For example, I am now trying to figure out if the boat can handle the hydraulic log loader that I've got waiting to go on board. A 6,500 lb steel Prentice that can reach out 22 ft with its grapple and pull logs up and out of the lake, loading them on shore or where ever I want them.
The big question is "Will the boat tip over when I do this?" A good question to get answered before I build it. So I go to http://www.boatdesign.net/ looking for guidance. Hiring a naval architect is not something I can afford, but I was hoping that some of the pro's that hang out on this site would at least give me either a "What? You're crazy!" or a "Well, it could work if..."
Instead, I get 2 professional naval architects, one in Italy and one in Japan, who kick things around, do a bunch of figuring and what-if runs on the computer and give me the answers I need.
Now it's one thing if you are a carpenter and someone asks you if you'd lend a hand painting their fence for the afternoon. But when you're a carpenter and someone asks you if you'd like to pound some nails, well, that's kinda hard to get enthused about. These guys do this for a living and, yet, they were willing to do it for me, for free. Pretty cool.
People, most people, want to be helpful, are plain hard-wired to make the people around them better off. Perhaps love is too strong a word, but let's call it various forms of that, weaker versions of love. And as they said way back when Amor Vincit Omnia!
If you look, you can see it all around you: the wave of the driver in the car passing by, someone who let's you cut in line, hands being held, smiles made. Sure, it's easy to point to all the bad stuff, but, there is this foundation of love being made as Paul McCartney sang "The love you take is equal to the love you make."
The full back-and-forth can be viewed at http://www.boatdesign.net/forums/boat-design/putting-log-loader-barge-28481-3.html
Love the project. Got to thinking about you stability issues, over the last few days. Since I am a mechanical engineer, and former farmboy, I will use a combined approach in proposing a possible solutions.
ReplyDeleteThe amount of leverage that the loader arm has against the boat, truck, or whatever is controlled by the length of the moment arm and the load applied to it.
The effective moment arm is the length of the hypotenuse of a right angle triangle formed by the height of the mounting (as side adjacent) and the max reach (as side opposite)
Thus the math is for a 10 high x 21 horizontal is 23.3 and them 5 high x 21 horizontal is 21.6. only about 7% improvement. If you could get close to a zero hounting height it would still be only ~14% improvement. Not nothing, but not a easy homerun solution.
I don't "like" the idea of widening the hull by ~6 feet, this loses ~3 feet of reach loader reach. Which is all-ready kind of limited at 21' - 1/2 of beam = 14.5 feet over the side reach. And I don't know if it won't create a bastardized looking "restoration".
So, what I would like to think about is too use the same concept as is used on the truck for stabilizers. Since the water is way to deep, we are going to need to use floats on our stabilizers.
Something along the range of 1000 gallon propane tanks, hydraulicaly deployable along each rear quarter of the boat. I would think that 8 foot would be a nice amount of outrigger per side. This would make the boat about as wide, as it is long, with outriggers out.
Each 1000 gallons tank (~4' diameter x 11 foot long) displaces ~8000 lbs of fresh water at about a 12ish foot distance from boat centerline. Leading me to believe that they would counteract most of the ~ 4000 lbs of load developed at the end of the loader arm.
But the farm kid says that math don't mean crap, and you ain't half as smart as you think you are!! So, farm kid say's: if at all possible, I would dig out a shallow pond in the back yard and do some serious load testing before heading for the deep blue.
They should not get in the way that much because the loaders ~20 foot reach cannot work the back corners on a 30 foot boat in any event. Plus, if you are working that close to shore, just park the tank on the bank. mark the shoprat
Hey Shoprat!
ReplyDeleteThe first comment placed on my blog and it's a beaut. Very interesting idea. I gotta say that I am hesitant to change the basic look of a historically valuable WWII vessel by widening it, but I don't want to "turtle" the thing so it needs to be stable for lifting.
In any event, thanks for the math that answers the lowering-the mast-idea and for taking the time to weigh in with an outside-the-box approach.
~martin
I am with you on preserving the look. That is what I like about having deployable outriggers. In the perfect world they would just lay on top of the back section of the deck, looking like deck cargo. Until it was time to use the boom, then they would fold out.
ReplyDeleteI would also be tempted to just "find" a large (enough) barge(s) and mount the log loader on a barge. The barge(s) could hold the required amount of wood. Then just use the tug to move the barge around. This way you end up with a "fleet"!! Just look at the tug as a semi-tractor, and the barges as trailers. mark