Page 307 describes the way the railway was constructed through Helmdon

(Approaching Helmdon from the north the line) "is spanned by a 25-foot bridge, carrying the public road between Helmdon and Sulgrave. The negotiations for the diversion of this road, which reduced the cost of the bridge by one-third, were carried to a successful issue by Mr F Douglas Fox, who was then acting as resident engineer of this section.

"The Helmdon Valley is next reached through which flows a stream liable to severe floods and intersected also by the Northampton and Banbury branch of the London and North Western Railway. The valley is crossed by two banks and a viaduct of nine arches, each of 34ft 3in span and of the same general design as those at Catesby and Brackley. The treacherous nature of the clay foundations necessitated the distance between the piers being bricked in with five rings of brindle brickwork in cement. The invert under the arch taking the London and North Western Railway was put in in six portions, the rails being supported on longitudinal timbers.

"Widening out to 57 ft the embankment provides accommodation for Helmdon Station (country type) which is approached by an overbridge of two spans of the steel-plate girder and jack arch type.

"At this place the contractors had their branch offices, workshops, running sheds etc. This site was selected for the convenience of a junction with the London and North Western Railway but the position entailed a very steep overland route.

"The line again enters a cutting containing 445,000 cubic yards, the material of which was composed of blue clay with a bed of disintegrated limestone rock, 15 ft thick, which was partially utilized for pitching and bottom ballasting."