TM 5-8113/AFM 88-9, Chap. 3
to pole. One pole may serve two van units having
equipment extending above ground will be grounded
long sides parallel and located not more than 12 feet
to protection system counterpoise.
apart. Protection equipment will be located and
217. Electrically-controlled target training
arranged in a manner that will not obstruct the oper-
system
ation of any radar electronic acquisition or tracking
a. General. Reliability of continuous operational
beam.
availability of electricallty-cont rolled target systems
c. Protection system. Down conductors of not less
for rifle squad tactical ranges is of such importance to
than No. 2 AWG bare copper on pole will be pro-
infantry training in the scheduling of firing periods
vided from lightning rod to ground rods located not
and to morale of' large numbers of troops that provi-
less than 6 feet from van and not less than 6 inches
sions of lightning protection is warranted. Lightning
from edge of hardstand. Spiral type grounds under
protection for rifle range support facilities need not
poles (butt grounds) are acceptable. Pole guys will be
be provided.
electrically conductive to ground, and guy anchor will
b. Control tower. Complete protection system will
be interconnected to pole ground rod below grade.
Each ground rod at pole will be interconnected below
be provided. The system should have at least two air
hardstand to ground rod of' van grounding system.
terminals installed on roof.
Where vans are clustered, van ground rods will be
interconnected in compliance with MIL-HDBK-419.
separately provided at each target mechanism box
assembly station of such rifle ranges, lightning pro-
tection counterpoise or grid will not be required for
216. Weapon system electronic facilities be-
protection of down range target area. Where such
low ground
control relays are not provided, grounding counter-
a. Protection included with other protection sys-
poise or grid will be provided above wiring in
tems. When external grounding system design is in-
trenches below grade to all targets from control
cluded for electromagnetic pulse (EMP) protection,
tower.
electromagnetic interference shielding or other pro-
218. Petroleum oil lubricants (POL) facilities
tection system, separate lightning protection will not
a. Storage tanks. Generally, protection for storage
be required.
tanks will depend on their inherent contact with
b. Protection not included in other protection sys-
earth. Where steel storage tanks are constructed on
tems. When external grounding system design does
foundations of concrete or masonry, grounding will
not include EMP protection, electromagnetic inter-
be provided in accordance with grounding schedule
ference shielding or other protection system, light-
show-n in table 21, regardless of tank height. Where
ning protection counterpoise will be provided includ-
steel tanks are constructed in direct contact all
ing connections to metallic objects below grade, such
around the perimeter with not less than 18 inches of
as the following:
earth, grounding will not be required. See AFM
(1) Electrical conduit.
85-16 for additional requirements pertaining to Air
(2) Mechanical piping.
Force facilities.
(3) Metal tanks.
(4) Manhole grounds.
Table 2-1. Fuel Storage Tank Grounding Schedule
(5) Missile cells or equivalent.
Tank Circumference--Feet
Ground Connections
(6) Internal grounding system of control build-
ings and power plants.
200
And Less
(7) Metal ducts for fans.
201
Through 300
(8) Tunnels.
301
Through 400
401
Through 500
The main counterpoise will be installed above each
501
Through 600
buried weapon system building, at least 2 feet below
601
Through 800
finished grade, and will extend beyond the building
801
And More
perimeter not less than 3 nor more than 8 feet. Main
counterpoise will be connected to ground rods located
b. Pump house. Protection for POL pump house
as in figure 23, and driven to a point at least 6
will be provided complete as required for the applica-
inches below normal ground water table level, where
ble type of building construction.
earth is available for driving. See also above for
c. Fill stands. Protection for fill stands will con-
building reinforcement system grounding. Metal
form to NFPA No. 78.
2-7
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