As we turned the corner in Duluth, the grey skies lifted and it turned out to be a bright sunny day but 10 degrees colder than the day before (about 22 ℉). There was no bad road all the way back to the Twin Cities. That only happened when we pulled into our neighborhood and there was 6 inches of snow in the driveway. All of my neighbors driveways were clear and in many cases the pavement was dry and clear. The physical chemistry of snow is always interesting. In this case the bottom few millimeters of the snow was liquefied, but the upper 5 inches plus was medium density snow, the kind that is good for cross country skiing. Clear it off and the liquid evaporates in the direct sunlight, even when it is well below the freezing temperature. In some cases sublimation occurs and the snow vaporizes directly from the solid state. But I was focused on additional theories.
People living in northern climes think a lot about moving snow. We have had some epic snowfalls. Some of my fantasies coming into this season included getting an enclosed tractor with climate control and the ability to move a massive amount of snow. The image I have is a condensation of a couple of images. The first is a cola commercial from many years ago - a set of combines cutting wheat. All of the operators in their climate controlled cabs drinking Coke (or Pepsi?). The second is a show about building ice castles in Norway and a small vehicle that was described an an airport runway snowblower that could move a tremendous amount of snow through a chute directly over the operators cab. Those are my grandiose commercial induced fantasies. Even a small tractor with a cab set up to move snow is ridiculously expensive and it needs a lot of ongoing maintenance. I have never been able to locate the manufacturer of the Norwegian snow blower.
The reality is that I have a 15 year old Toro 2 stage snow thrower and about 200 square feet of sidewalk and 1,000 square feet of driveway to clear. The snow thrower cuts a 24 inch path. In many ways the strategy is mathematical and practical. What is the most efficient way to clear away the snow? Is it just going back and forth and turning the chute on the snow blower on every turn or is it something else? Since moving into this house I have decided it is a right angled arc starting up the left hand side of the driveway and then turning back (and turning the chute on the snowblower) and heading back in the same direction. This moves all of the blown snow to the eastern side of the lot, away from the sidewalk and areas where ice might accumulate. It also results in fewer change in the chute direction that just going back and forth or the length of the driveway.
Mathematics aside - what are the practical aspects? The first of course is the weather. Is more snow expected? Do you really want to concentrate the effort if there is going to be another foot? In some cases of wet and heavy snow it is imperative. That layer cannot be allowed to freeze and it is the most difficult to handle with a snow blower. In this case I was left with about 1/2 inch of translucent slush that I had to scrape up with shovel before it all froze in the colder temperatures. The second is the surface that you are clearing. There are some web sites that recommend snowblower sizes based on whether your driveway is finished (asphalt or concrete) or not (gravel). In my case I have two different surfaces - a concrete driveway and a textured concrete sidewalk. I can't use the steel shovel on the textured concrete. I use a plastic shovel very similar to the metal shovel that my father used to shovel coal into a steam engine on the 1950s. One of my earliest recollection was being placed in the cab of a steam locomotive. My father was a locomotive fireman at the time and the engine was hand fired. His job was to keep coal burning to keep the steam pressure up. He explained to me at the time how the scoop shaped shovel was designed to slide large amounts of coal off of it and into the furnace without wasting any energy. To clear the sidewalk - I clear one edge and then cut across that using the same motion my father used to shovel coal. Snow is a lot lighter than coal but it takes me about 50 passes to clear it using this motion.
With every pass, I am careful to extend the stroke out onto the grass by about 2-3 inches. When my father first taught me to shovel snow, he said this was critical in the event that there was any melting of the snow. Without that 2-3 inch margin the water pooled on the sidewalk and created ice. With the margin the water soaked into the grass and no ice was formed. I have tried to pass that knowledge along to other sidewalk shovelers, but it falls on deaf ears. Either they don't believe me or they have their own theories of shoveling.
In addition to the theory of clearing snow and carrying it out, I get another thought from about 50 years ago. I have always been an insomniac and one night back then I was waiting for my father to come home from work. By then he was a railroad engineer and drove freight and iron ore trains. It was about midnight. It was snowing and drifting to a depth of about 3 or 4 feet on the street outside of our home. He told me that day before he left that they might need to plow snow off the tracks. The worst case scenario would be hitting deep snow and blowing it into the diesel engine air intakes on the top of the locomotive. That would kill the engines and result in a long restarting process that would slow him down. I kept staring out the window. The wind was so intense that I could not hear any trains even though we were only about 3 blocks from tracks. I could finally see him leaning into the wind and snow. He always wore union style clothes and none of it was really made for winter weather. He wore a chromer cap with ear flaps that offered limited protection. He was carrying a leather satchel that he called a "grip" that contained all of his important paperwork. He was wading through hip deep snow, using the exaggerated hurdler motion that you had to use to travel in deep snow without snowshoes. I was very happy to see him and even happier when he burst into the kitchen and it smelled like the fresh air version of diesel fuel, Lucky Strikes and leather.
I have a greater appreciation of these events than I used to. Early on it was easy to grasp the psychodynamic significance, especially when it came to countertransferences toward mechanics and anyone else who might smell of diesel fuel and cigarettes in my office. There were the associated issues of blue collar rage, exploitation of union workers, and a stronger affiliation with workers rather than management. These days I can think of it in terms of the brain systems that are represented and the underlying mechanisms that allow for this experience. I still feel happy when I have that image of my father pushing through deep snow toward home. It probably accounts to some degree for my affiliation with snow and winter weather. Every month or so I give a lecture and talk about the time frame, neuroscience and structures that are probably responsible for that experience.
Most of all I remind the students about how these structures allow for unique human experience. I like to say that if there are 7 billion humans on Earth, there are 7 billion unique conscious states. I suppose planning and fantasizing about clearing the snow is not that unique in the upper midwest.
But I doubt that any two of us learned to do that in the exact same way.
George Dawson, MD, DFAPA
