46 CFR 143.245: Readiness and testing of essential systems

Last reviewed: October 14, 2026

This section requires essential systems or equipment to be regularly tested and examined. Each towing vessel must perform the applicable tests in Table 143.245(b) of this section. The tests required by this section must be recorded in accordance with part 140 of this subchapter.

Applies toEach towing vessel, for its essential systems and equipment.

What it says

  1. Essential systems or equipment must be regularly tested and examined.

    46 CFR 143.245(a)“Essential systems or equipment must be regularly tested and examined.”

  2. Tests and examinations must verify that the system or equipment functions as designed.

    46 CFR 143.245(a)“Tests and examinations must verify that the system or equipment functions as designed.”

  3. If a component is found unsatisfactory, it must be repaired or replaced.

    46 CFR 143.245(a)“If a component is found unsatisfactory, it must be repaired or replaced.”

  4. Test and examination procedures must follow the manufacturer's instructions, or the Towing Safety Management System (TSMS) applicable to the vessel if the vessel has a TSMS.

    46 CFR 143.245(a)“Test and examination procedures must be in accordance with manufacturer's instructions or the Towing Safety Management System (TSMS) applicable to the vessel, if the vessel has a TSMS.”

  5. Each towing vessel must perform the applicable tests in Table 143.245(b) of this section.

    46 CFR 143.245(b)“Each towing vessel must perform the applicable tests in Table 143.245(b) of this section.”

  6. The tests required by this section must be recorded in accordance with part 140 of this subchapter.

    46 CFR 143.245(b)“The tests required by this section must be recorded in accordance with part 140 of this subchapter.”

  7. The table requires propulsion controls, ahead and astern at the operating station, to be tested before the vessel gets underway, but no more than once in any 24 hour period.

    46 CFR 143.245 Table 143.245(b)“Before the vessel gets underway, but no more than once in any 24 hour period.”

Common questions

How often must alarm setpoints be tested on a towing vessel?

Alarm setpoints must be tested twice every 5 years, with no more than 3 years elapsing since the last test.

“Twice every 5 years, with no more than 3 years elapsing since last test.”

What happens if a tested component is unsatisfactory?

If a component is found unsatisfactory, it must be repaired or replaced.

“If a component is found unsatisfactory, it must be repaired or replaced.”

Do towing vessel tests have to be recorded?

Yes. The tests required by this section must be recorded in accordance with part 140 of this subchapter.

“The tests required by this section must be recorded in accordance with part 140 of this subchapter.”

Which procedures must be used for testing essential equipment?

Procedures must follow the manufacturer's instructions or the TSMS applicable to the vessel, if the vessel has a TSMS.

“Test and examination procedures must be in accordance with manufacturer's instructions or the Towing Safety Management System (TSMS) applicable to the vessel, if the vessel has a TSMS.”

The text of 46 CFR 143.245

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

Readiness and testing

(a) Essential systems or equipment must be regularly tested and examined. Tests and examinations must verify that the system or equipment functions as designed. If a component is found unsatisfactory, it must be repaired or replaced. Test and examination procedures must be in accordance with manufacturer's instructions or the Towing Safety Management System (TSMS) applicable to the vessel, if the vessel has a TSMS.

(b) Each towing vessel must perform the applicable tests in Table 143.245(b) of this section. The tests required by this section must be recorded in accordance with part 140 of this subchapter.

Table 143.245(b)—Required Tests and Frequency Tests of: Frequency: Propulsion controls; ahead and astern at the operating station Before the vessel gets underway, but no more than once in any 24 hour period. Steering controls at the operating station Before the vessel gets underway, but no more than once in any 24 hour period. Pilothouse alerter system Weekly. All alternate steering and propulsion controls At least once every 3 months. Power supply for alarm actuation circuits for alarms required by § 143.230 At least once every 3 months. Communications required by § 143.240 Weekly. General alarm if the vessel is so equipped Weekly. Emergency lighting and power if the vessel is so equipped At least once every 3 months. Charge of storage batteries if the vessel is so equipped, for emergency lighting and power At least once every 3 months. Alarm setpoints Twice every 5 years, with no more than 3 years elapsing since last test. Pressure vessel relief valves Twice every 5 years, with no more than 3 years elapsing since last test. All other essential systems At least once every 3 months.

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.