As part of the Transpennine Route Upgrade (TRU), the viaduct will again have four lines along the whole 663 yards (606 m), and will additionally be electrified with a 25 kV overhead catenary by the 2030s.

Initially, the operators of that line were reluctant to provide a route into Huddersfield from the north, but in the face of opposing railway companies submitting bills through Parliament, the M&L optioned their own scheme which would have taken a route along the valley floor, thus making any station a dead-end as it could not rise to the height needed to exit the valley to the south or west.

[7] Whilst it is debated who was the engineer on the project, it was either Thomas Nicholson or A. S. Jee, who both worked on bridges and viaducts on the line between Stalybridge and Heaton Lodge Junction.

[8][note 3] Marshall states that Jee was the engineer, being appointed in July 1845, with Nowell & Hattersley being the contractors who started work on 10 October 1845.

[10] Construction of the viaduct started in 1845, but it was delayed in opening as it had to be re-profiled due to there being some error in achieving the correct gradients, and the entire track had to be taken up and replaced as the contractors had used the wrong size of sleeper despite it being stipulated quite clearly in the contract.

When seen from ground level, the original two-track width stone arch is visible, encased in iron spans at the top.

The land falls away from south to north, undulating as it does so, so the shallowest arch is that nearest the station in Huddersfield, but the height of the structure varies along its course.