confident of a 16% return. The London terminus, and track gauge The N&ER was to have its London terminus at Islington. The topography was such that this would have required tunnelling to reach it, and it was realised that this was an expensive proposition. An approach was made to the Commercial Railway (later the London and Blackwall Railway) with a view to using its final approach to London and Minories terminus. This was unsuccessful, so the ECR was contacted, with a view to using its Shoreditch terminus. This was agreed to, and Parliament ratified the arrangement, so the N&ER's planned line was rerouted south of Tottenham to join the ECR at . The rental for this arrangement was to be £7,000 a year, with an additional charge per passenger. The ECR agreed to build a separate terminus at Shoreditch for the N&ER. When the ECR determined its track gauge of , the N&ER had to adopt the same gauge in order to use the approach tracks. The first section of the ECR was opened on 18 June 1839, from a temporary terminus at Mile End to another temporary terminus at Romford. Contract award, and a retrenchment of scope At the end of 1837 a contract for construction of the line was awarded to David Macintosh. In March 1838 construction began, with Michael Borthwick as resident engineer. From the beginning, the N&ER was unable to raise the capital it needed for building its line. By May 1837 the contractor was in difficulties, and Robert Stephenson was appointed as engineer-in-chief, with Borthwick continuing as resident engineer. George Parker Bidder was appointed as the new contractor. Engineering contractors Grissell and Peto were approached late in 1837 about building the line as far as Bishop's Stortford. In March 1840 they started work between Stratford and Tottenham, and finally took over the work between Tottenham and Broxbourne from David McIntosh. The N&ER company obtained a further Act of Parliament, which received Royal Assent on 4 June 1840; the line beyond Bishop's Stortford to Cambridge was abandoned, and the share capital was reduced to £720,000. Opening On 15 September 1840 the N&ER started operation between the ECR's Stratford station and , a distance of about . At first this was a single track; it was doubled in 1841. Trains ran through from , but the ECR insisted that Shoreditch to Stratford journeys were exclusive to them.