Summary : an early horse-drawn line promoted by local interests including the Duke of Buccleuch and built to the 4'6” gauge for freight that proved unexpectedly popular with passengers. From Edinburgh's first station at St Leonards, the route passed in Scotland's first railway tunnel 518 metres long under the shoulder of Arthur's Seat, then by Duddingston Loch to Cairntows, where it joined what is now the Edinburgh South Suburban freight route. Turning right at Niddrie, it followed what became the Waverley Line to cross the North Esk at the graceful single-arch Glenesk Viaduct which is now again carrying passenger trains on the Borders Railway. An extension to along the Marquess of Lothian's waggonway to Newtongrange took it across the South Esk by the timber Dalhousie Viaduct whose abutments may just be seen behind the Sun Inn
Constructor : the Edinburgh & Dalkeith Railway in 1831, engineer James Jardine
Built primarily to bring Midlothian coal into Edinburgh, but it didn’t take long for an enterprising businessman, Michael Fox, to put a stagecoach on the tracks to carry passengers. . The tunnel formed an inclined plane into the station, with a gradient of 1:30 and waggons were hauled up on rope drawn by two steam engines (made by J & C Carmichael of Dundee), as the incline was too much for the horses.

Nicknamed the “Innocent Railway” because of its retention of horse traction after other lines had progressed to steam, the Edinburgh & Dalkeith was notable for its tunnel, for the cast-iron beam bridge over the Braid Burn that survives at Cairntows and for a timber viaduct on masonry piers in Dalkeith that was demolished in the 1960s.

Acquired by the North British Railway in 1847 and regauged for steam traction. The use of steam locomotives meant that the rope drawn incline was no longer needed, and an array of weigh stations, track and warehouses (including the largest bonded warehouses in the world) sprung up at the St Leonards Depot Opening of a direct route from Niddrie to the city centre led to loss of passenger trains from St Leonard's, but freight continued until 1968,  .In the 1980s the trackbed was converted to a shared footpath and cycle-route, with lighting provided in the tunnel.

The large warehouse found use as a bakery and then from 2019 as Holyrood which is Edinburgh’s first single malt distillery in almost a century.

The Red Wheel Heritage Plaque was erected during the Covid pandemic - it was formally unveiled on 26th November 2021 by Debs Newman, General Manager and Rob Carpenter, Founder of the Holyrood Distillery accompanied by National Transport Trust Vice Chairman, John Yellowlees and Deputy Chairman, Jerry Swift.

A full acccount of its history and how it gots its name appeared in Andy Arthur's Theadinburgh - which was published in September 2023 and can be downloaded here. NTT is grateful for Andy's permission.

Entry by John Yellowlees