l) access through floors into basement areas for installation,
servicing and removal of equipment, and personnel access,
m) resistance to wind, storm and typhoon damage to the structure
and to the internal equipment, and
n) acid-resistant floors and drains should be provided for battery
rooms covered by definitive designs. A separate battery room may not be
warranted for very small plants not covered by a definitive design.
15.3.4 Noise Control. Noise from the engine-generator units must be
considered in the design. See DM-3.10, Noise and Vibration Control of
Mechanical Equipment. The definitive drawings provide enclosed work spaces
for supervisory and operating personnel with sound-reducing windows for
observation of plant operating machinery. Acoustical treatment should be
designed in accordance with the following consideration:
a) While it is extremely difficult to predict noise levels in
engine-generating spaces, the data from three different engine manufacturers
can be used to permit approximation of noise levels for initial design.
b) In engine-generating spaces, it may be impossible to
economically reduce sound levels to those below hazardous area noise levels,
i.e. 84 decibels (db) or below. After the plant is in operation, sound
levels should be measured to determine what personal protection is required
to meet Code of Federal Regulations (CFR) 29 CFR 1910, Occupational Safety
and Health Administration (OSHA), Safety and Health Standards.
c) Design of rooms with operating personnel such as control areas
should be acoustically treated to provide attenuation of maximum sound
levels to 45 db under normal engine-generator operating conditions and 55 db
when all engine-generator units are operated at their nameplate rating.
15.4 Structural Criteria.
Refer to NAVFAC DM-2.01 Structural Engineering,
15.4.1 Foundations. Electric-generating plant foundations require careful
design because sites are frequently on marshy or filled ground close to
surface waters and/or to the groundwater table. A detailed subsurface study
is necessary in all cases to properly access the structural needs for the
building and equipment foundations. (Refer to Section 5 for
engine-generator foundations.) Seismic requirements for the site shall be
investigated as they pertain to foundations.
188.8.131.52 Extra Piling. Silencer and stack foundations, fuel oil tanks, and
other heavy auxiliary equipment may require extra piling.
184.108.40.206 Definitive Designs. Definitive drawings (refer to Section 1) show
the preferred building construction.
15.4.2 Floor Loads. The design of the engine room floor must provide for a
minimum 200 lb/ft2 (976 kg/m2) live load.