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Topic: Crossing the ice (Read 1060 times) |
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maryl
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OD-1 was out in his ski slope snow grooming machine (don't ask why he had one - he just did) and wanted to take a short cut across the lake behind Duffuses place. He knew the ice was only about 3 inches thick and that 2 snowmobiles and 4 men had gone through the ice just that morning. He also knew his machine was much larger and weighed as much as 10 snowmobiles. Yet he calmly drove across the middle of the lake to the other side without as much as the ice cracking under the heavy weight of his machine. He wasn't assisted by aliens or any other supernatural stuff like that. This is a real life teaser with no quirky tricks.
Why didn't he go through the ice?
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Chewdog
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Re: Crossing the ice
« Reply #1 on: Jul 23rd, 2003, 6:58pm » |
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Did there happen to be a bridge?
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towr
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Re: Crossing the ice
« Reply #2 on: Jul 24th, 2003, 1:49am » |
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Weight on it's own isn't very indicative, as long as it is distributed well, that is the pressure on the ice is low, he won't go through
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Wikipedia, Google, Mathworld, Integer sequence DB
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mistysakura
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Re: Crossing the ice
« Reply #3 on: Jul 24th, 2003, 4:59am » |
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And of course, the lake itself might only be 3 inches deep in the first place. Droughts...
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James Fingas
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Re: Crossing the ice
« Reply #4 on: Jul 30th, 2003, 1:47pm » |
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mistysakura,
In the middle of winter? 
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turtler7
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Re: Crossing the ice
« Reply #5 on: Aug 20th, 2003, 3:19pm » |
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i might be wrong on ice thickness i havent been to my uncles latly... he has a chart with all the weights for ice at his house/bait shop. I THINK these are right but dont give it 100% credibility.
4" i think is the ice thickness for a car... Snowmodile is liek 2" i think... So 3" should hold one of those machines. As well as
towr is correct in the weight distribution. People that weigh 200 pounds can walk on snow if they use snowshoes to distribute the weight. Same as a VERY heavy polar bear can walk on ice and snow because its large paws distribute the weight.
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Speaker
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Re: Crossing the ice
« Reply #6 on: Oct 7th, 2003, 12:22am » |
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Hey maryl, what is the real answer?
He used the slope grooming machine to push great piles of snow in front of him, which helped to distribute the weight of the machine more evenly. And, he drove in the shade, where the ice was stronger.
Or, it was a grooming machine for water skis. 
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maryl
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Speaker, towr had it.
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Speaker
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Re: Crossing the ice
« Reply #8 on: Oct 8th, 2003, 7:58pm » |
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Okay thanks.
You said that this was a real life teaser. So, we can assume that a person actually drove across the ice of a lake which two men and their snowmobiles had fallen through earlier that day.
My question. Was the guy so smart and aware of the distribution of the weight of his machine that he was certain it would not fall through?
Or, was he just lucky, his calmness a result of ignorance of the situation?
I guess you can only answer this if he was interviewed, or if you know the driver. Maybe I should give ole Bill Duffes a call and ask him. 
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| « Last Edit: Oct 8th, 2003, 7:59pm by Speaker » |
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Icarus
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Re: Crossing the ice
« Reply #9 on: Oct 8th, 2003, 9:10pm » |
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Actual incident or not, I don't know, but a snow grooming machine is made to ride over the top of the snow instead of digging deep grooves into the very snow it is intended to smooth. Any one operating such a machine should realize that the weight distribution that allows it to ride over the snow without crushing it should also be sufficient to spread out its weight on thin ice.
However, he did take more of a risk than he may of realized. If the water below the ice recedes any, the ice may not be well supported. This means that a significant portion of the load of his vehicle will be applied as a sheer force, which will easily cause the ice to crack. Once cracked, it will be unstable, even if it is now fully supported by water. The ice will tip, leaving him in the drink.
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Speaker
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Re: Crossing the ice
« Reply #10 on: Oct 8th, 2003, 9:26pm » |
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Okay, I do not know either. But, many years ago, if memory serves, the snow grooming machines left big tracks in the snow. They used them to remove moguls (bumps). They must have squished them or pushed them out of the way. So, there is some weight.
Now, I recall a large vehicle used in the far north for oil exploration. This vehicle was designed to drive across the tundra without leaving behind any damage (or very little damage), they had a picture of it driving over some oil explorer (exploiter). One of the tires was directly on top of the guy but he appeared unharmed. The idea was to convince us that they could explore for oil without destroying the ecology of the area.
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