these are container trains, with some serving the Daventry International Railfreight Terminal (DIRFT), which is between Northampton and Rugby (thus on the loop line). History When the London and Birmingham Railway (L&BR) was constructed in the 1830s, Northampton was by-passed, with the line running on high ground to the west via Kilsby Tunnel. Traditionally, this was said to have been because wealthy Northampton landowners objected to having a railway run through their land to reach the town. However, an alternative view is that Northampton was by-passed because the gradients would have been too steep for the early locomotives of the 1830s to easily cope with. Robert Stephenson the engineer of the London and Birmingham Railway was determined to avoid gradients steeper than 1:330 (that is 1 foot of rising or falling gradient for every 330 feet of distance). As Northampton is located in the Nene Valley, lower than Blisworth, the closest point the L&BR came, connecting the town would have required gradients significantly steeper than this. This meant however that Northampton, despite being a large town, did not have direct rail links to London. A branch from the main line was built to Northampton in the early 1840s: the Northampton and Peterborough Railway, from Blisworth, which gave the town indirect rail links to London and Birmingham. The successor to the L&BR, the London and North Western Railway (LNWR) decided to construct the loop line through Northampton in the 1870s. It was built as part of a wider scheme to double the capacity of the West Coast Main Line between and Rugby, by quadrupling the track; however, routing the additional tracks on a deviation via Northampton had the advantage of giving the town a much better rail service, including a direct service to London, and avoiding the expense of widening Kilsby Tunnel. The LNWR obtained Parliamentary approval for the line in 1875, and commenced construction in 1877. The line was opened for goods throughout on 1 August 1881, for passengers between Rugby and Northampton on 1 December 1881, and for passengers between Northampton and Roade on 3 April 1882. The loop line is a total of long, approximately longer than the direct line. The loop line made use of the existing but small Northampton Castle railway station which occupied part of the site of the historic Northampton Castle. The station needed to be expanded as part of the works, this required