standing still man!!

It looks like it would hurt me, and I don't care, I still wanna ride.

[Ironbar]

I read the thread twice, but all I could get out of it was "Blah, Blah, Blah, Blah, Blah, top speed, Blah, Blah, Blah, Blah, Blah, Blah, noisy, Blah, Blah, Blah, Blah, Blah, uses a lot of gas. :dancing:

[opto_isolator]

So how does this thing transfer power to the output shaft, it is like a power turbine setup that ships use (essentially 2 shafts, one the "gas generator" the second the "power turbine" - coupled only by the hot gases that are generated)?

[Anglin_AZ]

I read the thread twice, but all I could get out of it was "Blah, Blah, Blah, Blah, Blah, top speed, Blah, Blah, Blah, Blah, Blah, Blah, noisy, Blah, Blah, Blah, Blah, Blah, uses a lot of gas. :dancing:

Same here. I was thinking this would be better if there were bikini pics included with a boat like that. :tongueout:

[robin303]

Very Cool. We had the T-53 in the Cobras and Hueys.

[aircarver]

Seen enough videos of flat hulls going airborne, that it's not for me ... :alex:

.

[Atomic Punk]

that is awesome. does the exhaust push the tail end down much?

[MtBaldy]

So how does this thing transfer power to the output shaft, it is like a power turbine setup that ships use (essentially 2 shafts, one the "gas generator" the second the "power turbine" - coupled only by the hot gases that are generated)?

Pic 8 shows V-drive.

[MtBaldy]

People keep asking me about my handle, but I was never in the navy, however, have been building performance boats since the '60s. My handle comes from one of those project...a 1999 20' Rogers Bonneville with a 1350 hp Lycoming T-53 Gas Turbine stuffed in it. ]

Very cool. I'm jealous.

[alphacat]

That would be fun, fun, fun to drive.......

[GasTurbine]

So how does this thing transfer power to the output shaft, it is like a power turbine setup that ships use (essentially 2 shafts, one the "gas generator" the second the "power turbine" - coupled only by the hot gases that are generated)?

It does have two shafts, but not quite like you are saying...

"Turbo Props" as they are referred to, are basically jet engines that convert the thrust into (shaft driven) torque by adding vanes and turbine blades (wheels) at the exhaust.

They also add another set of vanes/blade wheel to power the compressor.

You can see in this picture, the first "wheel" powers the compressor. This assembly spins all the time. The second wheel is what is connected to the power shaft, and can be retarded, or even stopped completely for a short time.

http://www.n8wct.com/web/t53.jpg

Typically there is a geared planetary reduction unit at the output (3:1 on the T53) as the turbine speed run about 28k RPM, so it can get it down to around 9k RPM (much more manageable for rotors/props).

[GasTurbine]

that is awesome. does the exhaust push the tail end down much?

It has about 180 lbs of forward thrust. How did we find this out you ask?

We were running in on the trailer in a garage with a smooth floor, and the whole thing started moving forward slowly.

So to answer your question, it would be like having a 180 lb man standing on the stern at speed, and since the drive is articulate, you can trim it out.

[GasTurbine]

Seen enough videos of flat hulls going airborne, that it's not for me .

This is a v-hull. Pretty flat @ 13 degrees, but still a vee.

[Fear Night]

Got the video posted? I couldn't find it.

[GasTurbine]

Got the video posted? I couldn't find it.

Sorry, here it is. Its crappy tho...

[BigMoneyGrip]

With the exhaust kicked up like that, you could tube behind it!

[mgs]

Very nice!!!

[racerford]

Only 145mph? I would think you could get a bit moreout of it. Is it prop limited?

[GasTurbine]

Only 145mph? I would think you could get a bit moreout of it. Is it prop limited?

If you do the math...28k ran thru a 3:1 reduction, then thru a 1:.83 overdrive, gives you about 6k (full throttle) screw RPM. Run that through a 29" pitch screw, and you get 164.77 MPH, however, screws have slip. Nominal is about 10%, so that comes out to 148.29 MPH. It also depends on the wetted surface(s) and other drag coefficients.

We could stretch out the pitch some, but a 20' boat with a 13 degree v-hull is at its limits at 145...perhaps a bit over actually.