Severn Bridge station was opened in October 1879, the same year as the bridge. Located immediately to the west of the bridge, the station was intended to serve the village of Blakeney (the Forest of Dean Central Line only providing good facilities at their station in the village), but with the village 2 miles away on poor roads, it was probably a struggle to generate any major trade.
The Severn Bridge itself was an engineering achievement, but commercially somewhat of a "White Elephant". 4,162 feet in length. it consisted of 21 wrought-iron bowstring girders on concrete-filled cast piers sunk into the River Severn, with the railway around 70 feet above the river. The western (forest) end had a masonry viaduct carrying the line over the Gloucester-Newport line before entering Severn Bridge station, and the east end had a swing bridge over the Gloucester-Sharpness canal. The bridge was a speculative build, based on the possibility of increased trade from the forest, but the increased trade never materialised, and the opening of the Severn Tunnel in 1886 reduced its usefulness even further.
That saying, the bridge did have some use as a diversionary route if the Severn Tunnel was closed, and also meant that school traffic between Lydney and Berkeley didn't have to travel via Gloucester; this was enough to keep the bridge open. In 1956, trials were undertaken on the bridge to see if it would cope with heavier loadings, and as a result, in early 1960, work began on strengthening the bridge.
Despite being a potential navigation hazard for vessels using the river, the bridge had survived 80 years without any major mishaps. However, its luck ran out on the 25th October, 1960, when two tankers got lost in fog on the river and missed the entrance to the Sharpness Canal. They were subsequently swept upstream for another mile before they collided, first with each other, and then with the bridge, bringing down two spans. Five crewmen on the tankers were killed, and it was only good fortune that meant the death toll wasn't worse; the final train of the day had just passed over, and the engineers working on the bridge upgrades were on a break listening to a boxing match.
Although it was initially decided to repair the bridge, the timing of the accident could probably not have been worse. British Railways were now in the "Beeching Era", with major cutbacks on the horizon, and it is probably not a great surprise that at some point in 1962, it was decided to demolish the bridge instead of repairing it. It didn't help that the maritime insurance payment on the damage was a fraction of the cost required to repair it, and I also suspect that the bridge was now considered a major navigational hazard (in fact, there were more collisions with the bridge during the demolition phase). The bridge was removed by 1970.