In reply to Adam Long:
Thanks Adam, we guessed that must have been the reason although we did wonder if placing them at 90 degrees difference in angle to how a climber normally would, might not actually be the best way to practice? In Finland, if I remember right, it was done on the cliff with the both the trainee and the instructor on a ropes - but I suspect that was as much that batteries ran down and bits were blunted so quickly in the local granite, that you needed to get on with the task at hand, so it was more on the job training!