46 CFR 143.575: Electrical wiring and connections on towing vessels
Last reviewed: October 14, 2026
This section sets rules for how cables and wires are installed on a towing vessel. It covers support, routing, protection, connections and tank installations. It also limits extension cords and multi-outlet adapters (power strips).
Applies toEach cable and wire on a towing vessel, plus extension cords and multi-outlet adapters (power strips) used there.
What it says
Each conductor must have enough current-carrying capacity for the circuit in which it is used.
46 CFR 143.575(a)(1)“Each conductor must have sufficient current-carrying capacity for the circuit in which it is used.”
Cable hangers for overhead and vertical cable runs must be installed with metal supports and retention devices at least every 48 inches.
46 CFR 143.575(a)(2)“Cable hangers for overhead and vertical cable runs must be installed with metal supports and retention devices at least every 48 inches.”
Wire and cable runs must not be installed in bilges, across a normal walking path, or less than 24 inches from the path of movable machinery unless adequately protected.
46 CFR 143.575(a)(3)“Wire and cable runs must not be installed in bilges, across a normal walking path, or less than 24 inches from the path of movable machinery”
Twist-on type connectors may not be used for making joints in cables, facilitating a conductor splice, or extending the length of a circuit.
46 CFR 143.575(a)(4)“Twist-on type of connectors may not be used for making joints in cables, facilitating a conductor splice, or extending the length of a circuit.”
Each cable and wire must be located outside a tank, unless it supplies power to equipment in the tank.
46 CFR 143.575(a)(10)“Each cable and wire must be located outside a tank, unless it supplies power to equipment in the tank.”
Extension cords must not be used as a permanent connection to a source of electrical power.
46 CFR 143.575(b)“Extension cords must not be used as a permanent connection to a source of electrical power.”
Multi-outlet adapters (power strips) may not be connected to other adapters or otherwise used in a way that could overload the capacity of a receptacle.
46 CFR 143.575(c)“Multi-outlet adapters (power strips) may not be connected to other adapters (“daisy-chained”), or otherwise used in a manner that could overload the capacity of a receptacle.”
Common questions
How often must cable hangers be installed on a towing vessel?
Cable hangers for overhead and vertical cable runs must have metal supports and retention devices at least every 48 inches.
“Cable hangers for overhead and vertical cable runs must be installed with metal supports and retention devices at least every 48 inches.”
Can I use an extension cord as permanent wiring on a towing vessel?
No. Extension cords must not be used as a permanent connection to a source of electrical power.
“Extension cords must not be used as a permanent connection to a source of electrical power.”
Can wires be run inside a tank on a towing vessel?
Each cable and wire must be outside a tank unless it supplies power to equipment in the tank. If wire is in a tank, it must have sheathing or insulation compatible with the fluid in the tank.
“If wire is installed in a tank, it must have sheathing or wire insulation compatible with the fluid in a tank.”
Can I daisy-chain power strips on a towing vessel?
No. Multi-outlet adapters (power strips) may not be connected to other adapters.
“Multi-outlet adapters (power strips) may not be connected to other adapters (“daisy-chained”), or otherwise used in a manner that could overload the capacity of a receptacle.”
The text of 46 CFR 143.575
Electronic Code of Federal Regulations (eCFR), current as of March 31, 2026 · Read it on eCFR
Electrical conductors, connections, and equipment
(a) Each cable and wire on a towing vessel must be installed to meet the following requirements:
(1) Each conductor must have sufficient current-carrying capacity for the circuit in which it is used.
(2) Cable hangers for overhead and vertical cable runs must be installed with metal supports and retention devices at least every 48 inches.
(3) Each wire and cable run must be installed in a manner to prevent contact with personnel, mechanical hazards, and leaking fluids. Wire and cable runs must not be installed in bilges, across a normal walking path, or less than 24 inches from the path of movable machinery (e.g., cranes, elevators, forktrucks, etc., where the machinery location can change) unless adequately protected.
(4) Connections and terminations must be suitable for the installed conductors, and must retain the original electrical, mechanical, flame-retarding, and where necessary, fire-resisting properties of the conductor. If twist-on types of connectors are used, the connections must be made within an enclosure and the insulated cap of the connector must be secured to prevent loosening due to vibration. Twist-on type of connectors may not be used for making joints in cables, facilitating a conductor splice, or extending the length of a circuit.
(5) Each cable and wire must be installed so as to avoid or reduce interference with radio reception and compass indication.
(6) Each cable and wire must be protected from the weather.
(7) Each cable and wire must be supported in order to avoid chafing or other damage.
(8) Each cable and wire must be protected by metal coverings or other suitable means, if in areas subject to mechanical abuse.
(9) Each cable and wire must be suitable for low temperature and high humidity, if installed in refrigerated compartments.
(10) Each cable and wire must be located outside a tank, unless it supplies power to equipment in the tank.
(11) If wire is installed in a tank, it must have sheathing or wire insulation compatible with the fluid in a tank.
(b) Extension cords must not be used as a permanent connection to a source of electrical power.
(c) Multi-outlet adapters (power strips) may not be connected to other adapters (“daisy-chained”), or otherwise used in a manner that could overload the capacity of a receptacle.
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 March 31, 2026. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.