Super cavitating very high speed stealth surface vessel

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Super cavitating very high speed stealth surface vessel

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16 December 2014 at 19:03 #54388
Bob Abell 2
Participant
@bobabell2
Wow!……..Gerra load o` this fellas!

**LINK**

Not you, Paul!

Bob
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16 December 2014 at 19:03 #6989
Bob Abell 2
Participant
@bobabell2
Don`t let Paul see this!
16 December 2014 at 19:17 #54392
Paul T
Participant
@pault84577
Ok Bob I'll let you design this on.
1 January 2015 at 19:26 #54740
Andy Stoneman
Participant
@andystoneman15177
It doesn't do anything for me Bob, Its not steam propelled.

Andy
1 January 2015 at 19:28 #54741
Paul T
Participant
@pault84577
Andy

It could be flash steam powered.

Paul
1 January 2015 at 19:35 #54742
Bob Abell 2
Participant
@bobabell2
This is worth looking at, Paul……. I think this could be a worthy contender!

What thinkus thou?

Bob
1 January 2015 at 19:55 #54744
Paul T
Participant
@pault84577
Bob

This would be a truly spectacular model and would look amazing at speed.

How big?

Paul

Edited By Paul T on 01/01/2015 20:06:39
1 January 2015 at 20:08 #54745
Bob Abell 2
Participant
@bobabell2
How about……..4`-0"

Using the existing motors, if possible…………..MFA 850………One in each pod?

Don`t know how the ship is powered at the moment……….Is it jet powered in the pods/

I like the expanding wing things!

Hey!…….I can see a lights on, in the Drawing Office!

Bob
1 January 2015 at 20:28 #54747
Paul T
Participant
@pault84577
Bob

It would be designed to be built in five sections: hull, wings and sponsons, transport and storage wouldn't be a problem so 4ft would be achievable.

Looking at the drawing the propulsion is by counter rotating propellers in the nose of each sponson but there would be a lot of research to do as the science is really cutting edge.

Paul
1 January 2015 at 20:39 #54748
Bob Abell 2
Participant
@bobabell2
So the next project won't be an anticlimax afterall!

We could have four brushless motors in the pods, but how do we keep the water out?

They are a bit like submarines

Sounds like a great project though

Bob
2 January 2015 at 14:05 #54754
ashley needham
Participant
@ashleyneedham69188
Personally I would take those drawings with a pinch of salt. They will not be giving much away here. rather like looking at a cross section of Dan Dare`s Anastasia;

Brushless yes, ordinary waterjets/tunnelled props or simply ordinary props at the rear of the prods is as close as you will get. just consider that a model boat will be massivly overpowered compared to the original.

Getting a model to rise at it goes faster (using the outriggers) will be very difficult. Not that I KNOW, but you develop a feel for things when you dabble with the unusual.

This is no reason not try mind you….

Ashley
2 January 2015 at 14:54 #54757
Paul T
Participant
@pault84577
Hi Ashley

I've been delving into the internet all morning looking for information on this boat and apart from a couple of videos and photos (all showing the boat in the water) there isn't much to go on so it looks as though it will have to be drawn virtually from scratch.

From what I have seen so far the main problem wont be getting the boat to rise, conversely it will be stopping the sponsons from surfacing.

There is a lot of research to be done to understand the cavitation principal and even more work to translate the science into a format suitable for a working model.

It will be a challenge to design, build and sail.(lots of fun for me but not for the ducks when Bob sails the thing)

Paul
2 January 2015 at 17:37 #54761
Bob Abell 2
Participant
@bobabell2
The method of operation is clouded in mystery…….As it's top secret!

The sponsons are heavy and don't float????…….Why?

The boat sets off with the sponsons wide open, which allows the hull to float on the water surface

As the speed builds up the sponsons pivot down and surf the water?

The props are fore and aft in the sponsons

Have I got this right, Mr Designer, sir?

Sounds like a cracking project!

Bob
2 January 2015 at 18:23 #54762
Paul T
Participant
@pault84577
Bob

This might help explain,

The designers of the full size boat claim a combination of a stealth jet fighter and an attack helicopter in a boat.

Privately developed by JMS for possible use by the U.S. Navy, the boat would reportedly be invisible to enemy ships' radar, while also being faster and more economical than existing military vessels.

The company's big claim, however, is that GHOST is the world's first super-cavitating watercraft.

Supercavitation, in a nutshell, involves surrounding an object with a bubble of gas, so it can pass through the water with very little friction. In the case of GHOST, the objects in question are its two submerged buoyant tubular foils. Although the company isn't clear on how the process works, presumably the foils would have to be designed in such a way that when GHOST's gas turbines thrust it forward, water is deflected outward at the front of each foil, creating an envelope that closes behind it.
2 January 2015 at 18:34 #54764
Bob Abell 2
Participant
@bobabell2
Paul

That sounds splendid, but won`t the bubble of gas get washed away, as it speeds along?

Dare we send an Email to the designers?

Don`t see why not?

How will the latest legislation affect the plan marketing?

After all, we don`t receive any money in the process?

Bob
2 January 2015 at 18:43 #54765
Bob Abell 2
Participant
@bobabell2
Just found this……

**LINK**

Bob
2 January 2015 at 18:52 #54766
Paul T
Participant
@pault84577
Bob

Supposedly the gas jacket is constantly maintained but I haven't been able to find any information about the system so its difficult to make informed judgement.

I will keep looking.

At the moment I don't know what the new VAT rules will mean for the charity downloads but I will be contacting HMRC next week for definitive advice.

Paul
2 January 2015 at 19:30 #54769
Paul T
Participant
@pault84577
And it does look a bit like this from the film Battleship

Edited By Paul T on 02/01/2015 19:37:19
2 January 2015 at 19:52 #54770
Bob Abell 2
Participant
@bobabell2
Paul

Look at the spray on the 2nd last picture

What is causing it?

Bob
2 January 2015 at 20:20 #54771
Colin Bishop
Moderator
@colinbishop34627
I think it is water Bob…

It's the fireworks on the last image that worry me!

Colin
2 January 2015 at 22:16 #54773
Diede van Abs
Participant
@diedevanabs87670
Bob,

The spray is simple: It is a fast moving craft and the foils have a positive incline towards the hull, so water will climb up over the edge.

You can see on that same second picture they found out it were an issue and they (retro?)fitted a set of extra foils perpendicular to the foils, as spray guards…

This craft is extremely tempting and interesting to build, but don't underestimate the balance issues of it: because the surface area at sea level is extremely small, even the tiniest unbalance will result in a severely listing craft. Real life SWATH ships (which I count this one as) do have dynamic balancing systems to counter crew movement…

But PLEASE, design and build a model. It will be a great craft if you get it going!
3 January 2015 at 09:01 #54779
Bob Abell 2
Participant
@bobabell2
Hello Diede…..A Happy New Year to your good self

I knew you would emerge from the woodwork at the mention of a new exciting hair brained project

Your comment about computer control to trim the craft, is a bit disturbing!

It must be similar to those two scooter things that you stand on?

This will test the Drawing Office skills to the Nth degree!

I have already suggested the motors and gear to be housed in the main hull and have a Timing belt drive, through the legs to the prop shafts

The sponsons would then be buoyancy aids……….Alas, the idea was pooh poohed by him upstairs!

He's now having a few days in an obscure secret cave, stark naked, somewhere in Snowdonia, to sit and contemplate the design

All the best……Bob
3 January 2015 at 12:12 #54782
Diede van Abs
Participant
@diedevanabs87670
Hi Bob,

Best wishes for you all too!

Better keep the motors in the sponsons, to keep the center of gravity as low as possible.

The sponsons are the main buoyant bodies, they will be responsible for about 98% of the flotation when in rest. The remaining 2% will come from the foils.

The balance issue is because the sponsons will be completely submerged and the foils are the only bodies protruding from the water… and as their volume is very small, placement of batteries, receiver etc. will be very sensitive. The slightest unbalance will push one sponson way further into the water which causes the listing I mentioned.

It is not impossible to get it right, but it will be a tough challenge.

Now, I know you are not afraid of a challenge every now and then…

Edited By Diede van Abs on 03/01/2015 12:13:14
3 January 2015 at 17:03 #54792
Paul T
Participant
@pault84577
Dear All

In his infinite wisdom Capt Bob has had a blue sky moment and decided that it will help everyone to better understand what is going on if all aspects of this project are discussed on the open forum and not by private email.

So lets start this ball rolling:

I am currently in a secret cave in Snowdonia researching the real Ghost ship like fun I am…..I am actually in my nice warm lounge eating chocolate and drinking coffee but the research part is true.

The first stage of research is simply searching the internet for information about the real boat, I am looking for history, pictures and if possible drawings or blueprints.

Before I can start the drawing process I need either a set of designs for the real boat or some photographs showing side, top, front and rear elevations. It also helps to have details of the overall length, breadth etc. so that I can dimension and scale the drawings correctly.

All that I can say at this point is 'the better the information the better the drawings'

Paul……..back to the cave
3 January 2015 at 18:23 #54797
Bob Abell 2
Participant
@bobabell2
I seem to remember, I saw a program on the telly about a craft similar to Ghost?……Only a few weeks ago

Or have I been dreaming it?

We actually tried to visit Betws y Coed today in Snowdonia!

But had to turn back at Chester, the rain was simply incessant and there was no chance of finding Paul's secret cave

How long has Ghost been subject to the public gaze?

Bob
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