tended manner, and one smoke detecting zone shall be connected to the smoke density meter described in paragraph (f) of this section by means of 4-inch standard pipe. The connection shall be as short and as direct as practicable so that there will be no appreciable transit time of smoke from the smoke density meter to the control unit. All other zones shall be restricted in such a manne as to simulate a load on the suction fan equivalent to that of a 350-foot length of 4-inch standard pipe for each zone. Where the control unit is of the type in which the aural detector tests the combined discharge of all zones simultaneously sensitivity tests will be conducted with a control unit having the maximum number of zones for which approval is desired.

(2) With the system operating at rated supply voltage and the control unit adjusted for optimum performance, Type I smoke in quantities sufficient to give a "smoke density meter reading" of 2 percent shall be admitted to the smoke detecting zone under test.

(i) The smoke shall be detected by an observer directly in front of a visual detection type control unit.

(ii) The audible smoke alarm of an aural type control unit shall sound within one sampling cycle of the control unit.

(3) With no change in the adjustment of the control unit and no change in the "smoke density meter reading" from those of the preceding test, the supply potential of the smoke detector system shall be decreased to 30 percent of rated voltage.

(i) The smoke shall be detected by an observer directly in front of a visual detection type control unit.

(ii) The audible smoke alarm of an aural type control unit shall sound within one sampling cycle of the control unit.

(4) With the supply potential reduced to 80 percent of rated voltage and with no change in the adjustment of the control unit from the previous test, Type II smoke in quantities sufficient to give a "smoke density meter reading" of 5 percent shall be admitted to the smoke detector zone under test.

(i) The smoke shall be detected by an observer directly in front of a visual detection type control unit.

(ii) The audible smoke alarm of an aural type control unit shall sound within one sampling cycle of the control unit.

(h) Endurance requirements. The control unit shall be capable of being operated for 10,000 cycles at rated voltage without failure of any component or undue wear or pitting of any contact. Endurance test shall be conducted in accordance with § 161.002-16 (c)(7).

(i) Inclination test. The control unit shall operate successfully while undergoing the inclination test of § 161.00216(c)(4).

(j) Resistance to vibration. The control unit shall withstand without damage and without false operation the vibration test described in § 161.002-16(c)(3). The tests shall be performed with circuits in the normal supervisory position.

(k) Humidity test. The system shall withstand without damage the humidity test of § 161.002-16(c)(5).

[21 FR 9032, Nov. 21, 1956, as amended by CGFR 61-15, 26 FR 9301, Sept. 30, 19611

§ 161.002-16 Methods of sampling, inspection and testing.

(a) Sampling and inspection. Fire detecting equipment covered by this specification is not normally inspected at regularly scheduled factory inspections of production lots, but the Commander of the Coast Guard District may detail a marine inspector at any time to visit any place where such fire detecting equipment is manufactured to check materials and construction methods, and to conduct such tests and examinations as may be required to satisfy himself that the equipment is being manufactured in compliance with the requirements of this specification and with the manufacturer's plans and specifications approved by the Commandant.

(b) Type approval tests-(1) General. Type approval tests shall have as their purpose to demonstrate that a manufacturer is capable of producing equipment suitable for shipboard use in accordance with the specification re

value, generally satisfies this condition. Tests shall be conducted in an oven as described in paragraph (k)(1) of this section.

(7) The results obtained in repeat tests on the same rate-of-rise thermostat shall closely correspond, as shall also the results of tests on different samples having the same adjustment and setting.

(m) Prematur operation test. Clean fixed-temperature thermostats must not operate prematurely when subjected to high normal room temperature as given in Table 161.002-11(m) for a period of 30 days.

the fixed temperature type, and, if of the rate-of-rise type, shall operate at rates of rise not more than 25 percent greater than the rate at which it operated when tested clean.

(2) Thermostats, after being subjected to a 200-hour salt spray test in accordance with A. S. T. M. Standard B117, shall operate in 3 minutes or less if of the fixed temperature type, and, if of the rate-of-rise type, shall operate at rates of rise not more than 25 percent greater than the rate at which it operated when tested clean.

(0) Rough usage tests. Thermostats shall be tested to determine whether they may be dropped or subjected to moderately rough usage with the tools ordinarily used in installation, such as screwdriver, pliers, or hammer, depending upon the type of thermostat, without affecting their operation.

(p) Vibration tests. The thermostat shall be subjected to the vibration test described in § 161.002-16(c)(3). No false operation or breakage or injury to the thermostat shall result. Vibration test shall be performed in an ambient temperature approximately equal to the appropriate temperature indicated in Tabie 161.002-11(m).

(q) Dielectric strength test. The thermostat shall be capable of withstanding without damage the dielectric strength test of § 161.002-6(g)(1), after which test the insulation resistance shall be not less than that specified by § 161.002-6(g)(2).

§ 161.002-12 Manuai fire alarm systems.

(&) General. A manual fire alarm system shall consist of a power supply, a control unit on which are located visible and audible fire and trouble signalling devices, and fire alarm circuits as required originating from the control unit and terminating at manual fire alarm boxes. Power failure alarm devices may be separately housed from the control unit and may be bined with other power fail systems when specifically a

(b) Types. Manual fi shall be one of the a combination of

(1) Manual fir imposed on and gral part of t

wiring of an automatic fire detection system.

(2) Electrical system using manually operated fire alarm boxes.

(3) Other types as may be developed. (c) Power supply. The power supply shall be as specified for automatic fire detecting system by § 161.002-9.

(d) Manual fire alarm system control unit. The manual fire alarm system control unit shall be as specified for automatic fire detecting systems by § 161.002-10.

§ 161.002-13 Manual fire alarm boxes.

(a) A manual fire alarm box shall consist of a rugged cast metal junction box and cover on which is mounted a prominent operating lever to actuate the alarm. Pulling the operating lever shall shatter a window of glass or other suitable material, thereby automatically operating an alarm switch. Manual fire alarm boxes employing different methods of operation or different forms of construction or materials from that described in this paragraph will be considered provided the operation is equally positive, simple, quick and obvious.

(b) The operating instructions for the fire alarm box shall be clear, concise, conspicuous, and protected against obliteration.

(c) The fire alarm box shall be finished in typical bright red with the operating instructions finished in a contrasting color.

(d) The manual fire alarm box shall be operated manually in the intended manner not less than 100 times to assure reliable operation.

(e) The switch unit in the manual fire alarm box shall operate at least 10,000 cycles, making and breaking a direct-current load equal to the rated current of the switch at rated voltage without failure. The switch unit shall also be capable with the curr cent of rate conducted

§ 161.002-14 Watchman's supervisory systems.

(a) General. The watchman's supervisory system shall consist of apparatus to verify the presence of watchmen and the regular performance of their assigned duties.

(b) Types. The watchman's supervisory systems shall be one of the following types, or a combination of several types:

(1) A mechanical system consisting of portable spring-motor-driven recording clocks in conjunction with key stations located along the prescribed routes of the watchmen to operate the clock recording mechanism.

(2) An electrical system employing a recorder located at a central station in conjunction with key stations along the prescribed route of the watchmen. (3) Other types that may be developed.

(c) Portable spring-motor-driven recording clocks. (1) Each clock shall run for at least one week without rewinding and shall be substantially mounted and strongly encased. It shall be made so that the recordings cannot be seen without opening the case and so that the case cannot be opened without indicating, by a distinctive recording, the time of opening and closing.

(2) The records of the recording watch clock shall be legible and permanent.

(d) Key stations for use with portable recording watch clocks. (1) The key station shall be of substantial construction and provided with a hinged

cover.

The key shall be attached to the station by means of a strong link chain. The key stations shall be mounted in such a manner that they cannot be removed without giving evidence of removal.

(2) Keys shall be made so that they are difficult to duplicate, and shall be of a pattern susceptible of variations tending to reduce the probability that a set of keys for one clock will operate other clocks.

[21 FR 9032, Nov. 21, 1956, as amended by CGFR 59-7, 24 FR 3241, Apr. 25, 1959]

§ 161.002-15 Smoke detecting systems.

(a) General. The smoke detecting system shall consist of a means for continuously exhausting an air sample from the protected spaces and testing the air for contamination with smoke of all colors or particle sizes, together with visual or visual and aural means for indicating the presence of smoke. (1) The scope of this section is limited to systems which the control unit is to be located in the wheelhouse or fire control room. Where different arrangements of the detecting units are contemplated, the system may be examined and tested according to the intent of this section, and, if found to be substantially equivalent, may be approved.

(b) Types. The smoke detecting system shall be one of the following types:

(1) Visual detection type wherein the presence of smoke is detected visually and by sense of smell.

(2) Aural type wherein the presence of smoke is detected visually and audibly and by sense of smell.

(3) Visual or aural type combined with carbon dioxide extinguishing

system.

(4) Other types as may be developed. (c) Power supply. The power supply for smoke detecting systems shall be from the emergency lighting and power system as required by Subpart 113.70 in Part 113 of Subchapter J (Electrical Engineering) of this chapter.

(d) Suction fans. (1) Suction fans shall be provided in duplicate, with the system arranged for one fan to be operated at a time.

(2) The suction fans shall be of sufficient capacity to provide a suction at the control unit of at least 1 inch of water with each zone connected with 350 feet of 4 inch standard pipe.

(e) Smoke detecting system control unit-(1) General. A smoke detecting system control unit shall consist of a drip-proof enclosed panel containing the smoke indicating devices, trouble alarm signalling devices, power failure alarm devices, and overcurrent protection for the system and for the exhaust fans. Power failure alarm devices may be separately housed from the control unit and may be combined

with other power failure alarm systems when specifically approved.

(2) Sampling characteristics. The control unit shall be designed to extract air samples continuously from the smoke detecting zones. Visual detection of smoke in the air samples from all zones shall be continuous, except that the air samples may be diverted from the visual detector momentarily for aural detection purposes. Aural detection of smoke in the air samples from the several smoke detecting zones may be done in sequence in which case the unit shall cycle at a rate not to exceed 5 seconds per zone. Where aural detection of smoke in the air samples from all zones is accomplished simultaneously, the aural detector shall operate for at least 3 seconds in each minute.

(3) Visual smoke indication. The presence of smoke in the concentrations specified by paragraph (g) of this section in the air sample being exhausted from any of the protected spaces shall automatically be indicated visually to an observer directly in front of the control unit. The visual indication shall indicate the zone from which the smoke originated and shall be continuous so long as the smoke is present except as provided in paragraph (e)(2) of this section.

(4) Aural smoke indication. The presence of smoke in the concentrations specified by paragraph (g) of this section in the air sample being exhausted from any of the protected spaces shall in systems of the aural type, automatically be indicated by the sounding of a vibrating type fire bell with a gong diameter not smaller than 6 inches, nippled to or mounted on or in the control unit, the sounding of vibrating type fire bell with a gong diameter not smaller than 8 inches located in the engine room, and the lighting of a smoke indicator lamp.

(i) Means shall be provided to silence the audible signals, but the visible smoke indicator lamp shall remain lighted until the smoke alarm relay is manually reset.

(ii) Resetting the smoke alarm relay without restoring the fire bell silencing means to the normal position shall be indicated by trouble signals as de