There is a poem, I forget which, that mentions the Duckboard. It's not a piece of 'military' equipment, quite simply because ducks have smooth, webbed feet, when getting from a pond to the land, say, they slip, therefore the farmer puts slats of wood across a plank to provide a non slip surface for them to get out of the pond. Similarly in the mud of the trenches slatted planks were used to provide non slip mobility for the soldiers in the trenches.