1879 saw the Great Northern and London & North Western railways open a north-south joint line between the former's network at Bottesford - with a spur to Saxondale Junction - and the latter's cross country route from Rugby-Stamford. Three years on, the GN drove a ten-mile spur into Leicester where it created a new terminus at Belgrave Road. This opened for goods traffic on the 2nd October 1882.
The line's most notable structure was a tunnel of 516 yards between Ingarbsy and Thurnby, the latter being the provider of its official name. Square Spinney, a nearby area of woodland, is another of its aliases.
The bore is S-shaped, with trains travelling away from Leicester curving to the west as they entered and to the east on their exit. It featured two ventilation shafts.
The line took its last breath on 1st June 1964 although Belgrave Road was served for another five years by a reopened chord from the Midland Main Line.
Today the approach cutting on the Ingarsby side is completely buried and the tunnel filled with clay-like material at a point that probably coincides with the location of the northern shaft. Was the material simply poured down it? The substantial brick-built south portal has been blighted by the attachment of unsightly steel sheeting over the entrance. This though creates a bat-friendly microclimate inside, allowing the tunnel to become a recognised and protected hibernaculum.
The southern shaft is still open, reinforced by iron rods at its base, with daylight creating a pool on the floor. Overlooking this is an oversized refuge on the Down side. Around 150 yards further on is the blockage. Throughout, cable hangers still adorn the Up wall, negotiating several refuges. The neat brick lining curves inwards close to the floor so it can be presumed that there is an invert.