Military


US Maritime Administration Classification Systems

Maritime Administration vessels are classified by a system based on three groups of letters and numbers. For example, using the group classification C8-S-la the first group indicates the type of vessel (cargo, passenger, and tanker) and its approximate LWL. The second group indicates the type of propulsion, the number of propellers, and whether or not the vessel carries more than 12 passengers. The third group indicates the original design of the vessel or any modifications to the vessel. The C8 group covers cargo vessels with a length on the load waterline between 700 and 799 feet. The "S" means the vessel has a single propeller, is equipped with steam propulsion machinery, and carries no more than 12 passengers. Since there may be many vessels with these characteristics, an additional designation is necessary to identify the design of the particular vessel. The vessel designation is 1a. The number "1" means this is the original construction of the la design. The letter "a" indicates that this is the original design of the vessel. If major changes have been made to the vessel, then its designation alters to reflect these changes. For example, suppose that accommodations for 50 passengers are added to this vessel. Since the passengers are still fewer than 100, the first group does not change; it remains C8. The second classification group becomes S1 to indicate that the vessel can carry more than 12 passengers. The third group becomes 1b to show that this is the first major change to this vessel. The vessel designation would then become C8-S1-1b.

Classification of Ship Type and Length


Length at Load Waterline (ft)

  Ship (1) (2) (3) (4) (5) (6) (7) Remarks
 
B Barge up to 100 100 to 150 150 to 200 200 to 250 250 to 300 300 to 350 350 to 400 (1)
C Cargo up to 400 400 to 450 450 to 500 500 to 550 550 to 600 600 to 650 650 to 700 (1)
G Great Lakes
cargo
up to 300 300 to 350 350 to 400 400 to 450 450 to 500 500 to 550 550 to 600 (1)
H Great Lakes
passenger
up to 300 300 to 350 350 to 400 400 to 450 450 to 500 500 to 550 550 to 600 (2)
IB Integrated
tug-barge
up to 200 200 to 300 300 to 400 400 to 500 500 to 600 600 to 700 700 to 800 (1)
J Inland cargo up to 50 50 to 100 100 to 150 150 to 200 200 to 250 250 to 300 300 to 350 (2)
K Inland
passenger
up to 50 50 to 100 100 to 150 150 to 200 200 to 250 250 to 300 300 to 350 (2)
L Great Lakes
tanker (ore
or grain)
up to 400 400 to 450 450 to 500 500 to 550 550 to 600 600 to 650 650 to 700 (1)
LG Liquid gas up to 450 450 to 500 550 to 600 600 to 650 650 to 700 700 to 750 750 to 800 (1)
N Coastwise
cargo
up to 200 200 to 250 250 to 300 300 to 350 350 to 400 400 to 450 450 to 500 (2)
OB Combination
oil-bulk/ore
up to 450 450 to 500 500 to 550 550 to 600 600 to 650 650 to 700 700 to 800 (1)
P Passenger
(100 or
more)
up to 500 500 to 600 600 to 700 700 to 800 800 to 900 900 to 1000 1000 to 1100 (1)
Q Coastwise
passenger
up to 200 200 to 250 250 to 300 300 to 350 350 to 400 400 to 450 450 to 500 (2)
R Refrigerated up to 400 400 to 450 450 to 500 500 to 550 550 to 600 600 to 650 650 to 700 (2)
S Special X up to 200 200 to 300 300 to 400 400 to 500 500 to 600 600 to 700 700 to 800 (1, 3)
T Tanker up to 450 450 to 500 500 to 550 550 to 600 600 to 650 650 to 700 700 to 800 (1)
U Ferries up to 100 100 to 150 150 to 200 200 to 250 250 to 300 300 to 350 350 to 400 (2)
V Towing
vehicles
up to 50 50 to 100 100 to 150 150 to 200 200 over

1Larger vessels are designated by successive numbers in 100-foot increments (C8 for 700 through 799 ft, and so forth).

2Longer vessels are designated by successive numbers in 50-foot increments (H8 for 600 through 650 ft, and so forth).

3The special designation X applies to certain Navy ships built by MARAD and other ships so specialized that they don't fit any other designation.

Classification of Ship Machinery, Propellers, and Passenger Capability


Passenger Capability
Machinery Type Propellers 12 and Under1 Over 122

Steam Single S S1
Motor Single M M1
Steam and motor Single SM SM1
Turboelectric Single SE SE1
Diesel-electric Single ME ME1
Gas turbine Single G G1
Gas turboelectric Single GE GE1
Nuclear Single N N1

1For triple- and quadruple-screw vessels, add TR or Q respectively to single-screw designation. For example, a triple-screw motor ship is MTR.
2For triple- and quadruple-screw vessels, make digit 3 or 4 respectively. For example, quadruple-screw steam is S4.


Passenger Capability
Machinery Type Propellers 12 and Under1 Over 122

Steam Twin ST S2
Motor Twin MT M2
Steam and motor Twin SMT SM2
Turboelectric Twin SET SE2
Diesel-electric Twin MET ME2
Gas turbine Twin GT G2
Gas turboelectric Twin GET GE2
Nuclear Twin NT N2

1For triple- and quadruple-screw vessels, add TR or Q respectively to single-screw designation. For example, a triple-screw motor ship is MTR.
2For triple- and quadruple-screw vessels, make digit 3 or 4 respectively. For example, quadruple-screw steam is S4.



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