Thought I would share this (hopefully it posted picture) of a structural specially treated timber crib wall. It was quite a challenge, especially as the client reduced the working width to 2 inches wider than a bobcat530 !! The height of the stacked wall is just shy of 27ft ! - there are actually two walls stacked together to enable this height, the wall is not technically "structural" as it is infront of a rock face - it would need to have been about 14ft thick as apposed to its actual depth of around 8ft deep,to be fully structural. I'm not sure how these walls compare to the concrete alternatives in respect of construction times, but a relatively straightforward one usually can be built at a rate of about 300sq ft a day with a crew of three.