The railway was completed and opening was being planned for 1 June 1847; but on 2 May 1847 there was a collapse of the newly constructed railway tunnel at Southampton. The damage extended about and opened to the surface near the western end of the tunnel; it was caused by disturbance to the ground created around the route of the old Southampton and Salisbury Canal tunnel through which the new tunnel had cut. This was quickly restored, and on 20 May Captain Coddington conducted the formal inspection of the route, which continued the next day. He was satisfied with the standard of workmanship of the line, but commented adversely on the narrow opening of the overbridges, and the fact that the entire line west of Redbridge was single: the longest such length in England, he thought. He also criticised the sharp curve at Northam where the line joined the existing LSWR route; the company agreed to alter the curve to a larger radius. The public opening was planned for 1 June, but on 30 May the interior of the Southampton tunnel suffered further problems, with a large bulge in the walls indicating a section was sinking. With no connection to the mainline to London, the Blechynden terrace station was the terminus; the LSWR had to transport their locomotives there by road through the streets of Southampton. The Poole branch (to Lower Hamworthy) opened at the same time.