A DIGGER that was loaded incorrectly onto a Forest heritage railway engineering train was responsible for pulling down a 133-year-old Grade II-listed and £150,000 restored wrought iron footbridge, an investigation has ruled.

The Rail Accident Investigation Branch found that the eight-tonne digger had been improperly loaded by a Dean Forest Railway volunteer who had not completed the necessary training and misjudged the height of its arm when it struck the St Mary’s Halt station footbridge in Lydney.

A safety report stated: "At around 10.55am on Thursday, August 14, part of a 360-degree excavator being transported on a train struck the footbridge which carries a public footpath over the Dean Forest Railway at St Mary’s Halt station.

"The train was travelling at around 10mph when the accident occurred. The footbridge collapsed as a result of the collision, with parts of it falling onto the station platform and the moving train."

The train was transporting the heritage group's excavator from Lydney Junction to Whitecroft, and it was being shunted on a wagon in front of the locomotive which was invisible to the driver as the driving cab was at the rear.

The investigation found that the volunteer had passed the operator’s theory test for the railway's six-tonne excavator, but not the pracitical test, and was unqualified to load the eight-tonne machine, which should have had its bucket resting on the lower deck, rather than the higher deck.

"During the loading, the train driver and shunter went to inspect a different wagon in another part of the station yard and did not witness the loading activity," added the report.

"There was no requirement for the driver or shunter to check the load before the train departed and there is no equipment to allow out-of-gauge loads to be detected at Lydney Junction...

"Following the accident, a reconstruction showed that the top of the 8-tonne excavator’s dipper arm was 4.61m above rail level when the accident occurred.

"This meant it was 0.26 metres higher than the underside of the footbridge, making a collision inevitable...

"Since acquiring the 8-tonne excavator in 2024, Dean Forest Railway had not checked its loading gauge against structures on the railway, including the footbridges at St Mary’s Halt and at Parkend station.

"This risk was intended to be managed by training operators to correctly stow the bucket on the lower deck.

"There was also no method, or requirement, for staff or volunteers to check the height of loads on trains departing Lydney Junction which meant that out-of-gauge loads could not be identified."

It ruled: "This accident demonstrates the importance of heritage railway staff and volunteers:

• Only undertaking safety-critical tasks for which they have been trained and assessed as competent

• Being aware of any loading gauge restrictions when transporting large or unusual loads by train.

"This accident also underlines the importance of heritage railways undertaking appropriate risk assessments for their activities and implementing effective controls."