The Thames Tunnel Company was formed in 1824. It was the first tunnel to be completed under the River Thames, it connects Rotherhithe and Wapping. The project was immensely difficult and hazardous. On its completion, Marc Brunel was knighted in recognition of his achievement. On 25th March 1843, the tunnel was opened to foot traffic, with spiral staircases at each end providing access. Lack of funds had prevented the original plan of allowing horse-drawn transport, reaching the tunnel via spiral access ramps in 61m diameter shafts. However, the tunnel proved popular. On opening day 50,000 people walked through it, and one million people (about half the population of London in 1843) visited during the first 10 weeks, all paying a penny each. Shops were set up in the cross arches. In September 1865, the Thames Tunnel was sold to the East London Railway Company for £200,000. Track was laid and the first steam train ran through it on 7th December 1869. The line was electrified, and on 31st March 1913 the Metropolitan Railway began a service on the East London Line. The line was incorporated into the London Underground system on 29th January 1914 and goods trains used the tunnel into the 1960s. In December 2007, the tunnel was closed for refurbishment. In March 2010, it re-opened as part of the London Overground network.