Ship Design Codes Used by the U.S. Maritime Commission
The ship design classification system used by the U.S. Maritime Commission (MARCOM) employs the structure: C4-S2-A4
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where | represents |
C | ship type, as shown in the first table below |
4 | ship size, as shown in the first table below |
S | propulsion system, as shown in the second table below |
2 | passenger capacity and number of propellers, as shown in the second table below |
A | sequential letter indicating the specific design for this type of ship |
4 | sequential number indicating the specific revision to this design |
Type Code | Size Code (in ranges of LWL) | |||||||
1 | 2 | 3 | 4 | 5 | 6 | 7 | ||
B | barge | up to 100 | 100 to 150 | 150 to 200 | 200 to 250 | 250 to 300 | 300 to 350 | 350 to 400 |
C | freighter | up to 400 | 400 to 450 | 450 to 500 | 500 to 550 | 550 to 600 | 600 to 650 | 650 to 700 |
G | Great Lakes Cargo ship | up to 300 | 300 to 350 | 350 to 400 | 400 to 450 | 450 to 500 | 500 to 550 | 550 to 600 |
H | Great Lakes Passenger ship | up to 300 | 300 to 350 | 350 to 400 | 400 to 450 | 450 to 500 | 500 to 550 | 550 to 600 |
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 |
J | Inland Cargo ship | up to 50 | 50 to 100 | 100 to 150 | 150 to 200 | 200 to 250 | 250 to 300 | 300 to 350 |
K | Inland Passenger ship | up to 50 | 50 to 100 | 100 to 150 | 150 to 200 | 200 to 250 | 250 to 300 | 300 to 350 |
L | Great Lakes Bulker (Laker) | up to 400 | 400 to 450 | 450 to 500 | 500 to 550 | 550 to 600 | 600 to 650 | 650 to 700 |
LG | Liquid Gas Carrier | up to 450 | 450 to 500 | 550 to 600 | 600 to 650 | 650 to 700 | 700 to 750 | 750 to 800 |
N | Coastwise Cargo ship | up to 200 | 200 to 250 | 250 to 300 | 300 to 350 | 350 to 400 | 400 to 450 | 450 to 500 |
OB | Oil/Bulk/Ore Carrier | up to 450 | 450 to 500 | 500 to 550 | 550 to 600 | 600 to 650 | 650 to 700 | 700 to 800 |
P | passenger | up to 500 | 500 to 600 | 600 to 700 | 700 to 800 | 800 to 900 | 900 to 1000 | 1000 to 1100 |
Q | Coastwise Passenger ship | up to 200 | 200 to 250 | 250 to 300 | 300 to 350 | 350 to 400 | 400 to 450 | 450 to 500 |
R | Refrigerated Cargo ship | up to 400 | 400 to 450 | 450 to 500 | 500 to 550 | 550 to 600 | 600 to 650 | 650 to 700 |
S | Special Purpose ship | up to 200 | 200 to 300 | 300 to 400 | 400 to 500 | 500 to 600 | 600 to 700 | 700 to 800 |
T | tanker | up to 450 | 450 to 500 | 500 to 550 | 550 to 600 | 600 to 650 | 650 to 700 | 700 to 800 |
U | ferry | up to 100 | 100 to 150 | 150 to 200 | 200 to 250 | 250 to 300 | 300 to 350 | 350 to 400 |
V | tugboat | up to 50 | 50 to 100 | 100 to 150 | 150 to 200 | 200 over |
Notes:
- Larger ships have size codes that are incrementally larger.
- Liberty ships were EC2, the E being for Emergency.
- Victory ships were VC2, the V being for Victory.
Propulsion Code | Notes: | |
S | Steam | The letter code alone indicates a single-screw ship that carries 12 or fewer passengers. |
M | Motor | The suffix T indicates a twin-screw ship that carries 12 or fewer passengers. |
SM | Steam and motor | The suffix TR indicates a triple-screw ship that carries 12 or fewer passengers. |
SE | Turbo-electric | The suffix QR indicates a quadruple-screw ship that carries 12 or fewer passengers. |
ME | Diesel-electric | The suffix 1 indicates a single-screw ship that carries more than 12 passengers. |
G | Gas turbine | The suffix 2 indicates a twin-screw ship that carries more than 12 passengers. |
GE | Gas turbine-electric | The suffix 3 indicates a triple-screw ship that carries more than 12 passengers. |
N | Nuclear | The suffix 4 indicates a quadruple-screw ship that carries more than 12 passengers. |