---
kind: "section"
citation: "46 C.F.R. § 61.20-17"
title: "46"
number: "61.20-17"
heading: "Examination intervals."
url: "https://uscodex.org/cfr/46/61.20-17"
---

# §61.20-17. Examination intervals.

- (a) A lubricant that demonstrates the corrosion inhibiting properties of oil when tested in accordance with ASTM D665 (incorporated by reference, see [§ 61.03-1](/cfr/46/61.03-1.md)) is considered to be equivalent to oil for the purposes of the tailshaft examination interval.
- (b) Except as provided in [paragraphs (c) through (f)](#c..f) of this section, each tailshaft on a vessel must be examined twice within any 5-year period. No more than 3 years may elapse between any 2 tailshaft examinations.
- (c) Tailshafts on vessels fitted with multiple shafts must be examined once every 5 years.
- (d) Tailshafts with inaccessible portions fabricated of materials resistant to corrosion by sea water, or fitted with a continuous liner or a sealing gland which prevents sea water from contacting the shaft, must be examined once every 5 years if they are constructed or fitted with a taper, keyway, and propeller designed in accordance with the American Bureau of Shipping standards to reduce stress concentrations or are fitted with a flanged propeller. Accessible portions of tailshafts must be examined visually during each drydock examination.
- (e) Tailshafts with oil lubricated bearings, including bearings lubricated with a substance considered to be equivalent to oil under the provisions of [paragraph (a)](#a) of this section need not be drawn for examination—
  - (1) If tailshaft bearing clearance readings are taken whenever the vessel undergoes a drydock examination or underwater survey;
  - (2) If the inboard seal assemblies are examined whenever the vessel undergoes a drydock examination or underwater survey;
  - (3) If an analysis of the tailshaft bearing lubricant is performed semiannually in accordance with the lubrication system manufacturer's recommendations to determine bearing material content or the presence of other contaminants; and
  - (4) **If—**
    - (i) For tailshafts with a taper, the propeller is removed and the taper and the keyway (if fitted) are nondestructively tested at intervals not to exceed 5 years; or
    - (ii) For tailshafts with a propeller fitted to the shaft by means of a coupling flange, the propeller coupling bolts and flange radius are nondestructively tested whenever they are removed or made accessible in connection with overhaul or repairs.
- (f) Tailshafts on mobile offshore drilling units are not subject to examination intervals under [paragraphs (b) through (d)](#b..d) of this section if they are—
  - (1) Examined during each regularly scheduled drydocking; or
  - (2) **Regularly examined in a manner acceptable to the Commandant CG-CVC.**

## Notes

### Amendments

[CGD 95-027, 61 FR 26001, May 23, 1996, as amended by CGD 96-041, 61 FR 50728, Sept. 27, 1996; 61 FR 52497, Oct. 7, 1996; USCG-1999-5151, 64 FR 67180, Dec. 1, 1999; USCG-2009-0702, 74 FR 49229, Sept. 25, 2009; USCG-2012-0832, 77 FR 59778, Oct. 1, 2012; USCG-2020-0634, 89 FR 50189, June 12, 2024]

### Authority

Authority: 43 U.S.C. 1333; 46 U.S.C. 2103, 3306, 3307, 3703; sec. 617, Pub. L. 111-281, 124 Stat. 2905; E.O. 12234, 45 FR 58801, 3 CFR 1980 Comp., p. 277; Department of Homeland Security Delegation No. 00170.1, Revision No. 01.3.

### Source

Source: CGFR 68-82, 33 FR 18890, Dec. 18, 1968, unless otherwise noted.

### Amendments

[CGD 95-027, 61 FR 26001, May 23, 1996, as amended by CGD 96-041, 61 FR 50728, Sept. 27, 1996; 61 FR 52497, Oct. 7, 1996; USCG-1999-5151, 64 FR 67180, Dec. 1, 1999; USCG-2009-0702, 74 FR 49229, Sept. 25, 2009; USCG-2012-0832, 77 FR 59778, Oct. 1, 2012; USCG-2020-0634, 89 FR 50189, June 12, 2024]