---
kind: "section"
citation: "46 C.F.R. § 182.420"
title: "46"
number: "182.420"
heading: "Engine cooling."
url: "https://uscodex.org/cfr/46/182.420"
---

# §182.420. Engine cooling.

- (a) Except as otherwise provided in paragraphs [(b)](#b), [(c)](#c), [(d)](#d), and [(e)](#e) of this section, all engines must be water cooled and meet the requirements of this paragraph.
  - (1) The engine head, block, and exhaust manifold must be water-jacketed and cooled by water from a pump that operates whenever the engine is operating.
  - (2) A suitable hull strainer must be installed in the circulating raw water intake line of an engine cooling water system.
  - (3) A closed fresh water system may be used to cool the engine.
- (b) An engine water cooling system on a vessel of not more than 19.8 meters (65 feet) in length, carrying not more than 12 passengers, may comply with the requirements of ABYC P-4 (incorporated by reference; see [46 CFR 175.600](/cfr/46/175.600.md)) instead of the requirements of [paragraph (a)](#a) of this section.
- (c) On a vessel of not more than 19.8 meters (65 feet) in length carrying not more than 12 passengers, a propulsion gasoline engine may be air cooled when in compliance with the requirements of ABYC Project P-4.
- (d) An auxiliary gasoline engine may be air cooled when:
  - (1) It has a self-contained fuel system and it is installed on an open deck; or
  - (2) On a vessel of not more than 19.8 meters (65 feet) in length carrying not more than 12 passengers, it is in compliance with the requirements of ABYC P-4.
- (e) A propulsion or auxiliary diesel engine may be air cooled or employ an air cooled jacket water radiator when:
  - (1) Installed on an open deck and sufficient ventilation for machinery cooling is available;
  - (2) Installed in an enclosed or partially enclosed space for which ventilation for machinery cooling is provided, which complies with the requirement of [§ 182.465(b)](/cfr/46/182.465.md?p=b), and other necessary safeguards are taken so as not to endanger the vessel; or
  - (3) Installed on a vessel of not more than 19.8 meters (65 feet) in length carrying not more than 12 passengers, in compliance with the requirements of ABYC Project P-4.

## Notes

### Amendments

[CGD 85-080, 61 FR 986, Jan. 10, 1996, as amended by USCG-2003-16630, 73 FR 65207, Oct. 31, 2008]

### Authority

Authority: 46 U.S.C. 3306; E.O. 12234, 45 FR 58801, 3 CFR, 1980 Comp., p. 277; DHS Delegation No. 00170.1, Revision No. 01.4.

### Source

Source: CGD 85-080, 61 FR 986, Jan. 10, 1996, unless otherwise noted.

### Amendments

[CGD 85-080, 61 FR 986, Jan. 10, 1996, as amended by USCG-2003-16630, 73 FR 65207, Oct. 31, 2008]