The situation below ground caused problems when the foundations for Marland House were being dug in 1963, and the heading was reopened between the railway tunnel and the canal tunnel in 1965. This revealed that the brickwork was still in good condition at that point, but that the tunnel was largely filled with rubble as reported in 1847, and contained water below the level of the adjacent railway tunnel. The heading was sealed behind a partial relining of this section of the railway tunnel in 1983.