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Harrow Signal Box - Visit 2
Scope:
Date: Tuesday, 11 August 2026 - 10:00am BST A second visit has been arranged to view Harrow Signal Box. Opened in 1890, re-sited in 1948 and extended in 1960, it is London Underground's largest operational signal cabin. It is scheduled for closure as part of the Four Lines Modernisation (4LM) re-signalling programme.