TM 1-4920-500-13&P
0016 00
OPERATION DURING BLACKOUT CONDITIONS
NOTES
During blackout conditions, enter and leave shelter through personnel
entrance door only. Do not operate exterior area light.
Blackout override switch must remain in OFF position for duration of blackout
conditions.
1. Activate all interior lights and check from 25 feet (7.6 m) away to ensure light is not visible.
2. Place blackout override switch in OFF position.
OPERATION FOR IMPROVING SOIL CONDUCTIVITY FOR SHELTER GROUNDING
At sites where the soil quality is very poor or very dry, special steps need to be taken to enhance the soil
conductivity near the grounding rod. The first option is to drive the grounding rod deep enough to reach the moist
subsoil, if possible. If there is no moist subsoil or if the soil condition will not allow for deep penetration, the
second option is to drive the grounding rod as deeply as possible and apply water at regular intervals to keep the
soil moist.
The best way to substantially improve the effectiveness of the grounding rod is to use a salt and water mixture.
Use 1 pound of salt for each gallon of water. Dig a shallow trench at the distance of 18 inches around the
grounding rod so that the liquid does not run off. To replace the salt that leaches into the soil, mix salt with the
water at least once a week. Optionally, salt can be placed in the trench and then covered, which will leach into the
soil whenever it rains.
End of Work Package
