This length of Wall was originally excavated and restored by Clayton at some point after 1852 when he began excavations at Housesteads (Bruce 1867, 181; Bosanquet 1904, 193ff). In 1909 FG Simpson began to investigate the relationship between the Great Wall and the NW angle of Housesteads Fort during repairs to the curtain wall (Simpson G. 1976, 125-130, Plate XII). The interior of the NW angle tower was excavated, revealing a flagged floor over an earlier oven. The Wall was discovered to be narrow gauge with no evidence of Broad Wall foundations. In 1932 Birley excavated the line of the west fort ditch and concluded that the building of the Wall came after that of the fort (Birley et al. 1933, 83-85). In 1945 Simpson discovered the location of Turret 36b and the line of the Broad Wall, both of which had been dismantled when the fort was built, revealing that the building of the fort came between the construction of the Broad Wall and that of the Narrow Wall (Richmond & Simpson 1946, 134-7). Further excavations by Charlesworth along the line of the west ditch in 1970 revealed the line of the Broad Wall foundations along the S side of the Wall to the W of the fort and saw they had been cut into by the W fort ditch (Charlesworth 1971, 95-9). In conclusion, when the Wall was built on the W side it was only 6ft (1.83m) wide on Narrow foundations and had been brought along to join the towers NW corner, and in consequence, passed just N of the rounded tip of the ditch.