1851 saw the opening of the London & North Western's double-track connection between Rugby and Luffenham. It was singled in 1907 with the remaining line located on the Down side of the formation.

Between Seaton and Morcott, the route ran through a 448-yard tunnel.

Today, the southern approach cutting is almost impassable thanks to mud and foliage. The tunnel itself is dry except for the short section beneath the A47. At this point, an outlet drains hard water into the tunnel forming wonderful mineral deposits on the floor. There are no refuges but several telegraph wire brackets remain.