Edinburgh, Leith and Newhaven Railway
The Edinburgh, Leith and Newhaven Railway opened in 1842. It provided a direct link from Canonmills, on the north side of the New Town to Trinity Station near Newhaven harbour, just west of Leith.
In 1846 this horse-drawn railway was extended from Trinity westwards to the harbour at Granton, and a branch was built to the busy docks at the Port of Leith. The terminus of the Leith branch was at Citadel Station, and there was an intermediate stop at Bonnington.
To allow services to operate right into the heart of the city a substantial tunnel was built from Canonmills, under Scotland Street, Dublin Street and St Andrew Square to Canal Street Station. Canal Street no longer exists, but was located, just south of Princes Street on the north side of what is now the Waverley Station.
The Scotland Street Tunnel is 962m long, 7.3m wide and 5.2m high, with a steep 4% gradient climbing towards Canal Street. The roof of the tunnel is just below street level at Scotland Street, but is 15m deep at St. Andrew Street and 11m deep under Prince Street. Cable haulage was required, with a stationary winding engine at Canal Street.