#OnThisDay in 1955, 35011 General Steam Navigation left Eastleigh works to re-enter service with the British Railways Southern Region following major repair work. The modifications that were carried out to the entire Merchant Navy class were as a result of 35020 Bibby Lines accident at Crewkerne.
On the 24th April 1953, Bibby Line whilst on approach to Crewkerne station fractured her crank axle at high speed. Luckily no one was injured, but the incident resulted in the withdrawal of all Merchant Navy class locomotives from service whilst the cause of the failure was ascertained. An examination of other class members showed that the fracture, caused by metal fatigue, was a common fault. This led to a complete redesign of the crank axle and once installed saw the locomotives return to traffic. General Steam Navigation would continue to haul trains in her original condition until 7th June 1959 when she entered Eastleigh works for rebuilding.
The crank axle continues to be a significant challenge for our project, but without this challenge we would not be pursuing the goal of restoration as an original Merchant Navy. Aided by significant insight from Andrew Marshall (35006 group), we have clarity on the design of axle we should be aiming to have fabricated. This is the redesigned, balanced crank axle that was eventually fitted to all the Merchant Navy locomotives following the Crewkerne incident. Records suggest 35019 had the balanced crank axle fitted 4 years prior to rebuilding, so we can demonstrate it is applicable to our locomotive. We have studied the report into the Crewkerne incident, to help inform our decisions with the axle. We have had insight and support on the axle material from the wider heritage industry, including our friends at the A1/P2 trust and the Clan Project, both of whom have had similar issues of design to overcome. We are missing some of the drawings for the revised design, and we are also evaluating the correct and certifiable grade of steel to use, but our aim is to have the new crank axle ordered at least in 2021, if not manufactured. FEA studies of the design are underway at the University of Birmingham
Our current immediate objective is to restore her unique trailing truck which has led to the Trailing Truck Transformers Fund Club being set up to fund restoration of this unique component in 2021. You can find out how to join the exclusive club by visiting our website on the link below. Thank you
Photo: GSN leaving Exmouth Junction Shed on 5/9/57. The locomotive is believed to be heading to Exeter Central to work an up service (Copyright Brian Marshall)