Complex sentence: The Secondary armament consisted of 16x QF Mk I guns these sat in eight twin mounts, weighing 81 tons each, these were grouped at the four corners of the citadel, with a twin mount on the main deck and another superimposed above its nearer amidships.
Split into simpler sentences: The Secondary armament consisted of 16x guns, these sat in eight twin mounts, weighing 81 tons each. They were grouped at the four corners of the citadel, with a twin mount on the main deck and another superimposed above it nearer amidships.