Hand-Augering Priced as a Bound: Metres per Crew-Day and Cost per Metre Across Four Formations, and Why the Method Does Not Work in Laterite or Weathered Rock

A torque and penetration model prices hand augering across sand, clay, laterite, and weathered rock for a crew of four at US$5 per person per day. Sand needs 18.2 N m of torque, advances 6.0 m per crew-day, and reaches 18 m in 3.0 days at US$3.73 per metre; clay needs 45.6 N m, advances 3.6 m per crew-day, and costs US$6.16 per metre. Laterite (109.3 N m required) and weathered rock (273.3 N m) exceed the 60 N m sustained human torque limit by factors of 1.8 and 4.6, so the method does not work in those formations, independent of season length, since the nominal 25.0 days to water in weathered rock multiplies a rate the crew cannot produce. Rod-string losses cap useful depth near 30 m in any formation. SIMULATED, NOT MEASURED.