EDO4350 - Dorchester Prison Excavations, 1975, Trench 9

The site of the Prison Governor's house and a small extension to the prison were totally excavated for the Dorchester Excavation Committee in 1975. The large area to the west of the Prison, which is to be redeveloped in the immediate future, was trial-trenched as far a financial resources and standing features would allow. 260 sq. m were stripped to the natural chalk. A total of 11 trenches were excavated by hand and by machine. The earliest features on the site were three large slots, filled with chalk. They did not appear to be construction slots or drainiage gullies. One of these was cut by a large pit containing material of Flavian date. Three pits of this date, also filled with chalk, were excavated. Three apparently Roman post-holes and an occupation layer were excavated north of the early features. In the eastern trenches, vestiges of an extensive layer of rubble, probabaly of the 2nd century, were found. The earliest phase of the medieval Castle ditch was sectioned by hand. It had been dug to a depth of of 4.4m. This had been backfilled, and subsequently a smaller ditch was dug slightly to the east. After some silt had accumulated, this ditch was slighted. No remains of the bank were found, the area having been levelled in the 17th or 18th century. A small irregular curving ditch was excavated on the lip of the scarp leading down to the river. It seems to follow the line of one of the earthworks on Hutchin's plan of 1772, and may belong to the Civil War. Spreads of chalk found in several of the trial trenches probabaly relate to the lime kiln known to have existed on this site by the 18th century. Trench 9 was almost entirely machine dug and two large roman pits were excavated. Pit 1 was 1.3m square and 2.5m deep; pit 2 meaure 1.4m x 1.6m in plan and was over 2.5m deep but not bottomed. Each pit contained sherds of the same Samian vessel dateable to 90-100AD. Both pits were cut by the phase 2 medieval castle ditch, which had a V-profile 3.1m wide and 1.25m deep and was itself of two discernable phases.