USS Sarpedon

The registry attributes 4 vessels to Bethlehem Hingham Shipyard, with a median tonnage of 14,671 GT, delivered between 1942 and 1945. See the rest of that yard’s output.

IMO numbers are issued in broadly chronological blocks. Within 500 either side of 8624151 this registry holds 10 other vessels, whose median build year is 1986 and which range from 1966 to 1988. That places this hull’s registration in the same part of the series; no build year is recorded for this vessel itself.

Its IMO number, 8624151, carries its own check digit. The first six digits are weighted seven down to two and summed — 8×7 + 6×6 + 2×5 + 4×4 + 1×3 + 5×2 = 131 — and the last digit of that total, 1, must equal the seventh digit, 1. It does, so this number is well formed.