46 CFR 161.006-5: Motor lifeboat searchlight sampling and tests

Last reviewed: October 14, 2026

This section covers inspection and testing of motor lifeboat searchlights. They are not inspected at regularly scheduled factory inspections, but a Coast Guard District Commander may send an inspector at any time. The section also sets out four test methods: waterproof, beam candlepower, corrosion resistance and heat run.

Applies toMotor lifeboat searchlights specified by this subpart and their manufacturers.

What it says

  1. Motor lifeboat searchlights are not inspected at regularly scheduled factory inspections of production lots.

    46 CFR 161.006-5(a)“Motor lifeboat searchlights specified by this subpart are not inspected at regularly scheduled factory inspections of production lots”

  2. The Commander of the Coast Guard District may detail an inspector at any time to visit any place where the searchlights are manufactured.

    46 CFR 161.006-5(a)“the Commander of the Coast Guard District may detail an inspector at any time to visit any place where such searchlights are manufactured”

  3. In the waterproof test, the searchlight must be subjected for 5 minutes to a stream of water under a head of approximately 35 feet. No leakage may occur.

    46 CFR 161.006-5(b)(1)“The searchlight shall be subjected for 5 minutes to a stream of water under a head of approximately 35 feet”

  4. For the beam candlepower test, the searchlight must be operated at rated voltage with a seasoned lamp as specified in § 161.006-4(e).

    46 CFR 161.006-5(b)(2)“The searchlight shall be operated at rated voltage with a seasoned lamp as specified in § 161.006-4(e).”

  5. Beam candlepower measurements must be made at the corners of a 6-inch square in the center of the beam, at a distance of 32 feet immediately in front of the searchlight.

    46 CFR 161.006-5(b)(2)“Measurements of beam candlepower shall be made at the corners of a 6-inch square located in the center of the beam at a distance of 32 feet”

  6. The searchlight must undergo a 200-hour salt spray test in accordance with ASTM B 117, with no evidence of corrosion detrimental to its operation.

    46 CFR 161.006-5(b)(3)“There shall be no evidence of corrosion that will be detrimental to the operation of the searchlight.”

  7. In the heat run, the completely assembled searchlight must operate continuously for 2 hours at rated voltage, followed by the waterproof test. This cycle must be repeated 3 times.

    46 CFR 161.006-5(b)(4)“The searchlight, completely assembled, shall be operated continuously for 2 hours at rated voltage following which the waterproof test shall be conducted.”

Common questions

Are motor lifeboat searchlights inspected at regular factory inspections?

No. They are not inspected at regularly scheduled factory inspections of production lots, but the Commander of the Coast Guard District may detail an inspector at any time.

“Motor lifeboat searchlights specified by this subpart are not inspected at regularly scheduled factory inspections of production lots”

How long is the salt spray corrosion test for a lifeboat searchlight?

The searchlight must be subjected to a 200-hour salt spray test in accordance with ASTM B 117.

“The searchlight shall be subjected to a 200-hour salt spray test in accordance with ASTM B 117”

How many times is the heat run cycle repeated?

The cycle of 2 hours of operation followed by the waterproof test must be repeated 3 times.

“This cycle shall be repeated 3 times.”

The text of 46 CFR 161.006-5

Electronic Code of Federal Regulations (eCFR), current as of April 16, 2026 · Read it on eCFR

Sampling, inspections and tests

(a) General. Motor lifeboat searchlights specified by this subpart are not inspected at regularly scheduled factory inspections of production lots, but the Commander of the Coast Guard District may detail an inspector at any time to visit any place where such searchlights are manufactured to check materials and construction methods and to conduct such tests and examinations as may be required to satisfy himself that the searchlights are being manufactured in compliance with the requirements of this specification and with the manufacturer's plans and specifications approved by the Commandant.

(b) Methods of test—(1) Waterproof test. The searchlight shall be subjected for 5 minutes to a stream of water under a head of approximately 35 feet from a hose not less than 1 inch in diameter from a distance of approximately 10 feet. The hose nozzle shall be adjusted to give a solid stream at the enclosure. No leakage shall occur in this test.

(2) Beam candlepower. All light except that produced from the searchlight under test shall be excluded from the room in which measurements are made. The searchlight shall be operated at rated voltage with a seasoned lamp as specified in § 161.006-4(e). Measurements of beam candlepower shall be made at the corners of a 6-inch square located in the center of the beam at a distance of 32 feet immediately in front of the searchlight.

(3) Corrosion resistance. The searchlight shall be subjected to a 200-hour salt spray test in accordance with ASTM B 117 (incorporated by reference, see § 161.006-1). There shall be no evidence of corrosion that will be detrimental to the operation of the searchlight.

(4) Heat run. The searchlight, completely assembled, shall be operated continuously for 2 hours at rated voltage following which the waterproof test shall be conducted. This cycle shall be repeated 3 times. The ambient temperature shall be approximately 25 °C. The water stream shall be from an ordinary cold water tap.

Sections it refers to

The plain-English explanation on this page was written with AI from the regulation text above and checked automatically before publishing: every quote appears in the text, every number comes from it, and a second model confirmed each statement adds nothing the text doesn't say. Regulation text current as of April 16, 2026. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.