Monitor Temperatures in Winter for Optimal Cold Weather Performance

The waning months of 2013 and early 2014 brought a harsh and nasty winter. The bitter chill — complete with a polar vortex — lasted for months and tested the patience of anyone looking for a few rays of warm sunlight. From coast to coast, communities dealt with record low temperatures that dipped to nearly 40 degrees below zero in states, including Minnesota and Wisconsin.

Horizontal directional drilling (HDD) companies are placed into a precarious position when the thermometer falls: No matter how frigid the weather becomes, some projects and utility installations cannot be ignored. Business owners must walk a fine line when they determine whether to send their employees and equipment out into the bitter elements.

Many companies have protocols in place to determine when temperatures are too cold for man or machine. This threshold is typically around zero to 10 F. “Below these temperatures, it’s just brutal outside. This last winter we had record days below zero and a number of crews just couldn’t make it outside,” says Tim Williams, product specialist for RDO Equipment in Minnesota.

If a crew decides to brave the winter conditions, there are steps to take to ensure the equipment stays functional and the integrity of the jobsite is maintained.

Focus on Four Fluids

Successful winter boring is focused on the integrity of four fluids: water and drilling fluid, antifreeze, fuel and hydraulic oil.

Equipment maintenance in the below-freezing weather centers on water and cleanliness. With the importance of water to the HDD process, freezing temperatures can play a significant role.

With temperatures already below freezing, operators have a limited window of keeping their water from freezing. Water is needed not only to maintain lubricity and remove cuttings from the bore hole during the boring process, but also to help keep the equipment clean after a day on the job.

“A lot of guys will use a vacuum excavator equipped with a hot water heater on it and they’ll spray the machine down in the front, and get everything cleaned off at the end of the day,” Williams says.

Failing to clean the drill from top to bottom after each day of work can cause drilling fluid to freeze on the front of the rig and create headaches the next morning. Drilling fluid is crucial to a successful bore. However, it can create the greatest concerns if not removed after boring in the winter.

“When you’re drilling in the winter and you break a rod apart, all of that drilling fluid that’s inside of your rod comes out and goes over the whole front of the machine. What will happen is, if it sits there without being cleaned off, it can freeze around the hydraulic hoses and other drill components,” Williams says.

The third item on the winter fluid checklist is antifreeze. When the temperatures dip dangerously low, a mud pump can freeze and break quickly.

The operator should flush the system with environmentally friendly antifreeze when they are shutting down for a period of time or overnight.

“When temperatures reach freezing, contractors need to flush the mud system with antifreeze at completion of the bore or overnight,” Williams says.

Fuel concerns can mount in the winter, as well. When the weather is warmer, No. 2 diesel fuel is ideal for an HDD rig. Once colder temperatures arrive, gelling can be a concern with No. 2 fuel, which became a major problem last winter. To prevent this, make the temporary switch to No. 1 diesel fuel if the temperatures drop to winter lows.

Hydraulic circuits will also need additional considerations during cold operation. Additional warm-up time will be required to ensure the machine’s hydraulic circuits work properly. For some models, hydraulic oil weight should be considered and recommend following the manufacturer’s recommendations.

Lands of Ice and Snow

Shoveling snow is an unwelcomed chore, but that is just the tip of the iceberg for HDD crews. The underground frost can be far more challenging and greatly impede progress.

“The frost line in colder climates like Minnesota will go 4 ft deep. This last winter the frost line went down deeper just because of how cold it was. Once you get through the frost line, it’s no different than drilling in the summer or any other time of year,” Williams says.

Contractors use a variety of methods to thaw frozen ground. Frost burners are small cans that use propane to melt snow and ice on the jobsite. Crews turn on the cans at night and come back the next day to find the area of ground thawed. Backhoes can also be used to dig in and excavate launch and exit pits, but that can lead to more restoration.

“In the winter, there’s greater restoration, because contractors will need to come back in the spring, when everything thaws out and restore all of that ground that they’ve removed to get through the frost,” Williams says.

Keep Crews Safe from the Cold

The combination of personal protective equipment (PPE) and cold weather gear is essential for operator comfort and safety during the winter months. Outdoor labor of any kind can lead to a heightened risk of frostbite;. To help alleviate these concerns, crews should be equipped with warm and safe clothing, but also take sufficient breaks to escape the cold.

“It’s important that the crew take adequate breaks to warm up. Many times they are dealing with water and mud and can run the risk of getting wet. They’ve got to have time to dry off or take a break,” Williams says.

Preparation is essential for any HDD project, but with the uncertainty of winter weather, crews and contractors need to be especially proactive. If they are able to plan accordingly and monitor employees and equipment, successful boring can be accomplished in even the most frigid conditions.

Greg Ehm is a features writer for Two Rivers Marketing, Des Moines, Iowa.