 Before filming began , several of the main cast members were sent to a boot camp in South Africa and went through intensive and rigorous military training by former SAS and SBS soldiers . Stapleton and Winchester had more training than Birthistle , who just wanted to make sure she could at least be a believable soldier . The actors were trained in several aspects including running , teamwork , and weapons . Mealing meanwhile , did not go through as much training as the other actors , but did spend mornings training with a commander for the SBS who is also a military adviser on the show . Winchester recalled , " Sully and I would meet every morning at 6am . We would run to a chosen location and on the way we had to memorise street names and directions and then our trainers would say ' that car that you just passed what was the licence plate number ? ' Our trainers were ex @-@ SAS guys who made us study everything in detail , for example , we learnt step by step how to enter a room in twos , then alone . At the same time , we had to be constantly aware of where our weapon was trained . " 
