scope:

This specification covers various types of audible signals for alarm and signaling purposes on Navy ships.

The types of audible signals shall be designated in the following form, as specified (see 6.2.1):

IC/B1D1

"IC/" is the basic part of each audible signal designator, B indicates the general type of signal (see 1.2.2), 1 indicates special characteristics of the general type (see 1.2.3), D indicates type of supply current (see 1.2.4) and 1 indicates the supply voltage (see 1.2.5). When an audible signal may be used at more than one type of supply current, a combination of designators may be used in the type designation.

The basic indicator for Naval interior communication equipment shall be "IC/".

General type of signal shall be designated by a single letter as follows:

B - Bell Z - Buzzer H - Horn S - Siren E - Electronic

Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commander, Naval Sea Systems Command, SEA 55Z3, Department of the Navy, Washington, DC 20362-5101 by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter.

Special characteristics of the general type shall be designated by a number as follows:

Bells 1 - 3 inch diameter gong 2 - 8 inch diameter gong 3 - Cow bell shaped gong 4 - Single stroke bar chime 5 - Bus failure alarm signal Buzzers 1 - Low intensity, watertight Horns 1 - Nonresonated, 100 to 600 hertz (Hz), 95 decibels (dB) 2 - Resonated, 250 to 350 Hz, 95 dB 3 - Resonated, 300 to 350 Hz, 112 dB (general and motor boat navigational signal) 6 - Mechanical, 100 to 600 Hz, motorboat use, 90 dB 7 - Mechanical, 200 to 350 Hz, fog signal, 110 dB 8 - Motor-operated, 100 to 600 Hz, 103 dB

NOTE: Navigational horns constructed of corrosion resistant materials shall be identified by the letter "N" as the last element of the type designation.

Sirens 1 - Low pitch, 600 to 1200 Hz 2 - High pitch, 1750 to 2500 Hz Electronic signals 1 - Bus failure alarm signal 800 to 1800 Hz 3 - Switchboard, audible and remote signals 500 to 1000 Hz

Type of supply current shall be designated by a single letter as follows:

D - Direct current (dc) S - 60 Hz alternating current (ac) F - 400 Hz ac

Supply voltage shall be designated by a number as follows:

1 - 6-volt (V) supply 2 - 12-V supply 3 - 24-V supply 4 - 115-V supply 5 - 440-V supply

The audible signals furnished under this specification shall be identified by a part number as follows:

M15303-IC/B1D1 "M" prefix and specification no. Basic indicator for Naval interior communication equipment Type of audible signal (see 3.5) (defining a 3-inch diameter gong, operating on a 6 volt dc (Vdc) power supply)

intended Use:

The audible signals covered by this specification are to be used for signals and alarms on all Navy ships.