Mar 31, 2021

Jerry Mills: Pipe layers spur ideas for installing irrigation lines

I got my COVID-19 shot! No pain, no illness. I feel great.

I never worried about influenza and never got flu shots until last fall. (I am allergic to the egg-based flu vaccine). Modern flu does not often kill, and flu virus mutates slowly. New flu strains do not appear too often, making it easier to control.

On the other hand, COVID-19 appears to be constantly mutating. Last year, a young man with a weak immune system got five different strains in five months. Each strain was different enough from the previous strain that he had no immunity and got sick each time. He eventually died.

COVID-19 might go away if everyone is vaccinated quickly enough to catch all of the strains at once. Sadly, that will never happen.

The last solution is herd immunity, which means our bodies will get used to the virus and gradually develop immunity to it. Scientists say that will not happen either because the virus mutates faster than our systems can build immunity. Controls that worked for one form may not work when another form appears. Also, people with robust immune systems may resist infection, but when something happens to reduce their immunity, COVID-19 may be lurking near enough to infect them. Lastly, as we age we become more vulnerable to all infections. COVID-19 just happens to be one of the more lethal.

How do you install underground irrigation lines? I’ve been watching crews lay underground fiber optic lines across the farm and that appears the way to go for any system. Pipes are invisible, protected from machinery, weather and rodents. This is how they do it.

First, a man walks the proposed route with a magic wand that tells him what lies below the surface. He marks each location with appropriate colored paint to indicate pipes, wires, sewers, etc.

Next, the boring machine crew moves into position. The machine has a hollow arm with a screw on the end. The arm lies on a flatbed angled toward the ground at about 30 degrees. It has a water line attached. A smooth drilling pipe is then screwed onto the arm. The other end of the pipe has a drill head with a hole in it. The pipe is about eight feet long.

When in operation, the pipe rotates and is pushed forward through the earth while water blasts from the drill head. The water dissolves the soil, washes it back along the pipe and at the same time dislodges rocks. When the pipe has extended its full length, the operator reverses rotation, unscrewing the pipe from the arm. The arm then retracts and another pipe is laid in, to be attached at both ends and driven forward another eight feet. The operator said 600 feet represents a good day’s drilling.

Direction and depth of the bore are controlled by manipulating the drill head. There are different systems. In most cases, the drill head sends a signal up to a handheld receiver. It tells the angle of the bore, and direction and temperature of the drill head. The operator uses this information to manage the bore. He can change direction or go deep or shallow depending on the terrain, even under a stream, for instance, and then curve upward the surface.

The bore here is only two feet deep for home telephone service. An earlier bore carrying cross-continental fiber optic lines is six- to eight-feet deep on level land, making it safe from telephone and fence posts on the right-of-way above.

When completed, the drilling process reverses, dragging the new telephone line through the bore hole behind it.

This system would sure be good for installing water lines for drip systems in the orchards. I asked the operator what his service cost. He said anywhere between $3 and $6 a lineal foot. It would be worth it if one wants to go under instead of around serious obstructions, such as a woods patch.

Zero degrees this morning! Brrr.

— Jerry Mills, Mills Apple Farm