The data form (not included here) reveals an
(5) Wall selection for Maintenance Shop. The
planned walls between the Engine Rooms and the
through 8000 Hz) and low frequency values of 220,
Maintenance Shop will be of 10-in. -thick hollow-
220, 330, 550, and 880 ft.2 for the 31- through
core concrete block, if this is found to be acceptable
500-Hz octave bands, respectively. A copy of DD
acoustically. Each of these walls is 40 ft. x 12 ft.,
2
Form 2298 (Transmission Loss Requirement for
and each has a metal fireproof door of 2-ft. area.
Common Wall or Floor-Ceiling Between Source
Maintenance Shop sound levels due to full opera-
tion of both Engine Rooms must not exceed 84
Room and Receiving Room) is filled in for each En-
gine Room feeding noise to the Maintenance Shop.
dB(A), and a 60 dB SIL (corresponds approximate-
Figures 4-13 and 4-14 show that noise from En-
ly to an NC60 criterion) is preferred, if reason-
gine Room No. 1 will be acceptable in the 500-
ably attainable. The Room Constant of the Mainte-
nance Room is determined from DD Form 2295
through 2000-Hz bands (the SIL bands), but noise
from Engine Room No. 2 will exceed the desired
where the room dimensions are 40 ft. by 28 ft. by
12 ft. high. The ceiling has acoustic absorption
level by about 5 dB in the 500-Hz band.
[AIMA mounting type 1, 0.65 to 0.75 NRC range.].
4
4-18
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