Marine Safety Center Technical Note - U.S. Coast Guard

1. Tonnage Certification Process MTN 01-98 CH-11
1.4 Onboard Survey Tonnage Administrative Policy
the advice was incorrectly given or applied. As a consequence, a measurement organization shall
not certify tonnages on a vessel for which either: 1) an employee of the measurement
organization engaged in tonnage consulting; or 2) an employee of a contractor or subcontractor of
the measurement organization engaged in tonnage consulting and also provided measurement
services on the measurement organization’s behalf on the same vessel.
1.4 ONBOARD SURVEY
Once all work on the vessel that could affect the assigned tonnages or registered dimensions has been
completed, but before the appropriate tonnage certificate(s) is issued, the measurement organization shall
conduct an onboard survey (physical inspection) of the vessel. The purpose of this survey is to obtain
dimensions and other information required in the tonnage measurement process that is not readily
available from other sources, and to verify that:
(a) DIMENSIONAL INFORMATION
Previously available dimensional information used in the tonnage measurement process is correct
and of sufficient accuracy (e.g., drawings, computer models);
(b) SPACE UTILIZATION
Spaces which could have a bearing on the tonnage assignment according to their use are properly
accounted for (e.g., all cargo spaces have been identified on vessels measured under the
convention system);
(c) LABELING / MARKING
Tonnage-related labeling and marking of the vessel is correct;
(d) EXCLUDED SPACES
Excluded spaces (if applicable) meet the requirements of Section 69.61(g) of MTN 01-99 as
amended (e.g., are not fitted with means designed for securing cargo or stores);
(e) TONNAGE OPENINGS
Tonnage openings and associated tonnage opening cover plates (if applicable) meet the
requirements of Sections 69.117(d) and (e) of MTN 01-99 as amended.
(f) BALLAST SPACES
Ballast systems associated with exemptible water ballast tanks (if applicable) meet the
requirements Section 69.117(f) of MTN 01-99 as amended.
1.5 TONNAGE CERTIFICATE ISSUANCE
The measurement organization prepares and issues tonnage certificates to certify tonnages and registered
dimensions assigned in accordance with 46 CFR 69, Subparts B, C, or D as specified below. Tonnage
certificates shall be issued within 30 days of the completion of the onboard survey, except where prior
written authorization has otherwise been obtained from the MSC.
(a) U.S. TONNAGE CERTIFICATE
Issue a U.S. Tonnage Certificate if a vessel is assigned tonnages under the regulatory
measurement system (46 CFR 69 Subparts C or D). In addition, issue a U.S. Tonnage Certificate
if the vessel is assigned tonnages under the convention measurement system (46 CFR 69 Subpart
B) and the vessel is not issued an International Tonnage Certificate (1969).
(b) INTERNATIONAL TONNAGE CERTIFICATE (1969)
Issue an International Tonnage Certificate upon the request of the vessel's owner if the vessel is
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