Freight coupler research shows more freight can go by rail
Limits on how many tonnes a freight train can haul depend on coupler strength and are outlined in the Freight Trains Load Book, but this had not been reviewed for decades.
Stronger couplers have been introduced in the meantime, leaving the guidance out of date. The enhanced capabilities of the new couplers had not been fully realised, and freight trains lengths continued to be restricted.
RSSB recognised the need to review freight train load ratings to incorporate improvements in coupler performance.
The project team re-examined the engineering principles behind coupler ‘traction rating’ to enable the rail freight industry to unlock additional capacity.
This research has demonstrated that freight trains can haul more than the current limits allow based on the strength of wagon couplers.
The findings will allow industry to safely increase these limits without impacting operational performance. Longer, heavier freight trains will be possible using existing rolling stock assets and couplers.
To support industry to use these findings, RSSB created a tool to automate the calculation of these new limits and provided guidance on its use.
The revised coupler strength ratings have resulted in more than half of all wagons on the GB network receiving increased limits.
In real-world-representative journeys, this allowed up to five more wagons per train—26 wagons where current ratings would have allowed 21—and brought cost and
carbon savings as well.
The first operational increase in freight train length has been achieved, with Freightliner using the tool to run longer trains of bulk aggregates working out of Tunstead in
Derbyshire.