The forms are designed to have another set bolted on top of them so that they mate together and provide lateral support. Once a second set is added, the whole thing is 1200mm high, with the lower 600mm full of compacted material and the upper 600mm empty. The ramming process is then repeated until the upper set of forms is full. At this point there is a choice. You can either put a third set of forms on top of the second, making the whole setup 1800mm high or remove the formwork from the lower section and leap-frog it, only using two sets for four courses.

Here we are working on a corner.  Yep, that's me wire brushing the walls while the workers get on with the tough stuff. 

Notice the way we have leap-frogged the lowest form above the middle one.

 

Different corner, different angle.  The leap-frogging is even more obvious here. 

This is the finished height of the walls - 4 forms @ 600mm each. 

You can clearly see the end shutter which defines the end of a section.