Blackout Identification of Fuels and Lubes
Don’t be surprised if the sergeant calls you over for a lesson in Braille. He does’t expect you to go suddenly blind, and he can’t teach you how to read the PX blonde.
Fact is, you have to have some way of reading fuel and lubricant labels in a blackout. So they’ve developed a method of recognizing the different kinds of labels by the sense of touch.
It is done by a system of tagging — different shapes of tags for dlfferent kinds of fuel or lube, like OE (oil, engine) or GO (gear oil), and raised lettering to tell the grade, like 10, 30, or 50.
If the callouses on your stubby fingers are sensitive enough, you can feel the shape of the tag and trace out the shape of the letters and figures in the dark.
Fuels are marked with the octane rating or the symbol “K” (kerosene) or “D” (Diesel). Down in the corner of the fuel tag is a smaller letter indicating whether the product is Class A, B, C, or X. These clasuiflcatlons represent temperature ranges for which the fuel is designed. Class A is for the warmest weather, C or X for the coldest.
Lube tags carry only the official symbol, such as 0E 30 HD.
The tags will also have distinctive colors far easier daylight identification, like this:
=OE 10 HD.
=OE 3O HD or kerosene
(the shape of the tag Ii different).
=0E 50 HD.