Freightliner immediately made a major pitch to the BR Board to allow 8 ft 6in boxes to be carried on the East Coast Main Line (ECML), which involved lowering the track in Stoke area, as well as the tunnels at Peascliffe and Penmanshiel. The work was successfully completed at Stoke and Peascliffe, but Penmanshiel Tunnel collapsed during the project. The extent of the collapse meant that reconstruction was too expensive, resulting in the abandonment of around one kilometre (1,100 yards) of the existing ECML (including the tunnel itself), being replaced by a new section of line constructed in open cut to the west of the original course. The operation to reopen the railway took five months of round-the-clock working. Contractor Sir Robert McAlpine & Sons Ltd started work on the new alignment on 7 May 1979, and it was completed on 20 August. As a result of the work to re-align the railway line, it was also necessary to alter the course of the A1 trunk road. Ironically Freightliner would later withdraw its services on that stretch of the ECML.