The damaged Severn Railway Bridge stood for several years after the disaster
Fifty years after the Severn Railway Bridge disaster, a new theory has emerged which could explain exactly why it happened.
On 25 October 1960 two tanker barges collided in heavy fog near to Sharpness on the River Severn.
They got caught by the tide, lost control, and smashed into one of the bridge's pillars.
The bridge partially collapsed and one of the boats, which was carrying petrol, caught fire and exploded.
The other vessel was carrying a cargo of black oil which ignited and burnt for several hours.
Five men lost their lives in the disaster.
Now research has shown that it may have been a dangerous sideways current that caused the Wastdale H and the Arkendale H to collide.
Also a previously unseen report from a confidential preliminary enquiry into the disaster claims that one of the captains was 'inept' in the handling of his vessel.
In the formal public enquiry, which followed in May 1961, neither of the boat's skippers were blamed for the accident.
However, in researching a radio documentary to mark the 50th anniversary of the disaster, BBC Radio Gloucestershire reporter Andy Vivian has discovered a new set of statements and written evidence on the incident at the National Archives in Kew.
The confidential file gathered by the Board of Trade's Marine Safety Division which was responsible for carrying out a preliminary enquiry into the disaster, has never seen the light of day until now.
Two river barges collided with the Severn bridge in heavy fog in 1960
The official appointed to carry out the enquiry was P. W. Burgess, who was the senior surveyor for the port of Bristol.
The statements he collected provide more detail from George Thompson and James Dew, the two skippers involved, regarding the decisions they made that night, in the minutes after their vessels had collided and become joined together.
In response to this report officials at the Board of Trade were fairly complementary about Thompson's handling of the Arkendale H but issued some tempered criticism of the decisions made by Dew on the Wastdale H.
The report to a superior of the Marine Safety Division of the Board of Trade, Capt J H Quick, from his inferior Capt A C Manson states: "Since the distance to the bridge was something less than half a mile they had thus a maximum period of six minutes in which to extricate themselves and regain control.
"Being able to sit calmly after the event and weigh up the circumstances, I am of the opinion that the best chance of getting out of this situation would have been given had the Wastdale gone full astern and the Arkendale full ahead on port helm.
"This would have brought them apart and helped to bring them head to tide. I believe that an anchor underfoot might also have assisted.
"The Arkendale's master did in fact go ahead on port helm but his efforts were nullified by Wastdale's full ahead on starboard helm.
"To the extent that he went ahead on starboard helm to "push the other vessel off" I consider that the master of the Wastdale displayed ineptitude in the handling of his vessel, but this was by no means culpable negligence."
Another factor which has not been highlighted before has also come to light, and suggests that a natural phenomenon peculiar to the stretch of river where it occurred may have contributed to the accident.
Dense fog on the night of the incident meant the vessels both dropped past the entrance to Sharpness harbour and found themselves further upstream than they should have been, having to battle against an incoming tide to regain the harbour entrance.
The Severn Rail Bridge after the collision
The area they found themselves in was half a mile upstream, near the entrance to Sharpness old dock, which had long since been blocked off.
The shore here juts out into the river and is known as Sharpness Point, and the tide runs much faster here.
Prior to the collision, both vessels were travelling roughly in parallel, with the Wastdale on the shore side.
The Arkendale may have been making more progress since Thompson talks about the Wastdale dropping back out of the fog.
Captain Thompson said that the Wastdale then sheered round to starboard and hit the Arkendale near the bow.
Up until now this collision has been put down to the difficulties caused by the fog.
Fred Larkham from Newnham, who is probably the most experienced river man on the Severn today, and who understands better than anyone the tides on this stretch of the river, says the tanker skippers would have been unfamiliar with a dangerous current which occurs north of Sharpness:
"At the old dock there is a strong tide and also the back eddy which causes problems. This is caused by the tide rushing by the pier and it takes a starboard turn and comes back into the shore and then back down the gully and runs out by the pier.
"This could push the bow off. It would spin you into the main flood tide. Maybe one or two round turns in the tide and you'd be up to the area where the collision occurred."
To mark the 50th anniversary of the disaster two memorial stones have been unveiled on the banks of the Severn.
One is situated at Lydney Docks and a second is located at Purton.
Relatives and friends of the crew who lost their lives were there at the unveiling.
The plaques and their dedication ceremonies were organised by Paul Barnett, chairman of Friends of Purton.
There is also a special exhibition about the disaster currently showing at the Dean Heritage Museum until 16 January 2011.
You can find out more about the Severn Bridge Disaster by listening to Andy Vivian's six-part documentary on BBC Radio Gloucestershire all next week (25-30 October 2010), and for seven days afterwards on the BBC iPlayer, on
Chris Baxter's mid-morning programme
Faye Hatcher's programme
The Severn Bridge Disaster will also feature on BBC1's Inside Out (West) on Monday, 25 October, 2010. The programme will be
available on the BBC iPlayer
for 7 days after broadcast.