United States is the country of registry for 2,278 vessels in this directory. The most common class under that flag is vessels this registry holds no type classification for (977 ships), and the median vessel measures 1,706 GT. Browse every ship flagged United States.
Narrowing to both dimensions at once, this registry holds 239 tugs flying the United States flag.
USNS Sioux was built in 1981, making it 45 years old. It is one of 1,653 hulls in this registry delivered that year, a cohort whose median tonnage is 3,186 GT. Across the whole of the 1980s the registry holds 13,213 vessels, median 3,004 GT. The median build year across the entire registry is 1995.
The registry attributes 34 vessels to Marinette Marine, with a median tonnage of 1,930 GT, delivered between 1965 and 2014. See the rest of that yard’s output.
At 59.4 m overall, USNS Sioux is 27.0 m longer than the 32.3 m median for tugs on record.
IMO numbers are issued in broadly chronological blocks. Within 500 either side of 8835475 this registry holds 48 other vessels, whose median build year is 1984 and which range from 1944 to 1990. That places this hull’s registration in the same part of the series, consistent with its recorded build year of 1981.
Its IMO number, 8835475, carries its own check digit. The first six digits are weighted seven down to two and summed — 8×7 + 8×6 + 3×5 + 5×4 + 4×3 + 7×2 = 165 — and the last digit of that total, 5, must equal the seventh digit, 5. It does, so this number is well formed.
