The completed tunnel was inspected by Captain G. Wynne on 29 October 1849 ahead of entered service. Operational use During 1850, both the tunnel and the line were opened in to traffic. Once operational, the line provided a strategically important link to Radcliffe via the Clifton Viaduct. During 1901, a length of 272 yards of the tunnel was strengthened via the addition of steel ribs made from reused old rails, spaced at intervals of five feet; similar ribs were installed along another section of the tunnel in 1926; these measures were taken due to concerns of potential subsidence due to coal workings. It was primarily used by freight traffic, although a small number of passenger trains were also operated along the route prior to the Second World War. During the conflict, traffic through the tunnel was temporarily halted. Following the Second World War, the tunnel was never again used by passenger trains. During October 1947, it was reopened for a limited number of freight services. The structure was patched several times across its first century of use, resulting in irregular brickwork and construction joints throughout, hindering inspection. The land around the tunnel was developed considerably during its operational years; originally being agricultural purposes, it was urbanised and incorporated in the town of Swinton. The northern portal is situated close to Clifton Junction, where the line ran under the Manchester-Preston Line, the station providing an interchange. After passing over the Clifton Viaduct and through the station, the line entered the tunnel, which took a straight route under the Manchester-Southport line just to the east of Pendlebury railway station. The tunnel continued very close to St Augustine's Church, Pendlebury, under Temple Drive and the extreme south east corner of Victoria Park until it reached its southern portal in a cutting just beyond the then Swinton cricket ground (Barton Road) between Dorchester Road and Overdale. Collapse On 13 April 1953, 15 days prior to the main incident, several elements of brickwork fell from the roof of the tunnel at the site of an undocumented construction shaft. Immediate steps taken included the enactment of a stoppage on all rail traffic through the tunnel and daily inspections of the affected area to observe any further degradation. While preparations for emergency strengthening of the tunnel via the addition of ribbing were underway, such measures had not been implemented by the date of a more substantial collapse.