Man-made underground passage in Raystown

A stone-built Man-made underground passage, nestling against the S side of the earth-cut Man-made underground passage (ME045-036004-), was constructed during Phase 3, and the lining of the entrance passage to the older Man-made underground passage with stone may have been accomplished at the same time. The stone-built Man-made underground passage was entered through a drop-entrance at the S end, and this was visible as a small oval pit (dims 2.1m x 1.5m; D 0.18m) from which the passage (Wth 0.9m) extended NW (L 8.5m), but the first 3.5m of the NE wall and 1.5m of the SW wall had been robbed of stone. At the W end the passage turns N (L 2.6m) and narrowed to a creep (Wth 0.6m; H 0.6-0.9m) at the entrance to a rectangular chamber (max. dims 5.1m WNW-ESE; 2.4m NNE-SSW; surviving H 1-1.2m). The passage entered at the E end of the S chamber wall, with a slight step down to the chamber floor. There is a stone-framed entrance (Wth 0.7m; H 0.75m) to an earth-cut ramp at the W end of the N wall. The Man-made underground passage passage sloped down (H 0.74m) from the entrance to the chamber. The floor of the chamber had a covering of sandy silt and clay but the collapsed stone from the roof filled most of it. The chamber walls were doubled at places to support the corbelled roof, and a grain sample from the fill of the original construction trench yielded a C14 date of 640-770 cal. AD. The earthcut ramp (L 4.12m; Wth 0.83-0.86m) at the W end of the N wall is cut by the mill-race of Northern mill 2, but it is thought that the ramp is a construction feature which was closed with redeposited natural that spilled into the chamber. (Seaver 2009, vol. 1, 61-3) See the attached plans from Seaver (2009, vol. 2) _1 Phase 3 (fig. 23) _2 Plan of Man-made underground passage (fig. 62, N at L) Compiled by: Michael Moore Date of upload: 20 December 2021