WWI helmets offered better blast protection

[Still Waters]

Biomedical engineers from Duke University have demonstrated that, despite significant advancements in protection from ballistics and blunt impacts, modern military helmets are no better at protecting the brain from shock waves created by nearby blasts than their World War I counterparts. And one model in particular, the French Adrian helmet, actually performed better than modern designs in protecting from overhead blasts.

The research could help improve the blast protection of future helmets through choosing different materials, layering multiple materials of different acoustic impedance, or altering their geometry.

The results appeared online on February 13 in the journal PLOS ONE.

https://pratt.duke.edu/about/news/shockwave-helmets

https://www.dailymail.co.uk/sciencetech/article-8013311/A-French-infantry-helmet-WWI-offered-better-protection-modern-Army-helmet.html

[XenoFish]

Probably has to do with the bell type design. Instead of the vibration running downwards. They run down and out. Reducing travel time. That's my guess.