Abstract A previous assessment of the measurement unit employed in building the Antonine Wall compared the distance slabs with LiDAR-derived three-dimensional distances on the ground and concluded that it was the pes Drusianus . Using more precisely determined discovery locations, correcting an error in previous published calculations and making allowance for installations already built, establishes that the unit was the pes Monetalis . The wider implications are examined, concluding that postulated secondary forts were, indeed, later additions; that fortlets were an integral part of the original plan, though not all were constructed before the rampart; that there is no direct correlation between the location of the slabs and pre-existing installations; and that the Bridgeness–Avon sector was one of the earliest to be constructed.
Hanson et al. (Wed,) studied this question.