Following on my "How To" column of several months ago, I would like to pass on a few more tried and true techniques from the patch. Like cookbook authors, I have tested, again and again, each of these techniques and found that the regularly produce spectacular results. However, I must warn you again not to try any of this stuff at home, or in the presence of your boss. So, without much further ado:
How to rock gauge a tank
Those of you who have any familiarity with lease operations should understand the value of this technique. For decades, the lease operator (or pumper) has had to gauge the tanks at each of his tank batteries. To do this, he climbs the stairs to the top of the battery and walks along the catwalk, opening each thief hatch and dropping a gauge line in the tank to measure the amount of fluid in the tank. When he has determined the number of feet and inches of fluid (it ain't all oil in there) in the tank he refers to the strapping table for that particular tank to calculate the amount of fluid in the tank (bbl per inch time the height of the fluid column). Some of this work has been replaced by equipment that automatically measures the fluid level in a tank, but there are still a lot of folks climbing to the top of tank batteries.
Of course, all sorts of things, from snakes to goats to weather make it inconvenient (or down right irritating) to climb a tank battery. Deadly snakes often, for example, lurk in the shade of the tanks ready to administer their venom to any fool bent on approaching the tank battery. And goats? I once had a 2-hr stand off with a goat that had climbed the battery stairs and wandered to the end of the catwalk. Since I had no desire to share a catwalk 20 ft (6 m) off the ground with an irate goat I could not gauge the tanks. Threats, shouts, car horns, rocks - nothing would dislodge the goat. I skipped that battery that day and the next day the goat was gone.
So, what does one do when the snakes and goats are out, or the temperature is 120°F (48.8°C) or 10°F or (-12°C) with driving snow? Why you rock gauge, of course. To rock gauge a tank properly takes between three and five stones, depending on your skill. The stones should be as symmetrical as possible and 1.5 to 2 in. in diameter. This allows them to be heaved fairly accurately through a pick up window. On a really bad day you might want to have several dozen rocks in your truck. They store well in a gym basket.
To rock gauge a tank, drive to within 10 ft (3 m) of the tank. Grab a rock and hurl it at the tank. You will either get a tinny metallic sound, or a plunk, as the rock strikes the tank. The metallic sound is empty tankage and the plunk indicates liquid. Now you are engaged in a simple ranging procedure. Two to three more throws should let you determined the fluid level in the tank.
On a really cold day, rock gauging presents another fascinating opportunity - snake irritation. As the well fluid in the tanks is warm, snakes congregate under the tanks in winter. If, after the first heave, you hear about 20 rattlesnakes rattling in unison, you are in for a good day.
One other tip. A pile of small rocks near a tank is a sure tip off that you have been rock gauging. For some reason, most production foremen don't like this. So, from time to time, pick up your rocks. It is, after all, recycling.