Tunnelling was completed by the end of 1898, and, because a planned concrete lining to the cast iron tunnel rings was not installed, the internal diameter of the tunnels was generally . For Bank station, the CLR negotiated permission with the City Corporation to construct its ticket hall beneath a steel framework under the roadway and pavements at the junction of Threadneedle Street and Cornhill. This involved diverting pipework and cables into ducts beneath the subways linking the ticket hall to the street. Delays on this work were so costly that they nearly bankrupted the company. A further extension of time to 1900 was obtained through the "Central London Railway Act, 1899".