Twin hull sternwheeled landing craft

To rfleet1066;

Not entirely on topic. But my planing wheels in a 6 wheeled arrangement with a gatling gun at the bow might make a fast amphibious attack boat for marines etc.
http://www.ww.xbug.ca

Colin

 

Well, from what I hear, large planes use their wings as fuel tanks. I don't see why the pontoons couldn't be divided and used for fuel, water, waste. Or were you referring to something else? I mean they are huge, it would be a shame to waste all that space.

Or for that matter, "shelves" could be put in them and cheap, ready made plastic tanks set on them and secured.

 

fluid storage

That's a great idea, too. Thank-you. Yes, I was refering to something else. My connector trapezoids are comprized of fourteen totally enclosed sections that will hold about 110 gallons each. Great for fuel, not so good for fresh water.

Your idea of plastic tanks may be good for fresh water and waste water storage. These could go in the pontoons through the hatches(12 of them). I had toyed with the idea of using bladders there. There's a good source from the US Military.

Back in the day when we made low level cargo runs from Columbia we used waterbed matresses for aux fuel. When empty they were rolled up and tossed out the door of the DC-3.

To give you some idea of what the little voices are capable of guiding me to do, I will post a photo of my laboratory complex.

Ryland

 

Given the benefits, this request should be accommodated.

 

I think a large single paddle wheel in the center of the cat with rudders on the back of the hulls and 2 engines (1 in each hull) with chain drives to the wheel would overcome some of the problems of paddle wheel drive systems (one problem is how it responds to waves). Centralizing the wheel keeps the blade immersion more constant and having rudders at the end of a long moment arm will make it more steerable. Also most of the weight can be carried midships.

There are a lot of patents for articulated paddle wheels with mechanical linkages to keep the blades straight but I've never seen one that had a clear advantage over just a big wheel with a shallow draft.

A Length/Beam ratio around 5:1 might be good for your purposes. A wide beam would require a lot of engineering to make sure it can withstand the repeating stress loads.

I think air props are the best drive system, everything considered, except for the noise.

Colin
http://www.ww.xbug.ca

 

Pdf?

I'll try to post a drawing of the current progress.

Ryland

 

Ryland, that lab looks pretty groovy mate.................. you are havin' way too much fun. All the best from Jeff

 

Just looking at your drawing & now "thinking out loud" that the trade off on water clearance/underwing clearance might be solved with the incorporation of box or triangular trusses "into" the front & rear of the deck house structure, as the main connectives - kind of the full height of the house or even higher to include shade targa bar etc. Jeff.

 

Triangular trusses

Bear in mind, this is a river vessel. One foot waves would be extreme conditions. I am leaning toward an offset pilot house to maximize deck space. Still sizing things up, too..........the paddle wheel may not be the wise method of propulsion. I am seriously looking at a long-tail design. The savings in weight would be significant, and be resistant to river snags.
Thanks for the kind words regarding the laboratory. Yes, my "too-much-fun alarm" frequently is activated. I'll post a photo of the front door. Click to enlarge. Perhaps you will understand.
Ryland

 

Cat engine

I just found a new Cat/Perkins engine (85hp) for sale. I have no clue as how to match engine/trans ratio / wheel size. Surely there is some published info regarding this. Any ideas?

Ryland

 

Wheel diameter and speed will depend on the vessel speed in operation. Paddle area could be about equal to the swept disc area of an adequately sized (for the engine) prop. Large reduction gearing will be required, you might do this with toothed belts. Typically it's done with hydraulics.......

If the boat does 5 knots that's 506.5 feet per minute and the wheel is running at 50 RPM we get a pitch of of 10.13' * (wild guess)55% slip = 15.7'.........which is a paddle wheel with a diameter of about 60" to the outside of the paddles. Sounds kind-of in the ballpark? Each paddle might be about 6-7 sq ft if immersion depth is equal to paddle width.......

 

There is a little bit in the site I posted in post #12.

 

River boat progress

The vessel comes along. Deck is installed, thruster tubes finished, landing ramp ready to deck, working on the lift mechanism. Pilot house and longtail drive are next. I scrapped the idea of sternwheeling because of weight and efficiency concerns. I have a Cat diesel with a Velvet drive transmission 15 degree down angled so in the longtail configuration, the engine can remain level(ish).

Ryland

 

Electric grounding?

Pardon my ignorance (which prevails). But is it desired to isolate the DC electric system or is grounding using the hull as the negative pole a good idea? Clearly, I'm concerned about galvanic corrosion.

I'd love any advice regarding this and the rule(s) of thumb if any about anodes.

Ryland