It was during this period, between 1875 and 1879, that a remarkable feat of Victorian engineering was accomplished that is largely unknown or forgotten, except by those still living in its shadow. This was the construction of the East Midland Railway connecting line between Manton Junction and Glendon South Junction. Although covering a relatively short distance of just 16 miles, the work would involve the construction of 12 embankments, 16 cuttings, four tunnels and five viaducts. One of the five viaducts was to be something particularly special, and was known as the Harringworth Viaduct (nowadays, often referred to as the Welland or Seaton Viaduct). At a staggering length of 3,825ft (1,159m), it is still the longest structure of its type on Britain’s railway network.
The Harringworth Viaduct crosses the River Welland on the Rutland and Northamptonshire border, and is a grade II listed structure. It comprises 82 arches, each with a 42ft (12.7m) span. 71 of the supporting piers are 6ft (1.8m) thick, with a further 10 being double thickness and spaced evenly along its length. Each of these can be identified by a pilaster on its face and were designed to isolate the arches into ‘sets’, preventing any under-strain from being continued indefinitely from arch to arch. The average height of the arches is 57ft (17.2m), but the highest is 70ft (21.2m). The viaduct is constructed from some 30,000,000 bricks, all manufactured on site, with Derbyshire Gritstone springers, string courses and coping. As well as the bricks, construction required some 20,000 cubic yards of concrete, 19,000 cubic yards of stone, 37,543 cubic yards of lime mortar, and 5,876 cubic yards of cement.