Following a site investigation in 1967 to determine the nature and stratification of subsoils on the proposed line of the southern section of the inner relief road, further borings were needed on the sites of subways, a pedestrian concourse and retaining wall. Eight additional borings were drilled on the site. These revealed that fill was present in all boreholes and varied in depth between 1 ft. and 6 ft. In borehole 21, fill was proved to 12 ft and at borehole 25, a maximum penetration of 9 ft. into fill and old foundations was achieved. Fluvioglacial sand and gravels were found below made ground in boreholes 19, 20, 24 and 26. In borehole 26 the sand and gravel contained small pieces of 'ancient brick'. Underlying the sand and gravels was the London Clay. Standpipes were inserted into several borings and on the 18th September 1969 standing water levels were measured on three of these at between 51.1 ft A.O.D. and 65.7 ft. A.O.D. <1>