MIL-A-15303P

Abstract

This specification covers various types of audible signals for alarm and signaling purposes on Navy ships. <br>The types of audible signals shall be designated in the following form, as specified (see <a>6.2.1</a>): <br>IC/B1D1 <br>"IC/" is the basic part of each audible signal designator, B indicates the general type of signal (see <a>1.2.2</a>), 1 indicates special characteristics of the general type (see <a>1.2.3</a>), D indicates type of supply current (see <a>1.2.4</a>) and 1 indicates the supply voltage (see <a>1.2.5</a>). 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. <br>The basic indicator for Naval interior communication equipment shall be "IC/". <br>General type of signal shall be designated by a single letter as follows: </span><pre> B - Bell Z - Buzzer H - Horn S - Siren E - Electronic</pre> <br> <strong>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.</strong> <br>Special characteristics of the general type shall be designated by a number as follows: <pre> <u>Bells</u> 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 <u>Buzzers</u> 1 - Low intensity, watertight <u>Horns</u> 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</pre> <br> <br>NOTE: Navigational horns constructed of corrosion resistant materials shall be identified by the letter "N" as the last element of the type designation. <pre> <u>Sirens</u> 1 - Low pitch, 600 to 1200 Hz 2 - High pitch, 1750 to 2500 Hz <u>Electronic signals</u> 1 - Bus failure alarm signal 800 to 1800 Hz 3 - Switchboard, audible and remote signals 500 to 1000 Hz</pre> <br> <br>Type of supply current shall be designated by a single letter as follows: <pre> D - Direct current (dc) S - 60 Hz alternating current (ac) F - 400 Hz ac</pre> <br> <br>Supply voltage shall be designated by a number as follows: <pre> 1 - 6-volt (V) supply 2 - 12-V supply 3 - 24-V supply 4 - 115-V supply 5 - 440-V supply</pre> <br> <br>The audible signals furnished under this specification shall be identified by a part number as follows: <pre> M15303-IC/B1D1 "M" prefix and specification no. Basic indicator for Naval interior communication equipment Type of audible signal (see <a>3.5</a>) (defining a 3-inch diameter gong, operating on a 6 volt dc (Vdc) power supply)</pre> <br> <br><b><u>Intended Use:</u></b> The audible signals covered by this specification are to be used for signals and alarms on all Navy ships. <br>