Destructive Testing

[TheEdge]

Following on from the incident in Leeds which may or may not have revealed issues with the design and or crashability of the 800s are new designs put through the sort of destructive tests that other vehicles do?

Obviously cars go through things like the Euro NCAP tests, airliners get wings pulled till they snap or fusalages pressurised till they burst. Will Hitachi have slammed a IET into a wall or Stadler pushed a FLIRT onto its side down a hill?

 

[GB]

I am pretty sure (though stand to be corrected) that trains are not put through such full crash tests and its more design/standards/regulation driven.

 

[coppercapped]

Following on from the incident in Leeds which may or may not have revealed issues with the design and or crashability of the 800s are new designs put through the sort of destructive tests that other vehicles do?

Obviously cars go through things like the Euro NCAP tests, airliners get wings pulled till they snap or fusalages pressurised till they burst. Will Hitachi have slammed a IET into a wall or Stadler pushed a FLIRT onto its side down a hill?

Generally it is a mixture of destructive testing and computer modelling. Often components are crash tested to verify the computer model and the computer model is then used to show conformance with the standards and specifications.

The situations facing car, aircraft and railway safety are very different. Car crash testing is intended to demonstrate that the passenger cell provides adequate protection in the event of a collision up to the limit of the test specification. Aircraft testing is less to do with survivability as to ensure that the structure doesn't fail in the first place. Obviously there are safety requirements, the 'G' levels that seats can cope with and the number of emergency exits and so on, but the tests are not comparable to car crash testing: nobody slams a fuselage into a concrete block because that sort of accident doesn't happen in real life.

Railways are somewhere between the two. The nose can be, and is, crash tested but much of the other safety features are modelled.

The standard used in the European Union is EN 15227 Railway applications - Crashworthiness requirements for railway vehicle bodies which is described in its preamble as:

The requirements do not cover all possible accident scenarios but provide a level of crashworthiness that will reduce the consequences of an accident, when the active safety measures have been inadequate. The requirement is to provide a level of protection by addressing the most common types of collision that cause injuries and fatalities.

Both Vivarail and Hitachi have run crash tests to this standard. The Vivarail one was well publicised a couple of years ago. In the journal Hitachi Review Vol. 63 (2014), No. 10, page 646, the authors made the following statement:

European standards stipulate the collision safety standards shown in Fig. 11 for reasons that include past accidents and trains sharing the same track. As shown in Fig. 12, the lead car of the Class 800/801 has an crashworthy structure that crumples during a collision to absorb as much of the energy as possible and to minimize the accompanying accelerations. The crashworthy structure for the Class 800/801 is a further development of the technology used for the Class 395(4), (5), (6) rolling stock. In addition to being lighter and taking up less space, it complies with the latest TSI, the EN 15227 European standard for collision safety, and the GM/RT2100 UK railway standard for strength. The front of the car accommodates the crashworthy structure in the limited space available, while also balancing aerodynamic performance and exterior design, and housing the headlights and other similar devices, along with the switchgear, coupling system, and other equipment used when connecting rolling stock together in a trainset.
The first step in the development of the crashworthy structure was to determine its basic performance through dynamic crash testing of a full-size front end. This also included confirming that numerical analysis simulations could reproduce the test results. This numerical analysis technique was also used to verify collision safety performance by simulating a crash for a multi-car train, something that is difficult to test by experiment.

This should answer your question.

 

[Neil Urquhart]

I suspect that the high cost of rail vehicles combined with relatively low production runs (compared to cars for instance) makes it very unattractive to crash a brand new train. There have of course been some crash tests with older life expired stock, such as 46 009 being slammed into a flask at the end of its life. Incidentally, was the wagon used in the flask test the only instance of a brand new rail vehicle being destroyed in a test before use? I can't think of any other examples.