The design of the modular cabin mount was not resilient to frontal impact forces in the event of a collision. This increased the risk of their failure and separation of the cabin, removing the effectiveness of protection afforded by the collision posts.
The ATSB is satisfied that the actions undertaken by Progress Rail, including strengthening of the modular cabin mounts, will reduce the risk of this safety issue.
On 31 July 2020, Progress Rail advised the ATSB that, since they acquired the Downer EDI freight business in 2018, they have taken several actions to reduce the risk that the cabin may separate from the locomotive in the event of a collision. More specifically:
Progress Rail has instituted changes in the cab [cabin] mount design. Progress Rail has improved the strength of the subject mounts by changing the material of the outer casting from aluminium to steel for locomotives Progress Rail may sell to new customers. The new mounts have been tested to more than four times the strength in tension, compared with the original design specifications and meet the latest design requirements introduced in AS/RISSB 7520.1:2012.
We have established the breakpoint in manufacturing of Progress Rail’s locomotives and can confirm that all future locomotives will be delivered with the improved cabin mounts.
Progress Rail has notified its existing customer about our improvements to the cab mounts and has created an action plan for cab mount supersession. Only three locomotives manufactured by Progress Rail contain the original cab mounts, all of which were sold to a single operator. Progress Rail is working with the operator to replace these mounts in a program by the end of the year with the first unit’s replacement in progress.
Progress Rail is taking additional actions to notify all locomotive operators with an impacted locomotive about the cab mount supersession: While Progress Rail has only manufactured 3 locomotives with the older cab mount design, other locomotives manufactured by other parties remain in use in the industry with the older cab mount design. Progress Rail often services locomotives that include the older cab mount design. For any such service requests, Progress Rail made the decision to cease supply of the original mounts to any operators still using the old cab mount design in their locomotives, and it is also taking the following steps:
These actions and decisions have been made to reduce the likelihood a modular cab will separate from the locomotive during a collision by ensuring that cab mount supersession is implemented going forward, and by notifying industry operators of the improvements to the cab mounts so they have an opportunity to replace the cab mounts with the improved, revised design.
On 10 April 2023, Progress Rail advised that, during the installation of the new generation mount, they discovered that it could not be applied to all locomotives in the fleet. A second new mount has been developed with the supplier to fit to the affected locomotives. This second new mount design will be available to install within the second quarter of 2023.