Be safe on the ice!
With the lakes and ponds frozen over, now is a good time to talk about ice safety. There are many factors that affect the strength of ice, so it is hard to set any hard and fast rules about how thick it should be to be considered safe. Areas that have moving water or strong currents will have considerably thinner ice. Objects located below the surface such as stumps and rocks can affect the strength. Also, the structure of the ice greatly affects the strength. Clear or black ice is the strongest. Snow or frazzle ice is the weakest. One inch of clear ice can be as strong as six to eight inches of frazzle ice. Snow and contaminates on the surface can also greatly effect the strength.
One generally agreed-on formula for determining strength in clear, solid lake ice is P = (50) T squared, where P = the load-bearing capacity of the ice in pounds, and T = the ice thickness in inches. Example: If the ice is 8 inches thick, 50 X (8X8) = 3200 lbs.
This is the maximum short term load in motion.
Ice Maximum Load Table
Ice thickness Maximum Load
2 inches one person
4 inches one person fishing or a small group walking
5 inches a snowmobile
8 inches a car
10-12 inches a light truck
Remember this is for clear, solid lake ice. All factors that weaken the ice must be taken into account for safety. Use caution, especially early and late in the season. If you see standing water on top of the ice, it is a good indication that the ice may not be safe.
If you see someone fall through the ice, act quickly: call 911 immediately. Give the dispatcher as much information as you can as to the location, number of people involved, best access for rescue personnel, etc. Do not go out on the ice. Many times would-be rescuers become victims themselves. Remember, someone already fell through. This holds true for pets also. If the ice would not support a 45-50 pound dog, it will not support a full-grown adult. Call 911. The Shutesbury Fire Department has special equipment and training to safely deal with these situations.