Development Testing

In order to meet the FMVSS-208 standard, several development tests were conducted on Thatcham's Hyper-G reverse acceleration sled.

Sled tests are particularly useful for highlighting potential weaknesses, but only with an 100% impact barrier test can you be sure how the machine will perform in a real crash.

(This is why award of the FMVSS-208 certification requires 100% imapct testing)



Test 1: 20km/hr (12.4mph)  Machine: 1,000 litres Test Result: PASS


Comments:
This lower speed test was useful in highlighting the points of potential weakness. The machine remained attached to the vehicle floor, resulting in a successful test, but improvements were needed to the clamps.




Test 2 : 30km/hr (18.6mph)  Machine: 1,000 litres  Test Result: FAIL
Comments:
The tremendous energy involved in the impact is revealed by this development test. The steel underplates that were holding the machine in place simply ripped through the floor, allowing the machine to pitch forward, resulting in a failed test.

In addition, further strengthening of the clamps is needed as two of them failed. This test well illustrates why development testing is important, as parts of the chassis and clamping systems needed to be completely redesigned.

Once the design changes and improvements had been made, the test was repeated.




Test 3 : 30km/hr (18.6mph)  Machine: 1,000 litres Test Result: PASS
Comments:
A successful test at 18.6mph. After the lessons learned from the previous test, a completely new method of installation was devised which did not involve securing the machine to the vehicle floor.

The strengthened clamps, though remaining secured, still showed signs of imminent failure, and so needed to be not just strengthened but totally redesigned.



Test 4 : 50km/hr (31.1mph)  Machine: 1,000 litres Test Result: PASS
Comments:
The 30mph impact releases a huge amount of energy, but the chassis design changes and re-designed clamps were clearly effective. Despite the large forces involved, none of the clamps or anchorage points failed, and the machine stayed secured to the floor.

What Next?
Following the development tests and design changes that were made as a result, we are ready for the 100% impact barrier test.

See The 100% Impact Barrier Tests