TM 5-809-6/AFM 88-3, Chap. 6
ELECTRICAL AND COMMUNICATION STRUCTURES
structures, however, must be strong enough to resist the
climatic design load requirements for the site. Where special
Electrical and communication system structures will be
structure design is needed, design criteria will conform to the
designed in accordance with TM 5-811-1/AFM 88-9, Chap-
National Electrical Manufacturers Association (NEMA) SG-
ter 1 and the following. In all cases, the Institute of Electrical
6. General layouts and configurations for electrical support
and Electronics Engineers (IEEE) National Electric Safety
structures are given in TM 5-811-1/AFM 88-9, Chapter 1.
Code (NESC) will be considered as establishing minimum
Equipment foundations will be designed in accordance with
requirements for design of structures associated with electric
current practices; the safety factor for stability against
power systems. For aluminum towers and antennas, the one-
overturning and for resistance against sliding will be as set
third increase in allowable stresses under wind or seismic
forth in paragraph 1-6.
loads permitted in the Aluminum Association Specifications
for Aluminum Structures will not be used. Design of
electrical support systems for seismic restraint is covered in
TM 5-809-10/NAVFAC P-355/AFM 88-3, Chapter 13.
Antenna towers will be designed using applicable criteria
from the Electronic Industries Association (EIA) 222-D.
8-2. Transmission towers and poles
Design methods and stresses will be as appropriate for the
material used for the supporting structure.
Power transmission towers and pole structures will be
designed in accordance with the NESC (IEEE (22), and the
8-5. Underground structures
following ASCE publications: Manual 52, applicable tech-
nical papers in its Structural Division Journal (including
Underground structures associated with electrical and
Design of Steel Transmission Pole Structures), and Guide for
communication systems, e.g., manholes, handholes, pull
the Design and Use of Concrete Poles. In case of conflicting
boxes, etc., will be designed according to the criteria for
criteria, the most conservative method will be used.
manholes and inlets in paragraph 4-1. The need for water
8-3. Substation structures and equipment
examined, as well as cable bending radii and details of
required support systems, when establishing the layout and
Substation, switching station, and similar structures for
dimensions of such structures. Design will also comply with
supporting electrical equipment will be constructed, where
ASTM C 857 and C 858.
possible, of manufacturer*s standard unit components. All