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 Westinghouse to trade its NBC-affiliated Philadelphia cluster of KYW-AM (1060) and WPTZ-TV (channel 3) to NBC in exchange for WTAM-AM-FM and WNBK-TV in Cleveland. Westinghouse only agreed to the trade after NBC threatened not only to yank its programming from WPTZ, but also Westinghouse-owned WBZ-TV (channel 4) in Boston. NBC changed the callsigns of the Philadelphia stations to WRCV-AM-TV, while Westinghouse changed the Cleveland stations' callsigns to KYW-AM-FM-TV. NBC's then-ownership of Philadelphia's channel 3 was cited by CBS when it purchased its then-affiliate WCAU-TV in 1958, despite FCC rules at the time barring companies from owning stations with overlapping signals,