HMS Orlando was a Mersey-class wooden-hulled steam-powered (although fully rigged with sails) screw frigate built for the Royal Navy from 1856 to 1858 but not commissioned until 1861. Orlando and her sister ship Mersey were the longest wooden warships built for the Royal Navy. At 336 feet in length, Orlando was nearly twice the length of Victory, the flagship of Admiral Horatio Nelson at the Battle of Trafalgar. At 5,643 tons displacement, she was certainly a large and impressive looking ship in her day. She was heavily armed, and in comparison to many of her counterparts was quite fast with an approximate speed of 12½ knots, achieving 13½ on trials.

HMS Orlando
History
United Kingdom
Name	Orlando
Ordered	31 March 1855
Builder	Pembroke Dockyard
Cost	£187,042
Laid down	November 1856
Launched	16 June 1858
Completed	21 April 1859 at Portsmouth Dockyard
Commissioned	17 December 1861
Fate	Sold for breaking up 15 June 1871
General characteristics
Displacement	5,493 tons
Tons burthen	3,740 tons BM
Length	336 ft 9 in (102.64 m) overall, 300 ft 0.5 in (91.453 m) gundeck, 264 ft 3.25 in (80.5498 m) keel
Beam	52 ft 1 in (15.88 m)
Draught	29 ft (8.8 m)
Depth of hold	19 ft 10 in (6.05 m)
Propulsion	sails; 1000 shp auxiliary steam engine.
Speed	13.290kts on trial
Endurance	145 hours at full steam
Complement	around 600
Armament	1859: Upper deck: 12 x 8in/68-pounder shell guns Main Deck: 28 x 10in shell guns
Armour	none

The length, the unique aspect of the ship, was actually an Achilles' heel of Mersey and Orlando. The extreme length of the ship put enormous strains on her hull due to the unusual merging of heavy machinery, and a lengthy wooden hull, resulting in her seams opening up. They were pushing the limits of what was possible in wooden ship construction:

Even the biggest of the 5,000-6,000-ton wooden battleships of the mid-to-late 19th century and the 5,000-ton wooden motorships constructed in the United States during World War I did not exceed 340 feet in length or 60 feet in width. The longest of these ships, the Mersey-class frigates, were unsuccessful, and one, HMS Orlando, showed signs of structural failure after an 1863 voyage to the United States. The Orlando was scrapped in 1871 and the Mersey soon after. Both the Mersey-class frigates and the largest of the wooden battleships, the 121-gun Victoria class, required internal iron strapping to support the hull, as did many other ships of this kind. In short, the construction and use histories of these ships indicated that they were already pushing or had exceeded the practical limits for the size of wooden ships.^[1]

Britain had built two long frigates in 1858 – HMS Mersey and HMS Orlando – the longest, largest and most powerful single-decked wooden fighting ships. Over 335 feet long, they suffered from the strain of their length, proving too weak to face a ship of the line in close quarters.^[2]

In 1866 Orlando was laid up and was sold for breaking in 1871.