Easier assessment of freight vehicle loads using multiple transport types
Requirements for assessing the likelihood of freight wagon derailment were already in use, but a member reported that it was sometimes difficult to apply them. A Request for Help (RFH) was made to review one specific requirement.
Industry submitted a RFH for a requirement about freight wagon loading. This requirement minimises the risk of derailment. However, it could not be met within the loading limits of some vehicle types.
Further guidance and diagrams were also requested to show different loading scenarios for various suspension types. The guidance and diagrams needed to show how the worst case can be determined.
A wider review of GMRT2141 Permissible Track Forces and Resistance to Derailment and Roll-Over of Railway Vehicles and GMGN2641 Rail Industry Guidance Note on Static Vehicle Testing was needed.
RSSB gathered information about offset load requirements for review. It then developed a new approach. Flowcharts and standards documentation have been updated to help users.
RSSB used this information to understand the issues when applying offset load requirements. RSSB developed an alternative approach for wagons where a limitation on laden axle load restricts the offset that can be obtained. This permits operators to determine the maximum achievable offset within the axle load limitations. They need to document the reasons for the restriction.
The flowcharts were redrawn to improve readability. A new one was added as well as worked examples for particular cases to be used as guidance.
Improved guidance simplifies the assessment of new or modified vehicles for carrying intermodal load units. This speeds up the assessment process and reduces unnecessary work. Vehicles are able to enter service more efficiently as a result.
The improved guidance reduces the need for future deviation applications.
A possible ambiguity in the requirements has been removed. The flowcharts are now much clearer.
The changes in issue two of GMGN2641, together with those in GMRT2141 issue five, are estimated to benefit the industry by at least £3m over 5 years.