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Post by JohnV on May 22, 2020 20:50:17 GMT
Mine goes up and down that far. Water tank is about 750 ltr. that's a hell of a big water tank for a boat the size of yours
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Post by Deleted on May 22, 2020 20:52:15 GMT
Mine goes up and down that far. Water tank is about 750 ltr. That's due to having an excessively large tank on a small boat and also the roof box. It will be the roof box. Hydro-aerodynamic incompatibility. You can't misunderestimate these things.
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Post by Deleted on May 22, 2020 21:04:15 GMT
I'm sure quaysider and Telemachus would disagree with that. On the subject of stability I wonder if anyone has ever fitted automatic self levelling stabilisers into a canal boat. It seems improbable. in conjunction with Citroen Hydropneumatc suspension - should be a doddle.
............ alternatively do what salty sailors with a fixed keel do - attach legs to keep the boat upright.
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Post by Jim on May 22, 2020 21:06:35 GMT
I had the tank welded up out of polypropylene to fit the space under the bow deck. It's about 1.75m wide by 1m long by .5 deep, front face .6m, trapezoid shape.
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Post by Deleted on May 22, 2020 21:09:57 GMT
My slide rule is being serviced at the moment so am unable to verify the math.
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Post by Deleted on May 22, 2020 21:28:53 GMT
speed of a hull is a function of the square root of the waterline length in feet I've always been a little bit sceptical about the 1.34 rule for canal boat shaped vessels with vertical sides. I suspect this old formula may have been worked out using boats which have the shape of a boat under the water rather than a brick with pointed ends. I expect the rule applies well enough unless you are hoping to win the Americas Cup.
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Post by Deleted on May 22, 2020 21:32:24 GMT
1.34sqrt72 means that a 72 foot narrow boat would be able to do, off the top of my head, about 8.5 X 1.3 which is something like 10+ knots given enough installed power.
I know there were some experiments with soliton waves on well maintained canals but not sure if any narrow boats have achieved this speed in open deep water.
I suppose they just don't have enough installed power but you would have thought someone would test the theory.
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Post by Deleted on May 22, 2020 21:37:22 GMT
I've always been a little bit sceptical about the 1.34 rule for canal boat shaped vessels with vertical sides. I suspect this old formula may have been worked out using boats which have the shape of a boat under the water rather than a brick with pointed ends. I agree ..... one of my boat building books somewhere has a whole sectionΒ about the relationship between the block coefficient and the hull design speed As an aside, I worked here as a research assistant then later as a technician between 1977 and 1984. I cant remember much now but I did get to cut wax models, carried out tests with ship models under the 'carriage' and got to drive the wave maker.
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Post by Deleted on May 22, 2020 21:38:50 GMT
I have a theory that you would need considerably less depth of strawberry blancmange than water were you to dive into it. Despite years of campaigning the government has yet to undertake a full-scale experiment. The bloody fools.
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Post by Deleted on May 22, 2020 21:45:39 GMT
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Post by thebfg on May 23, 2020 1:13:49 GMT
I think a hammock would be bad for one's back, being bent all night. Being the thunderboat hammock expert I can put you straight. I get quality sleep in the hammock. The trick is to sleep diagonally that way your almost flat.
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Post by thebfg on May 23, 2020 1:16:43 GMT
I love hammocks and quite regularly sleep in mine hanging across the balcony. Not used it inside home or the boat though. I have thought about welding some form of clip in the van and using a hammock in there.
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Post by JohnV on May 23, 2020 5:54:31 GMT
I had the tank welded up out of polypropylene to fit the space under the bow deck. It's about 1.75m wide by 1m long by .5 deep, front face .6m, trapezoid face. I wasn't meaning that I thought it wrong by the way ...... just "that's a hell of a big tank for a boat that size"
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Post by JohnV on May 23, 2020 6:04:39 GMT
I have a theory that you would need considerably less depth of strawberry blancmange than water were you to dive into it. Despite years of campaigning the government has yet to undertake a full-scale experiment. The bloody fools. Unless there was a sudden craze for swimming pools filled with strawberry blancmange, I have sympathy for their viewpoint.
Using strawberry blancmange as a test material to produce a chart for safe diving depths in water, would require extensive calculations to ensure the figures could be reliably transposed from one medium to another.
If, at some point in the future of space exploration, a planet is discovered, that has seas of strawberry blancmange, it is unlikely that even then they will find it's lack a problem.
The wearing of a space suit would undoubtably introduce a variable into the equations that would render any Earth based research pointless, never mind any vagaries of gravity.
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Post by lollygagger on May 23, 2020 6:09:14 GMT
I have to disagree about narrow boats looking good with the bow in the air. Also about the water tank - they're bow of filled too. When I got mine I moved the water tank to the front from under the bed at the back (stupid place!!), stuffed the gas locker and every forward space (bow thruster locker got most of it) with every heavy engineering brick and storage heater brick (very good) I could find. I'm almost level but my gas locker vents are partly submerged. The stern came up maybe a few mm. The weight at the back is still there obviously. IMO it now looks much better!
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