The Monmouth Railway was to be a 3 ft 6in gauge plateway, on which ordinary wagons with plain wheels could run.

This would give a more convenient railway connection for mineral traffic from the Forest of Dean to the ironworks of Nantyglo, Ebbw Vale, and Dowlais.

Construction at the west end took place promptly, and the line from Little Mill to Usk opened for traffic on 2 June 1856.

From that date the company worked its own trains, using two locomotives hired in from the Newport, Abergavenny and Hereford Railway.

As a 3 ft 6in gauge horse-operated plateway, there were numerous sharp curves, unsuitable for locomotive operation, and the tunnel was of a small profile.

The Severn and Wye Company submitted a parliamentary bill in the 1872 session to convert its Milkwall Tramway to railway operation and extend it to Coleford.

Starting from this point the new line immediately passes under a peculiar iron girder bridge, which carries the public road from Coleford to Lydney over it.

From this bridge the line inclines downwards, and continues to do so more or less sharply throughout its length, reaching at its other end a level of over 450 feet below that of Coleford station...

For another quarter of a mile the line is carried along the hillside in a direction parallel to the Redbrook Road, but high above it... On the left are here seen some old lime kilns and ironworks...

The railway after passing up this embankment – which is about a mile from Coleford station – cuts off a corner of Bircham Wood, and continues its course along the hillside for another half a mile, when, with a sharp turn to the right, it sweeps rapidly round through a deep cutting and under a handsome little stone bridge, and suddenly brings into view the picturesque village of Newland... Less than half a mile further on the line, after having been carried down the hillside on a long embankment, enters by a sharp curve another deep cutting conducting it into a tunnel 280 yards long, which carries it under the ridge which here separates the Upper Redbrook Valley from the Whitecliff Valley.

After a short run through a red loam cutting the line enters the next station – Newland – two and a quarter miles from Coleford.

From the station the line makes a bold curve to the left and enters the Upper Redbrook Valley, the right slope of which it now follows for some distance.

After winding through a deep rock cutting the line crosses the Staunton Road Valley – three miles from Coleford – on a high embankment, which is carried over the highway below by a handsome stone bridge of great size and strength.

For nearly a mile further the line winds along the hillside, through several cuttings and a short tunnel, till the village of Upper Redbrook comes in sight for a moment, when it quickly bends to the right through a deep cutting in old red sandstone, and enters a curved tunnel about 270 yards long, the other end of which is in the Wye Valley.

As the line continues its course toward Monmouth – closely hugging the hillside and gradually falling in level – the railway from Chepstow to Monmouth is seen some 70 or 80 feet below, steadily rising as it approaches the hamlet of Wyesham, where the falling gradient of the Coleford Railway brings that line to the same level as its neighbour.

[11] The two stations, of the Severn and Wye and the Coleford Railway, were adjacent and there were shared sidings for the transfer of goods wagons, but through running was not possible; in fact a complex backshunt was involved to work vehicles through.

Shortly afterwards most of the track was lifted and the rails were taken to France in connection with the exigencies of World War I. Whitecliff Quarry continued to be productive, and its output was conveyed over 71 chains of the Coleford branch, and through the sidings at Coleford, requiring four reversals, and on to the former Severn and Wye system.

Ammunition was stored here during World War II, and Newland station was requisitioned by the Air Ministry as their local headquarters with the signal box becoming the guardroom.

In connection with this military presence the two tunnels at Redbrook were also used as ammunition stores after the ends of both structures had been securely bricked up.