Help with wooden ammo boxes.

[381st digger]

Hi all,
I couldn't quite decide where to post this but hopefully this is the right place.
Anybody know much about ammo boxes? These turned up today at a friends farm they seem ww1 to me they are 8ft long and 3 out of the 4 are made of oak. Take no notice of the bits of wood nailed to the top they are not related to the original item. In the bottom of the 3 oak boxes are shaped pieces of wood presumably to hold an artillery shell in place. Sorry about the poor photos it's was to dark in the barn.
If it helps the farm is right on the edge of an airfield that was used by airborne troops to cross the Rhine in ww2 so might have something to do with that?
I'm open to any suggestions.

Andy