Grave Digging and Ground Thawing

If you work professionally digging graves, you know it is labor-intensive work. This is even more true if you live in an area where winter makes its mighty presence known. Winter adds an extra layer of difficulty to any grave digging project, not to mention the extra layer of ice and snow that accompanies it. Learn how to best deal with these less-than-ideal circumstances.

How does grave digging become more difficult in winter due to frozen ground?

  • The job takes more time: If you’re lucky, the frozen ground will only add an extra couple of hours onto your digging project. In reality, it can often take an extra day or two to accomplish the same dig as it would in the summer months. Because of the extended time, you and your team may well experience lengthened work days, more exposure to the elements, and increased frustration. Not to mention getting behind on the work that must be done on projects that may begin to pile up.
  • Increased Safety Hazards: When working in freezing conditions, cemetery workers and burial ground custodians are at a heightened risk. As mentioned, you’re likely working long hours in the harsh cold, which can lead to cold stress problems including hypothermia and frostbite.Without proper ground preparation, workers may try to “muscle” the frozen ground into cooperation with shovels. This can easily lead to injuries that can put them out of commission for quite a while.This is also true of shoveling large amounts of snow from a dig site in order to prepare the ground for the burial site, which has been shown to put a lot of strain on individuals who are susceptible to experiencing heart attacks. While those in the grave preparation field are probably pretty used to working with a shovel in hand, it is still wise to be aware of putting too much strain on the body when shoveling, and winter is the time that this increase in risk takes place.
  • Tools Break More Easily: Tools should always be inspected before use, no matter what time of the year it may be. However, this is especially true in the winter months. Simply put, this is because the tools will experience more strain as they fight to penetrate the frozen ground. When a tool breaks unexpectedly, it can potentially harm the person digging. It also stalls the project while a replacement is purchased.Whether it’s your shovel, backhoe, shoring tools, protective gear, or ground heating solutions, never begin a job without thoroughly inspecting your tools to make sure they are up to the task at hand.

Frozen ground in winter conditions does not only affect those who are actually digging the grave site. Consider this:

In the past, many graves simply could not be dug due to frozen ground. While the technologies today have lessened this issue greatly, the difficulty of digging in adverse weather conditions still exists in some areas of the country, particularly in the northern states. For example, in North Dakota, the ground can freeze so remarkably that digging simply cannot take place with traditional methods. The work is paused for the entire winter! Yikes.

While this is a pain for the workers, it is nothing like the agony experienced by those who have to wait to bury their dead for a few weeks, if not a few months. In these situations, the deceased body is placed in a refrigeration unit to preserve it. This reality would mean a family would not be able to find closure after a loved one’s passing because the process would be re-lived a second time. What a terrible prospect for any grieving family! 

One such story, called “Where Death Comes in Winter, Burial Comes in Spring,” was explained in the NY Times several years ago, which told of a 4-year-old boy who had passed away. If this horror is not enough for any parent to face, the experience was amplified by the fact that the parents could not put him to rest until a month after his passing due to frozen ground. His mother said “Everybody was a disaster – It brought it all back fresh. It was horrible.”

No cemetery wants those who come with a deceased loved one to experience that type of misery. Thankfully, many cemeteries in the United States do not deal with circumstances that are quite as intense as these, but the reality of digging for a casket in frozen ground is difficult nonetheless.

Those who work in a cemetery preparing graves know that it is incredibly important to stay on schedule in order to get the job in a timely manner. This act of service allows the funeral and burial to go as smoothly as possible, aiding the family in its need for peace. Not even frozen ground can get in the way of something like that.

In order to avoid possible circumstances like those mentioned above, grave digging teams often need to use more tools in the winter than in the summer. Here are some helpful winter tools to keep your digging project running nicely, even in the intense cold. 

How to Dig a Grave In Frozen Ground

  • Jackhammer: Perhaps you have used a jackhammer on an icy dig and found it helps as you work to get through that solid layer of ice at the site. Many cemeteries opt to outline the burial site and then drill across the ground. This helps to break up the ground, which will then be easier to dig with a backhoe rather than a single sheet of frozen soil.
  • Frost Teeth: Another extra helper during the frigid winter months is called “Frost Teeth.” These babies really do look like large fangs and are attached to the end of the backhoe’s bucket. The “teeth” aid the backhoe in getting through the difficult top layers of frost and icy ground. It is then easier to excavate after that point.
  • Grave Burner/Frost Thawer: Another method is using propane in burner units that can heat up the ground. This method involves taking a large stove to the burial site and cooking the ground. This method will take several hours.
  • Ground Thawing Blankets: One of the latest technologies to arrive at burial preparation sites is heated blankets meant specifically for thawing out the frost, snow, and ice. Many grave digging teams now choose to utilize ground thawing blankets to drastically lessen the headache and time it takes to begin a winter dig for a future casket. 

These blankets are designed specifically to thaw out the ground within hours, with little effort on the part of those digging. This safe, reliable option has become quite popular in recent years, as it saves a lot of money in hours that would have been spent trying to cut through frozen ground by workers. Simply place the blanket on the ground several hours the dig, and the site will be ready and when you are.

At Powerblanket, we highly recommend checking out our ground thawing blankets as the solution to your winter digging problems. Here are some of the things you can expect from our quality product line.

  • High Watt Density Thaws Frozen Ground Fast.
  • Quickly Removes Frost Prior to Digging
  • Melt Snow and Ice From Ground Prior to Digging
  • Easily Installed and Removed
  • Easily Transportable
  • Safe and Certified to National Safety Standards
  • No-Mess Heating with Little Preparation Required

Powerblanket’s Ground Thawing Blankets were essential in saving the Hailey Cemetery time and money during the Idaho Winter of 2017. Wayne Burke, maintenance supervisor for the cemetery, said that winter was colder and less wet than previous years, which caused the soil to freeze much deeper than normal.

“There’s usually six inches of snow on the ground,” Burke said, adding that the snow acts as a layer of insulation, preventing the ground from freezing as much. “It always worked out great. But last year it got really cold and there was no snow.”

Burke knew he needed solutions fast to meet the demand of the cemetery’s burial service schedule. He reached out to Powerblanket, and within just two days of ordering, he received his game-changing Ground Thawing Blanket.

“You guys sent it just in time. I used it the first day, and only had it on for 12 hours. It still worked,” he said. “A few weeks later, I needed it again. We also loaned it to another cemetery, and they were really happy with how it worked too.”

Burke explained that in his years before discovering Powerblanket, he had used propane torches to thaw the frozen soil before digging. In addition, the cemetery landscaping had to be torn up and replaced after each dig.

But with his Ground Thawing Blanket, he was able to avoid this hassle. 

“It worked perfect,” he said. “It thawed about 14 inches down into the ground. The grass greened up and I was able to cut it up into strips and roll it up. The sod was in good shape and I stored it in our garage. After the burial, we put the dirt back in and rolled the sod back out. Normally, we tear the sod up and throw it away and replant in the springtime.”

Burke said the Ground Thawing Blanket was exactly what he needed to break through the tough winter soil, saving him hours of manual labor and nearly $100 in landscaping costs.

“I was really happy with it, and we’ll be using it again this year,” he said.

Burke knew that his traditional methods were just not going to cut it (the ground, that is) in such a cold winter. As he mentioned, the ground tends to freeze even more with no protection of a layer of snow. He knew it was time to consider other methods, and after doing his research, he found that Powerblanket’s offerings were the best fit to keep his burial projects right on schedule. 

We were happy to be the solution to his problem!

Another one of our recent customers had this to say about our ground thawing blankets:

Your blankets are absolutely excellent. Thanks to Powerblanket, we were able to quickly thaw the ground and complete our job. In fact, we estimate a savings of 10 hours per site, equaling a savings of $5,000 already. Calculating this into our thousands of sites, the savings are huge! We are excited about the time and money Powerblanket has saved us and look forward to future savings.

It’s these stories we absolutely love to hear from our customers. We love knowing that we are helping them get the job done as easily as possible in every way!

Of course, our ground thawing solutions have many applications in addition to digging graves in a cemetery setting. Here are some examples of other settings where our ground blankets have a big, positive impact on the job:image-ground-thawing-blankets

  • Prepping Frozen Ground for Pouring Concrete
  • Curing Poured Concrete in Winter (Which Prevents Weakened Concrete)
  • Melting Snow Off Walkways to Ensure Customer Safety
  • Keeping Construction Sites Safer for the Crew 
  • Heating Residential Doorway and Driveways to Increase Safety

Wonder if our heating solutions are the right fit for your company or situation? Give us a call. Our friendly staff here at Powerblanket is knowledgeable about all possible applications of these heating blankets. We are ready to answer any questions you may have, whether you are in the grave digging field or another line of work (such as other types of construction) that require ground thawing methods. 

Reach out to us today, and we will get you on your way to a better experience with each of your winter projects. Contact us at 801.506.0198 today.

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Frozen Ground and the Frost Line: How and Why it Freezes

How Deep Does the Ground Freeze in Winter?

Ground frost occurs when the ground contains water, and the temperature of the ground goes below 0° C (32° F). More than half of all the land in the Northern Hemisphere freezes and thaws every year, and is called seasonally frozen ground. One-fourth of the land in the Northern Hemisphere has an underground layer that stays frozen all year long. If the ground remains frozen for at least 2 years in a row it is called permafrost

What causes ground frost?

When ground is frozen solid, the water between the rocks, soil, and pebbles, and even inside the rocks, has frozen and becomes pore ice. So officially, the ground freezes when the water in the ground becomes ice.

Frost Depth

Frost Depth (or the frost line) is the deepest point to which ground water will freeze. Frost depths vary depending upon the frost line in each location and can have a great impact on many construction practices. For example, any crews digging to access utility lines or preparing ground for a concrete pour will need to be aware of their local frost depth.

When ground water freezes its volume expands by 9%. For this reason, pressure sensitive structures, such as water and sewer lines, need to be buried below the frost depth to avoid ruptures. When water turns into ice, it can expand with great force and cause the ground to swell. In areas with a cold winter season ground frost can damage roads. For example, water turning to ice under roads sometime creates frost heave. The expanding ice pushes up the road and creates a hump, which later, after a thaw, will create potholes  and sunken sections in a roadway.

The frost line varies depending on the length of time the air is cold. The longer the cold period, the deeper the ground will freeze. But the depth of frozen ground is limited, because Earth is warm deep inside.

What Affects the Frost Line?

Most of Earth’s heat comes from the Sun (Figure 1). The ground stores a lot of the Sun’s heat and reflects the rest into the air. Snow and ice are light colored and reflect more heat away. Ocean water and bare ground reflect less heat, instead absorbing it. This transfer of heat between the ground and the air is called the surface energy flux.

energy balance diagram

Figure 1. This diagram shows how the Earth’s atmosphere and the ground reflects and absorbs the Sun’s energy.

Credit: NASA Atmospheric Science Data Center

Heat is also coming from the inside of the Earth. The Earth’s core is very hot, and its heat moves towards the surface. Heat from volcanoes, rivers, lakes, and other sources can also spread through the ground. This heat keeps some areas unfrozen, even though surface temperatures are low.

In general, deeper permafrost is very old. One researcher found that the deepest part of the permafrost underneath Prudhoe Bay, Alaska, is more than 500,000 years old.

The Temperature Gradient

When the temperature of the ground drops below 0° C (32° F), it freezes; however, the ground temperature can be different from the temperature of the air above it. This temperature gradient means that layers deep within the ground may be colder or warmer than layers near the surface.

The top layer of ground may respond to conditions on the surface, but the layers below may not change as quickly. On a warm summer day, the surface of the ground absorbs heat and becomes hotter than the air. But the temperature a few feet underground may be much lower than the air. It is the opposite in the winter; the surface of the ground cools, but the layer deep underground may stay warmer than the surface. The upper layer of ground stops heat from moving between the cold air and the deeper layers of the ground, insulating itself.

How does the local landscape affect ground frost?

Ground frost is affected by more than just temperature swings, seasonal changes, and location. Snow, soil, plants, and other aspects of the local landscape also affect frozen ground.

Snow

A thick layer of snow acts like a blanket so that heat does not leave the ground. Only a thin layer of ground will freeze under a thick layer of snow.

Soil type

Some soils freeze more easily than others. Light-colored soils freeze sooner and stay frozen longer than dark soils. Light-colored soils and rocks reflect sunlight, keeping the ground cooler. Loose soils like sand have more space for water and ice forms more easily. Dense soils with small particles do not have as much space for water. Clay, for example, does not freeze as easily as sand.

Peat

Peat forms when dead plants do not fully decompose. The ground under peat is usually colder than ground not covered by a peat layer.  In the winter, peat freezes and allows heat to leave the ground. Because the heat escapes, more frozen ground and permafrost form.

Plants

In the summer, plants keep the soil underneath them cooler because they block some sunlight from reaching the ground. Evergreen trees especially keep the ground cooler. Evergreen trees do not lose their leaves in the winter. This means that the trees block sunlight from warming the ground. Plus, their branches block snow from reaching the ground underneath. The bare ground loses heat more easily. Permafrost often forms under evergreen trees.

Slopes

Hillsides and mountain slopes can affect frozen ground and permafrost. If a slope gets more sunlight because of the way it faces, the ground will be warmer and will be less likely to freeze. In the Northern Hemisphere, slopes that face south, towards the Sun, get more sunlight than shady slopes that face north. The opposite is true in the Southern Hemisphere.

Steep slopes are likely to contain frozen ground. The steepness of the slope affects how much sunlight it gets. Steep slopes do not get as much direct sunlight, so they are colder. Steep slopes do not hold snow cover very well, so the bare ground loses more heat. Wind direction also affects whether frozen ground forms. If a slope faces into the wind, the ground will lose more heat. Plus, the wind will blow snow away making the ground even colder.

Lakes and rivers

Lakes and rivers are sources of heat in cold places. The water is warmer than the surrounding air and can keep the ground beneath it warmer in the winter. Lakes and rivers might not have frozen ground under them. Or, they might have a thicker active layer compared to nearby land.

Powerblanket Ground Frost Solutions

“Your blankets are absolutely excellent. Thanks to the Powerblankets, we were able to quickly thaw the ground and complete our job. In fact, we estimate a savings of 10 hours per site equaling a savings of $5,000 already. Calculating this to our thousands of sites, the savings is huge! We are excited about the time and money Powerblanket has saved us and look forward to future savings.”

— Kim Herman OSP/COEI Operations Manager Precision Utilities Group

The frost line is a reality many industrial companies must face.  The high watt density in Powerblanket ground thawing products helps tackle the difficulty of thawing ground in harsh climates.  Use a Powerblanket ground heater to save time, money, and stress.  

frozen ground being thawed

 

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