Mackinac Bridge

At 42,414 gross tons, Mackinac Bridge is the 12,577th 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 7.1 times the typical vessel on record here. The largest measures 499,167 GT.

Among the 3,881 container ships held here, it ranks 1,514th by tonnage — larger than 59% of that group. Their median tonnage is 33,698 GT, and the largest tenth begin at 140,096 GT. The flag most often flown by this group is Liberia (498 ships). The yard that appears most often against it is HD Hyundai Heavy Industries, with 348 hulls on record.

Mackinac Bridge was built in 1986, making it 40 years old. It is one of 866 hulls in this registry delivered that year, a cohort whose median tonnage is 4,769 GT; within it this ship is the 64th 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 83 vessels to Kawasaki Heavy Industries, with a median tonnage of 30,812 GT, delivered between 1930 and 2020. See the rest of that yard’s output.

At 242.9 m overall, Mackinac Bridge is 21.3 m longer than the 221.6 m median for container ships on record.

IMO numbers are issued in broadly chronological blocks. Within 500 either side of 8604280 this registry holds 16 other vessels, whose median build year is 1987 and which range from 1986 to 1990. That places this hull’s registration in the same part of the series, consistent with its recorded build year of 1986.

Its IMO number, 8604280, carries its own check digit. The first six digits are weighted seven down to two and summed — 8×7 + 6×6 + 0×5 + 4×4 + 2×3 + 8×2 = 130 — and the last digit of that total, 0, must equal the seventh digit, 0. It does, so this number is well formed.