HMS Illustrious

At 20,600 gross tons, HMS Illustrious is the 26,304th largest of the 84,014 vessels in this registry that report a tonnage. The median across that set is 5,994 GT, so this hull is about 3.4 times the typical vessel on record here. The largest measures 499,167 GT.

Among the 611 naval / patrols held here, it ranks 37th by tonnage — larger than 87% of that group. Their median tonnage is 1,325 GT, and the largest tenth begin at 23,606 GT. The flag most often flown by this group is United States (136 ships). The yard that appears most often against it is Austal, with 33 hulls on record.

HMS Illustrious was built in 1982, making it 44 years old. It is one of 1,706 hulls in this registry delivered that year, a cohort whose median tonnage is 3,592 GT; within it this ship is the 292nd largest. 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 124 vessels to Swan Hunter, with a median tonnage of 6,944 GT, delivered between 1903 and 2006. See the rest of that yard’s output.

At 210.0 m overall, HMS Illustrious is 123.5 m longer than the 86.5 m median for naval / patrols on record, with a beam of 36.0 m and a draft of 7.5 m.

IMO numbers are issued in broadly chronological blocks. Within 500 either side of 8949563 this registry holds 34 other vessels, whose median build year is 1991 and which range from 1970 to 2002. That places this hull’s registration in the same part of the series, consistent with its recorded build year of 1982.

Its IMO number, 8949563, carries its own check digit. The first six digits are weighted seven down to two and summed — 8×7 + 9×6 + 4×5 + 9×4 + 5×3 + 6×2 = 193 — and the last digit of that total, 3, must equal the seventh digit, 3. It does, so this number is well formed.