Toddington Standard Locomotive Limited has provided an update on the overhaul of the boiler for Standard Class 4 2-6-0 No. 76077, currently being refurbished by Leaky Finders Ltd. in Devon. The overhaul, initially anticipated to be a routine restoration, has revealed unexpected complications requiring extensive repairs.
A recent Non-Destructive Testing (NDT) examination uncovered laminations in the steel platework of the boiler, necessitating additional repair work to ensure its long-term functionality. Laminations, which occur when impurities such as small deposits of slag form linear pockets within the steel during the rolling process, pose a challenge, especially in areas that require welding for patch repairs.
Further investigations revealed that many of the original Monel metal stays in the upper section of the firebox were either broken or flawed and required replacement. Additionally, a few rows of crown stays had experienced excessive wastage of their heads within the firebox, further complicating the restoration process.
Chris Irving, chairman of Toddington Standard Locomotive Limited, and Andrew Meredith, the company’s engineering director, met with NDT specialists and the boiler inspector at Leaky Finders in January to assess the situation and determine a way forward. They concluded that while the lamination issues were not an outright barrier to progress, the extent of repairs needed to restore the boiler to working order was far greater than originally anticipated.
Although the laminations alone did not pose an immediate threat to the structural integrity of the boiler—having functioned effectively throughout its British Railways service—their presence significantly impacts the welding process required for repairs. Cracks can form when welding occurs near lamination zones, weakening the metal structure. This challenge is further exacerbated by the quality of steel used during the boiler’s original construction at Darlington in 1952, a time when technology for identifying such flaws was unavailable.
Due to the necessary additional repairs, more firebox steelwork will have to be removed than initially planned, leading to the unavoidable loss of over 400 otherwise serviceable copper stays. Despite these challenges, Toddington Standard Locomotive Limited remains committed to completing the overhaul and ensuring the long-term operational future of No. 76077.
Once the restoration is complete, the locomotive will be paired with a new BR2A tender, identical to the type it was coupled with before its withdrawal from British Railways service.
