The capital city of Canada, Ottawa, is one of the coldest capital cities in the world. For decades, when the Rideau Canal in Ottawa freezes over in the winter, it becomes the world’s largest skating rink. At a length of over 7 km and including Dow Lake, there is certainly plenty of ice for everyone.
For almost 15 years, the ice on the Rideau Canal has been built, monitored, and maintained by a company named Capital Property Guardians. In 2018, they purchased an IceMap SmartTow GPR system (Figure 1) for measuring the ice thickness. IceMap uses ground penetrating radar (GPR) technology and specialized software to automatically display ice thickness in real-time to provide an easy-to-use solution for ice safety management.
Early in the season, when the ice in the canal has started to freeze and thicken, IceMap is deployed with a snowmobile to check the ice thickness (Figure 2).
The goal is for the ice to reach 30 cm thick; thick enough for trucks and an Ice Resurfacer machine to move safely on the ice (Figure 3). The Ice Resurfacer machine melts the top layer of ice that has been chewed up by skates, adds a thin layer of water and allows the ice to refreeze much smoother. The Zamboni brand Ice Resurfacer weighs almost 7 tons when full of water so, for obvious safety reasons, the ice needs to be thick enough to support it. Thirty centimeters of ice is also thick enough to allow food and beverage trailers to be towed onto the ice for the enjoyment of the skaters.
Says Robert Taillefer, owner of Capital Property Guardians: “The IceMap system allows us to measure the ice thickness and flood the thin areas with water to quickly increase the thickness. This allows us to thicken all the ice to the point where it can support the Zamboni. The earlier we can get the Zamboni on the ice, the earlier we can work on making the ice smooth for skaters and the longer the skating season will be (Figure 4). Before we had IceMap, we needed to drill many holes to confirm that the ice was thick enough to support the Zamboni and there was always a concern that a thin spot was missed that could result in a serious accident. IceMap minimizes that uncertainty.”
His customer, the National Capital Commission, loves the simple report he gives them; a Google Earth image that shows where the ice is greater than 30 cm thick in blue and, the places where the ice is less than 30 cm thick in red (like Figure 5). This allows them to quickly see where the work must be done to flood the ice and make it thick enough for safety.
IceMap is a unique technology and most people are not used to seeing it or know what it is used for. What is the oddest question that Robert has ever been asked while scanning the ice with IceMap in the middle of the night? Someone once stopped him and asked if he was the coroner removing a body from the ice! The IceMap sled is about 6 feet long and covered to protect the IceMap system electronics so it is not surprising that this question arose!
Further Reading:
https://www.macleans.ca/news/canada/smooth-operator-2/
IceMap data courtesy of Robert Taillefer, Capital Property Guardians
