Ensco 91

At 6,493 gross tons, Ensco 91 is the 41,043rd largest of the 84,014 vessels in this registry that report a tonnage. The median across that set is 5,994 GT. The largest measures 499,167 GT.

Among the 911 rig / offshore units held here, it ranks 521st by tonnage — larger than 39% of that group. Their median tonnage is 9,254 GT, and the largest tenth begin at 51,732 GT. The flag most often flown by this group is Liberia (179 ships). The yard that appears most often against it is Hanwha Ocean, with 27 hulls on record.

Vanuatu is the country of registry for 425 vessels in this directory, of which Ensco 91 is the 93rd largest by tonnage. The most common class under that flag is vessels this registry holds no type classification for (208 ships), and the median vessel measures 2,446 GT. Browse every ship flagged Vanuatu.

Narrowing to both dimensions at once, this registry holds 44 rig / offshore units flying the Vanuatu flag, of which 24 are larger by tonnage.

Ensco 91 was built in 1980, making it 46 years old. It is one of 1,736 hulls in this registry delivered that year, a cohort whose median tonnage is 2,301 GT; within it this ship is the 430th 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.

At 60.0 m overall, Ensco 91 is 14.0 m shorter than the 74.0 m median for rig / offshore units on record.

IMO numbers are issued in broadly chronological blocks. Within 500 either side of 8751784 this registry holds 73 other vessels, whose median build year is 1981 and which range from 1957 to 1989. That places this hull’s registration in the same part of the series, consistent with its recorded build year of 1980.

Its IMO number, 8751784, carries its own check digit. The first six digits are weighted seven down to two and summed — 8×7 + 7×6 + 5×5 = 164 — and the last digit of that total, 4, must equal the seventh digit, 4. It does, so this number is well formed.