(Editor’s Note: The following article was procured from the Wright County website).
There really is no sure answer. You can’t judge the strength of ice just by its appearance, age, thickness, temperature, or whether or not the ice is covered with snow. Strength is based on all these factors -- plus the depth of water under the ice, size of the water body, water chemistry and currents, the distribution of the load on the ice, and local climatic conditions.
The DNR does not measure ice thickness on Minnesota lakes. Your safety is your responsibility. Check ice thickness at least every 150 feet.
For new, clear ice only
• Under 4” - STAY OFF!;
• 4” - Ice fishing or other activities on foot ;
• 5” - 7” - Snowmobile or ATV;
• 8” - 12” - Car or small pickup;
• 12” - 15” - Medium truck.
White ice or “snow ice” is only about half as strong as new clear ice. Double the above thickness guidelines when traveling on white ice. Many factors other than thickness can cause ice to be unsafe.
Refrain from driving on ice whenever possible.
If one must drive a vehicle, be prepared to leave it in a hurry--keep windows down and have a simple emergency plan of action one has discussed with one’s passengers.
Stay away from alcoholic beverages.
Even “just a couple of beers” are enough to cause a careless error in judgment that could cost one their life. And contrary to common belief, alcohol actually makes one colder rather than warming one up.
Don’t “overdrive” one’s snowmobile’s headlight.
At even 30 miles per hour, it can take a much longer distance to stop on ice than one’s headlight shines. Many fatal snowmobile through-the-ice accidents occur because the machine was traveling too fast for the operator to stop when the headlamp illuminated the hole in the ice.
Wear a life vest under your winter gear.
Or wear one of the new flotation snowmobile suits. And it’s a good idea to carry a pair of ice picks that may be home made or purchased from most well stocked sporting goods stores that cater to winter anglers. It’s amazing how difficult it can be to pull oneself back onto the surface of unbroken but wet and slippery ice while wearing a snowmobile suit weighted down with 60 lbs of water. The ice picks really help pulling oneself back onto solid ice. CAUTION: Do NOT wear a flotation device when traveling across the ice in an enclosed vehicle!
Before Heading Out on Ice
Temperature, snow cover, currents, springs and rough fish all affect the relative safety of ice. Ice is seldom the same thickness over a single body of water; it can be two feet thick in one place and one inch thick a few yards away. Check the ice at least every 150 feet.
Ways to Check Ice Thickness
Ice chisel. An ice chisel is a metal rod with a sharp, flat blade welded onto one end. Drive the chisel into the ice, using a stabbing motion, to create a hole. Next, measure ice thickness with a tape measure.
Ice auger. There are three different kinds of augers: hand, electric and gas. Hand augers are low cost, light weight and quiet. Electric augers are also quiet, but use less manual labor than a hand auger. Gas augers drill through ice the fastest, but are heavier, noisier and generally more costly than hand or electric models. After drilling a hole with the ice auger, measure ice thickness with a tape measure.
Cordless drill. Using a cordless drill and a long, five-eighths inch wood auger bit, you can drill through eight inches of ice in less than 30 seconds. Most cordless drills that are at least 7.2 volts will work, but the type of bit is critical. You need a wood auger bit since they have a spiral called a “flute” around the shaft that metal drilling bits don’t. The flutes pull the ice chips out of the hole and help keep it from getting stuck, much in the way a full-sized ice auger works. After drilling a hole, measure ice thickness with a measure tape. Dry the bit and give it a quick spray of silicone lubricant after each use to prevent rust.
Tape measure. Use a tape measure to find ice’s true thickness. Put the tape measure into the hole and hook the bottom edge of ice before taking measurement. You can also use an ice fisherman’s ice skimmer with inch markings on the handle in place of the tape measure.
Don’t judge ice thickness by how easily a chisel or drill breaks the surface. It happens so quickly that it’s easy to overestimate the thickness.
Step-by-Step Instructions for Self-Rescue
What should one do if one falls through the ice?
First, try not to panic. This may be easier said than done, unless one has worked out a survival plan in advance. Read through these steps so that one can be prepared.
Don’t remove your winter clothing. Heavy clothes won’t drag you down, but instead can trap air to provide warmth and flotation. This is especially true with a snowmobile suit.
Turn toward the direction you came. That’s probably the strongest ice.
Place one’s hands and arms on the unbroken surface. This is where a pair of nails, sharpened screwdrivers or ice picks come in handy in providing the extra traction one needs to pull oneself up onto the ice.
Kick one’s feet and dig in one’s ice picks to work one’s way back onto the solid ice.
If one’s clothes have trapped a lot of water, one may have to lift oneself partially out of the water on one’s elbows to let the water drain before starting forward.
Lie flat on the ice once out and roll away from the hole to keep one’s weight spread out. This may help prevent one from breaking through again.
Get to a warm, dry, sheltered area and re-warm oneself immediately. In moderate to severe cases of cold water hypothermia, one must seek medical attention. Cold blood trapped in one’s extremities can come rushing back to one’s heart after beginning to re-warm. The shock of the chilled blood may cause ventricular fibrillation leading to a heart attack and death!
What if Someone Else Falls In?
What if someone else falls through and one is the only one around to help? First, call 911 for help. There is a good chance someone near may be carrying a cell phone.
Resist the urge to run up to the edge of the hole. This would most likely result in two victims in the water. Also, do not risk one’s own life to attempt to save a pet or other animal.
Preach, Reach, Throw, Row, Go.
Preach - Shout to the victim to encourage them to fight to survive and reassure them that help is on the way;
Reach - If one can safely reach the victim from shore, extend an object such as a rope, ladder, or jumper cables to the victim. If the person starts to pull oneself in, release one’s grip on the object and start over.
Throw - Toss one end of a rope or something that will float to the victim. Have them tie the rope around themselves before they are too weakened by the cold to grasp it.
Row - Find a light boat to push across the ice ahead of oneself. Push it to the edge of the hole, get into the boat and pull the victim in over the bow. It’s not a bad idea to attach some rope to the boat, so others can help pull oneself and the victim to safety.
Go - A non-professional shouldn’t go out on the ice to perform a rescue unless all other basic rescue techniques have been ruled out.
If the situation is too dangerous for one to perform the rescue, call 911 for help and keep reassuring the victim that help is on the way and urge them to fight to survive. Heroics by well-meaning but untrained rescuers sometimes result in two deaths.
Cars, pickups or SUVs should be parked at least 50 feet apart and moved every two hours to prevent sinking.
Tip: Make a hole next to the car. If water starts to overflow the top of the hole - the ice is sinking and it’s time to move the vehicle.
For more information on ice safety or to request free publications, contact the information center at: Phone: (651) 296-6157 (metro area) or 1-888-646-6367 (toll free outside the metro area). Or email: email@example.com (link sends email).