Turbine Jet Thrust Powered Boats

[BrianJohnson]

Hi Guys/Gals.

I'm brand-new to this site - it was suggested to look here from another site regarding Turbine boats that are powered by Jet Thrust alone - no reduction gearbox/prop etc.

Apart from a few replica's of Don Campbell's BlueBird K7, there doesn't seem to be a lot of info on RC thrust driven boats.

I know they're expensive. I know they're fiddly. But I have 2 x 30pounders that are for a long-term aircraft project.

Please - spare me the knockers and the negative bullschwab. I'm fully aware that thrust driven craft won't turn and handle like their prop driven cousins. Straightline but stable will do me for now.

Any info regarding thrust powered RC boats would be great.

Looking forward to any positive input...

BJ

 

[t_hedlund]

Very interesting idea, your line of thrust is going to be very important, you almost might need to come up with a way to slightly adjust it for water conditions, I remember some one taking about a rocket powered boat, which would be the same principle as what you are looking at.

What type of hull are you thinking?

 

[BrianJohnson]

Very interesting idea, your line of thrust is going to be very important, you almost might need to come up with a way to slightly adjust it for water conditions, I remember some one taking about a rocket powered boat, which would be the same principle as what you are looking at.

What type of hull are you thinking?

Thanks for your reply T.

That's my first big hurdle - what kind of hull.

From what I've read so far, a 3 or 4-point Hydro might be the go. Then there's 'roundnose' et al to consider.

Being new to this, I still have a lot of learning to do. I would be great to hear from someone who has gone down the Jet Thrust route with anything other than a BlueBird K7.

I've attached a pic of a thruster that I found on the AMT site - it's about 10 years old now, and I'm trying to contact the owner. It's an interesting design.

Lots of research to be done yet me thinks :unsure:

BJ

 

[BrianJohnson]

PS - Great pics on your site there T...

BJ

 

[t_hedlund]

Here is the thread i was think of, previous post

I also seem to remember a discussion a while back where someone was thinking about the same thing and how the rudder will be almost useless under power.

As far as hull choices i avoid mono , a cat might be a good choice.

Thank for looking at my pictures. I have a lot of fun taking them.

 

[BrianJohnson]

Here is the thread i was think of, previous post

I also seem to remember a discussion a while back where someone was thinking about the same thing and how the rudder will be almost useless under power.

As far as hull choices i avoid mono , a cat might be a good choice.

Thank for looking at my pictures. I have a lot of fun taking them.

These guys I found in the Galleries here have been tickling my fancy...

I wonder how they would go running on thrust alone...?

There was another one someone was making out of CF that was a similar design, but I didn't bookmark the page so I can't find it again.

BJ

 

[t_hedlund]

OK, The smoking Joe hull RTR with a .67 is going to be about 15lbs, i don't know what range a jet powered boat will come in at but you will need to create more thrust than it weights to get it moving. Also the big problem you will have is fitting the jet in 1/8 scale.

Most of the turbine powered hydroplanes have been 1/6 scale.

Here is a video of the 1/6 scale.

 

[BrianJohnson]

Most of what I've been able to read/view around the traps so far regarding RC Turbine powered boats are all reduction-gearbox prop driven boats.

What I'm looking for is a hull design that I can use/modify that will allow the boat to be driven by jet-thrust alone.

I doesn't have to be able to do fancy figure-8's etc - just zoom along the water and not flip/dunk itself.

I realise that there's many experienced RC boaters in here that may start quoting all sorts or reasons not to go down the thrust-only route.

If I want handling and competing and overtaking etc, I turn to the black-top and do my motor-racing.

Long story cut short, I'm a fair ways off getting my Aircraft up and running and being able to fly it using my Turbines - I just thought some form of boat would be a great way to hear that magnificent sound translated into some form of motion. Purely straight-line, if that's all it can do. Just run those Tubes up, and get some enjoyment out of seeing a craft I've built go from A to B without destroying itself along the way.

The Turbines and the RC gear I've already got. Plans I'm willing to pay for - no problems there. I have the time and the wherewithall to take my time in building from scratch. The only thing I don't have is a design to work from...

BJ

 

[dschigoda]

Most of what I've been able to read/view around the traps so far regarding RC Turbine powered boats are all reduction-gearbox prop driven boats.

What I'm looking for is a hull design that I can use/modify that will allow the boat to be driven by jet-thrust alone.

I doesn't have to be able to do fancy figure-8's etc - just zoom along the water and not flip/dunk itself.

I realise that there's many experienced RC boaters in here that may start quoting all sorts or reasons not to go down the thrust-only route.

If I want handling and competing and overtaking etc, I turn to the black-top and do my motor-racing.

Long story cut short, I'm a fair ways off getting my Aircraft up and running and being able to fly it using my Turbines - I just thought some form of boat would be a great way to hear that magnificent sound translated into some form of motion. Purely straight-line, if that's all it can do. Just run those Tubes up, and get some enjoyment out of seeing a craft I've built go from A to B without destroying itself along the way.

The Turbines and the RC gear I've already got. Plans I'm willing to pay for - no problems there. I have the time and the wherewithall to take my time in building from scratch. The only thing I don't have is a design to work from...

BJ

Back in the 1980's, I taped an hour long documentary TV show on Ken Warby (Austrailia) and his development of his world record holding, jet (thrust) powered hydroplane. As I recall it looked like a typical 3 point hydroplane from the 1980's, except it was a bit narrower, and more pointed in the front. It appeared to be undersized compared to the large jet engine perched in the hull. The air intakes were on either side of the driver. The driver was semi enclosed, open on top. It was a very cool looking boat, and the driver built it himself, at home!. The film had good footage of his speed passes, and Ken discussing and tweaking his set-up. In the end, he kept trimming his rudder shorter and shorter (to reduce both drag and pitch moment) until he set the world water speed record. ...I just did a search, here is a photo of the 317 mph (1977) boat, no afterburners, peaked at 345 mph, never used full throttle: http://boatracingfacts.com/forums/showthread.php?t=572 If you can build a model from photos, this might be a good one!

Dave

 

[dschigoda]

Here are some more pics of the record holding jet boat -

http://www.kenwarby.com/more_spirit.htm

 

[BrianJohnson]

Yanno Dave... I think I might just go down the route.

I have no plans whatsoever...but I hope I can reverse-engineer something the Sprit Of Australia and Aussie Spirit pics.

Not that easy for a n00b - but I'm stubborn :blink:

We shall see how it pans out...

BJ

 

[Blackout]

Hi Guys/Gals.

I'm brand-new to this site - it was suggested to look here from another site regarding Turbine boats that are powered by Jet Thrust alone - no reduction gearbox/prop etc.

Apart from a few replica's of Don Campbell's BlueBird K7, there doesn't seem to be a lot of info on RC thrust driven boats.

I know they're expensive. I know they're fiddly. But I have 2 x 30pounders that are for a long-term aircraft project.

Please - spare me the knockers and the negative bullschwab. I'm fully aware that thrust driven craft won't turn and handle like their prop driven cousins. Straightline but stable will do me for now.

Any info regarding thrust powered RC boats would be great.

Looking forward to any positive input...

BJ

The way I see it, you want to build an airboat powered by a jet turbine. Have you looked at the hull linked below? I have seen them perform well using a water rudder.

http://www.rcairboats.net/page3.html

There is allot of info on this hull at rcuniverse.com in the airboat forum.

 

[BrianJohnson]

I'm not sure how something like that would go, Blackout.

These Turbines have some reasonably serious grunt ~ 60lbs thrust between the two of them.

There's quite an amount of air being pushed around, if my test-bench runs are anything to go by.

Going by the current World Waterspeed Record's holder, Ken Warby, the hulls look like they need to be reasonably long and slender (to house the Turbine/s ??), with a decent pair of sponsons up front for stability.

I guess the trick is to come up with something that will plane well without a lot of draught/drag in the water...?

I've got some great side-on shots of Ken's second craft - Aussie Spirit - that I can probably scale the profile from. But I need one decent front-on shot so that I scale her across the beams... :unsure:

BJ

 

[BrianJohnson]

Finally got a front-on shot of Kens 'machine'.

Now, hopefully I can draw something up from just the two photos - side-on and front-on...

BJ

 

[Albert Araujo]

Hello BJ,

My name is Albert Araujo and I was one of the original designers and manufacturers of the micro turbines used in model jets. Our company was R.A. Microjets and we were known as RAM. I tested a 52" MHZ cat with an old and tired RAM 500 that had about ten pounds of static thrust. The weight of the boat was about 16 pounds plus fuel. To my surprise the boat ran just as nice as if it had a prop in the water. Acceleration was not as quick but was up on plane within a few seconds. Once on plane it ran great and did about 45 mph. Considering the weight and lack of power I think it do quite well. I wanted to build a 72" version with a 35 to 40 pound unit. I think it would be impressive and much simpler than the gearbox version.

Best of luck,

Albert

Hi Guys/Gals.

I'm brand-new to this site - it was suggested to look here from another site regarding Turbine boats that are powered by Jet Thrust alone - no reduction gearbox/prop etc.

Apart from a few replica's of Don Campbell's BlueBird K7, there doesn't seem to be a lot of info on RC thrust driven boats.

I know they're expensive. I know they're fiddly. But I have 2 x 30pounders that are for a long-term aircraft project.

Please - spare me the knockers and the negative bullschwab. I'm fully aware that thrust driven craft won't turn and handle like their prop driven cousins. Straightline but stable will do me for now.

Any info regarding thrust powered RC boats would be great.

Looking forward to any positive input...

BJ

 

[dschigoda]

Finally got a front-on shot of Kens 'machine'.

Now, hopefully I can draw something up from just the two photos - side-on and front-on...

BJ

Brian,

Here is a link to several free 3 point hydroplane plans. You might be able to look at these and get a general idea of 3 point hydroplane design, expecially the bottom of the tunnel and bottom of the sponsons. I'm guessing that the reason straight line hydros have a narrower tunnel is to reduce drag, and likely reduce some of the lift (at high speeds), to prevent blow-overs. Please post some pics as your project develops. http://www.astecmodels.co.uk/plans.htm

Dave

 

[dschigoda]

Also, if you are in a hurry, Blazer Marine sells some nice, fast, wood 3 point hydro kits, in various sizes that might work.

 

[BrianJohnson]

Thanks for all the great info dschigoda

I think I might do a bit of a 'hybrid' here - use some of those plans to get the general idea of how to make a boat, but base it on Ken Warby's second boat - "Aussie Spirit".

It got him 'safely to over 500kmh, so the basic design must be sound.

Making a model based on it might be a bit of a challenge - I'm sure weight distribution, sponson design etc. are quite critical to how she 'sails'...

I wonder if Ken would have any plans lying around that he'd care to share? I'm guessing that would be a pretty firm 'no', which I would understand. His boats are, after all, World Record holders..

BJ

 

[BrianJohnson]

Does anyone have any suggestions as to what materials are good to use on boats?

Assuming I'm not going to go down the 'make a plug first, then an epoxy/glass shell', is there a thin marine ply that does the job?

Or is plain old balsa/normal thin plywood (with perhaps an epoxy finishing coat) ok?

Any opinions?

BJ

 

[dschigoda]

Does anyone have any suggestions as to what materials are good to use on boats?

Assuming I'm not going to go down the 'make a plug first, then an epoxy/glass shell', is there a thin marine ply that does the job?

Or is plain old balsa/normal thin plywood (with perhaps an epoxy finishing coat) ok?

Any opinions?

BJ

I'm not sure how big your model will be, but if its in the 2-4' range, you could build it like an 1/8 Scale hydro, which is usually build "egg crate" style, with 3/16" or 1/8" birch aircraft plywood frames with 1/16" birch aircraft ply sheeting, sealed with epoxy finishing resin. Check out the 3 point hydro/scale hydro forum here for building examples. You could also build it using the wood over foam (WOF) technique, using pink or blue styrofoam from Home depot, and 1/16" birch aircraft ply and expoxy glue. Balsa would only be good for parts of the cowl (low stress, low strength). Good luck!