and closed the Scotland Street tunnel to Canal Street. The present Victorian station was built on the site. Along the tracks of this first station, Hanna, Donald & Wilson built some very impressive roofs. The station was extended in the late 19th century. In 1897, the impressive glass dome was added. Waverley has been in continual use since, under the auspices of the North British, the LNER, British Railways (rebranded as British Rail after 1965), Railtrack and latterly Network Rail. From its opening in its current form by the eastward tunnelled extension from Haymarket, Waverley has been the principal railway station in Edinburgh. From 1870 to 1965, the city had a second major station, Princes Street, operated by the rival Caledonian Railway, but this was never as important as Waverley. British Rail brought railway electrification in 1991 with electric trains on the East Coast Main Line to Glasgow Central and via York to London King's Cross. The station's large size and the unusual topography of its surroundings mean that it contains a large amount of valuable, centrally located land. The station's successive owners, British Rail, Railtrack and its current owner Network Rail have been criticised for underusing the valuable city-centre spaces available within, there being a legal covenant preventing any upwards extension, which would obstruct the view of Arthur's Seat from Princes Street. The elevated walkway linking the Waverley Steps (from Princes Street to Market Street) has been upgraded with the recommissioning of the suburban platforms (at the south) and provision of additional through platforms to the north to serve the increased proportion of through rail traffic. During 2006 and 2007, parts of Waverley were extensively refurbished, including two new through platforms and the electrification of platforms 12 to 18 in preparation for electric trains from the Airdrie-Bathgate Rail Link and future lines in Scotland to be electrified by the EGIP (Edinburgh/Glasgow Improvement Project). From 2010 to 2012, the glazing of the roof of Waverley station was entirely replaced with new strengthened clear glass panels, replacing the old of mixed surfaces including felt, cloudy wired glass and plastic sheet. Part of a £130 million upgrade, this has greatly increased the amount of natural light in the station. Recent developments From 2012 to 2014, improvements included: a new set of covered escalators at Waverley Steps leading to Princes Street (narrowing the huge set of previously open-air steps); a rebuilt and widened