Girls to take part in field gun run at Earl's Court
9 December 2012 Last updated at 08:24 GMT
Girls are to take part in the field gun run at the British Military Tournament for the first time in its history.
Chiara Fumagalli, 17, Fabia Maramotti, 17, and Abby Pape, 13, from Wellington College in Berkshire, are to be "gun runners" at Earl's Court this weekend.
They are part of the 45-strong teenage crew that will dismantle the huge guns, run with them over large obstacles, then reassemble and fire them.
Sian Lloyd went to see them in action.