This is a followup post to “GMax and HIC Considerations For New Playground Safety Surface Installations.”
ASET Services recently field tested a playground for the Wheaton Illinois Park Department. Their specification is what ASET calls a ‘True Performance Specification,’ or one that addresses the actual performance of the surface at the installation.
I’ve copied the portion of post performance testing section from their specification with their permission. In section 3.04-A Wheaton specified that the Gmax should not exceed 160, and that the HIC should not exceed 700. Both of these levels are well below the maximum levels allowed by ASTM F1290 (as of Sept, 2016) which sets maximum allowable levels for Gmax/HIC at 200/1000 respectively. Wheaton then decided that they would accept a final surface that failed to meet their desired 160/700 level but that there would be a price reduction for failing to hit their desired target. You can see that reduction in Section 3.04-B.
Since ASTM F1292 establishes a maximum allowable level of 200/1000 any surface that failed to meet those criteria would not be accepted and it would have to be replaced.
While Wheat used this unique approach on a Playground Surface, the same principles can be applied to any sport or play surface.
– First they established the performance they ultimately desired. In this case they selected Gmax and HIC levels below the maximum levels currently allowed. This should provide a surface that meets the required levels well into the future.
– Secondly they realized that job site conditions might make it difficult to hit those numbers exactly so they created performance blocks and associated those with specific reductions in the cost of the installation.
– Thirdly they established a level beyond which they would not accept the surface. In this case that was easy to establish because F1292 specifies maximum allowed Gmax/HIC levels to prevent catastrophic (fatal) head injuries.
So, how did they do with their selection? They selected playground safety tiles from the products submitted, and the field test found that the Gmax levels at the playground were approximately 90, and the HIC levels were approximately 400. Both Gmax and HIC were safely below their desired levels of 160/700.
I also spoke with a representative of the Wheaton Park District. He said there were concerns that specifying a target Gmax/HIC well below the industry standard of 200/1000 would cause the safety surface to be much more expensive. He was pleasantly surprised that the bids were not all that different than if the desired performance had remained at the maximum 200/1000 levels.
This is simply a case of the owner placing a value on the performance and safety of their playground surface. They wanted to make sure that the product was installed properly and that it performed to their expectations so they included field testing of the final product. Also, their graduated performance penalties limited the additional risk that the surface provider and installer had to burden. Setting very strict requirements combined with extreme penalties would have likely caused the cost of the project to be significantly higher, because of the risk that would be shifted to the provider.
For more information you can visit www.asetservices.com, where you’ll find information about all of the services they provide and the author, Paul Elliott http://asetservices.com/about-aset/. You can also visit www.aset-trueperformance.com to learn about developing a true performance specification similar to the one Wheaton employed. As always, if you have any questions please contact us.