A 19th‑century footbridge on the Dean Forest Railway collapsed after being struck by an incorrectly loaded excavator being moved by train, the Rail Accident Investigation Branch (RAIB) has concluded. The incident occurred at around 10:55 on 14 August at St Mary’s Halt in Lydney, Gloucestershire, while the volunteer‑run heritage line was closed to the public.
The train was transferring a 360‑degree, 8t excavator from Lydney Junction to Whitecroft, a distance of about 4.8km. Travelling at approximately 16km/h, the upper part of the excavator’s dipper arm hit the underside of the 1892 lattice‑girder footbridge, which carries a public right of way to a nearby lake and housing.
The impact caused sections of the wrought‑iron bridge and its cast‑iron supports to fall onto the platform and the moving train. No one was injured and no pedestrians were on the bridge at the time, but the structure, refurbished in 2022, suffered significant damage.
RAIB found the immediate cause was the way the excavator had been stowed on a mid‑20th‑century “Loriot” well wagon. Its bucket had been rested on the wagon’s raised upper deck, increasing the overall height so that the highest point of the boom reached 4.61m above rail level, around 0.26m higher than the measured 4.35m clearance beneath the bridge in 2022.
The train formation comprised a Class 08 diesel‑electric shunter propelling two four‑wheel well wagons and a bogie brake van at the front, crewed entirely by volunteers. Six volunteers were on the brake van, including a shunter acting as lookout on the leading veranda, who heard the collision and immediately instructed the driver to stop.
Dean Forest Railway owns three Loriot wagons and two excavators: a 6t machine acquired in 2009 and the 8t excavator bought in 2024. While some volunteers had completed accredited excavator training and railway‑specific instruction on loading and stowage, RAIB identified gaps in competence, documentation and supervision in this case.
The volunteer who loaded the 8t excavator had limited formal qualifications, having completed only the theory element of an excavator operator course in 2022 and not passed the practical test. They had experience loading and unloading the smaller 6t excavator, routinely stowing its bucket on the raised deck, a configuration that remained within the loading gauge for that machine but was unsuitable for the larger excavator.
The same volunteer had off‑loaded the 8t excavator once, five months earlier, but had never previously loaded it onto a wagon. RAIB found there was no requirement for the driver or shunter to inspect the load before departure, and no equipment at Lydney Junction to detect out‑of‑gauge loads.
Written instructions did not specify where an excavator bucket should be positioned when stowed on a Loriot wagon. A generic risk assessment for digger operations, first prepared in 2010 and later reviewed, did not cover transporting excavators by rail, and the railway had not reassessed its loading gauge against structures such as the St Mary’s Halt and Parkend footbridges after acquiring the larger machine.
Post‑incident testing demonstrated that the 8t excavator could be loaded to a much lower profile, with the highest part of the boom at 3.12m above rail level, which would have avoided any contact with the bridge. RAIB concluded that the railway had relied on operator training to manage loading‑gauge risks rather than embedding clear procedural controls.
The investigation also referenced RAIB’s 2015 report into a 2014 runaway and collision near Loughborough Central, which had already warned heritage railways about ensuring safety‑critical tasks are undertaken only by staff with appropriate competence. The Dean Forest Railway incident was found to echo those earlier concerns around staffing, training and control of shunting and train movements.
In its published findings, RAIB stated that the accident highlights the need for heritage railway staff and volunteers to undertake only those safety‑critical tasks for which they have been trained and assessed as competent. It also stressed the importance of being aware of loading‑gauge restrictions when transporting large or unusual loads, and of carrying out suitable risk assessments with effective controls for all operational activities.
