They had two pole masts fitted with fighting tops; each top carried a searchlight, and four additional searchlights were mounted on the forward and aft bridges. Their crew size varied over the course of their careers; "Irresistible" had a crew of 788 officers and ratings in 1901, and in 1910, "Formidable" had a crew of 711. After having been withdrawn from active service in 1917, "Implacable" had a crew of just 361. The ships carried a number of small boats that varied over the course of their careers, including a variety of steam and sail pinnaces, sail launches, cutters, galleys, whalers, three gigs, dinghies, and rafts.