Steam tug HERCULES (1907): hull from offsets

Full-size hull of the steam tug HERCULES (1907, 46 m) rebuilt in Rhino from the HAER lines plan and table of offsets (Library of Congress, HAER CA-62). 369 offsets transcribed and cross-checked on two sheets; least-squares section fit and loft into a closed solid. Deviation from the offsets: mean 4.3 mm, 90 % of points within 10 mm; max 36 mm where the original table is internally inconsistent (see deviation map). Hydrostatics at the waterline of the 1989 survey drawing: displacement 622 t, KB 2.42 m, BMt 1.71 m. Files: 3DM, STEP, IGES, offsets CSV.