This photo demonstrates the often monstrous sizes of WW1 guns aiming to hurl huge projectiles as far as 25 miles. This one is most likely a coastal gun, its breach being calibrated by technicians. Firing these monsters required the crew to stay well clear of the gun -- as far as 50 meters from the breach -- and fire it by a pull cable. The resulting blast easily blinded those uncaring ones who insisted on looking. The force of the combustion required re-sighting the gun after every shot.