Mechanical Fuses? (What are they and how they work)

[Giugiaro]

Hello Everyone!

I knew about these "Mechanical Fuses" that are installed on rolling stock to absorve energy in case of impact, but never got to understand how they look and work.
Supposedly they're ment to absorb kinetic energy during impact, breaking itself in the process, but how can a fixed part remove energy from a moving assembly under compression?

The "Mechanical Fuses" I've found on the internet are meant to break under traction. Not compression.
And the way road cars absorb kinetic energy is through deformation of its front and rear structure, lowering the acceleration of the occupants. Don't train bumpers and the very extreme parts of the structure already do this?

Does anyone know these things, show them and explain how they work?

 

[Richard Scott]

General principle is to increase time it takes for vehicle to decelerate, even though this may be a very short time it will reduce force on vehicle itself and it's passengers. Injury in impacts often caused by rate of deceleration so if can reduce that by increasing time of collision passengers will suffer fewer or reduced or possibly no injuries. Based around Newton's second law.