each segment was built, leading the gangs to use whatever supplies were available at that moment. The amount of construction material required was very large, equating to about of stone and mortar. It is not known how it was transported to the site, but that volume of material would have needed some 600 boat loads or 49,000 wagon loads, requiring 250 wagons pulled by 1,500–2,000 oxen to move it from the quarries to Pevensey. Given the scale of the requirements for land transportation, it seems more likely that the raw materials were instead moved by sea, though even this would have been a significant operation; it has been estimated that 18 vessels would have been needed for a continuous supply operation carried out over a season of 280 days. The curtain wall was not all built at once but was constructed in segments, as can be seen from vertical breaks in the stonework which mark where sections met. The wall is built on top of complex foundations constructed from rubble and timber set into a ditch deep. Oak piles were driven into the trench and packed with flint and clay, above which a horizontal framework of oak beams was set with more flint and clay. The foundation was finally covered over with cement before the walls were built on top. Some of the timbers have survived, allowing archaeologists to date the fort through dendrochronology. Other dating evidence was discredited in the 1970s. An excavation in 1906–08 found shattered tiles stamped HON AUG ANDRIA, which were used to attribute Pevensey Castle's construction to the reign of the early 5th century Emperor Honorius. However, later use of thermoluminescence dating revealed they had been made around the time of the excavation. It is suspected that Charles Dawson, who has been blamed for the Piltdown Man hoax, was the author of the forged tiles. Garrison Anderitum is recorded in the Notitia Dignitatum as the base of the praepositus numeri Abulcorum – an infantry unit or numerus of the limitanei or border forces. It also mentions army and naval units bearing the fort's name in connection with the Vicus Julius, in the Roman army in Gaul and stationed at Lutetia (modern Paris). This suggests that by the time the Notitia was written, the original garrison had been moved to Gaul and replaced with the numerus Abulcorum. The Abulci are mentioned in connection with the field