Donal G. McAllister

Donal G. McAllister was built in 1967, making it 59 years old. It is one of 496 hulls in this registry delivered that year, a cohort whose median tonnage is 757 GT. Across the whole of the 1960s the registry holds 4,074 vessels, median 844 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 33.2 m overall, Donal G. McAllister is within a metre of the 32.3 m median length for tugs on record.

IMO numbers are issued in broadly chronological blocks. Within 500 either side of 8980880 this registry holds 40 other vessels, whose median build year is 1967 and which range from 1955 to 2004. That places this hull’s registration in the same part of the series, consistent with its recorded build year of 1967.

Its IMO number, 8980880, carries its own check digit. The first six digits are weighted seven down to two and summed — 8×7 + 9×6 + 8×5 + 0×4 + 8×3 + 8×2 = 190 — and the last digit of that total, 0, must equal the seventh digit, 0. It does, so this number is well formed.