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Author Topic: Self Propelled Barge  (Read 2909 times)

F4TCT

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Self Propelled Barge
« on: September 08, 2012, 06:23:22 PM »

Hi Folks,

I wonder if anyone can offer some advice/guidance. Some of you may have seen my website which includes a big barge some 46" by 17". This barge is pulled along by my little wyeforce.

I have always wanted to motorize the barge and im very reluctant to start chopping bits out of it etc..

I today have been measuring up my barge and re-making CAD drawings of it so that the parts can be water jetted in the future. I have made a slight modification to the stern in which the proposed location of the twin 60mm props will go. A pair of rudders will also be installed.

This is the current towed barge, stern showing and the large fixed rudders which continue along the bottom to the bow would be removed (they were put there to make sure the barge tows straight).



Where the stern starts to slope up from the bottom (on picture above), this is the proposed new layout of the barge.



This shows the new stern more clearly - and drawn as near as damn it, actual size.



Now my question would be - Is there going to be sufficient space for water to enter the rear of the prop so that it can be propelled forward with enough force to move this 40KG (when ballasted) model with relative ease?

The second question would be - if i obviously removed the large fixed rudders at the stern and left on the runners underneath the bottom, would this cause any great issues in regard to turning when underway?

Or would a more sloped stern and use of steerable korts be a better solution?

I would also be installing a bow thruster either way.

Dan
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DaveB

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Re: Self Propelled Barge
« Reply #1 on: September 09, 2012, 07:07:14 AM »

Hi Dan
When i converted my Mountfleet lighter i cut out a section of hull and used cut off rainwater pipe to form a tunnel the prop is fairly close to the end of the cutout but no problems
Dave
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F4TCT

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Re: Self Propelled Barge
« Reply #2 on: September 09, 2012, 12:25:14 PM »

Thanks,

I know very little about hydro dynamics, however it just seems to me my design using the screws and rudders combination may not work as best as i want it to.

Steerable korts are probably the better option or even some sort of azimuth drive thing..

Dan
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Big Ada

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Re: Self Propelled Barge
« Reply #3 on: September 10, 2012, 06:30:50 PM »

Why not do away with the ballasting by cutting away the Hull bottom, and fitting Blue Foam under the deck for it to float on. At Chantry Model Boat Club based at Blue Water they have a 17ft ( 5 section) vessel made on this system and it sails great and weighs not a lot.
I have some photos if they give permission to use them.

Len.
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Netleyned

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Re: Self Propelled Barge
« Reply #4 on: September 10, 2012, 06:52:54 PM »



I think Dan is looking for answers to his propulsion
and steering issues rather than cutting the bottom
out. If the hull is full of water propulsion would have
to be above the hull AKA airboat. %)

Ned
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Big Ada

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Re: Self Propelled Barge
« Reply #5 on: September 11, 2012, 04:41:58 PM »

Hi Ned,
The rear section of the above boat is a watertight one with all the drive and controls in it.

Len.
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NFMike

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Re: Self Propelled Barge
« Reply #6 on: September 11, 2012, 05:06:30 PM »

Why not do away with the ballasting by cutting away the Hull bottom, and fitting Blue Foam under the deck for it to float on.
..........
The rear section of the above boat is a watertight one with all the drive and controls in it.

Ooh, that's cunning. Water ballast. And the sides, with no bottom, would act like keels.

Netleyned

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Re: Self Propelled Barge
« Reply #7 on: September 11, 2012, 06:03:05 PM »

Thanks for that Len.
All becomes clear.
As Mike says 'A cunning plan'


Ned
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tobyker

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Re: Self Propelled Barge
« Reply #8 on: September 11, 2012, 10:53:29 PM »

As shown it will motor forwards all right, but will  be an absolute pig going astern as all the thrust will be directed straight down and she will steer somewhat worse than the prototype Square Four with Earles forks, the handling of which was described by the Ariel chief tester as "like riding a drunken sow and trying to steer with its ears".
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NFMike

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Re: Self Propelled Barge
« Reply #9 on: September 12, 2012, 12:00:57 AM »

"like riding a drunken sow and trying to steer with its ears".

You know, when I first saw this thread that is very much how I thought a Self Propelled Barge should be and that Dan's beast would be quite prototypical :)
After all "It handles like a barge" is a well known put down of some motor vehicles.

F4TCT

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Re: Self Propelled Barge
« Reply #10 on: September 12, 2012, 08:49:51 AM »

It would still steer like a pig if it had steerable korts or even azimuth thrusters?

Dan  :}
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Big Ada

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Re: Self Propelled Barge
« Reply #11 on: September 12, 2012, 09:09:29 PM »

http://www.modelboatmayhem.co.uk/forum/index.php?topic=6588.msg389731#msg389731

This should show the sort of beast that uses the blue foam floatation system.

Len.
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dodes

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Re: Self Propelled Barge
« Reply #12 on: September 13, 2012, 02:22:25 PM »

There is a self propelled barge operating in the solent area for some time now, I believe it is the prototype you may have in mind. She has the same hull shape as your model and is driven bywhat is for want of a better description two oversize outboards, much the same as the British Army self propelled rafting system known as Maxi floats and it works very well. The barge is used for all kinds of work, from repairing jetty fronts to putting up beacons. It is secured in postion by dropping two verl long piles which it rides up and down with to tidal movement.
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F4TCT

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Re: Self Propelled Barge
« Reply #13 on: September 13, 2012, 02:32:30 PM »

Yes I know what you mean. We have a similar type thing here in Whitby which is the harbour dredge. My idea was to keep the props protected when grounding occurs.

It seems that going astern will prove to be the issue here. Turning I don't think will be as the runners under the hull would be removed and a bow thruster added along with rudders or steerable korts.

Dan
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