Building some trenches - WIP

I've been building some trenches ....

The above photo shows three sections, two ends and a longer centre section. The trenches are made using some thick shelving board (aprox 2cm thick) cut up into suitable lengths, stuck to some thick cardboard. The sides of the trenches are thinner cardboard, any gaps have been filled up with foamboard and cork tile.

I will be adding another section to contain a gun,

 the aim is to have enough trench sections to go across the table, representing a section of a beach for an invasion landing. Trench sections should be usable on their own as well.

I'll need plenty of sandbags !