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Interpretations of Vessel Tonnage Measurement Regulations

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Information about this document as published in the Federal Register.

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Coast Guard, DHS.




This notice advises the public of a recent change to Marine Safety Center Technical Note (MTN) 01-99, Tonnage Technical Policy, which is used for interpreting the Coast Guard?s vessel tonnage measurement regulations. This notice advises the public on how to obtain the recent change to the MTN, and summarizes the interpretations included in this change.


This notice is effective on April 22, 2005.

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If you have questions on this notice, call Peter Eareckson, Chief, Tonnage Division, United States Coast Guard Marine Safety Center, (202) 366-6502. If you have questions on viewing or submitting material to the docket, call Andrea M. Jenkins, Program Manager, Docket Operations, telephone (202) 366-0271.

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If you have comments on how the Marine Safety Center Technical Note (MTN) on tonnage measurement may be obtained and the process by which the MTN is periodically updated, please submit your comments, identified by Coast Guard docket number USCG-2003-16682, to the Docket Management Facility located at the U.S. Department of Transportation. To avoid duplication, please use only one of the following methods:

(1) Web site:

(2) Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Washington, DC 20590-0001.

(3) Fax: (202) 493-2251.

(4) Delivery: Room PL-401 on the Plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The telephone number is (202) 366-9329.

(5) Federal eRulemaking Portal:

Viewing Comments and Documents

To view comments, as well as documents mentioned in this notice as being available in the docket, go to at any time and conduct a simple search using the docket number. You may also visit the Docket Management Facility in room PL-401 on the Plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.


The Coast Guard is responsible for maintaining regulations for assigning gross and net tonnages and registered dimensions to vessels. These regulations are found in title 46, Code of Federal Regulations (CFR), part 69, Measurement of Vessels. A Federal Register notice published on December 22, 2003 (68 FR 71118), describes the process by which the Coast Guard establishes interpretations of these regulations to respond to novel situations, on a case-by-case basis, through policy decisions, and summarizes the interpretations in the MTN. Periodically, these interpretations are evaluated as to their appropriateness for incorporation into the tonnage measurement regulations.

The MTN is maintained by the Coast Guard Marine Safety Center (MSC) and is posted on the MSC's Web site at​hq/​msc. A copy of the current version of the MTN is available in the docket (see “Viewing Comments and Documents,” above). While the MTN is intended for use by organizations authorized to perform tonnage measurement on behalf of the Coast Guard, the Coast Guard recognizes that it contains information that may affect decisions on vessel designs and that the public may benefit by our making it widely available to parties other than authorized measurement organizations.

Change 7 to the MTN

The MSC periodically issues changes to the MTN to keep it up-to-date with relevant policy decisions. The most recent change (Change 7) was issued on March 29, 2005. Change 7 includes the following:

1. Clarifications on the treatment of overhanging roofs when evaluating excludable space associated with end openings.

2. Correction of an inconsistency introduced in a previous change to the MTN regarding treatment of partial decks.

3. Criteria for assessing when deck recesses and other discontinuities in the uppermost complete deck and the tonnage deck invalidate the “stem to stern” and “side to side” requirement for such decks, or can otherwise affect the location of the line of the respective deck.

4. Clarification of the method by which volumes of outside shaft tunnels and other hull recesses and deck recesses are not included in under-deck tonnage.

5. Clarification of the method of establishing offset adjustments when calculating the under-deck tonnage of vessels with unconventional hull forms.

6. Clarifications on the treatment of water closet spaces contained within passenger spaces occupied by more than one person.

7. Interpretations prohibiting the exemption as passenger space of space that rests on a break deck that is part of the uppermost complete deck.

8. Clarifications on the treatment as open space of semi-enclosed spaces that are outside the boundary bulkhead of a structure.

9. Interpretations relative to the treatment of exemptible water ballast tanks that consist of contiguous but distinct spaces of varying shapes and sizes.

10. Clarification that certain deductible spaces may be included in tonnage upon request of the vessel owner.

11. Clarification that dry cargo and stores spaces are any spaces not occupied by liquids or used for the accommodation or berthing of passengers or crew.

12. Criteria for assessing when watertight bulwarks and similar structures are included in the overall length. Start Printed Page 20925

To provide a mechanism for notification when a change to the MTN has been issued, the MSC's web site allows members of the public to add their e-mail addresses to an electronic mailing list for such notification. Also, the Coast Guard will continue to notify the public via a notice in the Federal Register of changes to the MTN that are believed to be of significant interest to the maritime industry.

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Howard L. Hime,

Acting Director of Standards Marine Safety, Security and Environmental Protection.

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[FR Doc. 05-8070 Filed 4-21-05; 8:45 am]