North London line then it was switched to . Later, it was cut back to . A tunnel, the Hampstead Heath tunnel, runs under Hampstead between and . The line is double track throughout, with a mix of triple and quadruple track between and . The former North Woolwich branch included a section of single track between Custom House and North Woolwich stations, and the Broad Street branch was at one time formed of quadruple track. During the February–May 2010 blockade, the , and stations were rebuilt to allow the extended East London line to serve Highbury & Islington on fully segregated tracks
Owned-and-operated television stations in the United States owned KTLA (channel 5) in Los Angeles and WBKB (channel 4, now WBBM-TV on channel 2) in Chicago, owned a share of the network. However, the FCC declared that Paramount controlled DuMont and thus forbade the network and the studio from acquiring any more stations. This was one of the factors that led to DuMont shutting down in August 1956. For much of the era from 1958 to 1986, the major network-owned stations were distributed as follows: ABC, CBS and NBC each owned stations in the top three markets (New York City, Los Angeles and Chicago). Between 1958 and 1965,