Congratulations to the recipients of Minnesota’s 2023 Build a Better Mousetrap Awards! First place goes to Otter Tail County for the Otter Claw and second place to the City of Bloomington for its Sidewalk Snow Blower Castors project. Redwood County and Big Stone County were runners-up.
The Minnesota Mousetrap competition is sponsored by the Minnesota Local Road Research Board and administered by Minnesota LTAP.
First place: Otter Claw
The Otter Tail County Highway Department needed a better way to clean out culvert debris. Highway maintenance workers developed the Otter Claw, an extendable culvert cleaner. This skid steer attachment extends up to 15 feet, allowing the operator to easily and safely remove large amounts of debris from previously hard-to-reach locations. The Otter Claw can also be used to place culvert sections during construction. Other uses include placing riprap alongside bridges, culverts, and roads and handling downed trees after storms. Developing the Otter Claw cost $6,000.
Second place: Sidewalk Snow Blower Castors
The City of Bloomington wanted a solution to the issues caused by its sidewalk snow blower shoes. The maintenance crew needed to replace many of these shoes as they wore out. The operators also had issues with the constant grating noise of the shoes, and occasionally there were injuries when a sidewalk heave would cause a sudden stop to the unit.
The crew decided to replace the snow blower shoes with castors. They tried a few different wheels before finding a style and material that worked well, and they fabricated the brackets with flat stock. Using castors on the city’s sidewalk snow blowing units has eliminated shoe wear, is quieter for the operators, and allows the machines to move safely over sidewalk heaves. The initial design took 15 hours, and the cost to fit eight units with the castors was $10,733 (including the prototyping).
Runners-up
Redwood County was a runner-up for its Road Shouldering Improvements project.
The other runner-up was Big Stone County, for its Self-Performed Calcium Chloride project. Used for dust control on gravel roads, calcium chloride was not being applied in a timely manner in the county. Additionally, cost for application was generally $0.10 to $0.15 per gallon higher than in neighboring counties.
After touring the operation of someone nearby who was mixing his own calcium chloride, county staff decided to adopt the same approach. The department already had a 5,000-gallon stainless steel tanker truck and a smaller tank on an F-550—so the crew had a stainless-steel spray bar fabricated for each truck and purchased a mixing cone, gas pumps, valves, and tanks for mixing granular flakes into a liquid. When the mixing operation moved inside the new county maintenance shop, it was hardwired with an electric pump and plumbed to the municipal water system, and the mixing cone was replaced with a small auger and hopper.
Dust control material can now be mixed when conditions are right, allowing for flexibility if applications need to be pushed back or paused due to weather conditions. Costs for the public are also lower than neighboring counties. The initial investment for the county was $10,000–15,000.