Back in the late 60's when I was a strapping athletic football player we had a kid playing quarterback that had a concussion. Instead of a football helmet he wore a crash helmet. It had holes drilled into the top and a single bar for a face mask. Back in those days the linemen had a t-bar face mask.
I played middle linebacker against a team that had a highschool all american tailback and he wore a crash helmet and I guarantee you he hit me with it more than once. Back in those days it was legal to hit helmet to helmet, block below the waist and no water.
I know those helmets took some pretty good licks lots of times.
Replace a light hit