1864(Spider Navy SN 0-17)
- Class: Achilles - 1 broadside ironclad of 1861
- Displacement: 9,829 tons
- Dimensions: 380' x 58'3" x 27'3"
- Machinery: 1-shaft, Penn HSET, 10 boilers, 5720ihp = 14.32 knots
- Sails: four masted rig, 44,000 sq ft
- Armour: Belt 4.5in w/ 18in wood backing, battery 4.5in, bulkheads 4.5in
- Armament: 4-110pdr BL, 16-100pdr 'Somerset' SB
- Complement: 709
- Builder: Chatham Dockyard
- Laid Down: 1 Aug 1861
- Launched: 23 Dec 1863
- Commissioned: 26 Nov 1864
- Notes: HMS Achilles was a lengthened version of the Warrior design, with improved protection. Re-armed in 1868 with 22-7in MLR and 4-8in MLR, and again in 1874 with 14-9in MLR, 2-7in MLR. Largest sail area on a Royal Navy warship, and only one with four masts, but it was unsatisfactory and modified in later years. Somewhat ungainly because of her great length, she nevertheless steamed and sailed well under most conditions. Seagoing service ended in 1885. Became base ship Hibernia in 1902; renamed Egmont in 1904, Egremont in 1918, and finally Pembroke in 1919. Sold for breakup in 1925.