It has but don't know how to find it . An excavation might help clarify .There seems little doubt about the pits and their width but not what they contained , timber posts are possible but as we don't know the depth of the pits we can't guess at a possible height of the posts . Roger Mercer suggested something like a ratio of 1:3 iirc for a max height . If they were pits for timbers then it would seem a waste of energy to have metre wide timbers cut down to a couple of metres or less .The depth of the ditch is unknown and I don't believe there is any way of knowing the height of the bank if there was one .