Just for fun, that spherical enclosure for zombies.

Eliminates all zombie movies.

Think about it. 100 volunteers walking around the neighbourhood in that,

and they have a spear or some projectile from within to kill the zombies.

And if they pile up, they can push some of them move the sphere from within and get out of there.  Or it should have a burst ability by spring. (That's the only factor of danger minus the blood that spills into the compartment but you'd be wearing something to repel that)

Either way... it has no motorized components and completely manual so... Doesn't really break.

The shape doesn't let you really pile up the bodies you can get out of it if you keep moving...

So technically, 1 sphere can kill a thousand zombies or more... XD