Damage in a bobsleigh start track braking system

This paper describes component failures which occurred to critical items used in the braking system of the University of Bath (UK) railed Bobsleigh start track. The system uses six parallel mounted heavy duty elastic cords to absorb the bobsleigh energy. These are securely anchored at one end and have a steel Catch Tube at their other ends which is caught by the Bobsleigh carriage as it passes and as the cords extend the bobsleigh comes to rest. This braking system has required excessive maintenance in service because the critical Catch Tube component has bent severely and the cords have frayed leading to unacceptable short operation life. This study has analysed three salient stages of the bobsleigh braking process, namely commencement of the braking action, the bobsleigh coming to rest and the moment of disengagement of the bobsleigh from the braking system. The analysis, which has involved developing theory for dealing with a beam which is subjected to a severe impact in bending, has helped improve understanding of why such critical components failed. This has lead to suggestions as to how the detail design can be significantly improved.