Caldon Low tramroad tunnel

The fourth and final tramroad linking the Caldon Low limestone quarries with Froghall Wharf on the Caldon Canal was built to the designs of James Trubshaw and completed in January 1847. It comprised four self-acting inclined planes of 3ft 6ins gauge and included a tunnel on the top section. The tunnel starts at the uphill end with a wide section which accommodated the three rail layout and four rail passing place, and then about a quarter of the way down narrows to a single track bore for the remainder. This image shows the tunnel at the point where the bore is narrowing down to single track. It was abandoned in 1920.