They were initially armed with six single QF 4 inch guns, unusually arranged with four on the forecastle - two sided in front of the wheelhouse and two sided abreast it - the remaining pair being sided on the quarterdeck. These guns were of a novel Elswick design for the Chileans and when the ships were rearmed they were replaced with standard Royal Navy models. As rearmed in 1918 they carried a BL 4.7 inch gun on the forecastle and another on a bandstand between the after pair of funnels, retained the pair of 4 inch guns abreast the wheelhouse and had two QF 2 pounder pom-poms.