Number of trucks parked in one spot??

[mixxedbagg]

So my family and I decide to do the ice fishing contest on Hill Lake today. We get there about an hour early and there are quite a few vehicles parked in the plowed area on the lake. My wife had NEVER been ice fishing before (I've never been able to talk her into going) and has never been in a vehicle on the ice. We see several dozen trucks in the little lot and they're still streaming in. She looks at me and says there's no way she's going out there with so many trucks in one spot. I didn't really know what to say to make her feel better--she did have a point...there were tons of trucks all in a small area on an unknown amount of ice. We talked about it for a little bit, and she said she'd be more comfortable having her first time out somewhere a little lonelier. We visited another lake and managed to each approach limits of decent sunnies with a half dozen crappies mixed in, so my wife and son had a pretty good time and didn't regret changing our plans, but I wish I would have had a better handle on what to say about the safety of the ice at Hill Lake.

Anyway, does anyone have any thoughts about the safety of ice in these situations where there are numerous vehicles in one spot? Are there past incidents at contests where the organizers misjudged what the ice could handle??

[DuckBlind]

I have been to a few tourneys in the past, one on Beebe... must have been 50 trucks side by side. There is a lot of ice right now. Guessing the folks who run these tourneys do their homework before allowing so many people to park in one place. Their not going to put people in a dangerous situation.

The only time I have heard about people going through has been at snowmobile races where dozens of semis were parked side by side near shore and broke through.

Think about that... semi trucks side by side... if the ice can handle that I am guessing trucks/cars should be fine.

[g_anoka]

The list of times vehicles have fallen through the ice in a case like you witnessed is long and distinguished. It is almost a yearly event at Waconia, seen it happen on West Rush, I think it has happened on Prior, and I also belive it happened one time at a snowmobile event when everyone parked their trucks and trailers in the same spot. Most often this happens near shore during early ice when the access parking lot is full, and the overflow parks out on the ice, right next to each other."Duh, if they are parked there and not falling through, I should be safe parking right next to them." So your wife was right to be concerned. Glad to hear you were able to have a good day of fishing.

[bikeoutback]

I've been to Perch Extravaganza the past couple years and it's massive. I know there has to be at least a couple thousand people (probably more). Even at best put 4 in a vehicle makes for 500 vehicles and then more than half are parked out on the ice. I'd say an estimated 300 vehicles is extremely on the conservative side. Also 4 wheelers,snowmobiles and even some guys pulling their wheel houses and perms off the lake as it's usually toward the end of the season. I've thought about whether it's safe but have never heard of a vehicle going in during it. Did hear that a few years ago though one almost went through. Only overheard it but an axle broke through right towards the end of the prize giveaway and they somehow drove it out or pulled it back up onto safe ice and saved it before it went through.

I wonder if this is a possibility why they let everyone park out there like that but I suppose they really can't stop them. It is insane heading over to the prize give away cause all across the lake it's just lines of trucks pouring into the resort.

[jigginjim]

I remmember going to a Waconia contest one winter, 9-11 inches of water came on top of the ice, where the cars and trucks were parked. There 6" of water over the ice in 1 part of the contest area.

[BobT]

I wouldn't trust those that run these events to do much calculating about ice strength. I recall a few years ago there was some event (snowmobile race?) on Detroit Lake where a bunch of trucks and trailers went through the ice. They had parked them like they were parked on a parking lot and the ice gave way. Pretty foolish.

[piker007]

I know the one in Lake city has been canceled a few times because of ice conditions. I think those guys do some homework as Ive never heard of people going through at a ice fishing contest. BUT on the ice its always best to trust your gut so if you/she didnt feel safe you made the right call.

[TurnUpTheFishing]

I've been to Perch Extravaganza the past couple years and it's massive. I know there has to be at least a couple thousand people (probably more). Even at best put 4 in a vehicle makes for 500 vehicles and then more than half are parked out on the ice. I'd say an estimated 300 vehicles is extremely on the conservative side. Also 4 wheelers,snowmobiles and even some guys pulling their wheel houses and perms off the lake as it's usually toward the end of the season. I've thought about whether it's safe but have never heard of a vehicle going in during it. Did hear that a few years ago though one almost went through. Only overheard it but an axle broke through right towards the end of the prize giveaway and they somehow drove it out or pulled it back up onto safe ice and saved it before it went through.

I was there too. Only reason it started going in was they parked right on/next to a pressure ridge.

I remember seeing a link posted a while back with info from the army corps of engineers. I dont remember exact numbers but I remember being surprised by just how strong ice really is when it hits thickness' of 18"+

[aanderud]

The army corp of engineers has done studies on ice strength and loads.

Here's a report:

http://www.mvp-wc.usace.army.mil/ice/safety.html

Specifically, there is a table related to loads and their spacing. The ice thicknesses are a bit less than what you normally read about, but the idea is that as ice thickness goes up, you can apply a larger load, but you also have to space them out quite far to keep it safe.

Code:

 
Load    Ice Thickness   Distance between loads
(tons) 	(inches)        (feet)
0.1     2               17
1       4               34
2       6               48
3       7               58
4       8               67
5       9               75
10      13              106
20      18              149
30      22              183
40      26              211

Quote:

The equation, graph, and table are valid when the load (such as a person on foot, or a wheeled or tracked vehicle) is distributed over a reasonable area of a continuous ice sheet. The larger the load, the greater the area it should cover for the calculation to remain valid. Neither large loads that are concentrated in relatively smaller areas, nor loads that are at or near the edge of a large opening in the ice, are safely described by the equation, graph, or table.In such cases, seek more advice.

The equation, graph and table assume clear, sound ice. If white, bubble-filled ice makes up part or all of the ice thickness, count it as only half as much clear ice.

Any recent large snowstorm creates a new load on the ice. If the new snow is heavy enough, the ice sheet will sag and its top surface will be submerged below the water level. Then water will flood the top of the ice sheet through cracks, saturating the lower layers of the snow. Until this slush is completely frozen, stay offthe ice sheet. When the saturated snow becomes frozen, it is an added thickness of white ice.

Contrary to what you would expect, a rapid, large air temperature drop makes an ice sheet brittle, and the ice may not be safe to use for 24 hours or more.

If the air temperature has been abovefreezing for at least 6 of the past 24 hours, multiply the load by 1.3 before you use the equation (or use the lower dashed line on the graph), obtaining a larger minimum ice thickness to account for any possible weakening. If the air temperature stays above freezing for 24 hours or more, the ice starts losing strength, and the equation, figure, and table no longer represent safe conditions. Stay off the ice!

You are likely to encounter cracks in the ice. Cracks are either wet or dry. If they are dry, they do not penetrate the ice sheet and are not a concern. If they are wet, multiply the load by 2, as shown on the graph, before you use the equation to obtain the required minimum ice thickness.If you plan to leave a load on the ice for extended periods, usually more than two hours, multiply the load by 2 (as shown by the upper dashed line in the graph) before you use the equation to find the required minimum ice thickness.

[Gordie]

This year is kind different in where you go and for the poutfest they are actually closing the lake to vehicals other than class 1,atvs and snowmoblies but I have been up there while there were ten fully loaded motorhomes parked out on the ice and most of them were towing a drop down house besides

I do remember one of my girl friends from Pennsylvainia who never was on the ice in her life and one night we went for a drive and when I stopped you guessed it it was on a lake when I informed her where she was she beat the cr-p out of me and freaked out when we got stuck so I got out and started pushing and the truck came unstuck and she floored it until she got to shore then I had to walk to shore

[OnAFly]

First time I brought my GF from Montana out on the ice, she wasn't real keen on driving a vehicle onto a lake. Once, she caught a couple nice crappies, she forgot all about it.

[Gekhang]

was out for the first time this past weekend and all the guys were pretty skeptical on the location we were at because of the amount of trucks and trailers in one location, but later we all just didnt care because if it wanted to break, it would have broken way before.

[robert aldrich]

5% chance of geting a fish in a contest. My dad did the math.

[LightningBG]

Code:

 
Load    Ice Thickness   Distance between loads
(tons) 	(inches)        (feet)
0.1     2               17
1       4               34
2       6               48
3       7               58
4       8               67
5       9               75
10      13              106
20      18              149
30      22              183
40      26              211

This is a tough table to understand.... So lets say the ice is 22 inches thick, which will hold 30 ton, which should be spaced out 183 ft apart. But I'm driving a vehicle that weighs 3 ton. So how many vehicles can I park and how close? Could I put 10 vehicle as close as I wanted and then space 183 ft another 10? What if the 10 were spaced across 183 ft. Then does there need to be any space between those and the next 10 taking up 183 ft?

[aanderud]

I don't know, it doesn't look that hard to understand to me -- at least not for ROUGH approximations, which I believe it was meant for. Put 30 tons on the ice (usually I'm guessing the army does this with heavier vehicles like semi-tractor-trailers, or possibly with tanks, or at the minimum some kind of HMMWV type vehicles). Now, space that load 183 feet from the next one. Think of a convoy situation, for instance. Does the study match exactly with a fishing contest parking lot, or a shanty-town in crappie-ville? No, but it's not very hard to make a close rough approximation, just like you did.

Go ahead and make up any number of ways to get to 30 tons -- 10 trucks weighing 3 tons each, for instance. Put those 10 trucks in a tight area (like you see with parking-lot type situations). Now, space the next group of 10 such that the center of mass is 183 feet away from this group's center of mass. Play with the spacing from there -- perhaps move them around evenly like you suggest. The key is not to overload any ONE area. I think it's a good guess that even spacing like you suggest would be even BETTER than point-loads of 30 tons every 183 feet.